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Bottom paint on prop
Hi,
I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? Thanks, Mike. |
Bottom paint on prop
keep in mind the weight of paint...you don't
want to "up set" the prop too much..... |
Bottom paint on prop
"beaufortnc" wrote in message ups.com... I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. Sorry, didn't really answer your question, but that's my conventional wisdom on the subject. JimB |
Bottom paint on prop
"beaufortnc" wrote:
Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? Bob has tried all the conventional wisdom things, and they don't work unless you are using your boat on a regular basis. And if you are using your boat on a regular basis, it probably doesn't matter what you use. grandma Rosalie |
Bottom paint on prop
On 20 Nov 2005 08:46:07 -0800, "beaufortnc"
wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Cheers |
Bottom paint on prop
There are some prop paints, but none of them work very well. I wanted
to try Vermilion as well, but that's been discontinued, I think. Also, adhesion to a bronze prop is a problem. Don a wetsuit and scrub it once in a while. mickey |
Bottom paint on prop
"News f2s" wrote in message ... "beaufortnc" wrote in message ups.com... I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. Sorry, didn't really answer your question, but that's my conventional wisdom on the subject. JimB hmmm... Ever thought of attaching a regular snorkel to some larger hose? Vacuum hose is great with a float at the loose end. You can stay down a lot longer. Some of the co2 you exhale will get re-inhaled each time. I havent passed out yet though.. Fingers crossed. DP |
Bottom paint on prop
I scrub my prop about once a month here in N. FL but the alligator in
the canal worries me a little. |
Bottom paint on prop
Bil,
This was very informative. Regarding your suggestion of epoxy primer followed by antifouling, which expoxy primer do you recommend, and what kind of antifouling ? I have saildrives with folding props. At last haulout I followed each of the many steps (Interlux Primecom as one layer comes to mind) required, but this seems simpler. Thanks. "Bil" wrote in message ... On 20 Nov 2005 08:46:07 -0800, "beaufortnc" wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Cheers |
Bottom paint on prop
On Mon, 21 Nov 2005 10:49:53 +1100, "d parker"
wrote: "News f2s" wrote in message ... /// Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. Sorry, didn't really answer your question, but that's my conventional wisdom on the subject. JimB hmmm... Ever thought of attaching a regular snorkel to some larger hose? Vacuum hose is great with a float at the loose end. You can stay down a lot longer. Some of the co2 you exhale will get re-inhaled each time. I havent passed out yet though.. Fingers crossed. DP How about a y fitting from the snorkel to two vacuum hoses, the float on one would have a caged ping pong ball for an outflow only and the float on the other would have a soft sprung flapper for an inflow only?? Brian Whatcott Altus OK |
Bottom paint on prop
Brian Whatcott wrote:
On Mon, 21 Nov 2005 10:49:53 +1100, "d parker" wrote: "News f2s" wrote in message ... /// Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. Sorry, didn't really answer your question, but that's my conventional wisdom on the subject. JimB hmmm... Ever thought of attaching a regular snorkel to some larger hose? Vacuum hose is great with a float at the loose end. You can stay down a lot longer. Some of the co2 you exhale will get re-inhaled each time. I havent passed out yet though.. Fingers crossed. DP How about a y fitting from the snorkel to two vacuum hoses, the float on one would have a caged ping pong ball for an outflow only and the float on the other would have a soft sprung flapper for an inflow only?? Brian Whatcott Altus OK All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. Terry K |
Bottom paint on prop
"Terry Spragg" wrote in message ... Brian Whatcott wrote: On Mon, 21 Nov 2005 10:49:53 +1100, "d parker" wrote: "News f2s" wrote in message ... /// Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. Sorry, didn't really answer your question, but that's my conventional wisdom on the subject. JimB hmmm... Ever thought of attaching a regular snorkel to some larger hose? Vacuum hose is great with a float at the loose end. You can stay down a lot longer. Some of the co2 you exhale will get re-inhaled each time. I havent passed out yet though.. Fingers crossed. DP How about a y fitting from the snorkel to two vacuum hoses, the float on one would have a caged ping pong ball for an outflow only and the float on the other would have a soft sprung flapper for an inflow only?? Brian Whatcott Altus OK All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. Terry K Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats why, in my initial post, i recomened a larger diameter hose you see :) DP |
Bottom paint on prop
On 20 Nov 2005 20:44:21 -0600, Dave wrote:
I did just what you're proposing last year. When the boat was hauled both the bottom paint and the barrier coat were gone, and the prop covered with barnacles. ============================================= There are primers and paints that work well, even here in SWFL, so do not take a defeatist position. My props and running gear were done by Olsen's in Ft Myers Beach last year and they have done extremely well. The primer they use is multi-step and bright yellow as they are applying it. Other than that I don't know what it is. Here are the Interlux recommendations: http://tinyurl.com/8mdqx |
Bottom paint on prop
On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II"
wrote: "Bil" wrote in On 20 Nov 2005 08:46:07 -0800, "beaufortnc" wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Bil, This was very informative. Regarding your suggestion of epoxy primer followed by antifouling, which expoxy primer do you recommend, and what kind of antifouling ? I have saildrives with folding props. At last haulout I followed each of the many steps (Interlux Primecom as one layer comes to mind) required, but this seems simpler. Thanks. Garland: I always beg epoxy primer from the yard which has hauled me out - the prop does not need much and I usually have no other use for it. So I take whatever the yard has in terms of left over epoxy primer. My sailboat is currently wearing International Micron Extran (International is called Interlux stateside), so that's the antifoul I use. To reiterate, the important steps a 1. to apply the antifouling onto the epoxy primer before the epoxy has dried (usually the manufacturer will detail the timing on the package); and 2. to leave the epoxy/antifoul to harden for at least a week. I have two props, a 2-blade and a 3-blade, so I antifoul whichever is not on the prop shaft (because I am usually on the hard for only 3 days - and that is not long enough for the primer/antifoul coatings to harden). Cheers |
Bottom paint on prop
"Terry Spragg" wrote in message ... Well, once a month I take a swim with a wire brush, take a few deep breaths and the see how long I can stay underwater hanging on to the prop shaft. But then I'm in warm water (never less than 18C) and it's clean and clear. hmmm... Ever thought of attaching a regular snorkel to some larger hose? Vacuum hose is great with a float at the loose end. You can stay down a lot longer. Some of the co2 you exhale will get re-inhaled each time. How about a y fitting from the snorkel to two vacuum hoses, the float on one would have a caged ping pong ball for an outflow only and the float on the other would have a soft sprung flapper for an inflow only?? All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. OK. Full story. Snorkel is attached to a long hose which goes up to the deck. Mask covers nose and eyes only. I breath out through the nose (which then bubbles out through the edges of the mask, good one way valve) and breath in through the snorkel. No need for any balls (unless the alligators are hungry). I've scrubbed a whole bottom this way. But I don't recommend anyone doing this unless they do some shallow water practice first, sitting in a pool. Ask a friend (!) to disconnect/block/duck the hose end into the water at random times to familiarise yourself with recovery routines. Then do this deeper. The purpose of these practice sessions, which you should do several times, is to get the feel of an imminent mouthful of water coming down the line, and develop routines to reduce your panic levels when it happens. Otherwise, feeling that gurgle in the pipe when you've just breathed out is quite a downer . . . don't ask. Oh, and have someone on deck looking out for you, with a bit of string to give you a couple of tugs if you should quickly come up for some reason. JimB |
Bottom paint on prop
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Bottom paint on prop
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Bottom paint on prop
In article ,
d parker wrote: All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. Terry K Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats why, in my initial post, i recomened a larger diameter hose you see :) When I was a kid, we decided to try this at the bottom of a swimming pool. I volunteered to be try breathing with the hose. There were four of us. I went below with the hose, then the other three kids took deep breaths and blew into the hose topside. I was able to extend my bottom time by about 2 minutes, until they got winded and I got dizzy. Well, I'm still hear and probably didn't damage too many brain cells. -- "j" ganz @@ www.sailnow.com |
Bottom paint on prop
Jonathan Ganz wrote:
In article , d parker wrote: All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. Terry K Yeh the harden hose is difficult at longer lengths. So is garden hose. Thats why, in my initial post, i recomened a larger diameter hose you see :) When I was a kid, we decided to try this at the bottom of a swimming pool. I volunteered to be try breathing with the hose. There were four of us. I went below with the hose, then the other three kids took deep breaths and blew into the hose topside. I was able to extend my bottom time by about 2 minutes, until they got winded and I got dizzy. Well, I'm still hear and probably didn't damage too many brain cells. Damaged them enough to use hear instead of here. |
Bottom paint on prop
Thanks !
"Bil" wrote in message ... On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II" wrote: "Bil" wrote in On 20 Nov 2005 08:46:07 -0800, "beaufortnc" wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Bil, This was very informative. Regarding your suggestion of epoxy primer followed by antifouling, which expoxy primer do you recommend, and what kind of antifouling ? I have saildrives with folding props. At last haulout I followed each of the many steps (Interlux Primecom as one layer comes to mind) required, but this seems simpler. Thanks. Garland: I always beg epoxy primer from the yard which has hauled me out - the prop does not need much and I usually have no other use for it. So I take whatever the yard has in terms of left over epoxy primer. My sailboat is currently wearing International Micron Extran (International is called Interlux stateside), so that's the antifoul I use. To reiterate, the important steps a 1. to apply the antifouling onto the epoxy primer before the epoxy has dried (usually the manufacturer will detail the timing on the package); and 2. to leave the epoxy/antifoul to harden for at least a week. I have two props, a 2-blade and a 3-blade, so I antifoul whichever is not on the prop shaft (because I am usually on the hard for only 3 days - and that is not long enough for the primer/antifoul coatings to harden). Cheers |
Bottom paint on prop
Hi,
I've never found any paint to be worth the bother on props or shafts. The only thing that's even worked for a little while is Lanolin grease - like Lanocote from Forespar. Warm it up and paint it on with a brush. There's a similiar product from NZ called Henley's Grease http://www.bestmarineimports.com/Props.html . I'm going to try it next year for no other reason than I gotta like a guy who names a grease after himself. I have no relation to either compay. Carl |
Bottom paint on prop
On Sun, 20 Nov 2005 23:00:22 -0400, Terry Spragg wrote:
Brian Whatcott wrote: All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Good Luck indeed, because if you go too far you are liable to have your lungs being sucked up the hose is what I heard (not sure how deep is too deep, anybody?) Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. that works, I've done that.. -- http://maps.google.com/maps?q=irelan...244,0.0822&t=k |
Bottom paint on prop
I haven't had much luck getting paint to stick to my props. Usually
only takes a couple of times out for it all to come off. I'm sure there are systems out there that will work but you could always try Boudreaux's Butt Paste. It works well for keeping the prop clean in between uses. Of course someone has to go under to apply it, but it is a cheap alternative. As for staying underwater long enough to do this, I just spliced 50' of air compressor hose between my primary and safe secondary regulators. I can leave my tank on the back of the boat and dive under. If anything goes wrong, I'm only 6' under water. I know the air compressor hose is technically unsafe to breathe out of, but I've been doing it for years with no ill effects. Later, Dan Schiro M/V Sea Ranch |
Bottom paint on prop
Iain Hibbert wrote:
On Sun, 20 Nov 2005 23:00:22 -0400, Terry Spragg wrote: Brian Whatcott wrote: All you need is an exhalation valve at the mask, and an iron lung to enable you to suck air below about 4 feet. Try it, just suck in through the mouth using a harden hose and exhale through your nose. Good luck. Good Luck indeed, because if you go too far you are liable to have your lungs being sucked up the hose is what I heard (not sure how deep is too deep, anybody?) That's dumb. All that happens is the hose collapses from the pressure. Nothing is going to push your lungs up the hose.......duh. Or a powered snorkel pump on a float on the surface, know as a hooka, and some dive weights. that works, I've done that.. |
Bottom paint on prop
Well, then just sit on the bottom at the shallow end of the pool so
that your head is about a foot under water, your lungs about 2 feet under. Then take a standard, one foot long snorkeling snorkel in your mouth upside down, so that you can point it to the surface. Try to inhale. This won't suck up your lungs, but give you a good idea of the principle. That's why snorkels are so short, duh. While you are in the pool take a thin garden hose to the deep end and see at what pressure it collapses. Don't try to inhale through it, you would just exhale quicker and deeper than you wanted. :) |
Bottom paint on prop
"Gary" wrote in message news:ixPgf.570915$oW2.460791@pd7tw1no... Iain Hibbert wrote: Good Luck indeed, because if you go too far you are liable to have your lungs being sucked up the hose is what I heard (not sure how deep is too deep, anybody?) That's dumb. All that happens is the hose collapses from the pressure. Nothing is going to push your lungs up the hose.......duh. What happens is that as you go deeper it becomes progressively more difficult to breath in, because your lung pressure is at atmospheric, whilst the water pressure is increasing at about half a pound per square inch for each foot of depth. The 'squeeze' that another poster has referred to. This limits me to a depth of about 4 - 5ft. Any deeper and I have a coughing fit after re-surfacing. Apparently that's caused by bits of the lungs collapsing, and the coughing is a reaction to the little subchambers unsticking again. Nasty feeling. That's another reason why I say - you don't do this without plenty of previous practice in the swimming pool to check out the feeling of all the things which may go wrong. Better just take that deep breath . . . air breathing diving of any sort is full of traps for the unwary. JimB |
Bottom paint on prop
News f2s wrote:
"Gary" wrote in message news:ixPgf.570915$oW2.460791@pd7tw1no... Iain Hibbert wrote: Good Luck indeed, because if you go too far you are liable to have your lungs being sucked up the hose is what I heard (not sure how deep is too deep, anybody?) That's dumb. All that happens is the hose collapses from the pressure. Nothing is going to push your lungs up the hose.......duh. What happens is that as you go deeper it becomes progressively more difficult to breath in, because your lung pressure is at atmospheric, whilst the water pressure is increasing at about half a pound per square inch for each foot of depth. Duh! Of course if the hose is reinforced and more rigid than your chest walls the you could get squeezed if you are not smart enough to hold your breath. The 'squeeze' that another poster has referred to. This limits me to a depth of about 4 - 5ft. Any deeper and I have a coughing fit after re-surfacing. Apparently that's caused by bits of the lungs collapsing, and the coughing is a reaction to the little subchambers unsticking again. Nasty feeling. The air needs to be pumped down at the ambient pressure of your lungs. After a couple feet *most* people can't suck hard enough to get air. You might be the exception. That's another reason why I say - you don't do this without plenty of previous practice in the swimming pool to check out the feeling of all the things which may go wrong. Better just take that deep breath . . . air breathing diving of any sort is full of traps for the unwary. Good idea, nobody ever drowned in a swimming pool. JimB |
Bottom paint on prop
"News f2s" wrote in message ... "Gary" wrote in message news:ixPgf.570915$oW2.460791@pd7tw1no... Iain Hibbert wrote: Snip That's another reason why I say - you don't do this without plenty of previous practice in the swimming pool to check out the feeling of all the things which may go wrong. Better just take that deep breath . . . air breathing diving of any sort is full of traps for the unwary. JimB air breathing diving of any sort is full of traps for the unwary. Reminds of the article in one of the recent Northwest Yachting magazinea describing the fellow living on his Hinckley?/Hallber-Rasey? 46 in Costa Rica. He became enamoured of free diving. Unfortunately one time he needed to come up there was a big power boat overhead. He drowned. Seems like a dumb way to lose a beautifull boat/life. |
Bottom paint on prop
"Gordon Wedman" wrote:
"News f2s" wrote in message ... "Gary" wrote in message news:ixPgf.570915$oW2.460791@pd7tw1no... Iain Hibbert wrote: Snip That's another reason why I say - you don't do this without plenty of previous practice in the swimming pool to check out the feeling of all the things which may go wrong. Better just take that deep breath . . . air breathing diving of any sort is full of traps for the unwary. JimB air breathing diving of any sort is full of traps for the unwary. Reminds of the article in one of the recent Northwest Yachting magazinea describing the fellow living on his Hinckley?/Hallber-Rasey? 46 in Costa Rica. He became enamoured of free diving. Unfortunately one time he needed to come up there was a big power boat overhead. He drowned. Seems like a dumb way to lose a beautifull boat/life. Some people can do quite well free-diving. My SIL does this for the lobster season in FL, and can stay down for a considerable time. Even I can dive on the prop and do some work on it if I wear fins. It is not that hard if you practice and it makes a reasonable workout. The only time I can't do too much is if the water is cold - I can't stay in too long in cold water, and if I wear a wet suit, I am too buoyant to stay down. It sounds to me like the guy in Costa Rica didn't have a dive flag or take appropriate safety measures - like having someone watching. grandma Rosalie |
Bottom paint on prop
Dave wrote:
On Wed, 23 Nov 2005 21:12:09 GMT, Rosalie B. said: if I wear a wet suit, I am too buoyant to stay down. Everyone is. That's what weight belts are for. But not when free diving. grandma Rosalie |
Bottom paint on prop
Dave wrote:
On Wed, 23 Nov 2005 23:16:08 GMT, Rosalie B. said: On Wed, 23 Nov 2005 21:12:09 GMT, Rosalie B. said: if I wear a wet suit, I am too buoyant to stay down. Everyone is. That's what weight belts are for. But not when free diving. Why not? The weight on the belt can be adjusted to provide neutral buoyancy just as it can with tanks on. Only difference I can see is that you might want to keep a very slight positive buoyancy rather than going for entirely neutral. I don't have enough confidence in my ability to do that. I've been positively buoyant my whole life even when I was young and fit and relatively skinny. I wouldn't know how to deal with neutral. (About 30 years ago I did a life saving class checkout for another instructor, and I required each student to 'save' me, tow me around the pool and pull me out, and one of the students commented as he was towing me that I was easy to tow because I was just like a flotation cushion.) grandma Rosalie |
Bottom paint on prop
Dave wrote:
On Wed, 23 Nov 2005 15:26:17 GMT, Gary said: Duh! Of course if the hose is reinforced and more rigid than your chest walls the you could get squeezed if you are not smart enough to hold your breath. Take your "Duh" and shove it, schmuck. You're simply continuing to display your own ignorance. The 'squeeze' that another poster has referred to. This limits me to a depth of about 4 - 5ft. Any deeper and I have a coughing fit after re-surfacing. Apparently that's caused by bits of the lungs collapsing, and the coughing is a reaction to the little subchambers unsticking again. Nasty feeling. The air needs to be pumped down at the ambient pressure of your lungs. After a couple feet *most* people can't suck hard enough to get air. You might be the exception. That's what those of us who know something about diving physics have been saying from the beginning, and what you've been totally oblivious to. Glad you're beginning to catch on. This schmuck is a Navy diver. How about you? |
Bottom paint on prop
Dave wrote:
On Wed, 23 Nov 2005 23:16:08 GMT, Rosalie B. said: On Wed, 23 Nov 2005 21:12:09 GMT, Rosalie B. said: if I wear a wet suit, I am too buoyant to stay down. Everyone is. That's what weight belts are for. But not when free diving. Why not? The weight on the belt can be adjusted to provide neutral buoyancy just as it can with tanks on. Only difference I can see is that you might want to keep a very slight positive buoyancy rather than going for entirely neutral. At depth, you mean? If weighted neutral at surface, you will be negative below 10 feet. With tanks and weights and a buoyancy vest and pressure air in your lungs and available to your vest, you can adjust your buoyancy, but free, the deeper you go, the less buoyancy you have, because your lungs full of air get compressed, and occupy less volume, displacing less water, so down you go. Without weights, it is more directly dependant on your fat percentage, since fat floats, but does not compress. Same compensation queerdom with sponge rubber wet suits, and in dry suits with trapped air, but to different degrees for each parameter. Diving gets complicated. I know just enough about diving to know I do not know enough. Take a course if you intend to start screwing around with weights and hookas and such like. If you start thinking you are Jaques Cousteau, and want to invent diving stuff like he did, you will probably end up married to Davey Jones, whatever you think about gay marriage. Terry K |
Bottom paint on prop
"Gary" wrote in message news:tS%gf.578681$oW2.415490@pd7tw1no... News f2s wrote: What happens is that as you go deeper it becomes progressively more difficult to breath in, because your lung pressure is at atmospheric, whilst the water pressure is increasing at about half a pound per square inch for each foot of depth. Duh! Of course if the hose is reinforced and more rigid than your chest walls the you could get squeezed if you are not smart enough to hold your breath. Gary, you also get squeezed if you hold your breath, though slightly less. This limits me to a depth of about 4 - 5ft. Any deeper and I have a coughing fit after re-surfacing. Apparently that's caused by bits of the lungs collapsing, and the coughing is a reaction to the little subchambers unsticking again. Nasty feeling. The air needs to be pumped down at the ambient pressure of your lungs. After a couple feet *most* people can't suck hard enough to get air. You might be the exception. We *were* talking about using a breathing pipe to inhale uncompressed air. I've tried this, and found a technique that allows me to breathe under a shallow hull, using a long pipe, just a little deeper than with a snorkel. I don't recommend it. And yes, I do have a tough rib cage. And yes, I hold my breath to go temporarily deeper, and I do the breathing cycle at the shallowest depth possible, and I usually work upside down - hands at 4ft and lungs at 2ft. All of which makes it possible to work around a prop wrapped with a fishing net without getting the tanks out. However, there are serious hazards in playing this game without a great deal of care, practice and preparation. Since you obviously have enough under water experience to make rather patronising comments, I'm sure you appreciate this. JimB |
Bottom paint on prop
Back to the topic:
If there is room between the propeller and the strut, put a donut zinc on the shaft between the two. Nothing grows on the zinc, of course, since it is constantly depleting. But it also seems to extend a zone of protection that prevents or greatly reduces growth within a few inches of the zinc. That's enough to keep the prop hub clean, which is where maximum growth occurs. A frequently used prop won't have much growth beyond the hub in any case. |
freediving
Rosalie B. wrote:
Some people can do quite well free-diving. My SIL does this for the lobster season in FL, and can stay down for a considerable time. Even I can dive on the prop and do some work on it if I wear fins. It is not that hard if you practice and it makes a reasonable workout. The only time I can't do too much is if the water is cold - I can't stay in too long in cold water, and if I wear a wet suit, I am too buoyant to stay down. It sounds to me like the guy in Costa Rica didn't have a dive flag or take appropriate safety measures - like having someone watching. It was reported in Lat 38's Electronic Latitude that he was the victim of shallow water blackout, not having a boat above him. Shallow water blackout occurs when you hyperventilate too much before a freedive, and then when down, you run out of O2. Your body uses increasing levels of CO2 to tell you when to breathe, and hyperventilating reduces blood CO2. So you don't get the urge to breathe, and pass out underwater. I've come close a few times (black spots as I come up). Now I only ever hyperventilate 3 deep breaths before a dive. Diving with a buddy close by might save you, but by the time they notice a problem you might be 20' deep and sinking... It reduces my bottom time slightly but I feel a lot safer Evan Gatehouse |
freediving
"Evan Gatehouse" wrote in message ... Shallow water blackout occurs when you hyperventilate too much before a freedive, and then when down, you run out of O2. Your body uses increasing levels of CO2 to tell you when to breathe, and hyperventilating reduces blood CO2. So you don't get the urge to breathe, and pass out underwater. Thanks for that one Evan. I wasn't aware. I've had a dizzy spell or two, and hadn't thought through the cause too carefully. JimB |
Bottom paint on prop
Desitin. Baby bottoms and props.
Tom "Garland Gray II" wrote in message news:fOsgf.12766$ih5.6397@dukeread11... Thanks ! "Bil" wrote in message ... On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II" wrote: "Bil" wrote in On 20 Nov 2005 08:46:07 -0800, "beaufortnc" wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Bil, This was very informative. Regarding your suggestion of epoxy primer followed by antifouling, which expoxy primer do you recommend, and what kind of antifouling ? I have saildrives with folding props. At last haulout I followed each of the many steps (Interlux Primecom as one layer comes to mind) required, but this seems simpler. Thanks. Garland: I always beg epoxy primer from the yard which has hauled me out - the prop does not need much and I usually have no other use for it. So I take whatever the yard has in terms of left over epoxy primer. My sailboat is currently wearing International Micron Extran (International is called Interlux stateside), so that's the antifoul I use. To reiterate, the important steps a 1. to apply the antifouling onto the epoxy primer before the epoxy has dried (usually the manufacturer will detail the timing on the package); and 2. to leave the epoxy/antifoul to harden for at least a week. I have two props, a 2-blade and a 3-blade, so I antifoul whichever is not on the prop shaft (because I am usually on the hard for only 3 days - and that is not long enough for the primer/antifoul coatings to harden). Cheers |
Bottom paint on prop
As I said to begin with - Bob has used all those methods and none have
worked - that includes Desitin, anhydrous lanolin, and various kinds and formulations of paint. The only thing that works is regular use. "Tom R." wrote: Desitin. Baby bottoms and props. Tom "Garland Gray II" wrote in message news:fOsgf.12766$ih5.6397@dukeread11... Thanks ! "Bil" wrote in message ... On Sun, 20 Nov 2005 19:08:32 -0500, "Garland Gray II" wrote: "Bil" wrote in On 20 Nov 2005 08:46:07 -0800, "beaufortnc" wrote: Hi, I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? What you use on your prop depends on your pattern of boating. Regular boat use, eg once or more a week, can mean no special treatment (depending on your local level of fouling). And on your prop: whether bronze or stainless steel or plastic etc. And on other characteristics of your prop, eg whether it's a surface prop, such as a Levi drive; or a deep prop; whether it's spinning at around 1,000 rpm or two or three times faster. If you have a new bronze prop, waxes applied during the polishing process can mean that no permanent treatment works until that wax is removed and, perhaps, an etch primer is used. Some treatments that do work: * Grease the prop: if you are cruising, but anchor or berth for up to a month, coating the prop with a salt-water resistant grease works (for about a month). I use a German-made grease, Bechem SW2, and send the cook over the side after taking a berth or anchorage. The grease spins off, taking any slime etc with it. No chance that it can change the balance of the prop. * Bagging the prop: a physical barrier, such as a plastic bag, works. But you have to send the cook (or the cook's assistant) over the side twice, once to install the bag, once to remove it. * Painting with an antifouling. Whether you use a hard or ablative antifouling matters little; the problem is getting the paint to adhere. New props are a problem, because of the waxes. Older props work better. And the primer/paint combination is important. One technique that works is to use an epoxy primer and to follow, within the prescribed recoating time (usually about an hour, before the epoxy primer has completely hardened) with antifouling. The next step is important: then leave to harden completely (ie about one week - any sooner and the primer will spin off). I've also used a zinc chromate primer, with some -but not complete - success. * Commercially applied silicon coatings. Expensive (applying yourself is not a good as paying the experts to apply). But works in many conditions, especially if the boat is used fairly often. Bil, This was very informative. Regarding your suggestion of epoxy primer followed by antifouling, which expoxy primer do you recommend, and what kind of antifouling ? I have saildrives with folding props. At last haulout I followed each of the many steps (Interlux Primecom as one layer comes to mind) required, but this seems simpler. Thanks. Garland: I always beg epoxy primer from the yard which has hauled me out - the prop does not need much and I usually have no other use for it. So I take whatever the yard has in terms of left over epoxy primer. My sailboat is currently wearing International Micron Extran (International is called Interlux stateside), so that's the antifoul I use. To reiterate, the important steps a 1. to apply the antifouling onto the epoxy primer before the epoxy has dried (usually the manufacturer will detail the timing on the package); and 2. to leave the epoxy/antifoul to harden for at least a week. I have two props, a 2-blade and a 3-blade, so I antifoul whichever is not on the prop shaft (because I am usually on the hard for only 3 days - and that is not long enough for the primer/antifoul coatings to harden). Cheers grandma Rosalie |
Bottom paint on prop
In article . com,
"beaufortnc" wrote: I'm prepping the bottom of my sailboat for barrier coat then ablative bottom paint. I'm thinking, however, that it might be a good idea to paint the prop with something like Trinidad instead of ablative. It seems to me that the ablative won't last long on the prop. What's the conventional wisdom here? I suspect something came up in the replies, but gave up when the thread took a strange turn. I've tried ablative, hard, "outboard" (TNT) and other options over the years and have yet to find something that actually kept our prop clean throughout the season. I'm about to try something that scares the living dickens out of me, but was recommended by the shop that installed our engine: NOTHING. No zinc, no copper or tin-based paints. The theory is that the slight electrical imbalance between the SS shaft and bronze prop will be sufficient to keep both clean. Since our shaft is isolated from everything else in the boat, the only thing eating away half of our zincs each year is the SS/Bronze imbalance. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
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