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#1
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If you have to solder
There seems to be differences of opinion regarding soldered
vs crimped terminals in a marine environment. As others have pointed out, ABYC allows soldering, but only in conjunction with a mechanical means of securing the wire to the terminal. The only practical mechanical means of course is a crimp connection. One poster suggested the ABYC is changing this. Be interesting to see the new rules. A google search on this topic reveals about equal numbers of those for and against soldering. Based on my electronics experience (50 years, plus a NASA course in soldering, for whatever that's worth), I'd recommend the following procedures...for smaller guage wire, that is... 1. Buy proper marine wire. The cheapo wire packs sold in auto parts stores (and I'd suspect in some marine stores as well), are junk. Look at any utility trailer home-wired for lights, and you'll notice the insulation falling off. Make sure the wire construction is tinned copper conductors, at least 7 strands, 19 strands is better, and an insulation temp rating of at least 75C. I buy nothing less than 105C wire myself. A nylon jacket over the primary insulation is prefered. Use your soldering iron to "tin" a few samples. If the solder doesn't immediatly flow, and just beads up, the wire conductor is oxidized. Don't use it, even if you intend to crimp and not solder. 2. Buy the proper crimp tool. A good one is expensive, but should last a lifetime. I like crimpers which make double "elliptical" crimps as opposed to the "indent" type. If you do use the indent style, make sure the indent is opposite the barrel seam. 3. Use proper terminals. As in the case of wire, beware of the cheap ones. The metal part should be tinned heavy-guage copper, (solder test the terminal just as you did the wire), the barrel should be seamless...actually the seams are usually brazed. The rear of the barrel should include a insulation grip as well. The terminal insulation should be temp rated equal to the wire, but often isn't. 4. Try it out. Cut some new wire into a few 6" to 12" samples. Use your new strippers to strip a bit of insulation from the ends. Inspect the stripped end very closely, under a glass if you're not 21 or younger, and verify that the insulation was cut cleanly, and that no strands were nicked, not even a little. Why? Because nicks will expose bare copper, which will oxidize pretty quickly. You may have to strip off a bit more to see the area of the original strip. 5. Crimp a few terminals on your wire samples. Try to pull the terminal from the wire. You shouldn't be able to. The wire should break first. Use a Exacto knife (or equiv) to remove the terminal insulation. Inspect the crimp area for signs of over crimping...exposed copper, tears, etc. 6. If you're the belt-and-suspenders type, and you just have to solder the terminal, here's how. After the terminal has been properly crimped, you should see the end of the wire exposed at the ring end of the terminal, if that makes sense. If the end of the wire is not even with, or slightly protruding (.020"), from the barrel, you're not stripping quite enough insulation. Then buy, beg, or steal from your electronics buddy some very small diameter (no larger than 18 guage, and new!!) rosin-core solder. Organic flux solder is better if you can find it. Use a fine tip soldering iron (I use a 15W pencil iron) to heat the junction of the wire and terminal, then touch the solder to the exposed wire. The goal is to just "paint" the end of the wire. Resist the temptation to make another "pass". If properly done, a glass should reveal the indivdual strands, and a very tiny fillet of solder between the wire and the terminal. NASA has shown over and over this is sufficient to make a proper solder connection, even if it doesn't look like it. If the solder joint looks like a blob, and hides the wire strands, you've used too much solder. A bit of practice will be invaluable before doing it for real on the boat. A "2-bits worth" observation while I'm on my soapbox.... A lot of power distribution panels are works of art. Labels, wire ties, neat routing, etc. But one thing I've see missing most often are drip loops and service loops. Drip loops ensure that water does not run onto the terminal if the wire is wetted. Service loops are an extra bit of wire (can be combined with drip loops), so that if a terminal does need to be replaced, you can cut back to fresh copper, and install a new terminal. On terminal blocks and bus bars, I tie wrap the "bundle" at every wire, and the bundle to something solid every 2" or so. (I still use nylon lacing cord...old habit I guess). The idea is to make the natural frequency of the unsupported portion of the wire much higher than any vibration likely to be encountered on a boat. If you choose to use this method, do not tie the bundle to metal. Reason? Most PVC insulation materials will "cold flow" and eventually allow the conductor to contact the metal. A nylon jacket is helpful in this regard. As always,double (heavy) wall heat shrink tubing is a good idea. (Again, don't use the cheap stuff from Radio Shack) Hope the above is somewhat useful to you. Norm B |
#2
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If you have to solder
Sounds like good info for all. Personally, I'm a believer in "tin - crimp -
solder". When maintence boss for a fleet of seasonal boats, I had one person who would go to each boat and check EACH electrical connection for corrosion and tightness. At first he considered this a waste of time .... then he began to run across loose and corroded connection ..... Shen |
#3
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If you have to solder
good advice.
If you're the belt-and-suspenders type, and you just have to solder the terminal, here's how. After the terminal has been properly crimped, you should see the end of the wire exposed at the ring end of the terminal, if that makes sense. If the end of the wire is not even with, or slightly protruding (.020"), from the barrel, you're not stripping quite enough insulation. Then buy, beg, or steal from your electronics buddy some very small diameter (no larger than 18 guage, and new!!) rosin-core solder. Organic flux solder is better if you can find it. Use a fine tip soldering iron (I use a 15W pencil iron) to heat the junction of the wire and terminal, then touch the solder to the exposed wire. The goal is to just "paint" the end of the wire. Resist the temptation to make another "pass". If properly done, a glass should reveal the indivdual strands, and a very tiny fillet of solder between the wire and the terminal. NASA has shown over and over this is sufficient to make a proper solder connection, even if it doesn't look like it. If the solder joint looks like a blob, and hides the wire strands, you've used too much solder. A bit of practice will be invaluable before doing it for real on the boat. |
#4
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If you have to solder
not bad, except the sequence in "crimp, tin, solder"
Sounds like good info for all. Personally, I'm a believer in "tin - crimp - solder". When maintence boss for a fleet of seasonal boats, I had one person who would go to each boat and check EACH electrical connection for corrosion and tightness. At first he considered this a waste of time .... then he began to run across loose and corroded connection ..... Shen |
#5
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If you have to solder
bject: If you have to solder
From: (JAXAshby) Date: 05/30/2004 18:38 Pacific Standard Time Message-id: not bad, except the sequence in "crimp, tin, solder" G As I said, I prefer "tin - crimp - solder". Always felt we got a much better continuous bond between all the parts this way. To each his/her own .... and I never had a problem with these connections in the time I remained there..... our biggest problem was things loosening up (screws and nuts). Shen |
#6
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If you have to solder
Not sure how one would tin the wire or the connector once
the crimp has been made. Proper wire is already tinned and so are many connectors. I remember reading many years ago in NASA Tech Briefs that crimpped connections are more reliable than soldered ones in the long run due to microcracks in the solder joint due to thermal cycling. Doug s/v Callista "JAXAshby" wrote in message ... not bad, except the sequence in "crimp, tin, solder" Sounds like good info for all. Personally, I'm a believer in "tin - crimp - solder". When maintence boss for a fleet of seasonal boats, I had one person who would go to each boat and check EACH electrical connection for corrosion and tightness. At first he considered this a waste of time .... then he began to run across loose and corroded connection ..... Shen |
#7
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If you have to solder
Subject: If you have to solder
From: "Doug Dotson" Date: 05/31/2004 12:26 Pacific Standard Time Message-id: Not sure how one would tin the wire or the connector once the crimp has been made. Same here G but I didn't want to bite... I've since learned that the method I describe is not always considered the best, but we were working with old and new wiring systems, and this seemed to hold up for extended periods of time which was an obvious plus. Shen Proper wire is already tinned and so are many connectors. I remember reading many years ago in NASA Tech Briefs that crimpped connections are more reliable than soldered ones in the long run due to microcracks in the solder joint due to thermal cycling. Doug s/v Callista |
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