"bilgeworthy" wrote in message
...
Hi, new varnisher here. When I brush it on carefully, I can see tiny
gas bubbles forming in the wake of the brushstroke.
snip..

Just a thought...do you stir the can of varnish slowly and carefully before
applying? (not like paint can shaking)

Varnishing can often be more "art" than "science". I don't consider myself
a "pro" by any means, but have spent enough time around the pros to pick up
some of their tricks. Sounds like you're using all the main ingredients to
a successful varnish job:

* using a good brush, "China Bristle" or better, although foam brushes have
worked for me,
* never shake the can, stir -and- strain the varnish to a separate
container,
* Schooner Varnish is the preferred varnish of the pros I know,

A couple things you didn't mention though, and I'd add:

* surface prep: make sure you thoroughly clean and tack rag the surface
before each coat (contaniments can cause what appear like bubbles).
* air temp / humidity: calm, cool and dry mornings are often the best time
to work, gives the varnish more time to settle before drying.
* lots of coats: 8 coats as a minimum, most pros I know go with 12 or more.
* brushing technique: sounds like you may be moving the brush too quickly,
thus generating bubbles. Also brush in one direction, not back and forth.
Try to "flow" the varnish on rather than "brush" it on.

Of course, there are days when the varnish just doesn't want to cooperate.
The "cheat" I've seen the pro's use is using very heavy coats, and "flowing"
the varnish on, then if it still won't level properly, they'll wet sand and
polish as a final touch.

Some folks love doing brightwork, others (like myself) see it as a necessary
evil. Trust me, you aren't the first to be frustrated with a varnish job
that just doesn't want to work.

Good luck!

Paul

The bubbles that form during curing are usually caused from varnishing
during rising temperature. . As cold wood warms the air in the pores
expands. I try to lay the first couple of coats late in the afternoon while
the wood is warm. As it cools the air contracts and sucks a bit more
varnish into the pores.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"bilgeworthy" wrote in message
...
Hi, new varnisher here. When I brush it on carefully, I can see tiny
gas bubbles forming in the wake of the brushstroke. Most of them pop
but some do not and others seem to form during the drying process. The
more I try and brush it out the worse it gets. The unhappy result is a
beautiful piece of wood with assorted pimples strewn about the finish.
I have tried expensive brushes and foam brushes with the same result.
I have tried straight varnish, thinner, cheap and dear and 216
(xylene) as brushing agents. I follow the routine from the Brightwork
Companion as well as I can. Not shaking or redipping from the can.
I'm working indoors with everything at room temp. I have used brand
new Schooner Varnish, some old junk in a can and a custom artists
mixture of Danar (Damar?) and magic emollients etc. They all act the
same. It's less noticeable on 25 year old teak than on newly made
woodwork but it's the same result even after 8 coats. I sand out the
flaws between coats. I am definitely open to suggestion at this point.
Gosh, the old teak just takes your breath away. If I can just take
care of this complexion problem.
Thank you.

Glen probably has the answer to your problem.

Porosity in the wood, even with several prior coats of varnish, will
sometimes make bubbles as the temperature changes. The use of a 'spit
coat' as the *first coat* usually solves the problem. A spit coat is
usually mixed as 40%-50% varnish and 60%-50% thinner appied heavy and
'worked-into the grain' with a brush. The extra solvent will greatly
'thin' the mix so that it will penetrate into the intersticies of the
wood cells. An alternative is to use a 'sealer' - usually a clear
penetrating acrylic that you apply, let cure, then lightly flat sand.
Sealers are not really a good idea as they are not UV stable and
enhance 'lifting' when the sealer eventually degrades in UV ---- better
to use a very thinned-out 'spit-coat(s)'. When I was a
'varnish-addict' I'd wait for the hottest time of the day to apply the
spit-coat : let wood get warm, then put up a shade so that the wood
begins to cool and apply the spit-coat on the 'cooling' wood. If the
spit-coat is warmed a bit, the better the 'penetration'. Also, watch
the barometer as a falling barometer will aid in 'off-gassing' during
varnish application.

I used to prefer(ed) to lay down the first few (4-5) coats with tung
oil based varnish for 'penetration' , let fully cure; then a few coats
of urethane based varnish for UV protection, let cure a month or two
then apply a 2-part clear (Interthane, etc) on top of that for
durability ..... and 3-4 years later remove it all when the first coat
lost 'adhesion'.

I gave up using brushes and found that using a small airbrush is vastly
superior ..... and then I discovered the modern 2-part acrylic/urethane
co-polymers with heavy UV protection that last 5-6 years; and, havent
opend a can of 'exterior' varnish since.

In article ,
says...
Hi, new varnisher here. When I brush it on carefully, I can see tiny
gas bubbles forming in the wake of the brushstroke. Most of them pop
but some do not and others seem to form during the drying process. The
more I try and brush it out the worse it gets. The unhappy result is a
beautiful piece of wood with assorted pimples strewn about the finish.
I have tried expensive brushes and foam brushes with the same result.
I have tried straight varnish, thinner, cheap and dear and 216
(xylene) as brushing agents. I follow the routine from the Brightwork
Companion as well as I can. Not shaking or redipping from the can.
I'm working indoors with everything at room temp. I have used brand
new Schooner Varnish, some old junk in a can and a custom artists
mixture of Danar (Damar?) and magic emollients etc. They all act the
same. It's less noticeable on 25 year old teak than on newly made
woodwork but it's the same result even after 8 coats. I sand out the
flaws between coats. I am definitely open to suggestion at this point.
Gosh, the old teak just takes your breath away. If I can just take
care of this complexion problem.
Thank you.


In my not inconsiderable experience with wood finishes I have to note
that varnish is one pain in the butt finish to apply when compared to
many other finishes. Unfortunately, with bright work, the options I have
open to me for other applications aren't viable.

First, gloss varnish doesn't need to be mixed. Semi and satin does.
Never shake the can, stir gently to avoid suspending air bubbles in the
finish before you even start applying it.

Thin your first coat or two by 50% and apply it with a rag.

If you use a brush be sure it is a natural hair brush, badger, and do
not tap off the excess into the can. Gently move the brush across the
mouth of the can to get excess finish off.

Thin the varnish to around 15% for follow up coats. The less viscous
coat allows air bubbles to escape faster.

Start you brush stroke with the brush tip and held almost vertically to
the surface being coated. Draw the brush slowly across the surface
lowering the angle of the brush as the varnish flows out.

Tip off the coat. That is, once you have the stroke finished very gently
and with just the tip of the brush touching the finish at 90 degrees
move it across the finish to knock out any bubbles you do get.

DO NOT over work the finish. It is almost impossible to not get some air
bubbles in the finish. As you have found, overworking the finish just
makes matters worse. That is what they make sandpaper for.

DO NOT try to sand off drips and sags. Use a sharp chisel or razor to
shave them off.

If at all possible DO NOT varnish in full sun. This causes the finish to
skin over much too fast to allow any air trapped in the grain of the
wood or laid down by the brush to escape.

DO NOT apply thick coats. Thin coats are best! Thick coats also slow the
rising air bubbles to the point where they become trapped in the curing
varnish.

DO Not bury bubbles and dust bumps under another coat. Sand them out
before the next coat. Waiting, of course till the coat is cured at least
eight hours. If I am using an oil based varnish steel wool is my
preferred medium for doing that job. If you are using water based
varnish steel wool is ok for the last coat but you have to use sandpaper
for the in between coats.

Decant the varnish to another container for application. Do not put your
brush into your main supply or dump anything left in the second
container back into your main supply. Doing either will contaminate your
main supply with anything your brush picks up. Pour slowly to avoid
introducing bubbles into the varnish.

Thin coats means you have to apply more of them which takes more time
but they avoid a lot of the problems inherent in applying varnish.

My preferred method of applying varnish is to head down to Lowe's or
Home Depot and pick up a large box of Scott's "Rags in a Box" wipe on
the above mentioned fifty percent thinned coats then thin the varnish
somewhere between fifteen to twenty percent, the figure isn't critical,
and wipe on the rest of the coats.

While the above method, what with thin coats and drying time between
coats, takes more time to get a good build then brushing on a few heavy
coats it avoids most of the problems brushing on heavy coats introduces,
air bubbles, drips and sags, dust collection, and can, if one is looking
for a really good finish, actually reduce the time it takes to get one
since you aren't trying to fix those problems.

The use of thin coats makes no difference in the durability of the final
finish.

I may have forgotten a few things there but it's somewhere to start.

Hope it helps
Mike G.
--
Mike G.
Heirloom Woods

www.heirloom-woods.net

Subject: help! my varnish has pimples,..
From: bilgeworthy

Hi, new varnisher here. When I brush it on carefully, I can see tiny
gas bubbles forming in the wake of the brushstroke. Most of them pop
but some do not and others seem to form during the drying process. The
more I try and brush it out the worse it gets. The unhappy result is a
beautiful piece of wood with assorted pimples strewn about the finish.
I have tried expensive brushes and foam brushes with the same result.
I have tried straight varnish, thinner, cheap and dear and 216
(xylene) as brushing agents. I follow the routine from the Brightwork
Companion as well as I can. Not shaking or redipping from the can.
I'm working indoors with everything at room temp. I have used brand
new Schooner Varnish, some old junk in a can and a custom artists
mixture of Danar (Damar?) and magic emollients etc. They all act the
same. It's less noticeable on 25 year old teak than on newly made
woodwork but it's the same result even after 8 coats. I sand out the
flaws between coats. I am definitely open to suggestion at this point.
Gosh, the old teak just takes your breath away. If I can just take
care of this complexion problem.

After 8 coats the bubbles would not be coming out of the wood.
So are your sure that they are not small bits of contamination? I've had people
tell me that the bubbles they see while applying varnish don't seem to fully
pop and go away. And after looking closely at them I've found them to not be
dried bubbles but particles of contamination or dust.
Are you filtering the varnish? Tacking off well?
Applying it outside? Or in a dust free room/area?

If they truly are bubbles perhaps you should add a bit more thinner (if your
adding any now) to give the bubbles less viscosity to fight and more time to
pop.

Capt. Bill

In article ,
says...
I used to prefer(ed) to lay down the first few (4-5) coats with tung
oil based varnish for 'penetration' , let fully cure; then a few coats
of urethane based varnish for UV protection, let cure a month or two
then apply a 2-part clear (Interthane, etc) on top of that for
durability ..... and 3-4 years later remove it all when the first coat
lost 'adhesion'.



Just an observation.

There are two based types of Varnish. Water or oil based. The difference
is that water based is thinned with water and the oil based with mineral
spirits, paint thinner. Even if not stated you can tell the difference
by looking at what is called for in the clean up instructions on the
can.

All oil based varnishes contain tung oil or some other type of curing
oil. These days it can be a modified soy oil of some sort. The resins in
a varnish, without the curing oil, would form an extremely brittle and
easily damged surface. The oil modifies and softens the final results
making it less brittle.

Penetration into the wood is dependant on the viscosity of the varnish
not the type of resin used. I agree completely on sealing the wood with
a coat or two of varnish thinned fifty percent. However, once that has
been done and the coats cure, there is no further "penetration by a
finish no matter how much it is thinned. The wood cells are already
sealed.

Urethane and polyurethane are simply the types of resins used in the
varnish deliniating them from non urethane varnishes Non urethane
varnish can use natural resins, rosin, amber, or man made resins that
form a weaker chemical link then the urethane resins.

Spar or marine varnish, in addition to UV inhibitors not found in other
varnishes, is what is termed long oil varnishes. They contain a higher
ratio of curing oil to resins so they are more flexible and better able
to accomodate, without cracking, the higher level of movement that wood
experiences in an outdoor enviroment.

The use of a non spar/marine varnish under coats of spar varnish can
actually defeat the purpose of using a long oil varnish by failing and
cracking long before the a spar varnish would have if it was used
without the undercoat of the short oil varnish.

NOTE; I am just giving some observations of spar and non spar varnish. I
am unfamiliar with the acrylic finish you refer too and am not making
any observations in regards to an acrylic finish Vs the spar/marine
varnish one finds off the shelf.

Take care


--
Mike G.
Heirloom Woods

www.heirloom-woods.net

In article , labomba182
@aol.com says...
after looking closely at them I've found them to not be
dried bubbles but particles of contamination or dust.



An excellent observation. I've found that in the hour or so it takes
varnish to dry out of tack it makes a better dust collector then any
HEPA filter and is capable of attracting dust from whole neighborhoods.


--
Mike G.
Heirloom Woods

www.heirloom-woods.net

On Fri, 28 Jan 2005 14:31:48 GMT, Rich Hampel
wrote:

then I discovered the modern 2-part acrylic/urethane
co-polymers with heavy UV protection that last 5-6 years; and, havent
opend a can of 'exterior' varnish since.
========================

Can you recommend a brand that you like?

I prefer "Honey Teak" by Signaturefinish.com ... starting to be
fairly common on the east coast. The wescoasters seem to prefer "5
Year Clear" by Smith & Co. ... which has a bit of an epoxy base.
The stuff is expensive, takes a bit of a learning curve .... in overall
cost and overall labor is much cheaper. Once the base coats are
applied a very simply scrub with a scotchbite pad and quick coat of
2-part clear yearly is all that it takes .... I double the clear
thickness every two years and simply power buff the clear coat .

The stuff is very easy to lay down and since it is a catalyzed coating
system, you can usually do the WHOLE job on a cool weekend. Initially
when applied they have an amber 'hue' but rapidly fade to a light
'honey' -clear color with UV exposure. Both can be hand-rubbed with
rotten stone and water (as one can do with varnish) for an
'ultra-gloss' finish.


In article , Wayne.B
wrote:

On Fri, 28 Jan 2005 14:31:48 GMT, Rich Hampel
wrote:

then I discovered the modern 2-part acrylic/urethane
co-polymers with heavy UV protection that last 5-6 years; and, havent
opend a can of 'exterior' varnish since.
========================

Can you recommend a brand that you like?