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tiny bubbles in varnish

Posted: Sat May 16, 2009 2:49 pm
by Dan Wolf
Gentlemen, I have placed about 6 coats of varnish (interlux schooner) and all looks good except those tiny bubbles. I have been using Jen foam brushes and a foam roller and tipping out. No luck. I tried thinning down with brushing liquid. still no luck. What do you think I'm doing wrong? Dan

Posted: Sat May 16, 2009 4:23 pm
by W Guy
Dan,
Stop mixing the champaign in with the varnish!!! Just kidding! :D
I don't know how the pros would advise you, but from my experience as a chemical engineer, I'd suggest heating up the mixture before applying it. The bubbles are trapped air. If the mixture is warmed, it will lay on more smoothly and the trapped air bubbles will rise to the surface and evaporate before they are trapped in the mix when it dries.

Verne :lol:

Posted: Sun May 17, 2009 4:59 am
by Dan Wolf
Well, what do you suggest to warm it up without, you know, fire? Do you think letting it sit in the sun for a while will do the trick? Also since you deal with chemicals, just how bad is this varnish for your nervous system? It seemed to throw me for a loop for a while and then I got charcoal resperator.

Posted: Sun May 17, 2009 5:15 am
by W Guy
I would use a heat gun (a hair dryer will do). I would also wear a respirator. Also, only stir the mix before applying. Never shake the can as that will fill it with trapped air bubbles.

Verne :)

Posted: Sun May 17, 2009 7:47 am
by Dan Wolf
OK- Thanks for the tip. I'll give it a shot. Thanks, Dan

Location location location

Posted: Wed May 20, 2009 6:11 am
by TreelineIII
Dan, I am also in Naperville. As well, I am taking advantage of the nice weather and doing some final varnish coats before I launch this weekend. I am curious what kind of boat you have. As well if you are in the area it might be nice to get together and discuss the trials and tribulations of these boats. Like you I too have built kayaks, and in the middle of another one right now. I have sent you a private message in your file if you want to contact me. It is nice to see what others have done. Looking forward to talking
By the way how did your varnish turn out?

Posted: Sat May 30, 2009 6:22 pm
by Dan Wolf
The varnish laid pretty good and the heat definitly helped. I can see a noticable difference between warm and cold varnish. I still picked up some bubbles, although small. I think the foam brush might be producing them when I add pressure while laying down varnish. I'll go for another coat and maybe split some areas up so I can go slower and not put soo much pressure on the stroke.

Posted: Sun Aug 02, 2009 11:53 am
by Dreamer
I have done almost no restortion work but I have refinished the rails on acres and acres of the teak on my 50ft Marine Trader (sold). One of the things I found is do not stir or shake the finish prior to brushing it. Only remove the amount of liquid from the original container you plan on using( do not use directly from the can unless you expect to use it all) Try to brush only with the grain and in only one direction, meaning, refrain from brushing back and forth. Adding thinner is OK for the first coat or two so it will absorb better but not afterwards as it requires you to stir and that creats bubbles. Keep a wet edge! Brushing the finish on before the previous coat has completly dried can be done if done quickly to build coats, after the last coat has dried to the touch . If you do it to soon, beyond that short window, the finish will tend to ripple and bubble. You then need to wait until the last coat has dried for at least 24 hours and lightly sand between coats with 220. That will give the next coat something to grip and to not peel off as an individual coat. I prefer to use natural hair brushes for that type of finish. Foam is ok for painting but not for varnish. Why save money on a cheap brush after a rather expensive restoration? The finish is what everyone sees! It is what makes or breaks the job. The job will be done only after about 12 coats (or more)