Tiny bubbles...

dpropson

Seaman
Joined
Nov 2, 2002
Messages
61
in my varnish! I've read the books, practiced. I keep getting tiny bubbles. I strain the varnish into a bowl. Swirl if thinning, never shake. Never stir. As I spread the varnish on, bam, bubbles. For the love of God! Help!<br /><br />Frustrated.<br /><br />Dennis
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Tiny bubbles...

GHowdy, Dpropson.<br /><br />I had the same problem when I tried to refinish the mahogany seats in my Boston Whaler Tender. <br /><br />Even after planing the old, dried up finish off, every type of varnish I tried bubbled. I ended up buying new seats and risers because everything else about the boat is perfect and I wanted the wood to be also.<br /><br />I think the problem is in previous prep or finish on the wood. I used the same Marine Polyurethane varnish on some new, never finished mahogany and had no problem.<br /><br />If you find a solution, please share it. I now have about a hundred bux worth of mahogany that I can't varnish. @#$%^!!!<br /><br />Good luck. :)
 

miloman

Lieutenant Junior Grade
Joined
Nov 3, 2002
Messages
1,181
Re: Tiny bubbles...

treat it as any wood you will have to chemically strip it say with a circa 1800 3 -4 times use a wood scrapper to remove 0000 steel wool dipped in remover to get the rest off mineral spirits wash well 80 grit 120 180 240 grit get it to complete fresh wood then you will have no problem if you look up furniture refinishing you would treat the wood in your boat the same as a piece of furnitire the reason for bubble is an accumulate of stripper or a bad base for the varnish to adhere to and pure surface prep. You will thin the varnish down with mineral spirits as per directions (generally 10% dillution ) apply a THIN coat sand with 200 grit apply another thin coat of same diluted varnish sand again and then 3-5 thin coats and it will look like a piece of glass JB if you need some more advice please feel free to email me DONT RUSH allow time for the stripper to work and the wood to dry
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Tiny bubbles...

Thanks, Miloman, I'll give that a try. :)
 

dpropson

Seaman
Joined
Nov 2, 2002
Messages
61
Re: Tiny bubbles...

Thanks for the thougths. The wood is bare so previous finish is not a problem. Maybe my coat was too thick. I'll try it again, thinner coat this time. Could I have had too high a percentage of thinner mixed in the varnish?
 

miloman

Lieutenant Junior Grade
Joined
Nov 3, 2002
Messages
1,181
Re: Tiny bubbles...

is it a spar varnish I think it says dilute it 10% but for sure if you have anything on the wood you will have trouble so I would wash with a mineral spirit 0000steel wool sand 180 grit and then a thin coat most home depots sell an spray can that you pump up take a look at it it might do the trick also what temp are you working in sometimes direct sun or a high temp environment will skin the product too fast not allowing it time to spread out
 

miloman

Lieutenant Junior Grade
Joined
Nov 3, 2002
Messages
1,181
Re: Tiny bubbles...

oh ya the process I have discribed will take the better part of a week you know 1/2 hour nightly remember tack cloth it between coats and make sure the environment is the proper temp
 

crab bait

Captain
Joined
Feb 5, 2002
Messages
3,831
Re: Tiny bubbles...

watch those cottonpickin' tack cloths.. they can ruin a job in a heart beat...<br />they can leave 'sticky' on the surface an the varnish 'bulls eyes' up...<br />i never use them...<br />i remove dust & stuff with cheese cloth an wet with thinner...<br /><br />the only varnish i like/use is EPAPHANNES but thats here nor there.. use what yo got..<br /><br />thin your varnish like MILO said... <br />but ONLY use interlux 333 thinner...<br /><br />it's very importaint...this thinner is special cause it evaporates much much slower ,,an allows the varish more time to level out...<br /><br />i'd coat the wood first with a coat of thin epoxy first .. then sand ,, wash with ammonia ,, then varnish... it'll seal the wood so no air bubs.. an it'll keep the varnish from EVER snap, crackin' & poppin' up/off ... so you'll never have to scrape it down in time & do it over again...<br /><br />but if'n you don't epoxy first,,, the first coat should be very very thined down so it soaks in deep an seals.. it'll give you a bubble-free surface on which to start....
 

NOSLEEP

Commander
Joined
Oct 30, 2002
Messages
2,442
Re: Tiny bubbles...

Hey you guys have worked with wood before.<br />If I had this good advice before, my ice<br />fishing shack would have been a work of art.
 

dpropson

Seaman
Joined
Nov 2, 2002
Messages
61
Re: Tiny bubbles...

Hey JB,<br /><br />I sanded down the first coat, applied a thinner second coat and I let the varnish sit for a few minutes until it settled down and lost that little cloudy look it gets after the thinner is introduced. I'm on my third coat and it looks like glass. I hope this helps.<br /><br />Dennis
 

Reel Appeal

Chief Petty Officer
Joined
Aug 19, 2002
Messages
566
Re: Tiny bubbles...

Sanding to a very fine grit is important,say 220 at least.Surface prep is key to a nice finish.Sand,brush off(or vacuum),tack cloth etc.<br />Never apply any varnish in direct sunlight or higher temps (as bubbling will likely occur)or on windy days if outside.Always use a high quality brush*(not a throw-away)such as badger hair that is designed to be used with the finish your using.This also keeps bristles out of your work.Apply in thin coats,sand lighlty/tack between coats and brush in one direction.
 

trollhole

Chief Petty Officer
Joined
Sep 19, 2001
Messages
423
Re: Tiny bubbles...

Little bubbles, ie: entrapped air, can be caused even with apparent properbrushing if the varnish is too thick or it is drying too fast. If your varnish is too thick you can thin it with the appropriate solvent so that it flows out better. This will also help if it is a hot, dry day and the varnish is tending to dry to fast (which doesn't allow the bubbles to come out before drying). Also, sometimes, if you are working overhead, gravity causes the bubbles to go up rather than out. also ... if the varnish is not well strained, you might have little specks, right out of the can which appear to be bubbles.<br /><br />The only thing you can do if you already have the problem is to sand and recoat. :D
 

ICEMAN

Petty Officer 1st Class
Joined
Dec 11, 2000
Messages
292
Re: Tiny bubbles...

I had the similar problem with tiny bubbles. Tried numerous things with the varnish. Even changed my technique to apply the coats. Fast, slow,criss cross coats. When I tried a different brush, the bubbles didn't appear. Found that some brushes can cause air to get in with the bristles.
 
Top