LumberJocks

Has this ever happened to you?

  • Advertise with us
Blog entry by zlatanv posted 01-07-2010 07:00 AM 1240 reads 0 times favorited 14 comments Add to Favorites Watch

Stained a small table a few days ago and had it in the kitchen bay window drying for a few days. Cold in the garage, today I turned on some heat and let it warm up a little so I could put on a coat poly. I put on one coat and let it set up for a couple of hours, after it dried a little but it was still slightly tacky I moved it back to the bay window in the house to dry fully over night before I do another coat. It sat there for about an hour or more, went to look at it and at first thought it was dust or something had blow onto it, but the top had little bubbles formed all over the top, perfect little air bubbles. None on the legs or aprons only on the top. Not sure what caused it? I felt the top when I brought it in the house and it felt dry but a little tacky. After I took the pics I rubbed my finger over the bubbles and they burst and lightly went over it with my finger to smooth it out.Photobucket PhotobucketPhotobucket

Any body have this happen to you? What would cause it, it was smooth when I took it in the house.

-- Z, Rockwall, TX



14 comments so far

View davidroberts's profile

davidroberts

1025 posts in 2950 days


#1 posted 01-07-2010 07:18 AM

air escaping from the wood pores, or wood faries with tiny straws. in the pictures, i noticed the bubbles appear on the open grain lines, not so much the closed grain. maybe a difference in pressure/temperture from the garage to the house, or maybe you woke the faries when you moved the table top. i drove through Rockwell on my way to Greenville last week. Ever ski in Ray Hubbard?

-- Better woodworking through old hand tools.

View Todd A. Clippinger's profile

Todd A. Clippinger

8901 posts in 3563 days


#2 posted 01-07-2010 07:20 AM

I had this happen when I placed a piece in the sun to accelerate drying.

From what I could gather is that air is trapped in the grain by the finish. The expanding trapped air forms the bubbles.

Keep the temperature stable when finishing.

Here is another one. After staining an oak project I placed it in the sun. Doesn’t have finish on it, just stain so it shouldn’t be a problem right?

Wrong – the stain kept bleeding out of the pores of the grain until it cooled down.

-- Todd A. Clippinger, Montana, http://americancraftsmanworkshop.com

View Todd A. Clippinger's profile

Todd A. Clippinger

8901 posts in 3563 days


#3 posted 01-07-2010 07:22 AM

David could be onto something with the theory on wood fairies.

-- Todd A. Clippinger, Montana, http://americancraftsmanworkshop.com

View Ecocandle's profile

Ecocandle

1013 posts in 2530 days


#4 posted 01-07-2010 07:23 AM

Here is an answer from Bob Flexner’s book, “Understanding Wood Finishing: How to select and apply the right finish”

pg. 26 Bubbles: Bubbles are the result of turbulence caused by the brush gliding over the surface. The finish is drying so fast that the bubbles don’t have time to pop out on their own.

Solution: work in a cooler room, the bubbles will have more time to pop out.
Solution: “Tip Off” Brush back over lightly, holding the brush almost vertical, to pop the bubbles before the finish skins over.
Solution: Add the appropriate thinner or retarder to slow the drying.

That is all he had to say on the subject. Well that I am aware of, I haven’t finished the book yet. It is very good. I don’t know if that helps at all, but I thought I should pass it along.

I am waaaay too knew to woodworking to have my on advice.

Good luck.

-- Brian Meeks, http://extremelyaverage.com

View zlatanv's profile

zlatanv

691 posts in 2698 days


#5 posted 01-07-2010 08:09 AM

David – I had a boat for three years, was trying to teach the kids to ski when they were younger, we did a bunch of tubing. Boat dock is about 100 yards from my house. It was fun for a while, but Dave Ramsey said “Sell the Boat”, so we did. I don’t like that guy.

Tod – This one did the same thing, had tiny little spots of stain coming out of the grain. I’m afraid to leave it dry overnight in the garage, it is supposed to freeze. I tried to put spray poly on a project once and left it in the garage, it was a little cooler and the poly became cloudy.

Will try it again tomorrow, will see what happens. Thanks.

-- Z, Rockwall, TX

View Todd A. Clippinger's profile

Todd A. Clippinger

8901 posts in 3563 days


#6 posted 01-07-2010 08:18 AM

Finishes won’t dry very well once you get below 65° or so. You need to take it in the house.

-- Todd A. Clippinger, Montana, http://americancraftsmanworkshop.com

View Bob Kollman's profile

Bob Kollman

1798 posts in 2655 days


#7 posted 01-07-2010 08:56 AM

Lawarence Welk syndrome, my question is did they dry into hard

Poly bubbles???

-- Bob Kenosha Wi.

View Scott Bryan's profile

Scott Bryan

27251 posts in 3286 days


#8 posted 01-07-2010 01:40 PM

Todd and David are on target with this problem. The bubbles are caused by air expanding and escaping from the pores as it is displaced by the finish and the change in temperature of the wood. The finish had already skimmed over leaving the air no room to escape. Solution is to start finishing in a warmer temperature, as Todd described. You did not say whether you were using a wipe on poly or not but it would also help with the problem.

-- Challenges are what make life interesting; overcoming them is what makes life meaningful- Joshua Marine

View zlatanv's profile

zlatanv

691 posts in 2698 days


#9 posted 01-07-2010 06:23 PM

Scott I used the brush on poly for the first coat so far.

Bob I popped the bubbles with my finger when it was still tacky and lightly rubbed them smooth.

I plan to put one or two more coats on and then use wipe on satin for the last coat. I applied it in the garage but moved it into the house after it was tacky. I’ll probably take the finish in to get it to room temp then try it. The finish to day is dry and fairly smooth, some dust nubs. Should work out OK.

Never seen that happen before. Thanks everyone.

-- Z, Rockwall, TX

View CaptainSkully's profile

CaptainSkully

1432 posts in 3022 days


#10 posted 01-07-2010 06:49 PM

This happened to me when I used Epiphanes varnish on some teak brightwork I did for a 41’ sailboat last month. I ended up having to sand it down and apply additional coats.

-- You can't control the wind, but you can trim your sails

View David's profile

David

183 posts in 3179 days


#11 posted 01-07-2010 09:11 PM

yep; particularly with porous wood like oak. Just sand it with some real fine paper, wipe it down with a tack cloth and put on another coat. Next time, thin your first coat to help fill the pores. I always do several coats any ways, so the first never looks that great, the 2nd better and after I get a few coats on; sand them smooth and top off with a real thin final coat.

-- Islandwoodworker@Gmail.com

View Jeison's profile

Jeison

951 posts in 2572 days


#12 posted 01-07-2010 09:15 PM

I keep telling you people, its the shop gremlins.

-- - Jei, Rockford IL - When in doubt, spray it with WD-40 and wrap it with duct tape. The details will attend to themselves.

View reggiek's profile

reggiek

2240 posts in 2734 days


#13 posted 01-07-2010 10:05 PM

I like the fairies or shop gremlins idea…...I just get this picture of Grizz in his dress…floating over your table with a wand…..man is that scary…..

But the real truth is what Todd, Brian and David pointed out.

-- Woodworking.....My small slice of heaven!

View stefang's profile

stefang

15512 posts in 2798 days


#14 posted 01-07-2010 10:39 PM

You have to use the James Bond method “stir but don’t shake”. I’m no expert and that is the only thing I could think of that might be causing the problem.

-- Mike, an American living in Norway.

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com