Wood finish advice please

[doug hodder]

Rick, are you using oil or water based material? I found that the water based stuff gets more air in it... don't shake the can...stir only...a more open grain wood will allow the material to seep into the pores, as it does, it has to displace the air in those pores and they sort of cook out...typical on a first coat in epoxy...I've had them get the size of dimes in epoxy...don't brush cross grain, and don't go too fast, it wants to whip more air into the material...for the initial coats, you might want to consider a thin foam roller for smooth surfaces, don't go fast when applying...coats quicker...but with what you have so far...sand and build up layers...just my thoughts on it...Doug

[Miriam C.]

I have a related question (forgive me for using this same discussion but the advice is so good I wanted to keep it all in on place)

When I brush on the spar urethane there are tons of bubbles and they don't work themselves out.

Can someone describe their brushing actions (speed, number of brush swipes , pressure?, thickness of urethane put down per brush, etc) so that I can get an idea of the proper way to brush this on?

Or are the bubbles normal and sanding in-between coats takes care of it? What about the final coat and bubbles?

Thanks so much.
--rick

Great Question and definately related.

I haven't used Spar yet, but when I used polyurathane on a desk top, my son suggested I apply the first thin coat with a sweat sock (fuzzy side up). (first year wood shop)

It work beautifully so I finished with it. The thing you can't do is shake clear finishes. They all bubble. It's like beating an egg white.

PS~I sanded between coats with a 3M 320 grit between finish paper.(by hand)

Now if I had practiced staining. A staining tutorial wouldn't go amiss here.

Miriam

[tonyj]

You can also create a wiping poly by thinning with turpentine 20-50%. Apply with a cloth like Miriam said, or a staining sponge (the ones covered with terry cloth). It puts on a very thin coat, so you apply multiple thin coats.

I always thin poly, and contrary to instructions, I tip off the bubbles with a brush or foam brush as it is drying.

[Podunkfla]

I can't add much to what has already been said... Most varnishes do work better with a brush made for them. The better brushes, like Purdy brand do cost a lot, but they last for years and sure lay down a nice smooth coat. Just clean them good with spirits then wash them with dish soap.

OR... do what most sign painters do. Wash them in spirits then wet them with thin motor oil! Squeese out the excess, shape the tip to a wedge and put them back in their factory sleeve or wrap in newspaper. When you go to use it again slosh it in some spirits and shake it out... then paint. The motor oil will keep paint from ever cloging up the hilt of the brush and will never dry out in storage. I've got 20 year old brushes I still use.

As for bubbles... Thin the first coat until the bubbles will self level & pop. For large flat areas some people like to use a pad coater instead of a brush. The don't have much tendancy to create bubbles. Thinning till you get a wiping varnish is good too... Just takes more coats to build your finish.

Oh... like he said above, never shake varnish; just stir it if you have to mix thinner into it. When you are done for the day, week of whatever... Store the can upside down! It will never skin over the top that way.

Of course... I'm spoiled. I much prefer to just spray most finishes. No bubble problems at all.

Friend ~ Brick