Best ways to fill in grain on plysood for a smooth finish?

[cracker39]

Most luan and even the oak ply I bought has a grain that you can feel, and will shoe up when painted. From experiece, what seals and smooths out the grain best? I think I've read about thinning wood filler with water or solvent if it's not water based, and brushing it on, letting it dry, then sanding. There may be ready made products that I don't know about, as I haven't asked the paint people about it yet.

On another thread, it was mentioned that a mixture of 1/3 poly varnish and 2/3 thinner makes a good sealer for water proofing. I'll probably do that first with a couple of applications before using a filler and primer. I'm finishing with enamel paint.

[Chris C]

One simple word..................EPOXY

[cracker39]

Chris, would that be epoxy paint? The only epoxy I've ever used was glue. It seems that using epoxy is a lot of work and expense. I took the time to Google for info and I think a water-bases paste wood filler may be better for me to work with. It still sounds like a lot of work. If first thought of just spraying with a couple of coats of poly varnisn (minwax helmsman spar varnish) and sanding, then priming and painting. I've used it on pine and spruce, but not on oak or luan plywood. I may test a piece to see how it works. I have lots of excess pieces laying around.

[SteveH]

Dale,

I think Chris is right. Nothing seals wood like epoxy. Yes, it's like the glue, but you can thin it with alcohol and it will paint on with a brush just like varnish. But, it will wick into the wood and harden sealing the wood and making it stronger. I've worked a lot with the epoxy resin from West Marine called West System, and it is a good product.

[tk]

I've never tried it but I've heard of using spackle. Apply, let it dry, sand, paint. Lot cheaper than epoxy, but like I said, I've never tried it.

tk

[SteveH]

tk,

Spackling compound is good for dry wall. It works easy, it's cheap, and fills good. However, it will not stand any abuse, is not water repellant, and will not strengthen the wood surface like epoxy will. Just my opinion.

[cracker39]

I was looking more for something to close the grain and make a smooth finish, rather than sealing and strengtnening the wood. I'll probably use poly varnish to do that, but I don't think it has enough body to seal and smooth the grain.

[rainjer]

It would also depend on the type of paint you would want to use.

I my opinion, nothing beats:
1) Sand with 220 grit.
2) Take a damp rag & wipe the wood down & let it dry. This will raise the "soft" grain. (which raises when you put paint on if you don't do that)
3) Re-sand with 220 grit on a random orbital sander.

You can repeat steps 2 & 3 if you think you need it.

4) You can then apply a sanding sealer if you choose. (it will give you a more even finish)
5) Re-sand again and you are ready to paint.

I have use that process on many woodworking projects to to get a glass smooth finish.

I know it is a lot of sanding, but you will be happy with the results.

And remember, use you fingers to check the finish, not your eyes. You will be amazed what you can feel & not see.

You could also try automotive body filler.

[doug hodder]

I've done 2 boats and 2 tears using epoxy...you can finish off wood just like a car hood...I apply it with a roller and tip it off with a roller cut in half held in a spring clamp...just remember, what ever you do underneath, will show through when you paint it...bad job on the bondo/sand scratches, etc, will result in a bad job in the paint...you can shoot paint directly on top of epoxy also, no primer needed, I've done it a bunch and it's according to the tech support guys at West Systems, any bondo work however will need to be sealed off prior to any automotive type paint applied over it...If you want a "bright" finish, meaning clear on top of the wood, again, any left over sand scratches, pencil line etc, bad stain or dye is going to show.. If you want to seal the luan for paint application and aren't worried about the grain, a reduced coat of lacquer sprayed will seal it off and you can shoot paint or build up layers of varnish directly over that...can't put a water, or thinner based varathane down and then shoot automotive paint over that...the reducers in the paint are too hot for the first coat and it will craze/ bubble/ and lift...and that's my experience...PS Cracker...it does have enough body to do what you want...but it ain't going to happen in 1 or 2 coats...on boats, I do about 6 coats of rolled/sanded epoxy and then 2 coats of clear...on the tear sides 4 coats epoxy and 2 clear...the more time you put into it, the better it'll look, you just decide when enough is enough...no real short cuts on this sort of thing... and after all...you put all the time and effort into it, do you really want to cut a corner and end up with something that you aren't happy with? It looks great!!! give it the finish it deserves!!! Doug

[Woodbutcher]

Most luan and even the oak ply I bought has a grain that you can feel, and will shoe up when painted. From experiece, what seals and smooths out the grain best? I think I've read about thinning wood filler with water or solvent if it's not water based, and brushing it on, letting it dry, then sanding. There may be ready made products that I don't know about, as I haven't asked the paint people about it yet.

On another thread, it was mentioned that a mixture of 1/3 poly varnish and 2/3 thinner makes a good sealer for water proofing. I'll probably do that first with a couple of applications before using a filler and primer. I'm finishing with enamel paint.

Can I ask why if you are going to paint your project you use Oak or Luan to start with? It seem that you are adding a lot of extra work. Why not use Birch or Maple? Both closed grained woods and very nice to paint. I don't know from your post how smooth you are looking for but I have 2 suggestions that might help. There is a powdered wood fill that you mix with water to the consistancy of pancake batter. Its made by Durham Rock Putty I believe. It comes in a big can with a pry off top. Every body sells it. It dries fast like bondo. But just use a plastic bonbo applicator (like a sgueegy). Apply a thin skim coat. It does dry like a rock and sands harder then you think, so put it on sparingly. Try it on a scrap piece first to see if you like it. Second I like to use Bin, a Shellac based primer by Bullseye (Zinseer). This dries fast and has a good build. Sand with 320 grit paper between coats and if needed block sand to take down the high spots.

[Gaston]

I'm doing an "automotive type finish (pearl paint and clear coat) on the cabinets inside mine. I sealed the luan paneling with with thinned epoxy then primmed with an automotive pulyurethane filler primer before the top coat. sand with a guide coat to find the "grain pattern areas and repeat the primer and guide coat till smooth. lots of work

[DestinDave]

Another option to filling in the grain and minor low-spots would be to spread a thin coat of sealer such as KILZ but use a plastic spreader instead of a brush or ruller. Apply it in long strokes at a diagonal to the run of the grain (like from corner to opposite corner). This was you get the product into the tiny valleys of the grain but scrape it off the high spots. One application is usually enough, a light sanding, and you have a smooth finish for a primer coat.

[cracker39]

Why did I use oak or luan if I was going to paint and wanted a smooth finish? The oak was on sale really cheap, and my lack of experience with it was why I bought it. I've used luan before and it used to have a smoother finish than today's luan. My boat and truck topper that I built with luan skins were both smooth without using any filler. I don't think the luan I have now will be that smooth, and I know the oak won't. So, I am in for lots of pre-painting work.

I'll try to reduce the amouht of sanding by coating the filler on the plywood, letting it dry, then filling my screw holes with bondo and make one sanding for both. Then, repeat the filler and bondo touch up if needed on the holes.

[Chris C]

Dale,

Sorry I'm just now getting back to you. As Doug said, epoxy will give you a top-notch finish...................it's not easy to do, but if you want a showroom look, epoxy will do it.

[BILLYL]

I build guitars and the woods I use are open grained (Maghony, swamp ash, etc). To get that smooth finish - I use epoxy. Spread it out nice and thin - fill the grain and then sand smooth. I will first prep the wood by sanding - usually 400 grit (your case I would use 220) The I shoot a couple of coats of sealer ( I use laquer) and then apply the epoxy.

Epoxy is the way to go if you want that smooth finish.

Bill