Filling Grain on Oak Veneer

Advice on using a pore filler after staining and sealing, to fill grain without hiding the dark grain pattern. March 12, 2006

We are doing a staining job for 6 Columns and some light trays that were all veneered with Red Oak. We are trying to achieve an extremely smooth finish without the deep red oak grain being indented. Are there any pre fillers that can be used to fill the grain so it isn't indented and the finish is all the same level? Or, do we have to keep shooting the clear and sanding it down with a block until it fills the deep grains?

This is our finishing process:
First we sand the veneer with a 120 grit and then we sand it with a 220 grit. Remove all dust off the veneer and then shoot 2 100% coats of ML Campbell WoodSong 2 Microton spray stain (WS2 M307 Red). After the stain dries, we shoot 3 coats of ML Campbell Magnalac Precatalyzed Lacquer (C144 14 Satin-35). Between each Lacquer coat we sand with a 220 and leave the 3rd coat unsanded.

The result is very nice as far as consistency but the deep grains of the red oak veneer are not filling up the way we want. We even tried heavily sanding the veneer before shooting the stain to smooth it out some and it just lost that dark color grain it had. Does anyone have any ideas?

Forum Responses
(Finishing Forum)
From Paul Snyder, forum technical advisor:
Check with your supplier to see if they have a paste wood pore filler. You could use a catalyzed sealer and keep sanding it back aggressively until the pores are filled and leveled, but that's quite a bit of work. It's easier to stain the wood, seal it, smooth the sealer, then use a pore filler.

From contributor A:
A vinyl sealer will do a better job in bridging the pores of the oak. Don't put so much finish (MagnaLaq) on that the pores exceed the 4-5 mil dry film. It will only cost you later on when the pores start to exhibit problems from too thick of a coating. You should also think about switching to MagnaMax. This is what I use and it is easy to get a nice finish, very forgiving. I haven't heard too many nice things about the MagnaLaq, although I have never used it.

From the original questioner:
I attached a picture of the finish we did. If you look at the reflective part on the right side of the picture you will see the deep grooves or open pores. All I want to be able to do is fill those open pores up without losing the black or dark grain.

From contributor B:
Based on the pictures I've seen, Id suggest that you use a translucent grain filler whenever you use oak, mahogany etc. if you want to maintain the black grain. You can use pumice and linseed oil (after staining) or you can use plaster of paris and linseed oil as alternative.

From the original questioner:
Thanks for all the responses. It looks like there are a few ways to fill the grains/pores. We will try the pore filling paste first on a sample and see how that works. What color tint should we use for the paste to simulate the deep grain of the red oak? We want to keep the deep grains dark, so should we go with a brown or black?

From Paul Snyder, forum technical advisor:
Try a sample with burnt umber, one with Van Dyke brown, and one with black Ruben. Black is pretty stark, although you may like it after trying a sample.

From the original questioner:
To Paul Snyder, forum technical advisor: I noticed above you said "It's easier to stain the wood, seal it, smooth the sealer, then use a pore filler". In other words, I do this in this order: sand, stain, seal, sand, pore filler, sand, clear?

From Paul Snyder, forum technical advisor:
After the pore filler you may be able to get away with synthetic steel wool to clean up the field. It depends on how much of the filler is still on the surface after it dries. If you need to be more aggressive, a light sanding with 220 or finer grit will do the job. You may need a second application of the pore filler to get the surface completely level.

From the original questioner:
I'm going to pick up the pore filler tomorrow. Can you recommend any good brands for me to look for? Or any brands to stay away from?

From Paul Snyder, forum technical advisor:
If you're working with a finishing supplier, they should have a pore filler and tint it if you want them to. I use Chemcraft's and it works fine. I prefer oil-based versus water-based because of the longer working time. Behlen also has a good pore filler.