Paste Wood Filler -- When and how to use it

[George Bokros]

I have been reading and filing some articles on using past wood filler. I have never used it and wonder of its benefits for a smooth finish on open grain woods like oak.

Questions.......

When do you use it, before or after staining. Seems applying after staining you would hide some of the coloring the stain or dye imparts to the wood. If applied prior to stain or dye would it inhibit the penetration of the stain or dye?

I believe you can mix stain / dye / tint / colorant into the filler to obtain coloring, is this true?

Can you recommend some reading material that will help understand using paste filler and its benefits and drawbacks?

Thanks

George

[Rich Engelhardt]

George,
You might want to ask this in the finishing forum or ask to move this thread over there.

[John Downey]

Also, ask about grain filling, not wood filler. I passed this thread over a couple times thinking you were asking about putty :D

Products like Pore-O-Pac come in a variety of colors. No idea what you would use to adjust the tint though. I often use straight pumice powder to rub out oil finishes, followed by rottenstone. Time consuming but gives the effect I want.

[Jeff Duncan]

The simple way to think about it is…..do you want more of a plastic look, or a wood grain look?

Using pore filler will give you a flat clean surface, better for buffing out finishes for sure. Finishing without pore filler on woods like oak and even mahogany will allow some of the wood "train" to show through.

As far as mixing and matching you just want to be safe and stay within a given companies "family" of products. They're usually designed to work together which makes it much easier to avoid products that don't play well together.

"Understanding Wood Finishes" by Bob Flexner is a great introduction to finishing. "The Wood Finishing Book" by Dresdner is also a good one to take a look at.

good luck,
JeffD

[john lawson]

Typically you buy the grain filler already colored or stained. Take Walnut for example, Sherwin Williams makes a product that I used on a very large conference table. In this case I had two coats of precat lacquer on it and decided the finish was not acceptable due to the grain being too open. So, I stripped the finish off and applied the grain filler.

Now, you are only supposed to use two coats of precat lacquer the grain filler was critical to achieve a smooth finish on this table. It was a large conference table going in a bank boardroom, so the grain filler was really a very important part of the finish. In my case it worked great. Two coats of lacquer gave me a very smooth and first class finish. I could not have achieved without the grain filler.

Mahogony is another wood that is often filled. Usually with a dark or almost black grain filler. Because it fills the grain, and the grain is normally open and obvious, the filler is not evident, may sound contradictory but true nonetheless.

I don't use grain filler often. It is a pain to use, lot of rubbing and manual labor, but it really doe a nice job.

good luck

[Steve Jenkins]

There are a couple ways you can use paste wood filler. One is to put a colored filler on bare wood and it will fill and stain at the same time. The other is to put down a wash coat (thinned 3-4 parts thinner to one part finish) of finish then use the filler. This will seal the wood so the filler won't stain the wood but just fill the pores. The reason for using a wash coat is that you want to seal the surface of the wood but not round over the edges of the pores like would happen if you used a standard strength finish. If the edges of the pores are rounded over the filler will not stick into them as well. You can get some interesting effects by using a filler that is colored with one of the primary colors if you seal first as only the pores get the color.
I typically use a brush to liberally apply the filler then wipe off in a circular motion with cheesecloth turning the cheesecloth often during the process as the filler will build up on it and you can start to remove some of the filler from the pores. You can also use a squeegee to remove most of it.
After removing the bulk of it in a circular motion ( this packs it into the grain) polish off lightly with the grain to remove any haze. Let dry thoroughly before topcoating.
I prefer solvent based rather than water based and typically thin it with mineral spirits to about the consistancy of heavy cream. You can also use naptha to thin but it will dry faster.
As with anything finish related, practice on some scrap not your project.

[Prashun Patel]

IMHO, most of the times, colorant should go onto raw wood. The only time I put down something beforehand is a washcoat of shellac to prevent blotchiness. However, a pore filler (be it putty, thinned paste wood filler, or grain filler) seals the wood too unpredictably to be used before base coloring. The exception can be gel stains, which don't rely as much on penetration, but that's another story. I like only to apply dye on raw wood.

Here's how I'd do it if I had to pore fill:

Sand
Dye (or stain)
Wash coat(s) of shellac or top coat to seal in dye (or stain)
Fill pores
Topcoat