Filling Joints and Nail Holes

Advice on choosing a wood filler, and a discussion about whether filling certain holes and cracks is worth the trouble. March 29, 2008

I am considering using Famowood solvent based filler (natural color) to cover the slight lines on the joints between the rails and stiles, nail holes, etc. (not knots or large holes) of cabinet doors prior to staining. The majority of the lumber used is alder. We use oil based stains and spray Valspar CV. Any words of widsom?

Forum Responses
(Finishing Forum)
From contributor K:
Great stuff! Fast drying and sands easy. I suggest trying to match the color with the stain. My experience is the natural filler does not get as dark as the wood does when stained with a wiping stain. As it dries in the can, you can add Famowood solvent back into the can to reconstitute it. I actually like to use it in a variety of viscosities for different needs.

From the original questioner:
Thanks for the response. We had been using the Elmer's waterbased filler and really had no problems, except that I get it at Home Depot and it is a hassle to remember to get it. I will get the Famowood from one of my finish suppliers. I was a little concerned it might take too long to dry, being solvent based, as well as the CV adhesion. I will definitely add stain to match as needed.

From contributor B:
I would not add stain to it, but just buy the right color to start with. If you're using alder solids, buy alder filler. It will match much better than natural.

From contributor C:
If you're going to use Famowood or similar product, remember to sand the joints as flush as you can before applying. Too many shops I've worked at want to apply the filler before any sanding has been done. What then happens is that the Famowood has not been forced deep enough into the joint and when the sanding is done, open areas will appear and a second coat will need to be applied, costing extra time and labor.

From contributor R:
Rails and stiles should have tight joints that don't require a filler. Nail holes really have no place on rails and stiles either.

From contributor K:
I agree, in a perfect world where time is of no concern! But when trying to be time efficient when building 25 or 30 cabinet doors on an air clamping table in a one man shop, one needs to move the work along. It is a necessity to pin the joints together in order to take the door out of the clamps and build the next one.

From contributor I:
One trick that I use that spares problems with cracks is to line each side of the crack with masking tape before applying the Famowood or fix putty and then pulling it up as soon as the putty is applied. This keeps the putty from filling the grain where you don't want it. Pulling the tape up almost immediately after keeps you from pulling the dried putty up with the tape.

From contributor J:
The solvent based Famowood is good for filling larger defects like nail holes, but it's bigger particle size does not work well on smaller, tighter cracks and veneer seams, etc. For smaller defects, use the water based. It seems to be ground finer and does a better job of working into tighter areas. I have used the Elmer's and liked it, but it can be hard to find.

From the original questioner:
Thanks to all for your constructive comments. Out of curiosity over contributor R's comment, I checked leftover finished doors for defects in the rail/stile joints. They looked perfect in all cases. I also checked for nail holes. I found them imperceptible. No one client could possibly tell there was a nail being used, much less complain about it. I checked both clear and glazed doors. I even checked doors that had just gone through the belt sander. I could hardly see any holes, even blowing the dust off. And they still get puttied and had to go through the orbital pad machine and the fladder machine. I won't be losing sleep over this issue any time soon, or ever. I think that given we have been using the Elmer's product for as long as I've had my shop, and it works, I am going to stay with it.

From contributor Q:
I am also not a fan of filling natural joint lines. Perhaps this is not so much an issue of your joints needing to be filled as much as it is satisfying your own standard and customary practice to do so regardless of how fine the joint line is. I do finish work as a sub for cabinetmakers. I have run into those whose joints were well executed, and who still feel compelled to fill the tiniest smidgen of break line at the joint.

I am very familiar with Famowood and I would say if your joint lines are so fine that you have trouble getting Famowood forced into them, then your joint lines will most likely pass muster with any discriminating customer. Is it possible you could be expending a lot of time and energy filling joints to achieve a standard that matters only in your own perception of "how it's done"?

A dark or heavy pigmented color may hide it, but filler tends to draw more attention to the joint since one color of filler is rarely going to match perfectly with your wood. Light and medium natural looking stain colors will require the filler be touched up or else it stands out like a sore thumb. Filler also has a tendency to shrink and pop out of the joint. Don't forget as a finish on wood changes with age, the fill may not change with it. You add up all the time spent for this step and it can get to be pretty substantial.

When I talked this through with one builder I work for, I had the impression he simply needed someone he trusted to tell him he didn't need to do this. Of course it may have helped that I told him his finishing costs would be less if he stopped filling his joint lines. His joints were perfectly fine and it was pure obsessiveness and force of habit that caused him to think they needed filler.

On your nail holes, if they are very small as you say, consider filling these just before your final coat with colored wax sticks such as Mohawk or others. This is an easy and fast way to fill and is invisible since you can pick from assorted colors that match perfectly with the color of that particular area of the finish. As far as it goes, you could treat any slightly objectionable joint gaps in the same way.