Working with Wormy Chestnut

Advice on machining and finishing wormy Chestnut. February 21, 2011

Any advice for finishing rare and beautiful wormy chestnut wood on a dining table? My wood varies from almost clear to looking like a target board for a shotgun. Would a black filler be advisable to get a smoother finish, or just leave it alone? There are also sections of the boards that appear to have termite damage, though the supplier swears this is merely due to the age of the wood, and part of the character. The customer specified wormy chestnut, but what are the acceptable standards? Has anyone used a paste filler to level the surface? Or would this detract from the distressed look? I have this vision of tipping the gravy boat at turkey dinner and having it collect in all the worm holes and cracks.

Forum Responses
(Finishing Forum)
From contributor S:
If you're concerned about the holes, then I've found epoxy works great. I used it on some character oak just to fill the cracks and worm holes and it worked great. It's clear, so you see the original color/texture, but you still get your level/smooth surface (i.e. no gravy pockets). It's fun to watch people try to touch the cracks and worm holes and then realize that they are filled. I then topcoated with my normal clear coat (Target).

From the original questioner:
I thought about that. What type of epoxy did you use? I'm either going to use a flat urethane or a hand rubbed lacquer for the final finish. Will the epoxy have any effect on the sheen?

From contributor S:
I've used both West Systems and Loc-tite brand; both worked very well. The actual sheen was not altered where the epoxy was, but the epoxy did fill the pores anywhere I got it on the surrounding wood, which did show up in raking light. I ended up using a toothpick to get the epoxy in the worm holes, and a small piece of scrap on the larger knots/cracks.

From contributor M:
I have been collecting American chestnut (turn of the century) furniture for years. Of course this was from before the blight that wiped out the commercial crop. Most dealers confuse chestnut and elm with oak. Not because they look anything alike, but because the same furniture that was done in chestnut and elm was later done in oak, after it was commercially milled out. Treat it just as you would oak. It will take a light dye stain well. Be careful - it is more porous than most oaks. I never fill oak or chestnut; it should look a little on the rustic side. West Systems 500 line of epoxy will work well. Pick up their Microfearing filler and add to thicken the epoxy. If you add the filler, then 944 colorant, then mix it up to get the right consistency and tone, then add the catalyst, it works well. Due to the scarcity of the wood, you can substitute sassafras if you do not want the holes.

From the original questioner:
I don't want to stain at all; this wood is too pretty on its own. All I am interested in is learning a technique that will fill the holes and defects without losing the rustic character. I've considered using an epoxy resin but I don't want a glossy look or that smooth of a finished texture. I feel it's important to feel the wood while having a finish that will withstand many years of use. That said, as you may have figured out by now, I'm a talented woodworker but a novice finisher, so all input will be greatly appreciated!

From contributor R:
Put masking tape around the holes to keep the epoxy out of the wood pores. The sheen of the finish will not be affected by the epoxy unless you do a very thin coat.

From the original questioner:
That would be extremely tedious. Have you ever seen a piece of wormy chestnut? On just one 6" x 6' board there could be a hundred or more worm holes. I was thinking more on the lines of spreading the resin or filler with a plastic squeegee and after it cures, sanding down to bare wood, then applying the topcoat.

From contributor A:
Go for it, if your customer likes that look.

From contributor Q:
Syringes work very well for filling worm holes and come in many sizes.

From contributor D:
I have worked extensively with wormy chestnut for the last 20 years. It has character that can not be compared. I have never made a dining table with it and may be more than a little worried about the longevity of such a piece. The wood is soft and will splinter on its edges. Are you planning on laying up ply or working with solid stock?

As for the finishing, I have never felt the need to fill wormy chestnut, but then again, I have never built a dining table. I would be concerned with spills and bacteria in the holes. If you use an epoxy, I would probably use a complete epoxy system, fill and finish. This will help to curb some of the splintering and hardness.

Good luck with this piece. Watch your fingers if you are using a shaper with this wood. It has a tendency to disintegrate without warning.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor C:
We had an outdoor table made out of old barn beams which are wormy chestnut. The problem we encountered was cracking and cupping. We applied One Time stain/sealer. Epoxy sounds like a possibility in your case though.