Black Epoxy for Black Walnut

[Danny Hamsley]

I have tried several different fillers to fill small holes and cracks in black walnut, but I have not found anything that really matches and does the job. There are times when I have a nice piece of black walnut with a portion of the pith showing, and I want to use the piece. Since the pith is chambered and black, I think that a black epoxy would look fine since there is a lot of black spots/mineral streaks in walnut naturally, and while the black epoxy would not hide the area being filled, it might enhance it and match in a harmony kind of way. Has anyone used black epoxy this way and can anyone recommend a suitable black epoxy for wood?

[Chris Fournier]

I have done this many times and the black epoxy looks great! You don't buy black epoxy, you make it; buy some black earth oxide powder from LV and mix it into the epoxy - there you go. Don't use 5 minute epoxy if you can avoid it - it's brittle and it yellows. In a pinch I have used carbon black from toner cartidges and it works like a treat as well. The earth oxide sample kit from LV will give you a pallet to really come up with your own epoxy colours to patch whatever you need.

[John Coloccia]

I have tried several different fillers to fill small holes and cracks in black walnut, but I have not found anything that really matches and does the job. There are times when I have a nice piece of black walnut with a portion of the pith showing, and I want to use the piece. Since the pith is chambered and black, I think that a black epoxy would look fine since there is a lot of black spots/mineral streaks in walnut naturally, and while the black epoxy would not hide the area being filled, it might enhance it and match in a harmony kind of way. Has anyone used black epoxy this way and can anyone recommend a suitable black epoxy for wood?

Couple of things you can do:

1) StewMac (www.stewmac.com) carries black epoxy. This particular one has a long working time and sands very well. It's designed to do inlays on black fiberboard. It is BLACK. Good stuff.

2) You can take any regular epoxy and tint it yourself. Transtint works just dandy for this. The only reason I use Stewmac's black epoxy as opposed to tinting it myself is just a matter of convenience. I do it enough that I don't want to be tinting all the time. The advantage is you can get any color you want.

3) Fill with sawdust and epoxy. I try to take sawdust off with different grits of paper, files and rasps, and then mix it up. It looks more natural like that.

The problem with all of these, if it's a problem for you, is that none of it will take any stain.

[John Coloccia]

I have done this many times and the black epoxy looks great! You don't buy black epoxy, you make it; buy some black earth oxide powder from LV and mix it into the epoxy - there you go. Don't use 5 minute epoxy if you can avoid it - it's brittle and it yellows. In a pinch I have used carbon black from toner cartidges and it works like a treat as well. The earth oxide sample kit from LV will give you a pallet to really come up with your own epoxy colours to patch whatever you need.

I don't think those are available anymore. I don't know why they stopped carrying them. Maybe you have another source?

[Brian Penning]

I've been happy with the results from mixing black milkpaint in to my epoxy.
Might want to overfill the hole so the air bubbles will be above the surface prior to sanding.

[Tony Bilello]

I buy my touch-up powders from woodfinishersdepot.com. They have a full line of finishing/refinishing and touch-up chemicals.

[Jeff Monson]

A dark shade of transtint in clear epoxy will be virtually black. Works well for filling voids and cracks. Levels well with a card scraper when cured.

[Ted Wong]

Whenever there is a natural opening in the wood (splits, knot holes, cracks, etc.) and I want a flat surface I fill the hole with a mixture of end grand filings and epoxy. The color comes out pretty au natural and blends well with the surrounding area. Use a rasp coarser type of file to get larger size filings that will mean less epoxy and more wood.

[Jim Matthews]

I wonder if superglue (medium thickness, but not so thick as epoxy) with sawdust worked into the crack would hold?
If the crack is more than 1/16" at the widest, the epoxy may be under stress as humidity changes.

A superglue slurry is unlikely to fail...

[Chris Fournier]

I don't think those are available anymore. I don't know why they stopped carrying them. Maybe you have another source?

http://kremerpigments.com/

These guys are in your backyard John and they have primary colours! Easy to deal with too.

[Steve Griffin]

I like to use those little jars of Testors hobby paint. A drop or two is all you need.

I keep a jar of used nails for mixing, and some melamine little blocks to mix on.

I use 5 min epoxy, and never seen it turn yellow or brittle. It usually takes all day to really dry though.

Mixing sawdust with epoxy or glues sounds like a good idea, but I can't think of a single time where I've tried that "trick" and it didn't look horrible. I do sometimes stuff the bottom of big knot holes with sawdust to save money on epoxy.

-Steve

[Danny Hamsley]

This is exactly the info that I hoped to get! John, I ordered some slow setting black this morning. Thanks!

[george wilson]

Maybe when filled with black pigment of some kind it's different. In my own experience I have found that 5 minute epoxy does not get as hard as the 2 hour stuff. I use it all the time,thinned with alcohol,to fill the pores in my guitars. I sand it off when it gets "leather hard" in about an hour or less(the alcohol slows it down.) Once it is set,it never shrinks under a finish,revealing the pores,like lacquer sealer always does.

[Neil Bosdet]

I prefer to mix sawdust from the same wood with clear epoxy. Works great for me.

[Prashun Patel]

Another trick is to use coffee grounds in epoxy.

Superglue/ca glue will work fine on thin cracks, and in gel form can be fine for even larger cracks. But it sets quicker, so mixing colors is tricky.

You'll be surprised how little colorant (dye, stain, or dust) you require to tint epoxy.

If your void is large, then beware filling with a solid like dust or grounds will result in an unnatural (Trex-Decking) type of texture. In that case, sometimes straight epoxy looks smooth and better (to my untrained eye).

[Peter Parrinello]

Brownells has a 2 part epoxy called acraglas gel and a selection of dyes that works very well and is easy to work with

[David Helm]

+1 on using sanding flour from the same wood. The epoxy darkens it a bit, but if you collect flour from different shades you just go a shade lighter. In my opinion it is the most natural looking.

[Jim Jakosh]

I have been using the 5 minute epoxy from Harbor Freight with a few drops of Testors black paint and it works great. Then I tried using Rustoleum black oil based paint and it works too but takes longer to dry. In Arizona, the guys at the saw mill use black bed line materia for filling voids and embedding turquoise into wood and it works great but is $275 for a 5 gallon can. I tried using the black paint in Bondo for filling large areas and it does not dry very well, but turns very black. I have found they have black Goop Epoxy Sealer at Walmart at $27 for 2# can with the hardener.
Has anyone tried that for filling wood?

I will also look into the Stewart Mcdonald Epoxy.

thanks, Jim

[Dennis Ford]

I use graphite to tint epoxy black (at least until I run out of what I have). I have also used CA glue and prefer that for small openings. One caution: it is a very bad idea to fill a void before the wood is really dry.

[Scott T Smith]

Danny, my favorite method is to use West system epoxy (206 hardener) and an artist oil paint in the desired color. You can pick up the artist oil paint (pigment in a tube) at a Michael's or craft shop. Many shades are available in case you want to experiment with different shades of black.

Have also used ground up charcoal briquettes (powdered) placed in the void with CA drops added to it. It's a bit more porous than the epoxy.

One trick to getting the bubbles out of the epoxy is to tape the "show" side and put the epoxy in from the back (if it's a void all the way through the plank), or use a heat gun on the epoxy after it's in place. The heat gun will help to relieve the air and bring the bubbles to the surface.

[Bill Adamsen]

+1 on the graphite. I would also test just clear unthickened epoxy. I have found that the light is "captured" in the hole and the filled holes appear dark. Just my experience.

[Peter Quinn]

+1 on the graphite. I would also test just clear unthickened epoxy. I have found that the light is "captured" in the hole and the filled holes appear dark. Just my experience.

This is what I have always done, just clear seems to look more natural in small to medium knots once the finish goes on that any tints or fillers. West systems makes a hardener that dries clear with no wax blush, though you would mostly be scraping that off anyway. Ive used just the regular 207 hardener with good results in walnut and oak, lets the natural color come through, looks more natural than almost anything else.

[Bill Adamsen]

I've used just the regular 207 hardener with good results in walnut and oak, lets the natural color come through, looks more natural than almost anything else.

I typically use the 206. I only recently started using the 207 for coating based on recommendations in this forum and it works great for that with minimal amine blush. I suspect the 206 is stronger but the 207 is less viscous ... likely either would work fine.

One trick. The temperature should be descending when you mix and fill. You want the wood to be cooling so that it is pulling in air rather than pushing it out. This way you minimize the entrainment of air bubbles in the epoxy. I always try to schedule to do my glue ups last thing in the day.

[glenn bradley]

I have done this. Works fine. I used a few drops of Trans-Tint black because I had it. I know people use India ink as well. I did not use any particular epoxy as the fill was on a vertical panel. If I were patching on a coffee table surface I would be more specific.

[Mike Schuch]

When I installed the granite counter tops in my kitchen I bought an epoxy coloring kit for a few bucks and mixed several colors to match the various colors in the granite. It worked great and hid the seams perfectly! The coloring kit wasn't that expensive, has enough colors to mix pretty much any imaginable shade and is made to be compatible with epoxy.