Est. 1998 — 27 years of woodworking knowledge
Filling knot holes with epoxy or other
Alan Young
I am building a Farmhouse styled table. The top is hickory. Most of the surface is clean and knots free. The knots or knot holes that are there are fine to include as this is casual to almost rustic piece. I do however want the surface to be level and free of voids so I was planning on filling the existing knot holes with epoxy.- Is there any particular type that I should use and or avoid?
-Alan
Re: Filling knot holes with epoxy or other
Howard Norman
I have used the West brand several times in situations like you describe. I usually add a little carbon black to color the epoxy.
Re: Filling knot holes with epoxy or other
AZ in Colorado Springs
I built a table recently with a top made from wormy maple. I used epoxy I got at Walmart (5 minute stuff) for the purpose you describe.
It also had a knot missing. I borrowed a lesson from patching a hole in sheetrock a few years ago. I stuffed some steel wool into the middle of the cavity, then put Tiebond II and wood shavings on top of it. Let it dry several days. Then coated that with some walnut colored wood filler, and then a bit of epoxy over the top. Turned the top over and did the same to the bottom side. The repair blended in very well, as there was an area of dark streaking where the knot came out. (I did not have the knot to glue into the hole.)
Re: Filling knot holes with epoxy
Mark Mandell - Gone Round In New Jersey
Hi Alan,
I use several kinds of epoxy as I work with "character" wood a lot. For anything over 1/8" and less than 1/2" thick I use System 3 general purpose resin with "fast" catalyst; thicker pours n3eed slower catalyst to control the reaction heat. I measure by weight [100/44] per Sys-3 directions. For small cracks, checks, and such, I use thinner resin and slower catalyst ("Mirror Coat" or equivalent) to get better penetration. Depending on the application, I can color the resin with epoxy pigment (black or white) or use Trans-Tint dyes to tint the mix. I also use wood flour to thicken the mix for paste applications.
Small tip: Before applying your filler, do two things:
1. Check to see if you need to seal the opposite face of the wood to prevent leakage. Masking tape doesn't hold well, but a quick brush with Anchorseal (wax emulsion) covered with a piece of plastic wrap does well and removes easily.
2. Also give the surface around your "repair" a quick swipe or two with a paper towel and dewaxed shellac to prevent the epoxy from staining the surrounding wood. Cleans off nicely with sanding.
Example
Mark Mandell - Gone Round In New Jersey
Before:
After:
This was done in two pours; the first to about 1/4" and the second 3/4" to fill the 1" deep cavity using clear resin and medium catalyst to give the mix-air time to migrate to the surface. Sanded to 320 and finished with waterborne acrylic lacquer.
Re: Filling knot holes with epoxy or other
JL
I usually mix an epoxy (whatever type) - and add about 20% or so sawdust or wood chops. I've had reasonable luck adding up to 30-40% sawdust. It gives it a bit of color and makes it somewhat easier to color (dye or stain).
Re: Filling knot holes with epoxy or other
john lucas
I mix a mild amount of black or brown india ink. I want the the epoxy to be brown or black but I want it to be somewhat transparent. That way the glue picks up the color of knot and looks better. I've used a of different brands. It doesn't seem to matter.
Thanks all!
Re: Filling knot holes with epoxy or other
TomD
+1 I use the west graphite powder, which is just pure graphite. It makes a nice black, and can be mixed up to about 20% in this type of application. I like good grade of epoxy, and this stuff has lasted 20 years with no sign of problems. There can be issues if the material is in direct sunlight, and mixing the graphite heavy will deter penetration of the light.