waterproof wood filler recommendations please

[Randall J Cox]

I'm making some cutting boards for Christmas presents to relatives. I'm using primarily ash with some oak combined. I have some smallish knot holes to fill after running through my planer. Looking for a good wood filler that is light colored and totally waterproof. What have you had good luck with in this sort of application? Thanks. Randy

[Jim Becker]

Epoxy, tinted with dye to whatever shade you want/need. Do keep in mind that if these boards are to be used, there will be a difference in "feel" as a knife crosses the filler and they may stand out when you coat with mineral oil.

[Mac McQuinn]

Food grade Wood Filler??

Mac

[John Blazy]

I second epoxy. So versatile, especially as a filler. Great adhesion, waterproof, no shrinkage, easily colored with tints or sawdust. Need to prewet the surfaces/inside knots with straight epoxy to soak in, then fill with the sawdust mixed epoxy.

[Frank Drackman]

I love epoxy for a filler but have switched to Behlen furniture powder to tint instead of TransTint dye. I have better luck matching the color. If I want to celebrate the defect I still use black TransTint.


Epoxy, tinted with dye to whatever shade you want/need. Do keep in mind that if these boards are to be used, there will be a difference in "feel" as a knife crosses the filler and they may stand out when you coat with mineral oil.

[Peter Aeschliman]

I'm curious- is epoxy food-safe? I've always assumed it isn't, but haven't looked into it.

[Mike Cutler]

I'm curious- is epoxy food-safe? I've always assumed it isn't, but haven't looked into it.

Peter
As with all things to do with the Fed's, there is a classification and spec for food grade epoxy.

To the OP

Epoxy filling sticks will work for big voids. Small voids will just need to be filled with epoxy, tint and some type of thixotropic agent, wood flour, micro balloons, silica,etc.
T-88 by System Three is a good choice, it already has the thixotropic agent blended into the resin.

[Randall J Cox]

Ok, I have already run the glued up boards thru my planer. Now I have the smallish knot holes (3-4 max) to fill (1/4" in dia or less). (Next time I use better wood!!) If I use epoxy, how do I level it? I won't run it back through the planer and possibly ruin my blades that were just sharpened. Ditto for using a chisel given how hard epoxy is (or maybe an old chisel that I would need to grind down and resharpen anyway?). If I try and sand it down, I probably will lower the softer wood around it. Maybe a dremel with fine sandpaper? Or maybe I just plan to fill to surface or less and leave it alone? Any thoughts? Randy PS I have thought about using my Titebond III (waterproof) glue mixed with sawdust - would that work?

[Jim Becker]

Epoxy is relatively soft, in my experience...it sands out just fine.

Do be aware that TB-II isn't "completely" waterproof, but it's about as good as you can get with a PVA glue in that respect. It's all I use.

[Wayne Lomman]

To sand the epoxy flat, use a hard flat sanding block such as an off cut of timber and new sharp sandpaper. Also, you can trim it with a sharp chisel etc when it is nearly cured, same as with polyester filler. Cheers

[Randall J Cox]

Guess I had no idea you could trim or sand epoxy, always thought it was rock hard when dry and would damage chisels. As you can tell, haven't worked with epoxy before... Thanks all. Another learning experience. Randy

[Yonak Hawkins]

I find Bondo to be more economical and I believe it has similar weather, hardness, integrity and workability properties as epoxy. It may not have as long of a work window, however.