sawdust/glue filler?

[Rick Gould]

I need to fill a large split (circular sector) in an oak round to be used as an outdoor table top. I've nailed a piece of scrap into the split, leaving about a half-inch depth still to be brought up to level. I'd like the color of the fill material to match the oak as closely as possible. I have a large amount of the sawdust left from sanding the surface. My first attempt at mixing the fine sawdust with glue to use as fill was a failure: too much dust for too little glue? Is a sawdust/glue mixture the way to fill in the remaining gap? Will it shrink as it sets? What proportions? Are other methods better? A sawdust/polyurethane mix?

Thanks for any advice, Rick

[Lew Hodgett]

You probably don't want to hear this, but since this is an outdoor application, my approach would be epoxy and micro-balloons.

Tape the bottom of the crack shut with duct tape, then mix up some epoxy and add micro-balloons to make a runny catsup consistency, then pour it in the crack and let cure.

My guess is that it will probably take at least 2-3 applications in the split is as large as you suggest.

Pour the last fill proud, then sand flush when cured.

IMHO, sawdust and glue will never get the jib done.

HTH

[George]

Why not regularize the sides of the check and insert an end-grained oak or contrasting wood wedge?

Anything else will look like filler anyway, so might as well make it look as if you wanted something unique.

[wch]

What the heck are micro-balloons? Do gnats get a high voice if they inhale the helium? ;-)

Will

[Andy Dingley]

Tiny hollow glass (white) or phenolic (brown) spheres. I've no idea how small, you can't even feel that they're spherical between your fingers, they're like dust.

As they're ultra-light weight and ultra-thin walled, they make a very lightweight filler for fibreglass work. Being thin walled, they're also easy to sand. Get them from West System Epoxy - they're not even expensive.

Phenolic microballoons + epoxy are my basic filler recipe for wood. A little green and yellow artist's acrylic paint tints them to match.

[B a r r y]

Any hobby shop that carries radio control airplane stuff will also have them.

Barry

[Andy Dingley]

Price is steep though. I can buy a big drum from West for less than a small tin from the model shop (where I did indeed first encounter them)