another Epoxy question:

I have used the purchased white fluff stuff for a thickener, but I was wondering if sawdust can be used.

I am a “wood butcher” and produce the stuff in various thicknesses on a daily basis and I am forever dumping out five gallon buckets of it it.

when I was mixing some today, the thought occurred to me.

Yay or Nay ???



Wood dust is used for filleting corners all the time.


Yes - but

– Last Updated: Dec-16-08 9:47 PM EST –

Like Jim says, sawdust and epoxy is a common thing for filleting, and filling in boo-boos.

Sawdust and the fluffy white stuff do different things however.

Mix sawdust and epoxy together and you get a putty-like mix of sawdust and epoxy. Technically, this would be called a slurry.

Mix the fluffy white stuff and epoxy together and it causes the epoxy to become thixotropic.

Does it matter? Probably not, but I can't help it, I'm a pedant. And I rarely have the opportunity to use the word "thixotropic".

wood flour and epoxy make the best
wood glue ever.

I have used both, but if I’m using the
mix for gluing irregular surfaces, I would rather use the colloidal silica. There’s too much risk that granules in the sawdust would interfere with the surfaces getting pushed together properly.

And of course, for fairing, you might want to use microballoons, if you want to keep weight down.

Got for it Jack … try rice next : 0
You will see what you can get away with once you start mixing it in … before you throw it @ anything though, let it sit to see what will happen. Resin might just all run right out of it if mixed neat.

Make sure your ‘filler’ is dry too.

Um, no they don’t
Wood flour and epoxy make a pretty good glue, but I’ve found that epoxy and colloidial silica make a much stronger glue, has a much nicer final finish, and it’s way, way cleaner to work with. Just my humble opinion.


Now please define "thixotropic"
sounds like a paddling place somewhere near the equator



funny that you should add that
After I was finished working with the epoxy, I smeared the rest on a piece of pine and then put another piece on top of that and clamped them together as a test.

I figure I would give them the old “break apart” test today.



Thank you everyone

– Last Updated: Dec-17-08 12:54 PM EST –

I swear if I make it to 100 I will still only know a smidgeon of what there is to learn.

Maybe now I can make my first million by selling all the sawdust that I have been dumping to the multitude of epoxy workers


Trip report - the Gulf of Thixotropic

– Last Updated: Dec-17-08 6:11 AM EST –

What it really means is that you can load a mix of fluffy white stuff and epoxy in a syringe or squeeze bottle to shoot a bead that will keep it's shape, or fill a gap.

If you put a mix of sawdust and epoxy in a squeeze bottle it's not coming out.

I’ll never look at a lowly ketchup bottle in the same light as I have all my life.



Means you have a “non newtonian” liquid.

Just being a smart arse there.

If you take maple syrup & stir it vigorously its viscosity remains the same. It is defined as a newtonian liquid

If you take a yoghurt and stir vigorously the viscosity drops. It is defined as a non newtonian liquid.

What size syringe
is needed to force an epoxy/rice mix through the needle?


Turkey Baster kine : )

Yep, amazing what you can grab from
around the house to use as filler when you need too …LOL

you’re doing it wrong
I’ve mixed epoxy and woodflour many time to fill a large syringe. It comes out just fine. Just have to mix the proper ratio.

I have a mental image of
Rice Krispy Treats made with West System instead of Karo Syrup…


What to do with extra sawdust
I put my sawdust into the compost pile. Avoid any from treated wood, though.

Don’t dump lacquer thinner on it …
Ask my wood worker brother why … LOL