saw dust and epoxy

Problems, how to use. Also see: "EPOXY", in the left-hand column of the Home page.

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saw dust and epoxy

Post by semerje »

it is cool to mix epoxy and saw dust to make a paste without any other fillers?

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Post by FDMSIV »

I did it quite a bit, wood Flour is really just fine saw dust. I used a shopvac with a random orbit sander and some 120 grit disk to sand clean scrap. I would then empty the shopvac and I had some good mixer.

A few pointers that I discovered.

The epoxy/saw dust mix will be slightly darker than the wood the saw dust came from.

Only use very very fine dust, and try to get out the chunkier particles.

If you have them, add microspheres. Epoxy and saw dust only make for a very solid, hard to sand mixture. The microsphere make it a little easier to sand.

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Post by Fred5150 »

I was planning on doing just what you guys are talking about except with my belt sander.....I was wondering about the color compatibility.
Where do you get microspheres??

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Post by HouTexBBC »

Microspheres (a.k.a. Micro Balloons) can be found at many boatbuilding supply places. Glen-L sells it as does RAKA, US Composites etc.

I agree with FDMSIV, however I eventually decided to quit using my own dust. I never tried adding micro ballons but in general it always came out too course for my liking. I used dust from my sanders and while it seemed very fine, it was actually very course in the mix as compared to the wood flour I purchased. I had dust from a mixture of sanding grits so that may have been the problem. I just like the consistency of the store bought flour.

As far as color, I too have never been able to get a decent color match. I guess it is the epoxy that darkens it so much.


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Post by basilkies »

TAP plastics has microspheres in various sizes.

Another good filler is fiberglass sandings from when you put cloth down on your boat and sand it.

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Re: saw dust and epoxy

Post by slociviccoupe »

if its in a non visable area, cotton flocking can be used mixed with epoxy to fill gaps, it is aircraft aproved and structural. Better to me than microballoons.

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Re: saw dust and epoxy

Post by BulldogBoater »

I have used wood flour from my the bag on my belt sanders. It seems that I produce the flour about the same speed I need it.

I too mixed it with microspheres, carbosil, etc. It makes for a smoother sand and lightens the color for a better match.

Soloboat reported using his wife's sifter to get the unwanted larger pieces out of his wood flour. Don't know that I would try her pound cake though :D

Good Luck,

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Re: saw dust and epoxy

Post by Cranky Badger »

Don't know that I would try her pound cake though :D
Cause you can pound nails with it ? :mrgreen:
Sounds kinda like a ricochet biscuit...

Hehe... I had some gross results with sawdust myself...till I started saving the dust from the bag on the sander. It's a good filler for casting as well, if you're into that.

Another source for glassing stuff I haven't seen mentioned much: Jamestown Distributors. I haven't used them myself but I've heard good things. The Duckworks site might be a place to try as well. But only after making sure that our fine forum host, Glen-L, doesn't have what you need.

Just a thought guys...try some Interlux Epiglass HT9000 resin. It dries almost clear and it's great when you're trying to match tone (like in a repair). This is how it looks cured:
Last edited by Cranky Badger on Fri Jun 12, 2009 5:07 pm, edited 1 time in total.

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Re: saw dust and epoxy

Post by Caber-Feidh »

Microballoons and epoxy is the way to go. The weight of the mixture is deceptively light, it creates a great bond. Even with a very high filler content is sticks better than anything. I have tried about every high strength fairing compound I could find. I was looking for a compound to fair the wear ring adapter in jet pumps, they would suck even the big $ ($50/pint) 3m stuff off the first time the pump was run. I used some Glen-l supplied balloons, mixed 4/1 by weight with silica, and mixed way, way over the normal ratio with slow epoxy (to a consistency similar to cold silicone RTV). It made the perfect filler. Easy to sand. A top coat of epoxy to provide a glass-smooth finish, and it was done.

I would not ever again save the $ on the balloons, and use wood flour. And I am the quintessential cheapskate! (just ask the DA, :wink: )
Some plan to stroll through Saint Peter's Gates, I plan to go through them at 150mph... backwards... in a screaming ball of flame, with a glimmer belt wrapped around my head, and a NOx button in my hand.

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Re: saw dust and epoxy

Post by Soloboat »

dont forget the fibreglass used for insulation works as a great filler. so does POUND CAKE for the stomach. If you do not fill the stomach chine logs are more difficult to bend beer becomes more difficult to absorb. :)
) Champagne dreams and wishes are possible on a beer budget. Just build the boat.
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