Did a search, didn’t come up with much, so here’s my question:
How will adding sawdust to thicken up epoxy into a paste affect strength?
Composites are generally stronger that the resin by itself…but in this case I have
no actual knowledge.
Thanks!
Pat
S’long as sawdust is uniformly fine, no problem, just a hair weaker than microballoons because it doesn’t completely soak in the resin, but it’s strong enough for any repair job.
Make sure that sawdust is dry. Sawdust “catches” damp easily and damp is no good with epoxy.
Thanks for the replies, I’m going to give it a go I think. My sawdust is from the collection bag of the belt sander, so it’s pretty uniform and fine. As to damp, I guess I’ll spread it out on a baking sheet and heat at 200 degrees for a bit or something like that. Didn’t think of the damp factor.
Pat
Thanks for the replies, I’m going to give it a go I think. My sawdust is from the collection bag of the belt sander, so it’s pretty uniform and fine. As to damp, I guess I’ll spread it out on a baking sheet and heat at 200 degrees for a bit or something like that. Didn’t think of the damp factor.
Pat
For a small quantity of sawdust, a (!!!carefully monitored!!!) microwave might be the convenient ticket.
-Samiam
Composites are stronger as long as all the materials are strong. Composites take advantage to of certain properties of each material. A lot of the time one of the advantgeous properties is economy.
For example: Reinforced concrete. Concrete is economical to make and easy to place in a structural shape. It is strong in compression and weak in tension. So reinforcing steel in cast in the concrete to increase tensile strength. You have a composite that in stronger in compression and tension. Steel is strong in both properties but cost prohibitive for structural walls, etc. There are steel structures of course but economy drives construction and so we have composite concrete structures.
Sawdust is not strong. It will basically weaken you composite. Structurally, each piece of dust creates a non-structural void because the wood is more compressable than the epoxy and cannot sufficiently transfer forces from the epoxy on one side of the dust particle to the epoxy on the other side.
Sawdust and epoxy is not stronger than staight epoxy. That’s not always a bad thing. If you want your epoxy to look like wood, and it’s stong enough for your application, you’re good to go. If you want your epoxy to me more sandable, weak fillers like sawdust will make it easier to work with.
My 2 cents.