Hi guys, I am gearing up to refinish my Champlain. Doing some research on West Systems website, I came across aluminum powder as an additive in the epoxy resin. It is touted to add abrasion resistance and dries to a battleship grey color. I am considering using this in the project. Has any one had any experience using aluminum power in their refinishing projects? Any thoughts or concerns that you may have? Thanks!

Maybe. If it is laid on thick, with reinforcement like a skid plate then it might give some abrasion resistance along with the grey coloration. Graphite powder is used for this as well which gives a black color to the epoxy.

I'm just guessing, but with the very thin coat of a hull refinish I'm not sure it would make much difference in abrasion resistance. It likely depends on the type of abrasion too: it will have limited effect with a loaded canoe when met with the hardness of sub-surface rocks, but might make a substantial difference in abrasion resistance if dragging an empty canoe across sand. It will certainly tint the color to grey, though.

I think the bigger durability concern with a refinish is to mechanically roughen the existing surface and clean with a residue-free solvent to ensure good adhesion to the existing surface. New epoxy will stick (but not crosslink) to existing composite surface, so you want a good clean mechanical bond to increase adhesion.

I'm sure it'll be tough...That's essentially what JB weld is.

From what limited amounts I've seen, the metal powder + epoxy looks like metal.

... so the question is do you want a canoe that looks like an aluminum canoe?

Does not make sense to me. Aluminum is not a hard metal, and is probably not significantly harder than the epoxy. Aluminum on the Mohr hardness scale(1-10) is 2.5-3. Glass on the other hand is 6-7. So milled glass fibers or silica powder would increase abrasion resistance better than aluminum. Aluminum oxide, corundum, is much harder yet. It is the grit in most sandpapers, but I have never seen it in a powdered form that could be used as an additive for epoxy resin.

Carbon powder in epoxy will make it slippery to slide off of rocks easier. It is very strong, but particularly abrasion resistant.

After all is said and done, it is still the epoxy that binds it all together and when it come in contact with a rock there will be a scratch.

Long ago I noticed that patches on my wood strip boats seemed to be more resistant to scratching than the rest of the hull. I often used very fine 2 ounce cloth to cover repairs. The fabric fills to smooth with very little epoxy. There is even lighter fiberglass cloth available. The next boat I build will have a veil of 3/4 ounce cloth over the structural layers instead of layers of resin to fill and bury the weave.

Probably a typo, but I believe the hardness rating should be Mohs hardness, not Mohr hardness. I sell glass and ceramic products, and I am familiar with Mohs. And Doh's, and Larry, and Curly as well. https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness

Tomster

Thanks guys. I came across it on the website when looking at the coloring additives. I actually think I would like the battleship grey look. Plus the added benefit of added toughness. As mentioned, the other additive is graphite powder which adds a low friction quality and turns black. Either would be something different than the standard skin color.

Another thing... sanding? Epoxy is tough enough to sand smooth. I wonder how that changes with the aluminum powder??