mahogany strength

[navahoIII]

Is mahogany (1 1/2" thick) strong enough to serve as a motor mount between two steel brackets, or should oak be used?

[Roger]

I have seen some fast growth mahogany that is quite soft and other slow growth stuff that would likely dull a carbide saw. Mahog comes in varous grades, and there are many varieties of mahogany.

[algonquin]

In reality 1 ½ inch mahogany should do the trick but my personal preference would be 2 pieces of 3/4 or 1 inch marine plywood glued or epoxied together and then covered with 3 or 4 coats of marine grade urethane. The plywood will not stress crack while other solid hardwoods may crack over time and use. Brad

[GreenLake]

I second that.

For gluing these together, any waterproof glue would do, but make sure you coat the plywood with a suitable epoxy before covering it with the urethane (and to also cover the insides of any holes you drill).

Epoxies made for lamination are probably fine, as are low viscosity formulations intended to soak into bare wood. You might be able to get the latter from lumber or paint stores.

The purpose of the epoxy is just to provide a better grip on the wood than varnish does over time, and with that, to provide more durable waterproofing.

I would apply the same treatment to solid wood for an exposed appliation like this. By sealing out moisture as effectively as the epoxies do, you would expect to see less cracking and similar problems, even in solid wood, because the wood would no longer expand/contract as much.

[navahoIII]

Thanks all for the excellent advice!