Hi ,

Seeing how I'm on a roll , I may as well ask this one ...

How or what is a good way to attach the aluminum pads to the maple motor mounts ?

One set I have done , was to daedo the maple mounts and use #4 X 1/2" wood screws to attach the 1/8" thick aluminum pads to the mounts(with counter sunk holes) . Then , I can drill through holes in the aluminum pads and maple mounts and "Tee nut" them , opposite the pads .
What I'd like to know , is it all right to epoxy the pads to the maple mounts , for extra security ?

I'm sure I've asked this before , but I think the subject was lost in the last site "crash" .

Thanks ,

Rob Killick

Rob I usually just tack them in place with thin CA. If the screws and engine bolts don't hold'em 

Ditto.

 Rob, I think you might be making it much harder than it needs to be. I could see doing it your way if you intended to try several different engines in the model. But if not, keep it simple.

The trick to getting epoxy to stick to aluminum is smear a little on then sand it with the epoxy. This breaks the oxidation and lets the epoxy get to bare metal. If you sand it before applying epoxy it will oxidize before you can get anything on it. Same reason aluminum can't be soldered with normal methods.

I have been applying thin CA to the motor mount (wood) area. Let it soak in and then wipe clean. I do it a couple of times. I also put CA in the mounting holes to seal them before I put the t-nuts in the farside. Then before I mount the engine I apply Silicone between the wood and the aluminum plates. I always screw the plates down. Wipe off any excess sealant. As Brett says probably not needed and the extra screws are always a place for the oil to migrate to. Although I've never had a problem. The rest of the compartment gets brushed sealed with resin.

I use a 1/2" square mount and a 3/8 square engine "pad". The engine bolts to the pad and the pad bolts to the maple mounts. It's very stable (though it does take some mill work) and allow new pads for different engines, whatever.