Can you glass to aluminum?

[MSG Hall]

I’m kind of doubt’n it, the different expantion/contraction rates in the heat and cold would probably break the bond. But I thought I’d ask the experts… what do you think?

This is a boat project I have been thinking about. I would like to put a 3’ tunnel in my aluminum Jon so I can raise the motor.

[SteveH]

Obviously, I have no experience with it, but I think it would work if you cleaned and ruffed up the aluminum at the joint, and used epoxy resin. If it came loose later, you could always seal the joint with silicone and rivit it back together if the glass is thick enough.

[madjack]

...you should be able to rough up the Al and use thickened epoxy...depending upon what you are using it for, I would recommend a mechanical fastener(rivets, etc.) as well............
madjack

[mb82]

Depends on the usage of the boat. My buddy had a tunnel put into his jonboat so he could put his jetdrive up higher then the underside of the boat. That was about 5 years ago and with abuse the welds of the tunnel are coming apart so I am not sure fiberglass would work. By abuse I mean hey look at that class III rapid lets go up it. The boat has been drug across more rocks in the James River then I want to think about.

[Bad-Dawg]

I have embedded all kinds of Aluminum objects into a fiberglass/epoxy matrix on several projects, and have used epoxy (Jb Weld and Marine tex) to rebuild Aluminum objects. Works fairly good but you may want to consider that this tunnel will have a lot of pressure on it so it will need a fairly large lap joint. It's certainly do-able.

B-D

[angib]

The epoxy to aluminium bond is good but I second bad-dawg's comment about the size of the joint. Also no adhesive copes well with peeling forces, so the joint design needs to avoid that.

While I think of it, it may be worth adding that the epoxy to stainless steel bond is awful and nothing that I know of will make it any good.

Andrew

[HossHoffer]

The definitive answer is a resounding yes. Glass works very well on aluminum. We do many repairs on aluminum parts with fiberglass in the aviation industry. The bonding surface should be sanded clean and is often prepped with phosphoric acid. I would add however that in an engine mount application fiberglass does not make a good hard point (if I understand correctly that you plan to mount the engine on the tunnel) and you would have to engineer some metal reinforcements for that.

[Alphacarina]

Epoxy to (roughened) alumunum would make a good bond - If you're wanting to use polyester resin (common fiberglass) I would drill a few dozen small (1/8th inch) holes in the aluminum where ever you can to increase the strength of the bond

Don

[glassice]

Maybe we use ALU for molds . no matter what you do you can make it pop .you need to mechanical tie it down small holes pop rivets