Motor Mounts Keep Breaking Loose.. Help???

[NativePaul]

Epoxy and Polyester do not bond together well, try one of the other glues recomended here.

[Brod]

It's prob. because the tunnel is flexing from the inertia of the crash plus the weight of the motor. Stiffen up the tunnel floor with some glass or cf.

Agreed,floor is bending and flexing,loosening the bond on the glue/hull.

[ED66677]

that's why I kept the plywood rail... no epoxy no CF no nothing!

[properchopper]

Agreed,floor is bending and flexing,loosening the bond on the glue/hull.

The solution is in post #13.

[Alexgar]

i like jb weld also

[Tuslow1]

Well my CF came in today and I think I ordered a tab bit too much, but the good thing is now I know how big 4 yards really is and I don't think I'll need anymore for some years to come.
I was looking at how pretty and wet the CF looks thinking to my self "Damn thats alot" when the Fun Governer said "and you better use it all" as she walked out of the room!!!

[Tuslow1]

Now back to the "JB" topic, just mix it 50/50 and that will bond the mount inplace for life? No micro balloons, baking soda or cement mix?

[AlanN]

JB weld is for those who do not know how to use epoxy correctly or do not use the right epoxy.

West Systems or Mas.

Of course alot has to be said about how your mount is designed and made.

I bit my tongue on this topic for days....just couldn't stand it anymore.

[Doug Smock]

Of course alot has to be said about how the design of your mount is created.

I bit my tongue on this topic for days....just couldn't stand it anymore.

Me too.
I have never had a motor mount come loose and I crash as hard and often as the next guy.
Crashed a mono at 88mph, tore the aft portion of the deck off, but the motor mount stayed in the boat.LOL

FWIW I've had good luck with 30 min Z-Poxy.
Carry on JB Welders!!!

Doug

[BakedMopar]

JB weld is for those who do not know how to use right epoxy or do not use the right epoxy.

West Systems or Mas.

Of course alot has to be said about how the design of your mount is created.

I bit my tongue on this topic for days....just couldn't stand it anymore.

Thanks for establishing that we uneducated. It however does not answer the OP.

[AlanN]

No baked mopar it does not directly answer the question. But 30 minute epoxy (and there are different grades out there) does not hold or cure as well as top shelf epoxy. There are plenty of good suggestions here but I am not going to repeat them. Stiffen the hull...use rails....did anyone think of a rear support for the motor? Longer cans have more leverage against the mount. I have seen jb weld used for everything but in the end it always dries up, becomes brittle and breaks anyways. Besides that it looks like $%^# in a hull.

[BakedMopar]

I have been using Hawaii Fiberglass Marine epoxy with great success up until now. My boat consists of 4" rail that extend 14". Motor mount is front and rear support. The Rico hulls have virtually no flex ( it does have a carbon floor). The rails just did not stick to the hull. I could be that the hull is not fully cured yet? I re-did it with the marine 5200 ahesive. Hopefully it holds better.

[6S HYDRO]

i agree about the look of the jb weld in a boat