Best motor mount epoxy / cement ?

[Chilli]

200 grit rough up (make sure the sand paper comes up black!), alcohol wipe and JB weld.

20 blow overs at 70+ and still solid as a rock.

[tlandauer]

West Systems epoxy calls out Acetone by name as prep and I've used it for 20 years without fail. I'd also recommend roughing the area with very course grit to increase the effective bonding area on the hull. The more surface it has to bond to, the better.
My $0.02 :)

I use West System with their heavy fillet, the thick consistency prevents run-away epoxy and when cured, it is very tough ( I tried to break the cured left over epoxy in the mixing cup to no avail) and the bound is really strong too.
I am rather curious about the G Flex, think will get some for my next build.
When I got my Aero Marine MM hull last August, the hull smelled like uncured glue (I liked the smell tho, lol...) but I found that on their CF layer I can feel some slipperiness, I thought it might be oil , I sanded with 100 grit until, yes, until I saw black. The fume was so strong that if I close the hatch the next day it smells like fresh from the factory, never died out. Here is the thing, if I sanded the motor area and the servo area but only managed to epoxy the motor mount, the next day for some reason the servo area feels slippery again, I always had to sand prior to any epoxing. I asked this question a few times because the front of the boat there is soft filler outside between the upper and lower halves. To this day, it is still soft, and releasing smell.

[Alfa Spirit]

Chip, Somethin' aint right. Do this when you re-mount the motor. You won't see it when the boat's out on the water

[ATTACH=CONFIG]91309[/ATTACH]

That' s a very good idea, interesting.

[chipgibbs]

I stayed up late last night and got the carbon fiber motor mount sides epoxied onto the hull again. I ruffed the piss out of it with 120 grit then wiped it down with acetone and used the G-flex to anchor it. This morning I sanded it again with 120 and added some 1oz fiber glass cloth on a bias into the fillets on both sides of both motor mount sides....I think this will hold it.
The fiberglass disappears into the black carbon background but, I know it's there.
IMAG0909.jpg

CG3

[jcald2000]

G-Flex is made to flex, I want mine solid.

[iamandrew]

yeah prop chops idea isnt that bad, some of the wood could help with motor vibration as well as support the bracket.

[properchopper]

I'll second the notion that properly {chopperly} prepping the area to be bonded to is of maximum importance. I've done lots of builds in which the hull comes right from the mold and onto my workbench and there's still curing going on so I have to wait a few days (curing, and full hardening of the resin can take months, btw). Roughening up with agressive sandpaper, like 80 grit, and cleaning off with alcohol, lighter fluid, or carb cleaner (dimethyl ketone/methyl alcohol/toluol) and then allowing sufficient drying time is essential.

[Basstronics]

Im a firm believe in JB Weld. If you JB Weld that motor mount down it aint coming out without the bottom of the hull! lol

[chipgibbs]

Thanks for the replies. I feel like the added prep and extra glass in the fillets should hold it together this time.

CG3