Mounting ProMariner ProSport20 on Gulfstream

[can129]

I am changing my PM12 charger over to a PM20 and the new charger is larger. My PM12 was mounted on the transom under the hatch but due to my fuel filter I can not mount the PM20 there. Thinking of mounting it against the fwd bulkhead under the hatch at the back seat. Do you think the forward wall is thick enough or should I mount it to a plywood back plate and mount it to the wall? Also, when I drill the holes into the fiberglass, what is the best way to drill and not chip the gelcoat on the outside.
Thanks for any suggestions or comments. CAN

 

[BobP]

If it's just glass, use nuts/waskers and machine bolts/washers. That a 4 bolt mount charger. Pick a bolt size smaller than predilled hole size, and not a tight fit.

If it's 1/2 thick core backed or more, can use screws, same on size.

To avoid cracking the gelcoat and watching it extend over time, you over size the hole only of the the depth of the gelcoat.

I just run backwards a larger size bit deep enough so the screw doesn't try to expand the gelcoat as it screws in.
Running it backwards prevents the bit from going all the way readily.

Can use silicone above waterline to seal holes. GE silcone II window and door almond is popular and cheap at the depot, never seen a small tube only cartridges though. Can use just about anything else too.

 

[seabob4]

...To avoid cracking the gelcoat and watching it extend over time, you over size the hole only of the the depth of the gelcoat.

Believe it or not, one of the best ways to prevent gel cracks from drill hole is once the hole is drilled, take your apex screw bit and c'sink rthe hole through the gel with that. I've worked for Wellcraft, Hydra-sports, Intrepid, Stamas Yacht, and Proline...they all do it the same way...

 

[NOTHING ELSE MATTERS]

...To avoid cracking the gelcoat and watching it extend over time, you over size the hole only of the the depth of the gelcoat.

Believe it or not, one of the best ways to prevent gel cracks from drill hole is once the hole is drilled, take your apex screw bit and c'sink rthe hole through the gel with that. I've worked for Wellcraft, Hydra-sports, Intrepid, Stamas Yacht, and Proline...they all do it the same way...

Been doing the screw bit thingie too.