Amp mounting location: behind helm?

[JWPrendergast]

Im going to mount a small sized amp (JL M600/6) behind the helm. Im trying to figure out what to mount it to. I thought about glueing starboard to one of the surfaces, but just read about nothing (except adhesives that cost $$$) stick to starboard. Would you use an MDF and just cover it with glass resin?

This picture is on the port side of the helm, after the bow cushion was removed. This is the location I would like to install the amp, but dont want to bolt through to the other side.

 

[Cory]

how about a plastic cutting board? Probably big enough for one amp

 

[JCampbell]

What you could do is make a mounting plate for the amp. Make a cutout behind the amp in the board or plastic to aid in cooling. Get some hex female standoffs that match the thread of the cushion bolts. Secure them on with Loctite Blue and let dry. Then get two more bolts to bolt the plate to the standoffs. I would use the blue Loctite on those as well.

 

[David Analog]

Avoid MDF in a boat. Use plywood. Confirm the plywood is constructed with a solvent based adhesive versus a water based. Cabinet grade birch plywood is great. Resin coat it with a standard polyester fiberglass resin. Cover it with a marine grade non-mildew carpet rather than automotive trunk liner/carpet.
If the mounting location backs up to the bow mold with cushions behind it then you can pre-drill with a stop and run a number of shallow S.S. screws directly into that surface. Keep the pattern more centered rather than spread out if there is much contour to that surface. Any screw tip point that barely penetrates the opposite side will be into the cushion HDPE backing which presents no risk of damage. Just don't get carried away and verify the perimeter of the cushion.
Or, you can remove the cushion and double-nut machine bolts from the opposite side that will provide you with a HD non-rotating mounting stud. A few fender and lock washers and they are set.
If up against the hull surface or a console surface with an exposed opposite side then roughen up the interior gelcoat surface with coarse sand paper, clean it up with a bit of paint cleaner, mineral spirits or acetone (easy does it), and glue resin-coated birch mounting blocks to that surface. A good adhesive would be a fiberglass/strand/filler like KittyHair, TigerHair, BondoGlass or comparable product. Note, unlike a pure body filler, these glass strand compounds have serious structural strength. Mix it 50/50 with the polyester resin and you have a permanent bond to that surface that will support weight no matter how choppy the lake is. Splash a little white paint on the blocks just because you are picky.

 

[__ScottyDont]

I mounted to the wall opposite the seat cushion as David is talking about and through bolted by taking the cushions off. Worked perfect

 

[drjames1107]

Mine is a 242LS but I used Ply wood covered with indoor/outdoor carpet. Mounted the amp to the board and used L brackets to mount under helm compartment.

 

[Murf'n'surf]

You can use a West Systems Six10 adhesive and glue 4" x 4" squares of 3/4" plywood to that fiberglass wall. Then screw your starboard amp board to the plywood. Sand the gel before gluing. You might even get awaybwith screwing into that wall if it's thicker than 1/2".

http://www.jamestowndistributors.com/mobileportal/show_product.do?pid=52008&engine=msn&keyword=west_system_six_10

 

[JWPrendergast]

I like David Analogs suggestion. Ill make my way on up to lowes today and get some birch plywood (I saw it up there the other day) and use resin to adhere strips to the fiberglass of the boat. I can then mount a board with the amp attached to it on the strips. Dont think ill bother with carpet as its not visible to almost anyone (ill probably slap some white paint on there, though). Thanks for all you help everyone!

 

[David Analog]

I like David Analogs suggestion. Ill make my way on up to lowes today and get some birch plywood (I saw it up there the other day) and use resin to adhere strips to the fiberglass of the boat. I can then mount a board with the amp attached to it on the strips. Dont think ill bother with carpet as its not visible to almost anyone (ill probably slap some white paint on there, though). Thanks for all you help everyone!

It will take more than resin alone to adhere to the boat fiberglass. But the paint department at Lowes or Home Depot should have every BondoGlass, polyester fiberglass resin, and all else that is needed.
It's worthwhile to put a decent sandpaper or flat file corner and edge radius on everything so that you get a thicker application of resin and/or paint. Resin and paint tend to withdraw and thin on a hard radius.