What to use to fasten amp board to back/inside of helm area?

[stevenk2]

After running a season on my AR195 with a cheap 4-channel small footprint amp, I'm looking to upgrade to a larger 6-channel one to properly power the Polks and some new tower speakers that I'll be getting. The small 4-channel amp fit perfectly in the shelf area in behind the helm, but the 6-channel amp is going to be quite a bit bigger. For neatness sake and to keep it at least somewhat out of the way in the storage cuddy behind the helm, I was going to mount it on a board, then fasten the board (vertically) to the fiberglass on the backside of the helm (i.e. inside the storage cuddy). However, I don't really like the idea of drilling holes in the fiberglass and bolting it - is there an adhesive or epoxy that I can use that would be strong and durable enough for this? I was originally thinking of just running a bead of Liquid Nails, but I don't know how that stands up to use in the marine environment.

FYI, I'll likely be using plywood painted with marine-grade paint or a piece of resin board to mount the amp on.

 

[white2kstang]

I mounted mine mount board to the front of the compartment behind the bow seat with bolts through the panel from the front. Not sure I'd trust any adhesive with the cost of the amps I mounted and the weight and vibration it's going to need to hold up to. Fiberglass right behind the bow seat is easy to drill through and it's only two screws to pull the seat back on my 2019. Bolts are hidden behind the seat back.

 

[tdonoughue]

I did the same location. But I am not all fancy with the mount boards. I had some rubber spacers lying around (about 1/2" thick), so I used those to create space below the amp and attached it directly to the fiberglass.

Obviously the mount boards are better...

 

[Mike Clark]

I used a sheet of Polyethylene 3/8 thick x 24" x 24" and cut to the size I needed. Got it at McMaster Carr- Water resistant. Part # 8619K434 $ 34.00
If you know the exact size you need, can order smaller and save some money.

 

[stevenk2]

Thanks for all of the info/advice! After doing a bit of mock-up inside the helm cuddy, I found that a 24" x 20" piece of board fits perfectly inside, and there is just enough of a lip on the shelf area of the backside of the helm (about 1.5" - 2") that will allow me to drill through and bolt the upper part of the board to the fiberglass without having to make visible holes on the outside of the helm. Then on the bottom, I'll use a couple of angle brackets to secure it to the floor. Wiring could be fun, given the positioning of my amp and sub, but since I'm extending all of the leads and making a bus bar on the board, I should be able to give enough slack to allow for servicing outside of the helm. Then just re-insert and bolt back down again when I'm all done. Should be pretty clean once complete.

Now the next fun part is getting the wiring done for the tower speakers...……..

 

[tdonoughue]

Gee, I have no idea what you mean... https://jetboaters.net/threads/wiring-the-tower.25955/

 

[Ronnie]

Here is the amp/electronics board I installed recently. 5 bolts hold it in place. Three go through the board, fiberglass shelf wall and into a 2”x4”. The other 2 go directly into the fiberglass under the shelf. Nothing protrudes into the cockpit.
I still have to clean up the wiring.

The board is 1/2” plywood that I sealed by painting it. The four amps power 11 speakers soon to be 13. I used 0 gauge wire from the battery compartment to the board, an led / speaker signal splitter and 5 distribution blocks (2 fused) are also mounted to the board.
Also attached is a pic of what’s going on in the battery compartment right now. Again I still need to clean up the wiring.

 

[tdonoughue]

That's a lot of work! Looking good. I'm going to need to do this someday; it looks so neat and clean. Question: did you consider a cutting board (or more expensive starboard) for the base rather than the plywood? What made you select the plywood?

 

[Ronnie]

@tdonoughue , thank you. “A lot of work” is an understatement, if I tried to count up the hours I’ve spent in this so far I may may cry myself into a depression but the installation and clean up should be complete soon so I can move on to the next set of modifications and repairs. I chose plywood because I could get it and more of it if necessary easily (I live about a mile from a Lowe’s and Home Depot stores) and it’s relatively inexpensive (I went for the sanded precut 4’x4’ size) for $25ish. I also used it for the same purpose several times in the past.

FYI I considered relocating it to the wall that makes up the back of the starboard bow seat, the compartment under the copilot’s seat and either the forward or aft wall of the head compartment but kept it here because it’s off the ground (less likely to get wet) and for the most part nobody goes into the helm compartment but me, so the amps shouldn’t get banged up nor the wires tangled up by people trying to store or retrieve things.

 

[stevenk2]

Very nice, Ronnie - that's pretty much exactly what I had in mind and what I'm doing with mine (though I'll only have one 6-channel amp powering the 4 stock Polk DB speakers + 2 new tower speakers). The premise is the same though - make a central location behind the helm to keep the wiring all together and accessible, while at the same time keeping the wiring neat and organized. I'm going to try to keep the wiring lugs on the amp and sub accessible, but with the orientation of the units on the board, there's really no way to get around one side of them facing away from the compartment door, so I'll likely have to wire things up first, then slide the board into place and bolt it down. I'll leave service loops on all of the wiring so that I have the length I need to get the board in and out without tugging on any wires or having to perform any acrobatics to undo stuff. Ideally, it should just be 4 bolts/screws to unfasten the board, then just slide it out for servicing.

 

[stevenk2]

Gee, I have no idea what you mean... https://jetboaters.net/threads/wiring-the-tower.25955/

Yeah, not really looking forward to that, though I do have the newer powder-coated tower, so hopefully it's a bit easier.

 

[tdonoughue]

Actually, so far, @stevenk2 , it is not as bad as I thought. Knock on wood... Made pretty good progress through the hard part. Now I just have to finish the easy part...

 

[stevenk2]

Finished up this weekend - turned out pretty good, both from the mounting/wiring standpoint as well as the sound quality. Had to really work on fishing a pull string down through the tower - that was a real joy. There's just enough of a lip there coming out on the underside of the tower to make things difficult using fish tape, but once I got it past that and had the pull string through, the rest was a cinch after that. The board is secured to the lip on the back of the helm with bolts and large flat washers, and I used a single wide L-bracket in the center of the board to secure the bottom to the floor - it's not going anyplace.

Biggest concern now is if heat dissipation will be an issue during the summer months. I did a burn-in over the weekend at moderate volume levels for a couple of hours with the cuddy door closed, and the amp was only slightly warm to the touch. Ambient temps were in the mid-70's though - obviously it'll be a bit warmer out on the water this summer. I'll just have to keep a close eye on things and pay attention to see if it starts cutting out as we heat up in June/July/August.

 

[4x15mph]

I mounted mine mount board to the front of the compartment behind the bow seat with bolts through the panel from the front. Not sure I'd trust any adhesive with the cost of the amps I mounted and the weight and vibration it's going to need to hold up to. Fiberglass right behind the bow seat is easy to drill through and it's only two screws to pull the seat back on my 2019. Bolts are hidden behind the seat back.

Is this the STBD/Helm compartment or the Port side?

 

[stevenk2]

Is this the STBD/Helm compartment or the Port side?

Sorry, should have been a little more clear on that. This is on the starboard side, behind where all of the electronics are in the helm. It was just easier to do it there, and honestly, with the vertical mount I went with, it doesn't really eat up that much space in there either. The most I had to do is to relocate the fire extinguisher.

 

[white2kstang]

Is this the STBD/Helm compartment or the Port side?

Starboard on mine.

 

[anmut]

My installer put it on the port side. Mounted two JL amps up behind the port bow seat backrest would be.

 

[Ronnie]

The general recommendations I’ve seen state to mount amps as close to the battery (ies) as possible. Of course I did the exact opposite but I didn’t have to buy and run a lot of long rca cables as a result. The alternative would have had me run short positive and negative leads and four pairs of rca cables from the amps to the head unit as well as a long remote lead to turn the amps on.

 

[Julian]

I recall seeing on of these boards being put in with a long piano hinge so they can easily swing it out to access the amps.....looked very clever.

https://jetboaters.net/threads/amp-panel-redesign-adding-hinges-swivel-questions.21630/

 

[stevenk2]

I recall seeing on of these boards being put in with a long piano hinge so they can easily swing it out to access the amps.....looked very clever.

https://jetboaters.net/threads/amp-panel-redesign-adding-hinges-swivel-questions.21630/

That's awesome - I hadn't really thought about doing something like that. It would definitely make accessing/adjusting things easier, the main limiting factor being the cuddy doorway of course. Still, easier than having to unbolt everything and sliding the entire mounting board out.

Maybe I'll redo mine like that when it comes time for version 2.0?