Installing accessories over engine bay insulation

May 6, 2010
472
1984 Oday 39 79 Milwaukee
First boat with insulation in the engine bay. Fuel filter, fuel pump and other miscellaneous items are mounted to the sides, through bolted to the aft cabins. I need to reconfigure the arrangement and add a few items - mostly buss bars - but don't want the aft cabins to look like swiss cheese. I'm thinking about making a plywood mounting board (sealed and painted) and using some of the existing holes to attach it with stand-offs so it doesn't squish the insulation, then I can get everything off the insulation and onto the board. Any issues with this idea, or any better suggestions?

Thanks,
Scott
 
May 6, 2010
472
1984 Oday 39 79 Milwaukee
Scott. Check out this. I looked at it and it is in my product list when I insulate my engine room and do the electrical refit.
http://www.weldmountsystem.com/
I've seen those, but I've seen some reports of them not always holding and since I will have fuel and electrical stuff on the mounting board I don't want to take any chances. I'd also have to cut through the insulation to install them. I'd prefer something where I can use some of the existing bolt holes to attach a new mounting platform.
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Some pictures would help for informed recommendations.
 
May 6, 2010
472
1984 Oday 39 79 Milwaukee
Some pictures would help for informed recommendations.
Not sure this will help, but this is the area where I want to re-arrange the existing items and secure the new items. Also pictured is the backside of the engine bay/aft cabin bulkhead with all of the fasteners. I'm not crazy about how everything mounted to the bulkhead compresses the insulation, so I'm wondering if it is feasible to fasten another plywood panel using some of the existing fastener holes, and using stand-offs so that the insulation isn't compressed. Then all the items that need mounting could be screwed directly to the plywood panel instead of the bulkhead.
 

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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
I wouldn't worry too much about compressing some insulation. That insulation is for sound deadening, not for heat protection.

I would be concerned about the AC outlet in a metal box and I would be concerned about the type of wiring you plan to install in the engine compartment. The heat in the engine compartment will increase the resistance of any wiring runs that go through the compartment. Increased resistance leads to voltage drop, so wires and cables will have to be sized to compensate.
 
Oct 6, 2007
1,023
Hunter H30 1982 Chicago IL
I’ve had success with cutting small wood mounting blocks into the insulation where I need them and sealing them with Mylar tape. That way the accessories are mounted over solid blocking and don’t crush the insulation.

If you create a mounting board in front of the insulation, you minimize the locations where the insulation is either crushed or interrupted, but you will have placed a noise reflecting surface in front of your otherwise sound absorbing insulation, which defeats part of it’s purpose. You will also effectively reduce the size of you engine compartment where every inch counts.

Bus bars in the engine compartment? Not sure what is going on there, and I am no electrician, but I think of bus bars as something that belongs in a reliably dry location behind an electrical panel or at least behind a cover of some sort.
 

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May 6, 2010
472
1984 Oday 39 79 Milwaukee
I wouldn't worry too much about compressing some insulation. That insulation is for sound deadening, not for heat protection.

I would be concerned about the AC outlet in a metal box and I would be concerned about the type of wiring you plan to install in the engine compartment. The heat in the engine compartment will increase the resistance of any wiring runs that go through the compartment. Increased resistance leads to voltage drop, so wires and cables will have to be sized to compensate.
I'm making my way through the wiring updates, installed a new charger, new batteries, battery switch, ACR, service disconnect, replaced the trailer connectors, removed about 500 feet of abandoned and improper wiring. Still have a few things to address as you noted however :) All of the wiring in the engine bay is sized at or above Blue Sea Systems recommendations for use and location.
 
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May 6, 2010
472
1984 Oday 39 79 Milwaukee
@LeslieTroyer shamed me into buying a Racor 500MA to replace the 500FG that is there currently. Fortunately I was able to find an uninstalled used one for less than the cost of adding a bowl to mine :)
 
Nov 6, 2017
76
Catalina 30 5611 Stratford, Ct
I would compress the insulation behind some sort of spacer and I would be sure to seal the area of compression to insure that in the event that some kind of failure, say a fuel leak would not get behind the insulation.