Power to truck bed - criticize my plan

Alloy

Well-known member
Thank you everyone for your detailed input! I have a couple more 101 type questions.

1. What material would you recommend I mount the engine bay components (relay, circuit breaker) on? I'm a woodworker but don't imagine plywood is a good choice. Metal or anything conductive seems like a bad idea. I could just grab a random piece of stiff household plastic, but I have no idea how melty it might be.
2. Anything to look out for in wire loom selection? I don't think it needs to be weatherproof.
Plywood works doesn't cost much easy to work with can be painted or use clear urethane.
Another option is polyethylene marine board (Starboard or Seaboard) but the thickness should be upgraded 1/8"-1/4 i.e. 1/2" plywood = 3/4" marine board.

I hate loom. Preffer the nylon wire wrap.


1580343014402.png

Sometimes (rarley) I use a short section of loom for chafe protection but most of the time I'll split a pcs of rubber hose.

Amperage of the wire is reduced when bundling wires together.
 
Last edited:

VanWaLife

Active member
I've mounted circuit breakers, etc. directly to dry areas of inner fender / firewall without any trouble. Always a good idea to use terminal covers. One school of thought is that if you have a wire come loose you want it to ground out and blow a fuse or breaker as opposed to having it flop around hot for you to find next time you're fumbling around without enough light. If you do want a piece of plastic I'd just peruse the electrical aisle of Home Depot and look for a pvc box cover or something similar. I think those should withstand ambient engine bay temps if you avoid exhaust and other hotspots. The higher quality split looms (i.e. marine) have better heat / flame resistance than your basic auto parts store stuff, but the auto parts store stuff is way cheaper and has worked just fine for me.

When mounting stuff in areas of the engine bay that see a little moisture, I typically cut some standoffs from metal tubing to keep the components dry. I have found Rivnuts (EG astro brand on Amazon) to save a lot of time when mounting little electrical bits and pieces assuming there's enough room to get the tool in to set the Rivnut.
IMG_2062.JPGIMG_2061.JPG
 

shade

Well-known member
1. I like 1/4" polycarbonate. It can be drilled, sawed, sanded, etc. It can also be heated and formed, if needed.

2. Take your pick on wire loom, but a good source for marine grade wire is: http://www.genuinedealz.com/marine-wire
They'll also make up custom cables.

Take time to read that Marine How To link I posted earlier on Marine Wire Termination, and poke around the rest of Rod Collins' site. RC goes into great detail in his articles, and you'll likely learn things you didn't even know you should know. The modular crimper he sells is quite nice, and his recommendations on quality terminals is worth heeding. I splurged for an FTZ heavy cable crimper, Rod's crimper, and FTZ terminals.
 

shade

Well-known member
I stopped using polycarbonate because it crazes and solvent/stress cracks.
Yes, if it's exposed to chemicals that induce such things, such as tapping fluid. Many years of UV exposure will also degrade it, like most plastics. If the OP is using it for guards on an outdoor milling center for several years, it may not be the best material.

That seems unlikely, though.
 

Alloy

Well-known member
Yes, if it's exposed to chemicals that induce such things, such as tapping fluid. Many years of UV exposure will also degrade it, like most plastics. If the OP is using it for guards on an outdoor milling center for several years, it may not be the best material.

That seems unlikely, though.

I used polycarbonate for years in temp from 15F to 90F. Lost count of the pcs that stress cracked around mounting holes. Clamping not bolting solved the breaking but all showed yellowing/crazing. I may still have some bronze "UV stable" polycarbonate that was in the sun for 5 years. I'll try to post a picture of it.
 

shade

Well-known member
I used polycarbonate for years in temp from 15F to 90F. Lost count of the pcs that stress cracked around mounting holes. Clamping not bolting solved the breaking but all showed yellowing/crazing. I may still have some bronze "UV stable" polycarbonate that was in the sun for 5 years. I'll try to post a picture of it.
I've seen plenty of UV damaged polycarbonate sheet. I already said that UV light degrades it, just like most plastics. Unless the OP drives around without a hood on their truck, I doubt that'll be a concern.

If the stress cracking you saw was on polycarbonate that was yellowing or crazing, something was attacking it (UV and/or chemicals). In that state, PC becomes brittle over time, so it's no surprise you'd see failures. Again, unlikely the OP will install it in that kind of environment.
 

Alloy

Well-known member
I've seen plenty of UV damaged polycarbonate sheet. I already said that UV light degrades it, just like most plastics. Unless the OP drives around without a hood on their truck, I doubt that'll be a concern.

If the stress cracking you saw was on polycarbonate that was yellowing or crazing, something was attacking it (UV and/or chemicals). In that state, PC becomes brittle over time, so it's no surprise you'd see failures. Again, unlikely the OP will install it in that kind of environment.

All cracking was inside a building or outside but none was in a heated space. One example is a set of 1/4" door panels that were drilled and tapped to mount the hinges. Within a year the PC cracked from the 50% of the holes. The repair was done with 1/4" PC but this time with nuts and bolts and holes drilled 3-4 sizes over. PC lasted 4-5 years but still cracked. I replaced with 1/4" Starboard (only one available at the time) and were 7-8 years old when I last looked at them which was 5-6 years ago.

Yes if inside out of the sun there will be no crazing. The only thing the OP has to worry about is hot/cold cracking and impact when cold....none of which is an issue for Seaboard / Starboard:)
 
Last edited:

Forum statistics

Threads
185,529
Messages
2,875,555
Members
224,922
Latest member
Randy Towles
Top