Insulation and wire question

[Tripmaker]

Yes an insulation question in the electrical section. Is it ok, safe, or generally a bad idea to use spray foam around wiring? Will the foam react with the rubber on the wiring and possibly cause a short? I'm using 12 gauge so hopefully overheating should not be an issue. Lights are all LED so minimal draw and a fantastic fan.

I am insulating 1 1/2 walls with EPS and routing for wires where I can. But there are some areas that unavoidably have gaps in the insulation, around boxes 12V and AC, and wiring junctions with tap splices etc. What are your thoughts?

[lrrowe]

I recall reading warnings about the potential of EPS foam reacting with the insulation on wires. Whether it is true or not, I do not know. Anyway, I covered all my 12V wires that are exposed to EPS foam with duct tape. Was this needed or will it work if needed, I do not know, but I feel better anyway.

[H.A.]

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[Tripmaker]

Thanks guys. Yes I meant plastic or whatever common wiring is covered with. I too recall reading somewhere, I believe on this forum, that spray foam should not be used around wiring, but I don't recall the reasoning. I would do a test with the foam and wire but once you start a can you have to continue or the tube plugs up. Maybe someone who has done it will chime in. If not the duct tape idea is not bad.

[bobhenry]

I have ran upon a similar problem and am in hopes someone has had so experience with the drop tail utility trailers.

I am tired of knocking off the fender mounted lights that are set so low the catch anything and everything.

I just purchased a rather tired and rusty but very solid little 4 x 8 flat bed utility trailer ( for $200.00 ) with the air gate
for the gal pals ZTR lawn mower.

I am hoping to mount the lights on the underside of the air gate. This puts the lights at a bit closer to eye level and may
make the trailer tail lights more noticeable.



I see three problems

1. Protecting the wire while getting it over the vertical square tube that supports the expanded metal.

2. the hinge point from under the trailer bed to up the drop tail.

3. mounting the lights in some manner that will not have bolts sticking thru the expanded metal and
thus pointing upward when the ramp is dropped.

I am sure the wire can be routed thru some EMT or PVC piping to protect it on the drop gate. And even
when dropped the lights are held up high enough to be protected from the ground. Seems my biggest concern would be having the
tail of the trailer come into contact with something like a curb that may slice the wires. It is like I need a solid tube fitting that
is hinged or can articulate at least 90 degrees.

Any Ideas ?

[capnTelescope]

Maybe something like this?

Route the tail light wiring, however it works, thru hard conduit to the hinge point (green circle). Then convolute tubing from the frame to the tailgate. then hard conduit from there to the lights.

Copper wire doesn't like being flexed a lot. In the day, I had to repair many a minivan power side door with broken wires. Unless the GP is running a *really* busy mowing service this should last indefinitely, barring injury to the wiring. After all, how often does one load up their riding mower for transport? (rhetorical question)

"Hard conduit" is defined as whatever you got. I would guess an articulated fitting would be hard to find and expensive.

As for mounting the lights, mount them on a wood block that you could screw into from the inside side of the gate?

$0.02, please.

[Tripmaker]

Would it be easier to mount the lights on PVC poles on either side, similar to what some boat trailers have?

[bobhenry]

The trailer is a true flat bed ! Pool table flat !

No fenders to wreck on, no side rails to ram the deck into, and I wanted to keep it that way so adding " goal posts " is not in the plan.

I took some time at lunch and went to the plumbing shop for some ideas. When I told the clerk I was looking for a fitting that would swing 90 degrees I knew immediately I had lost him. So I asked to brows a bit. It took about 3 minutes and I fell on the answer. If you take a threaded male 90 degree elbow with a glue in female pvc on the other end, you can now take a threaded coupling and install the two threaded elbows into the coupling . You now have a "u" shaped fitting. By NOT tightening, the assembly will rotate 90 degrees on the threads. One fitting facing forward to accept the pvc tube that protects the wiring from the coupler and the fitting is allowed to extend just beyond the drop down gate and will be either pointed up when at rest or will rotate on the threads rearward when the gate is in the load position. I am now able to glue in stubs forward to the tongue and upward to the light housings. I may need to heat and custom bend the straight legs a bit to form them close to the tail to keep them out of harms way. Zip ties in the expanded metal and u clamps under the bed should keep all the pvc tubing secure.
Large washers thru the top of the expanded metal when in the load position would allow screws to be placed into wood blocking that has been mounted to the light housings. If cut to the correct size they may even be able to be inserted into a larger carlon type electrical box again mounted on what would be the rear of the air gate. All painted to match It should blend well with the gate proper.

[MtnDon]

Regarding foam insulation and electric wiring. One thought is that if a wire run is fully encapsulated in foam the wire may run warmer whan run at or near the rated maximum amps.

[noseoil]

Bob, what about a tubing bender spring (3/8") or a screen door spring for the movement part?

[Tripmaker]

Don, At this point I am wired, insulated, and skinned in AL. I'm not too concerned about over heating though as I ran 12G wire and have used all LED lighting. The biggest load is the fantastic fan and that is on its own circuit. So far everything seems to be fine. Thanks for your thoughts.

[bobhenry]

Bob, what about a tubing bender spring (3/8") or a screen door spring for the movement part?

Screen door spring

What a totally excellent idea ! tough enough to take a direct impact and ultra flexible.

MAN WHAT A GREAT IDEA !

[Dale M.]

You are over thinking all this... Years ago I had a trailer that was a dedicated "buggy" hauler with two individual ramps... simply put a length of conduit from hinge point to lamps to thread wire through to secure/protect wire (not enclosing whole wire route in conduit).. At hinge I just let wire flex (large "U" shape put horizontally) at hinge point in all the years I towed it never failed.... For lamps I used carriage bolt (cut to length) with head of bolt on top side (tire side) of ramp...

Dale