About to drill through the roof to mount solar panels- tips?

[Sentinelist]

Just that. 🙂 I've got 200W of solar I'm planning on wiring up today.

[sky_free]

silversand wrote:
Sky: it sounds like you have stale product? Virtually all caulking and seam sealant goes bad after some time period on the shelf (1 year; 16 months; etc...). Caulking not sold before expiry date is often shipped back to manufacturer by retailer (or, distributor). However, I have seen (on many occasions) very badly expired caulking on numerous building supply store (and, RV parts store) shelves! Some of it (after I've done a squeeze test on the tube) had turned into nearly cured rubber-like substance.

Sealant is a very tricky thing: always check the expiry date of the caulking (marked on every tube). I never buy sealant of the expiry date is within 6 months of ending.

eg. my Fast-Cure 3M 4200 is still in excellent shape after 3.7 years on the camper exterior. The Pro Flex (Geocel) is in fairly good shape around my TPO roof-line after 9 years, however, I will be replacing the TPO caulking this summer (with Geocel: designed for TPO contact).

Very possible. I didn't know about that and never looked at the expiration date. Good to know -- thanks.

[bigfootford]

I store all my used caulk and glues in the beer fridge in my shop....
Plug the ends with a nail or wooden dowel. The caulk lasts well over a year. CA, white, resin, 2 part epoxy glues for years.

Dicor and Proflex for me.

Jim

[silversand]

Sky: it sounds like you have stale product? Virtually all caulking and seam sealant goes bad after some time period on the shelf (1 year; 16 months; etc...). Caulking not sold before expiry date is often shipped back to manufacturer by retailer (or, distributor). However, I have seen (on many occasions) very badly expired caulking on numerous building supply store (and, RV parts store) shelves! Some of it (after I've done a squeeze test on the tube) had turned into nearly cured rubber-like substance.

Sealant is a very tricky thing: always check the expiry date of the caulking (marked on every tube). I never buy sealant of the expiry date is within 6 months of ending.

eg. my Fast-Cure 3M 4200 is still in excellent shape after 3.7 years on the camper exterior. The Pro Flex (Geocel) is in fairly good shape around my TPO roof-line after 9 years, however, I will be replacing the TPO caulking this summer (with Geocel: designed for TPO contact).

[sky_free]

FYI, I used 3M 5200 as a more permanent seam sealer on my TT based on advice I got here. After a year it had turned yellow, shrunk and peeled, to the point where I just scraped it off (very easily!). Maybe others are having good luck with it, but I didn't. The Dicor on the roof that I used for my solar install was still as good as new.

[Geewizard]

..

[silversand]

This is how my roof penetration looks on the inside of the camper......and I used a mop to put the Dicor on...

:E

Dicor? Or, 3M 5200 ? Is there any cable restraint system?

[Geewizard]

..

[bigfootford]

Tamnative wrote:

mlts22 wrote:
For people who use the fridge vent, would I have to use plenum rated cable because it is being routed what is pretty much a chimney flue?

I used a length of conduit to run my wire,more for the ease of running it than fire though.

You do not run the wires down the flue. The area has room to run the wires down the side of the cavity. Restrain them with cable ties.

I would run each panels individual wires from the panels to the rear of the fridge area. There I would combine the + and - leads, then run larger wire to your solar controller. If anything happens to one panel you can quickly isolate by disconnecting one panel right there in the fridge access area.

My solar install link

A picture from my thread.


There are lot's of great solar install threads that are all linked in the TC university projects etc:

TC university, scroll down to Solar installs

Jim

[Tamnative]

mlts22 wrote:
For people who use the fridge vent, would I have to use plenum rated cable because it is being routed what is pretty much a chimney flue?

I used a length of conduit to run my wire,more for the ease of running it than fire though.

[silversand]

....you should also consider waterproof "through the deck" wire feed-through fittings (used for marine applications, and can also be used in RV applications):

-right angle feed-through compression-ring housings here-->

....explore these solutions. Far better than drilling a hole in the roof and slopping sealant around the raw "edges" with no restraint.

S-

[Ski_Pro_3]

Plenum cable is designed to not put out harmful smoke IF it burns. Seeing as this is in a camper, it probably won't matter as a fire is going to be right there, not 3 or 4 floors away with the smoke moving throughout the building via the ducting.

[mlts22]

For people who use the fridge vent, would I have to use plenum rated cable because it is being routed what is pretty much a chimney flue?

[HMS_Beagle]

Unisolar is no longer in business and there is no warrantee. They are amorphous Si cells and not as efficient in watts/sq ft by about half. They are however, more resistant to shading and lay right on the roof.

My only other comment is not to use Dicor sealant. I personally wouldn't use it for anything on anything. If you want a permanent seal, use 3M 5200 or the Sikaflex equivalent. If you want a bit less bond strength and UV resistance (to keep the sealant from yellowing in the sun) use 3M 4000 UV. Or you could use Dicor, then do it again next year, and again the following year....

[sky_free]

I used the Unisolar 68-watt ones for my TT and they were OK but if I had to put additional panels on my TC I wouldn't get them again. They are really big for the amount of power they produce, and are difficult to handle when you are trying to stick them on. Because they are so big, they were usually partially shaded and that really affects the power output. They have also gotten a lot more expensive in the past 2 years for some reason.