Mounting solar arrays to the roof of a Bigfoot

[HMS_Beagle]

I mounted two 100W Renogy arrays to the top of my Bigfoot 10.4E. A Bigfoot is pretty watertight other than all the holes the factory seems to think is necessary in the roof, I did not want to contribute more. So I used these glue on mounts. I was pleasantly surprised when I received them as they are a heavy ABS molding, the thinnest section is probably 3/8" thick. They are available in "corner" and "side" styles, and can be glued or screwed to the roof. These in the picture have been cut down a bit as I will explain:



I laid them out on the roof and had to use a mix of the corner and side pieces, first because things were in the way, and second because the roof of a Bigfoot is crowned. The mounts are made assuming a flat mounting surface, if the roof is crowned it angles them relative to the flat solar panels. So I got them into position, shined them to mate with the solar panels, then scored them to the roof:



Next I built a simple fixture and milled the to the scored lines. It helps to have a Deckel CNC mill with the universal table that swivels and tilts in both directions! This would not be necessary for a flat roof:



Each one was masked off in preparation for bonding. Their directions suggest Sikaflex or similar, I used 3M 5200 which has a higher claimed bond strength. I lightly sanded the roof and cleaned it with acetone and the ABS mount with mineral spirits (acetone will eat them):



A liberal application of 5200, then dropped in place with solar panels on top to insure everything is aligned. I cleaned the excess sealant and as soon as I could (about 20 minutes) I peeled the tape to leave the edges clean, but left the panels in place until the sealant gelled.



The Fast 5200 takes about 24 hours to really cure (the slow version can take 5 days or more), so I waited until the next day to drill holes through the mounts into the panel frames. Zero holes in the roof. Will they come off? I don't think so, but I will take a look from time to time. The corner pieces nicely guard the corners from branches etc., the whole installation is nestled between the other roof penetrations and is hardly visible from the ground:

[Victory402]

Great install! Love those Renogy panels too.

[wintersun]

If the panels are wired in parallel the effect of any shading will at most reduce their output by 20% and then only during the early hours of the day during the winter months. Having a larger panel in place will more than compensate in actual use.

[Camper_Jeff___K]

A nice clean install for sure. My only question is, are you getting any shadow problems from your vent covers shadowing the panels. Probably not when the covers are down but when up if you are parked the wrong way, I imagine you get shadows on the panels shutting them down for the most part.

[bigfootford]

HMS Beagle wrote:
An update: now driven a few hundred freeway miles, panels appear to be staying put without problems. 200 watts seems to be plenty - even after the heater is run a bit overnight, if it is sunny, by 10 AM all is charged full again. I have actually unhooked the charge cable from the truck (another story) and don't seem to have to worry about power in the camper at all! One of the more worthwhile mods for your camper....

Those extra watts of panels will be nice when the weather is overcast and harvest is way down and you still recover ah used!

I removed the fuse for the charge line in my truck instead of disconnecting the charge wire from the truck's charge system. Easy to put it back in if needed.

Jim

[HMS_Beagle]

An update: now driven a few hundred freeway miles, panels appear to be staying put without problems. 200 watts seems to be plenty - even after the heater is run a bit overnight, if it is sunny, by 10 AM all is charged full again. I have actually unhooked the charge cable from the truck (another story) and don't seem to have to worry about power in the camper at all! One of the more worthwhile mods for your camper....

[HMS_Beagle]

Yep! Already love it. Getting easily 10 amps charge on a normal sunny day. Even though I improved the charging circuit from the truck, recharging lead acids 100% takes time, since the acceptance rate drops dramatically as they approach full. This is less of a problem with flooded cells as they aren't real picky about being fully recharged, but AGMs seem to need full recharges periodically or they die prematurely. We found that even if we drove 2 or 3 hours each day, it was not enough to fully recharge the house batteries. We might be down 50 amp hours overnight (the heater is the biggest user) and would only regain 30 or so. Solar - provided you don't park in the shade - is relentless, charging most of the day, parked or driving. I also don't have to think about plugging in periodically when the camper is sitting at home. Actually I don't have to think about power much at all now.

[bigfootford]

Nice.... Going to love that solar!

Jim

[msiminoff]

Beautiful installation. Thanks for sharing!
-Mark

[pugslyyy]

Nice. I'm still getting used to how good the adhesives have become these days. I'm so used to screwing/bolting stuff down.

[Sentinelist]

Very nice product, install, and that Deckel! Thanks for sharing and the heads up on this in my thread.

[HMS_Beagle]

Thanks. The mounts are surprisingly inexpensive, $24 for a set of 4 corner pieces, $15 for a pair of side pieces, free shipping. When you see the picture you think they are a thin plastic molding like you are so used to getting, but they are a very substantial piece of plastic. They have a recess in the base but are otherwise solid. I have milled the base down on this one, they start out about 3/8 thick:

[Golden_HVAC]

Great work.

I used 6" long pieces of aluminum angle from Home Depot, probably much less expensive.

Fred.