Solar, Yakima box, rack scoured off by microburst!

[Makalu1]

A powerful microburst hit our van just south of Wendover Nevada Saturday and removed a heavy 300W solar panel, a full Yakima rocket box and almost all of the rack. We were driving slowly and the wind hit from the right side. We heard what sounded like a bang but didn't see or feel anything else in the midst of the storm. After driving out the other end we stopped to see what the bang was about and saw an empty roof.

The force of the wind seems to have simply ripped most of the small bolts and washers right out of the fiberglass roof and lifted the entire package up and off. Fortunately, it also seems to have happened very cleanly, almost surgically, leaving very little damage to the fiberglass top other than a bit of ragged fiberglass (and what looks like thin wood sandwiched in between) right around the bolt holes.

For a 2001 the top looks in good condition with just a few minor spidery hairline cracks in the unpainted gelcoat surface.

So, now that I've got a nice clean surface , I'm thinking putting on a Raptor or other lining. From everything I've read on here that's a good idea. I'd really prefer to give this job to a pro, so if anyone's got any recommendations for a shop in the Salt Lake City area please let me know!

Any suggestions on a good material to use to temporarily fill the holes in the roof where the rack bolts ripped out? Obviously waterproof but easy to remove when the roof gets prepped for Raptor lining.

Also, looking at how the Yakima rack was attached it's only got 4 or 5 small bolts about a foot apart holding it onto the outer edge of the roof just outside the canvas attachment (thank heaven not inside!). It doesn't appear that there was ever any additional reinforcement for the bolts. I suppose this might have been a good thing in that it allowed for a cleaner "removal" by the wind, but it also seems absurdly flimsy. Any thoughts on using a thin strip of something to hold all this together a little better, or just leave well enough along?

Thanks for your input!

Scott Madsen, Salt Lake City

[boywonder]

wow.......................!!!!!!!!


If it's for a couple weeks until raptor liner I'd just use duct tape....or the real duct tape that's aluminum...to cover over your holes.

[BroncoHauler]

Dang, are you sure you weren't in Kansas with Auntie Em and Uncle Henry?

Herb

[Makalu1]

Boywonder, that's simple and clean, good idea. Hoping I can get the rest taken care of pretty quickly. Meantime I'm sure going to miss that solar power and fridge!

[Scalf77]

I believe SMB puts the screws in every other mounting hole on the tracks, so I would use every possible mounting hole. Also, the washers supplied with the tracks may be great if installed on a metal roof. I swapped out for larger fender washers.



-greg

[Twoxentrix]

Yeh, that's unfortunate. Looking at you pic's, I'll point out the area where the bolts pulled through the fiberglass top look like they were previously covered with dirt buildup (look at the tear & chipped fiberglass around the hole), suggesting you may have already had the front bolts pull through prior to this incident

[posplayr]

This picture shows quite clearly that the bolts are easily pulling through. If you double-bolt with a say a 6" square x 1/8" thick aluminum plate it would be acting like a super washer adding a significant increase to the overall strength.

https://www.sportsmobileforum.com/fo...rst-28864.html

Adding some fiberglass to the bottom surface to thicken it by about 1/4" will help distribute the load if it doesn't bond really well but could be messy. However, given the size of the holes, you are probably looking at some type of fiberglass repair regardless.

I might be tempted to sand the bottom and layup the 1/4" fiberglass over a say a 6-9" square area and then loosely bolt in the 6" square aluminum plate from below (enough to squeeze out the majority of the resin). This actually makes the FG stronger as there is an optimum ratio between resin and FG. Too dry it will be weak, too wet and it is also weak.

Of course you would pre-drill all this and you would have to work through wet fiberglass with an awl to get the bolts through. Use some 2" painter tape to tape off the whole perimeter to avoid dripping.

You can also tape off the roof so as to avoid having to do any final sanding there as well.


If you did not need any fiberglass work then I would make a 6" square pad out of soft ABS to soften the point forces on the FG from the aluminum
m plate.
You can do this top and bottom and use some of the 3M sealer.

https://www.ebay.com/itm/20276094877...QaAg_dEALw_wcB

https://www.amazon.com/3M-Marine-Adh...15134227&psc=1


Basically, if you make a sandwich out of it you can spread the load out over a much wider area and fill the fiberglass hole inside of the sandwich.

Something else that I have done for mounting my 350W solar panel is to use a 1/2" thick ABS-like this:

https://www.ebay.com/itm/35344210416...MAAOSwH1FgaGiJ

You now have enough material so that you can create a pocket around the bolt holes that you will with sealer and it creates a substantial waterproof seal where there are any perferations.

[Makalu1]

Am I correct in assuming that the other 10 or so prominent bolts on the roof are where the roof is attached to the penthouse frame? If so, and nothing is leaking right now, I may elect to cover those with Raptor or other liner. Looking at the roof more closely I may need a little more fiberglass repair work than I thought. Blah.

[unreng]

posplayr has the same idea...

Another option instead of fender washers is to buy some flat stainless or aluminum sheet and make your own washer.
If you had 2-inch x 2-inch sheet or 3-inch x 3-inch sheet at 1/8-inch thick or 3/16-inch thick, that's a much larger area to spread a load. or whatever size rectangle works best for the design.

This sheet on ebay can be cut to create four 3-inch x 3-inch "washers" and they're in salt lake = https://www.ebay.com/itm/23253557036...YAAOSwBiRZcNJw

FYI - recommend reviewing this thread for replacing the SMB attaching hardware = https://www.sportsmobileforum.com/fo...p-6987-22.html

or this one = https://www.sportsmobileforum.com/fo...se-9109-3.html

[posplayr]

Originally Posted by unreng

posplayr has the same idea...

I just have to cringe when people use double-sided tape and claim " I have not had any problems and been holding for 2 years"

Any body with any familiarity with residential solar panel-loading calculations knows that "uplift" is the biggest load. Depending upon what your local area and code require you could be looking at requiring hold-down strength to sustain 120-160 mph winds.

In a very benign example, say you are driving 70 mph and you have a "micro burst" of another 70 mph. So you are going from 70 mph to 70+70=140 mph.

The wind speed is now doubled and the power is now 8X. Now you could argue that it is only pressure-related which is only a 4X increase in force over the 70 mph forces.

Add on a rack-mounted solar that is spaced with plenty of room to allow wind underneath it and you have a very high potential hazard.


I attached pictures of my mounts that are using threadserts in the roof, but I was able to use different rights of the ABS to account for the curvature of the roof along with use the cavities to ensure a water-tight seal using the 3M sealer.

These are standard Renogy Z mounts. Notice how low they would be without my spacers t account for roof curvature.

My roof is now coated with an elastomeric coating which is very common in AZ so the combination of while 3M sealer and elastomeric just kind of blen in.

The ABS is nice t have on my metal roof, but on fiberglass, it is well-advised to avoid stress risers that can just cut the fiberglass. You might even consider rounding the edges of the ABS that go directly against the FB.


I can't actually remember right now because it is so long ago, but I bought a new Toyota pickup and a Snugtop rear cover back in 1987. I mounted board racks and I was real leery of drilling holes into what seemed like a semi-hollow shell. I may or may not have added an extra layer of fiber glass to the inside. i know I would have put something to cushion both outside (rack mount) and inside (oversized plate). You don't want metal right against the fiberglass.