SuperStrut Gold-Galvanized Solar Panel Mount Question

[rs14smith]

Hi all,

I've seen a few people use gold-galvanized superstrut (http://www.lowes.com/pd_20281-53911-...ductId=3128119) to make a simple solar panel mount, and I would like to use a similar design. However, I will need to cut my superstrut since the pieces are extremely long when you buy them from the store. My question is, after I cut it, do I need to spray anything on the sprayed end to prevent any corrosion/rust from occurring? And if so, what do you recommend?

[solarix]

You'll probably be fine doing that, but personally, I don't use anything but aluminum and stainless steel for solar mounting. Solar panels last 40 to 50 years - why mount them with something that is inherently subject to corrosion? Look in the yellow pages and call up your regional aluminum supplier for some 2x2x1/8" angle aluminum. Use IronRidge integrated grounding clamps to fasten the solar panels. Simple, inexpensive, lasts forever.

[russ]

You'll probably be fine doing that, but personally, I don't use anything but aluminum and stainless steel for solar mounting. Solar panels last 40 to 50 years - why mount them with something that is inherently subject to corrosion? Look in the yellow pages and call up your regional aluminum supplier for some 2x2x1/8" angle aluminum. Use IronRidge integrated grounding clamps to fasten the solar panels. Simple, inexpensive, lasts forever.

Makes better sense to do as you say - spend a few more bucks up front and get the return in years to come.

[peakbagger]

I used superstrut for a couple of arrays. I am not aware of any gold colored cold galvanizing compound for touch up. I would not use superstrut in a high corrosion area like the coast. Even in a low corrosion area you should isolate the aluminum panel frames from the superstrut. If you have building inspector that reads the code he may require an professional to sign off on the racking design. In that case, buy a racking system from a racking manufacturer. A general hint is that standard unistrut is limited on span, double or triple height will take lot longer distributed load but that is not available at Lowes or Home Depot and has to bought from an electrical supply house.

[russ]

I used superstrut for a couple of arrays. I am not aware of any gold colored cold galvanizing compound for touch up. I would not use superstrut in a high corrosion area like the coast. Even in a low corrosion area you should isolate the aluminum panel frames from the superstrut. If you have building inspector that reads the code he may require an professional to sign off on the racking design. In that case, buy a racking system from a racking manufacturer. A general hint is that standard unistrut is limited on span, double or triple height will take lot longer distributed load but that is not available at Lowes or Home Depot and has to bought from an electrical supply house.

I have yet to se a cold galvanizing material that was actually any good - other than to the manufacturer.

[peakbagger]

I used to work at an industrial facility with a very aggressive atmosphere. I used Tnemec products and there zinc primer was great stuff. http://www.tnemec.com/product/#findProducts. Unfortunately its gray. As long as the cut is fresh and oil wasn't used to cut it, the Tnemec zinc will hold quite well. The reality is that galvanized will self heal so that end cuts wont progress for a long time in a low corrosion atmosphere. When I lived near the coast, cuts needed to be touched up but up in the mountains, I don't bother.

The hassle with Tnemec products is they have to be bought from distributors and I think the smallest container is a gallon. If the steel is prepped properly (SP6) which few homeowners can accomplish, the primer will last for years.

[russ]

If the steel is prepped properly (SP6) which few homeowners can accomplish, the primer will last for years.

You might go into what SP6 is.

The problem with touch up is that it is usually near impossible to do proper and necessary surface preparation.

[rs14smith]

Thanks for the update guys. What's usually the best place to buy affordable (not extremely expensive) railing mounts for your solar panels?

Thanks

[peakbagger]

I tried to post a link earlier on SP6. SP6 is near white metal sandblasting. The surface texture obtained is very rough and paint bonds to it tenaciously. Inevitably when perfectly coated steel is installed in a factory there is rework and touch up required during the installation. Generally the best surface finish obtainable in the field is SP 3 which is power tool cleaned, basically grind it down to bare metal and apply a primer and top coat. I worked at the same plant long enough that I got to see how painting systems lasted. The gold standard was a catalyzed polyurethane topcoat with a zinc rich primer with contrasting colors between the primer and the top coat. If they missed a spot with the top coat it was quite obvious. Epoxy was great stuff indoors but it chalked up outdoors. After 10 years or so the touch up work would usually be quite obvious. A lot of industrial environments use galvanized steel these days but they also loose a lot when cut in the field.

Catalyzed poly is usually real toxic to mix and apply and once it sets, its impossible to clean. Epoxy is a bit more forgiving but still once its sets, its note coming off.

I got a gallon of the zinc rich epoxy and used it on pickup truck I had, I wire brushed and then sanded it before applying. It stuck quite well but was rough and lasted longer than the truck did.

[russ]

Thanks