diy solar

diy solar

zinc vs stainless vs galvanized vs aluminum hardware.

I think I read from Unistrut catalog that zinc electroplated "pre galvanized" could hold up outdoors 5 years, vs. hot-dipped galvanized 20 years.

Some of my hardware is just welded 1/4" plain steel. It has a nice brown patina.
My ground mount array is mostly 2" galvanized conduit, galvanized or aluminum brackets, aluminum rails, stainless hardware.
Stainless hardware on clear anodized aluminum I was able to unbolt 18 years later. I think the mill finish too.
Mild San Jose environment, away from the coast, 10 miles from the Bay, not in the fog.
It all depends on the fittings and quality of them and the environment… I learned many lessons on my sailboat boat for 10 years poking around the south coast and Caribbean… I bought 250 ft of 3/8 inch , Hot dipped, Triple B , chain, 42 years ago for anchor chain…for my sail boat …( it wain’t cheap back then at all) .I still have half of it outside in my truck and yard and shed….I sailed with it for ten years …
and have drug everything I have owned since then around at some point, over every surface imaginable with it and it is still perfect… no rust, no enlongation or deformation. , no nothing… it will be here long after I’m gone for sure…
I hope the next owner pays it the respect it’s due..It’s old school stuff.
BUT, in the eighty’s most all of this was made here in the US… . Nowdays I would say who knows what stuff will do… let the buyer beware…
buy as good as you can…..it’s a new world with different ways, new expectations .
J.
 
I have a ground mount array on unistrut and used the standard zinc green box hardware from Lowe’s and it’s been through one season and there’s zero rust streaks so far. Lowe’s also has hot dipped galvanized but I hate working with it.
I have tried many type fasteners and hinges and etc and have had similar results from lowes and the next batch much different results…PUZZLING….. I no longe live on a boat so all of those worry’s have changed… but it seems the consistency of what one buys nowdays is all over the place at times…
Some one said here the other day that everyone needs to find a decent ships chandlery in person or online to deal with when they are trying to find certain type gear… That’s true…

I just know when I want to try for long term use on anything I try to use the proper grade stainless for that application….on that project.
It’s not always possible due to price or availability or they don’t even make that piece in SS. ???
Its just the only path I know to a “ set and forget it” type results .
if I knew of somthing better I would use that…
Good luck on your array, I’m working on my new one now…
thanks , Jim.
 
Keep in mind that most stainless fasteners have much less strength than a common zinc plated bolt. Using stainless can sometimes be self defeating because you have greatly distanced the metal nobility difference and one will loose. There are several grades of stainless sometimes the weakest in strength has the best corrosion resistants for the metal metal you are fastening it to. If you are by the coast and get salt air, things can be worse. Just can’t recall anyone using stainless on strut. Things I’ve learned about strut. The longer the diagonal brace(corner to corner)the less of them you need. Short corner braces are worthless. Get a metal cutting Circular saw with a Diablo metal blade. Fun and fast but use a face shield. After knocking down the sharp edges you should paint it with the paint below. You can’t hardly tell what end you painted! The plan was to give the bolts a good soaking with it once I seen a smattering of rust but that day isn’t here. Go with 1/2-13 bolts and washer for max long term strength. Adamax strut (Lowe’s) is as good as Uinistrut and has the same hole spacing, dimensions and strength. Sometimes can’t tell unless you look for the mark. Have fun, be careful.
 

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Avoid these nuts. I find the crimp to retain spring damages threads, bolt has to be forced in, galling so it can't be removed.
Have to chase 100% of them with tap before they are usable.

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I also haven't been able to use galvanized bolts in channel nuts, at least lately. Maybe if they come from channel vendor, not random Lowes stock?

Channel vendors do carry stainless channels and hardware, also aluminum channels, but higher priced and not so readily available.

Corner brackets? I suppose can be useful; I diagonal brace my structures.
 
"Cold dipped" a.k.a. zinc-rich paint, vs electroplated (which I think has been referred to as pre-galvanized?)



The paint seems to be an option for welded joints, etc.; those areas are wider than just a scratch (which can be spanned by a water droplet), would rust with atmospheric moisture exposure.
 
Again, just go online and buy stainless steel screws, nuts, bolts, washers. That's it.

Forget electroplate, forget hot dipped, definitely forget aluminum, and titanium is for spaceships. Unless you're on a boat or a plane, any grade of SS will be way more than adequate for what you're doing. (Don't be tempted to use split lockwashers; They're garbage and a myth)

PS- I've always liked McMaster-Carr for their online selection and ease of shopping. Buy extras and keep them for backup. When you're mid-project, and you dig through your own spares bin of nuts and bolts, and you find just what you need without placing an order, it's like Christmas times a thousand.
 
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Again, just go online and buy stainless steel screws, nuts, bolts, washers. That's it.

Forget electroplate, forget hot dipped, definitely forget aluminum, and titanium is for spaceships. Unless you're on a boat or a plane, any grade of SS will be way more than adequate for what you're doing. (Don't be tempted to use split lockwashers; They're garbage and a myth)

PS- I've always liked McMaster-Carr for their online selection and ease of shopping. Buy extras and keep them for backup. When you're mid-project, and you dig through your own spares bin of nuts and bolts, and you find just what you need without placing an order, it's like Christmas times a thousand.
Absolutely .. .buy good , buy once , do it right..move on …?…

I will be probably clobbered for saying that,

BUT, I have installed and worked on and used literally many hundreds of SS fitting , parts and fasteners in my life , mostly in a marine environment…I have never had ,or seen ,even one failure with any of it ,unless it was subjected to an “ unfair load ,stresses or condition” ..
But truthfull that was in a time before the importation of so many foreign parts …late 70s and the eighties..TILL about early 90s.

im sure there has been some , but it’s a rare event unless your doing somthing wrong or using poor quality parts…
I do not know if the same conditions would exist today…
Theres not much I know for sure about anything today…
ya just buy the best ya can.

JIM.
 
Absolutely .. .buy good , buy once , do it right..move on …?…

I will be probably clobbered for saying that,

BUT, I have installed and worked on and used literally many hundreds of SS fitting , parts and fasteners in my life , mostly in a marine environment…I have never had ,or seen ,even one failure with any of it ,unless it was subjected to an “ unfair load ,stresses or condition” ..
But truthfull that was in a time before the importation of so many foreign parts …late 70s and the eighties..TILL about early 90s.

im sure there has been some , but it’s a rare event unless your doing somthing wrong or using poor quality parts…
I do not know if the same conditions would exist today…
Theres not much I know for sure about anything today…
ya just buy the best ya can.

JIM.
I have removed a lot of solar racking over the years. Often I come across SS bolts which are really difficult to remove. Not sure if it has anything to do with the aluminum racking reacting with the SS. They seem to have a salty looking substance on the threads. Not sure if this is what's called galling or what but many times it's so bad that I end up snapping the bolts to get them off.
 
I have removed a lot of solar racking over the years. Often I come across SS bolts which are really difficult to remove. Not sure if it has anything to do with the aluminum racking reacting with the SS. They seem to have a salty looking substance on the threads. Not sure if this is what's called galling or what but many times it's so bad that I end up snapping the bolts to get them off.
That is the corrosion poweder of the aluminum being destroyed but the dis similar metals .that happens all the time on aluminum masts and the SS screws holding on the fittings and spars.
basically the bolts freeze.
Steel lug nuts up here in the snow areas do the same when put into aluminum wheels …sometimes the will break off or have to cut off the car with act/ Oxi torch…
I have always used a thing layer of silicon between the SS and aluminum and it stops the corrosion and allows disassembly even years later….
there is many ways to successfully mount the parts , that’s just one.
 
That is the corrosion poweder of the aluminum being destroyed but the dis similar metals .that happens all the time on aluminum masts and the SS screws holding on the fittings and spars.
basically the bolts freeze.
Steel lug nuts up here in the snow areas do the same when put into aluminum wheels …sometimes the will break off or have to cut off the car with act/ Oxi torch…
I have always used a thing layer of silicon between the SS and aluminum and it stops the corrosion and allows disassembly even years later….
there is many ways to successfully mount the parts , that’s just one.
Good to know. I have my trusty cannister of NOALOX special ID. Great stuff.
 
Avoid these nuts. I find the crimp to retain spring damages threads, bolt has to be forced in, galling so it can't be removed.
Have to chase 100% of them with tap before they are usable.

Right now I love these things ... I have to cut half the spring so it is only about 1" long but I put all the bolts / washers / etc on the panel plus these nuts before mounting so I get several good threads going on my screws.

This lets me lift up the whole panel and index these nuts into the frame then I slide the panel into position where I need it. Doing it from the end is easiest as you don't have to worry about alignment but I think I can do it "on the face" as well if I orient the nuts ahead of time. (we will see)
 
They may be fine for smaller threads. It is 1/2-13 where crimp is too close to threads.

I also have trouble sliding them in channels with slotted back, spring snagging on slots.
There are other designs with plastic retainers. But mostly I use plain ones.

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I did mount a couple panels on channel with nuts, a small ground mount to power fans.
They are zinc plated, think I used stainless bolts through holes in PV panel frames. Wish they were available in aluminum.
Maybe this won't rust up solid like if both mild steel.
I think some sort of grease would be good. For the most part my yard equipment I'm able to disassemble.
 
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