PV Panels to a Wooden Rack... help!

MadJack
MadJack Solar Expert Posts: 47 ✭✭
I want to mount my Kyocera 235's to a wooden rack that is anchored to the ground. (very low wind location)
Panels are 1.75" thick and have mounting holes 11" from the end of each corner.
Does anyone know where I can buy just the 'clips' or other type of attachment?

Thanks...

Comments

  • Dusty
    Dusty Solar Expert Posts: 271 ✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    I bought mid and end clips from the host of this website. They have a chart that tells you which clips to order based on the thickness of your panels.

    http://www.solar-electric.com/twoseunsopam.html


    They worked very well, but I used them with the Iron Ridge rails that I mounted to my wooden uprights.

    Dusty
    MadJack wrote: »
    I want to mount my Kyocera 235's to a wooden rack that is anchored to the ground. (very low wind location)
    Panels are 1.75" thick and have mounting holes 11" from the end of each corner.
    Does anyone know where I can buy just the 'clips' or other type of attachment?

    Thanks...
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: PV Panels to a Wooden Rack... help!

    "Solar Guppy" used gutter clips for mounting his arrays:

    Roof Mounting a SunForce 50044


    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    There is nothing wrong with mounting them with the mounting hole(if they have them), and you might find it easier, since if you use the aluminum angle you can be sure the aluminum frame is off the Lumber.

    Lots of things to be careful about, the new pressure treated wood doesn't play well with metals, so use the least suseptable to oxidizing Stainless steel nuts and bolts, and add a buffer of plastic, or some other material that will be unaffected by the PT salts, I've heard of rubber roof material and tar paper being used.

    This is the way I did mine with some scrap aluminum, and plastic between the aluminum and PT lumber, The outside plastic is getting brittle after 5 years, but between is still pliable;

    Attachment not found.



    Clips are designed so that roof installs can be done from above the panels so ground mounting is easier in that respect.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    A word about wood: maintenance.

    Even pressure treated isn't "set and forget". Depending on what your climate is like it will need to be coated every few years with a good exterior sealant/stain/paint. Really harsh environments (like near salt water) may require frequent attention. Usually you can judge PT's condition by dribbling water on it; if it beads up, it's okay. If it soaks in it needs treatment. There are different grades of PT as well. #3 would be minimal for this sort of thing, and #5 (marine) the best. But good luck finding it. Most yards only carry #3 (ground contact).

    I mention this because if you don't look after it it will in time check, crack, warp, twist ... and take your panels with it when it goes.
  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    Re: PV Panels to a Wooden Rack... help!

    Don't be cheap with your $$$ solar system. Modules are designed to last 25-50 years. The mounting needs to last the same. Call your local aluminum supplier and use 2" x 2" x 3/16" 6061 structural aluminum angle. Predrill it for your module's hole pattern and use 1/4" stainless or duracon bolts with Keps nuts (built in star washer). Don't drill holes in the module frames - it violates the warranty.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Re: PV Panels to a Wooden Rack... help!
    I mention this because if you don't look after it it will in time check, crack, warp, twist ... and take your panels with it when it goes.

    Maintenance is important part of any system or mount, I'm 5years in on mine and don't think I really need to do anything to them at this point (and I do have 1 long span 2x4 that could use replacing as it has warped), but the panels are stress refliefed(relieved?) and not dependent on the frame, and actually only 2 of the 3 have the structures not dependent on the frames) They have survived 60+mph straight line winds. I've lived in much harsher enviroments(Florida coast) and properly done wood is not an issue.

    I'll build a wood structure for my 6KW system this fall, Concrete footers with embeded anchors for a PT wood framework(I'll admit pressure treated is no longer particularly good for earth contact, no asenic and copper) And if your green minded wood does grow 'in' trees.

    FWIW - old pressure treated wood is pretty neat, I was doing a lot cleanup in my camping community, and discovered a piece of wood under some mulched down leaves, as I dug it up I discovered it was a full sheet of pressure treated plywood some of it 3-4 inches underground, I pulled it up and washed it off, and it looked pretty good,.. when I was building my battery box I decided to use the old PT plywood for the floor, last year I dropped a 1100lb battery into the box, and all is still fine. I had put in cross joists at 10" centers, and added some extra supports under them)

    And check your holes present, or install instructions, all my panels larger than 115watts came drilled out for 5/16th bolts or larger.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    I agree with Photowit's recommendations on mounting. Specifically, the clips you were asking about work well for mounting to rails from the top down. Photowit's method is MUCH more reliable. With the clips, if even ONE clips comes loose the rest will follow. Since you may be mounting to wood, over time one or more could loosen and a breeze would take panels off.

    Phil
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    Re the reaction between pressure treated and metal: After I built my last PV rack in 2007, I found the aluminum structure was too flexible, so (stainless) bolted pressure treated to the aluminum to stiffen it up, which it did. After the first year however I noticed corrosion of the aluminum where it was in contact with the PT wood. Cured that by placing a plastic tape between the metal and PT wood, so there is no direct contact, and grease in and around any bolt holes. That ended the problem. BTW, I've never had a warping issue with the PT lumber we get here in Nova Scotia. Thankful for that. My PT deck is now over 20 years old and still as solid as new. My underground root cellar, walled and roofed with PT was built in 1982 and is still good to go, still in constant use, but the PT from back then used different chemicals than is allowed today.
  • MadJack
    MadJack Solar Expert Posts: 47 ✭✭
    Re: PV Panels to a Wooden Rack... help!

    I thank you all for suggestions & comments. I have found a solution that will work and installs simply.

    I cut 1/8" x 1" aluminum flatbar into 1 1/2" pieces, then drilled one 11/64 hole for a coated deck screw, and one 3/8" hole for a stainless bolt. I put the bolt through the flat bar and bolted it to the back of the panel. When I have the panel in place on the rack, I insert the deck screw through the other [smaller] hole into the wooden rack.
    Since the aluminum frame of the pv panel is 1/16" thick, it will fail first.
    And the 3/8" stainless bolt head plus the aluminum keep the panels 3/8" up off the wood. I will try to post pics if i can figure out how...
  • Dill
    Dill Solar Expert Posts: 170 ✭✭
    Re: PV Panels to a Wooden Rack... help!

    any one have any more info on the Solar Guppy method? I found the gutter clips, but the photos in the above referenced post were kind of small and difficult to see.
  • alyaz
    alyaz Solar Expert Posts: 114 ✭✭✭
    Re: PV Panels to a Wooden Rack... help!

    I'm sure there are a million ways to attach panels to PT wood, but fwiw, this is what I ended up doing.

    I used 4x6 PT wood off the edge of my deck to frame up a mount and then lagged the 4x6 PT wood to the deck. From there I mounted the aluminum racks to hold the new 240 watt panels. I used a plastic membrane material between all aluminum and PT wood. I also used plastic washers and plastic inserts so that none of the lags touched the aluminum mounts. I had four aluminum frames welded up that are adjustable and will swing up onto the deck so the panels can be adjusted/cleaned/worked on/ and the area under the panels can be accessed. All the mounting hardware for the panels is stainless.

    So far, so good. :-)
    3.3 kW solar.  3 Midnite Solar controllers; 5 lightening suppressors.  Magnum’s inverter; auto gen start, BMK.  Davidson 2 v FLA’s - 24v bank.  Perkins diesel gen.