Re: A couple questions about solar Reply #25 – September 06, 2017, 01:04:23 pm If gluing with 5200 should the gel coat be sanded down to fiberglass for the best bond? Quote Selected
Re: A couple questions about solar Reply #26 – September 06, 2017, 01:30:13 pm Quote from: wa_desert_rat – November 07, 2015, 05:22:03 pm each panel has 4 stand-off mounts and they are about 1.5 sq CraigI attached these to standard door hinges and used 3M 5200 to the roof of my class B over a year ago. I modified the hinges so I can remove the pins to ficilitate tilting the panel(altho I have yet to do so...)I have since read that 5200 does not like UV but good so far.Jim Quote Selected
Re: A couple questions about solar Reply #27 – September 06, 2017, 01:53:22 pm Ken, I actually scrubbed with acetone and a scotch brite pad first to make sure any organic stuff (oil, wax etc) was gone and then cleaned with denatured alcohol. Thanks for reminding me of the denatured bit. I have no idea what the difference between that and isopropyl alcohol is. The 3M cleaner / bond enhancer was the last step.Opinions follow... A 1.5" square mounting tab is 2.25 sq in x 91 psi tensile strength for the 3M VHB tape is 204 pounds of holding per corner under perfect conditions. That might be OK for small panels but with any reasonable safety margin not enough for bigger panls. My 300 watt panels are 39x77. I used 2"x12" brackets, one per corner. I would not use 3M 5200 to bond the brackets to the roof by itself. Maybe with screws. It is tough and allows for some misalignment with the roof curve but this is not quite what it was intended for. Seal around the edges of the brackets to keep water and air from getting under them with 3M 4000UV. Some use Dicor. I am partial to the 3M stuff. Quote Selected 1 Likes
Topic: A couple questions about solar