Advice on attaching big solar panel

Discussion in 'Tech/Mech General' started by treeman, Aug 24, 2012.

  1. treeman

    treeman Read Only Funster

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    Wondering if anyone has some good advice on attaching a large solar panel. I've read through the hints and tips and looked at other articles on here but my installation has a few differences.
    My van roof is very old, over 26 years old, and has crazing of the roof skin appearing. It is still 100% water tight I'd like to keep it that way so I'm a bit nervous about drilling too many holes through it. Also it's all nicely lined inside and hate the thought of how to get access from inside.
    Also the panel is rather large, about 1.5m x 1m and over 17kg so wondering if that weight might cause an issue?
    Currently have it sat on the roof rack but that has got to go as adds too much height and is cracked in places.
    I'm happy to install like Techno100's good article, but will Sikaflex 512 bond well enough to a rough'ish old roof and how many brackets do you think I might need? 6 per panel?
    [​IMG]

    Old roof - showing it's age...

    [​IMG]
     
    Last edited: Aug 24, 2012
  2. vwalan

    vwalan Funster

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    give the roof a good rub down think i might just stic the panels down with 3 inch aluminium angle might put a few rivets through if i could . i would use peeling rivets as they expand the grip area . far better than normal pop rivetts . i would possibly do it like my trailer . by using the aluminium across the front and back it stops branches hooking under the panels . mine have been like is for about 9 yrs now . i have added another three a couple of foot behind those three .no probs so far.


    bet jj knows where these were taken .hee hee.
     

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    Last edited: Aug 24, 2012
  3. Reallyretired

    Reallyretired Funster

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    Your roof appears to not have a lot of flat areas big enough for your panels. If you do fit it directly to the roof it looks like the mounting brackets will have to be at the sides, even though as stated earlier there are advantages in mounting at the front and back. To give yourself the biggest sticking area I suggest you have brackets the full length of the panel. Sikaflex should be quite adequate to mount as long as you clean the crud off the roof first, its what most installers use, often using quite small brackets, its strong stuff.:thumb:
     
  4. treeman

    treeman Read Only Funster

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    Yes, at least 2 gulleys span the panel width and the roof side-to-side is slightly curved so side mounting it is. I agree that a long bracket is best with as much clean contact surface as possible to the roof. I'm going to order some ali angle and Sikaflex and go for it I think!
     
  5. Johno

    Johno Read Only Funster

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    I have used Sikaflex with complete success on several occaisions on glassfibre roofs, but a thought has just occurred to me ( a rare event these days) that when sticking to a metal roof the Sikaflex is only sticking to the layer of paintwork on the roof so the strength of adhesion will be dependant on the adhesion of the paint to the metal of the roof.
    My thinking may completely wrong:Doh: but I would only be happy if the paint was removed to expose bare metal to stick the brackets onto rather than relying on the paint to take the strain.:Smile:

    John.
     
  6. treeman

    treeman Read Only Funster

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    Fair point, luckily my roof is all fibreglass so I'm thinking a good rub down on the stick-to areas to get a good key for the Sikaflex to bond to and off I go.
     
  7. Johno

    Johno Read Only Funster

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    A solar panel fixing kit by Sikaflex is available which contains a suitable cleaner and primer for fibreglass plus the adhesive it's a bit expensive at around £36 but it does ensure good adhesion I got mine on line from "Clever Solar" who sell a lot of good quality solar products but again fairly expensive probably as they seem to be mainly of German origin:Smile: rather than Chinese.:Sad:

    John.
     
  8. treeman

    treeman Read Only Funster

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    Had another thought - was pondering the worth of making the brackets so that you could lift up one side of the panel to angle towards the sunlight. When I experimented with a free standing panel I was surprised how much extra power the panel produced at 45' angle compared to flat. Was thinking primarily for when we go skiiing in the winter when the sun is low and also want the snow to slide off easier.
    On the down side an angled panel looses the sun earlier than a flat panel so not sure if it's worth the effort (and the fact it's a 215w panel so on a normal day it produces fair amount of energy already)

    Any thoughts or experiences of angled panels and installation difficulties?
     
  9. Reallyretired

    Reallyretired Funster

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    I suppose the disadvantages are that you have to park the right way round with regard to the sun, and you have to make sure you don't drive off with it up. I would go for the convenience of the 'fix and forget' rather than trying to squeeze out the last amp. In practice solar power is always 'famine or feast' with a large excess in the summer and b^gg$r all in the winter.
     
  10. vwalan

    vwalan Funster

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    hi if you look back at the pics i put up. my mate as his fixed on the roof hatches of his ex prison cell truck. he can lift either side if he requires to slope some . luckily they donr seem to shade the other side . you cant beat lots of panels .
    you can go on and on trying to get more power but in the end another couple of panels is nice and easy.
     
  11. treeman

    treeman Read Only Funster

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    That picture was what made me think about it.

    I think I'll go for the "fix and forget" route as often over-complicating makes things worse in my experience!
     
  12. motorhomelover

    motorhomelover

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    brackets /drill fix / seal with lap seal

    why take risks of blowing a full panel for the sake of a proper fix
    sticaflex may be good but not as good as a full proper fix and seal job

    belt n brasses springs to mind for good reason
    any glue can and will fail a good old through fixing is there for life :thumb:

    sorry for the double entry LOL
     
    Last edited: Aug 27, 2012
  13. motorhomelover

    motorhomelover

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    brackets /drill fix / seal with lap seal

    why take risks of blowing a full panel for the sake of a proper fix
    sticaflex may be good but not as good as a full proper fix and seal job

    belt n brasses springs to mind for good reason
    any glue can and will fail a good old through fixing is there for life :thumb:
     
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