Epoxy for encapsulating cells (great DIY thread with photos!)

[DeltaFox 25]

I'll show you a place where the sylgard is $36.87 a peace but you have to buy three of them if you go here.:Superior Essex. and go to the onling shopping then look for DC-184-1.1 Three of them comes out to $125.44
I do know how exspensive everthing gets. Here in my town I had trouble to get the lumber companeys to cut a size that I wanted for my first panel . I got so tirer of this I went out and bought a table saw to do it myself.
It seams tha everthing cost me extra because where I'm at .( Cheyenne , Wyoming) There more into wind generaters here.

[PaulOtt]

DeltaFox 25, hey and thanks for the reply. Yeah, I'm certain the Sylgard is fantastic stuff, but my biggest problem is the price. The main reason I'm doing a solar panel myself rather than buying one already made is to save money, and it's hard to justify spending $50-$60 on the encapsulant in addition to the other supplies (glass, caulk, etc). At this point I'm almost wishing I had bought these panels instead.

Sure, there is some satisfaction in doing it myself, but honestly I don't care to pay much extra for that. That's why I was wondering how scheek's encapsulant was doing.

[DeltaFox 25]

PaulOtt, Sylgard is made for PV use. It doesn't harden like a brick. It's made with heat and expansion in mind. I have three panels outside now with sylgard on them and it's been through -21 below zero and wind and it's still holding up real good. When I put it on it was average warm and it started setting up just shortly after I got done with it. It feels like a rubbery surface.
Look around on the INTERNET to see if you can find it there cheaper.

[PaulOtt]

scheek, the epoxy you use for the back of your solar panels, how much does it harden? I'm looking for something cheaper than the Sylgard, but want to make sure the stuff they use for roads won't cause problems when the solar cells heat up and cool down. If the epoxy isn't flexible enough, or expands and contracts too differently in relation to the solar cells, I'm worried it might cause it to crack or something along those lines. Thoughts?

[DeltaFox 25]

That was for a pint of the stuff. I get 3 sylgerds for 115.00

[scheek]

If I could find a way to ship I would sell you some. Let me look around at Walmart for a container of some sort.

What you are looking at for 175 is way to much material and cost.

[DeltaFox 25]

I was looking on the internet and found some RTV and it said it was 183.00 per LBS. Could you tell us did you have to buy a large amount at first.?
I found a place that has it for $175.00. I might buy it for my next one.

[Vern2]

Video on encapsulation. (If you can stand the music.) http://www.youtube.com/watch?v=3tLiYNmemQ4

Vern

[scheek]

Actually the coverage is very smooth and thin. I was very pleased with the finish. My cost was less than $5.00. I guess the pic was deceiving. I used less than a 1/2 size-small styrofoam coffee cup. What's that? 4oz.

I was afraid to do both sides. Keep us posted on your results.

[hjcg2001]

NO covered on front. Have only tested them outside twice. Did Great. I would say with the epoxy I used a small styrofoam coffee cup would be plenty to do a 36 cell panel.

I saw your pictures, and the encapsulant look bulky, have you tried to apply just a thin layer of epoxy?? that way you can save a lot of money. I was reading a book that i found in internet, the guy of the book was using a GE silicone but i guess they are similar.This guy says this on his book....

------------------------------------------------------------------------
GE RTV 615 optically clear silicone is used to coat the top of the cells. For this particular panel with 3x6 cells we used 6.7 grams of part A and .67 grams of part B. The silicone is cut with Xylene for ease of application. An extremely thin coating is all that is needed. You can use from about 33 1/3 % to 20% silicone.
-------------------------------------------------------------------------


The idea is to cover the front and the back of the cell that would make our panel to be protected from moisture and all that stuff.


I dont know what you guys think about?

[DeltaFox 25]

Do you have any pictures that you can show us. I just finished my 4th panel all 36 cells the next one is going to be 72 cells. I used sylgerd to coat them and It seems to, be holding yo real good.

[scheek]

NO covered on front. Have only tested them outside twice. Did Great. I would say with the epoxy I used a small styrofoam coffee cup would be plenty to do a 36 cell panel.

[hjcg2001]

Not sure about your question. Do what? Build frame or the use of epoxy?

How should we match the Thermal Expansion Coefficient?

scheek how are your panels doing???

How many bottles of epoxy did you use for your 36cell panel. Also another question the cells are not covered on the front right?

[scheek]

Not sure about your question. Do what? Build frame or the use of epoxy?

[hjcg2001]

For long term use, to prevent thermal stress, you need to match "Thermal Expansion Coefficient" for both the silicon cells, and the potting compound. Otherwise, a few months of hot/cold - day/night cycles will crack the cells. Like the way a bi-metal thermostat works, a thermostat bends, but PV cells don't like to bend.

So how should we do that? Im starting on this and i have read a lot.
The most complicated part is to do long lasting diy panels.

Thanks in advance for your advice.