Solar panel diy oven for laminating EVA and Tedlar

[pa2500]

good work. What kind material is the plastic bag?

I made some tests with a trash bag, but it melts and break with temperature.

Thanks

[wiboater4]

@pa2500 Just some clear plastic sheet I bought at a hardware store. You only need to get up to about 250 degrees farenheit to melt the EVA. The plastic should take that ok. I made a bag by melting the edges of the plastic together with the heat gun and a steel ruler to hold the edge til it melted.

[pa2500]

@wiboater4 Thanks, very useful.

I have a homemade vacum pump, made with a fridge engine. Do you thing that could be enought vacum?

The heat gun can resist 80 minutes working???

[wiboater4]

@pa2500 I think the homemade vacuum pump should work ok. I didn't have any problems with my heat gun, it has two setting s 250 and 500 degrees, I used the 500 degree setting. The heat gun is taking in cool air because it is outside the box except for the very end that is thru the foam board. You need a small hole on the opposite end to let pressure out. have solar panel supported on 2 wood strips above bottom of foam board

[pa2500]

@wiboater4 I did it with a litle box and works!!! The fridge compressor works fine to. 

I made test with a normal glass (not tempered). Could ihave problems with normal glass for the panel (60 x 100 cm)?

[wiboater4]

@pa2500 probably be ok for that small size but tempered would be better. I used old storm door glass.

[pa2500]

@wiboater4 after various tests, finally i did it almost without bubles. But now i've a big problem. All times that i made vacum on cells the cell cracks along tabbing wire conection.

did you had this problem?

[wiboater4]

@pa2500 No I diidtn't, maybe you have to much solder on them, I also put some sheets or blankets in between the plastic and the Tedlar backing to help the airflow on the vacuum. That might help reduce tht pressure on the tabbing wires. I don't had any solder to the cells when I solder tht tabbing wires on. there is a video how I do it.

[pa2500]

@wiboater4 I don't use solder on the tabing wire. I've planified it thinking about this point.

In the back I put a blanket to redistribute the presure.

How much time do you wait heating EVA before aply presure.

Did you made some presure test before vacuum when it's cold? This could be the point when my cells crack.

I allways make a test before, to make me sure that vacuum is efective into the bag.

The cracks almost imperceptible when EVA is melted, but if do in cold i can see it

[wiboater4]

@pa2500 I put vacuum on before I start heating. Maybe just use light vacuum pressure at first then increase after it starts melting.

[pa2500]

@wiboater4 Thanks for all information, this is my first panel.

I had a problem in the last moment and i couldn't complete the cure process in one corner. Is dangerous warn it again to finish the process?

[pa2500]

@wiboater4 plus.google.com/photos/1183622­25082484803045/albums/56973057­43901947713/569787988761939134­6

[wiboater4]

@pa2500 You can reheat it again or just take a heat gun and carefully heat the one area if it isn't to big.

[pa2500]

@wiboater4 is a normal glass, not tempered glass, it crash when aply heat in a zone. I need to heat it into the autoclave. Wath do you think? is dangerous?

[wiboater4]

@pa2500 I reheated mine in the oven after I heated it once with no problems.Is the EVA still translucent in the spot that you misssed? If it is you can reheat it and melt it like the rest.

[jona2279]

nice setup!

how long and at what temperature do you keep your solarpanels in there?

[wiboater4]

@jona2279 I think it was about 2 hours . The temperature went past the maximum of the temp prob I used so I think about 245 to 250 degrees Farenheit . check the other video's it might be on there.

[bazb85]

umm, why vacuum? your blowing in at the same time.. Heat gun inside the box and seal it?

[wiboater4]

@bazb85 The vacuum is on the bag around the solar panel to pull the cells down tight against the glass and the EVA, Tedlar tight to the cells until it all melts together.

[wiboater4]

Thank you

[vichalas]

good job