Well, that took about five days.

[Volvo farmer]

I had a feeling this would happen. We had a considerable amount of rain yesterday. These have only been out in the weather since Monday. I guess I'll open this one up with some vents at the top and bottom and see if it clears up.

Bummer.

[willib]

those are some nice cells , were they ebay ?

[stephent]

Yeah--bummer. Looks like a leak somewhere for that much H2O.

What kind of silicone sealant did you use to do it with to start with?

That stuff releases a bit of water to start with curing and then it's not really waterproof afterwards. It passes a bit of water naturally. (teensy bit).

Might want to look at a butyl rubber type--but watch getting it close to the copper or silicon devices, I wouldn't or don't know exactly if it's "compatable" with those.

Some basic type silicone sealants are rather nasty put close or confined with electronics--the acetic acid part released when curing.

Also silicone's cure in water vapor or even plain old touch it type water.

If the stuff smells like vinegar when curing--tain't good for electronic stuff.

There are low/no acetic acid type sealing compounds around that will keep out water and not mess up electronic stuff, but then again you need a "sunlight' resistance in it too.

Might be a bit pricey to find just the right thing--but then again you have a sizable investment in just PV's to protect.

[Ungrounded Lightning Rod]

I'd also consider caulking from yachting supply stores such as West Marine.

Formulas are proprietary but they're really good at keeping water out under tough conditions - like the mounting hardware for the rigging, cleats, and such.  Lots of force, flex, temperature extremes, and water exposure, both fresh and salt.

[Volvo farmer]

Yeah, Evergreen surplus from cusdn. The price now is twice what I paid for them a year ago, and I'm sorta wishing I had used the money for commercial panels at the time.

[Volvo farmer]

These were sealed up by a commercial glass shop. It's not silicone, it's some sort of black butyl that's heated and shot into the void. I think the problem is where the wires come out, the glass guy was worried about that as well.

[Volvo farmer]

I might consider that, but I'm going to try venting it first. Got to at least get the water out before I try resealing it.

[stephent]

Well, those folks should know how to seal windows alright.

That butyl stuff is probably the best choice for what you are doing.

A bit of ventilation and a day or so sun on them and it should be mostly gone.

If the rain quits that is.

Just watch mixing another type sealant with the existing butyl stuff....sometimes it makes the original stuff disintegrate close to the new/different stuff.

[inode buddha]

The butyl rubber stuff is commonly available as a ribbon or strip about 1/2 inch diameter and 15 feet long, sold as a windshield sealer/gasket at auto supply stores. Less than 20 bucks.

[luckeydog]

I had the same problem as you have. I did solve this by drilling two small holes on opposite sides of the aluminium frame. then I inserted small 1/4" tubes. It took about a week or so to get all the moisture out wile it baked in the sun but it did work. I have not had any more problems since i did this. If you choose to do this make sure the tubes are positioned one high and one low. I live in a dry climate here in Colorado so i don't know if this will work in areas where the humidity is high. the way i look at it you have nothing to loose. there is one other guy that put mineral oil in his panel and says he has had no ill affects. I don't know what effect this would have on the cells, I was too chicken to try it.

the Panel looks good

Luckeydog

[Stonebrain]

Lucky dog said the essential,

One thing,leave it vented,but take care rain can't come in.

condensation is because moist can't get out.

Even if a tiny bit of moist get in for mysterious

reasons this is not a problem if it can get out.

cheers,

stonebrain

[amiklic1]

Well, I',m realy sorry for what happened to you. But, it's not uncommn, even if the glueing job is done by profesionals, as in your case. You can take a look into my revious posts, where I described the same problems with some of panels I manufacture. As you used hot butyl glue, I doubt that's the problem. To give you some good advice, I would like to know the thickness and width of that butyl on the edges. My panels were built with just a few mm width, and that caused the problems.

Drilling holes is OK, but it would lead to cell and interconnections rust in a eriod of time.

I think you shoud go with bus bar to get out of a panel, instead of the wire. There is allways an air between the wire and it's insulaton.

At the end, I think you have the problems with the moisture contained in the air that's inside the panels. You can solve that b using some inet gas inside (very easy and cheap to apply, just go to some welding guy and ask him to apply some gs to the hoes you made prior of it. Be carreful with gas characteristics- I use Argon, it's heavier that air, so I apply it to the bottom hole, and also got the above one to let the air let out. For 0.3 m3 of air inside I apply 5m3 of gas, just to be sure). Other way is to use silica in aluminium bars used in windows production, but that way you have to go at least 6mm wide between the front glass and back plate.

Anyway, it's best to go with gas, apply plenty of it and then silicone seal the holes.

I wish you all the best with that.

[Volvo farmer]

These were made using a perforated aluminum spacer between the glass panels, the same thing used in almost all double pane windows. The aluminum tube is filled with a dessicant to absorb any moisture that might be trapped between the panes. Then this heated butyl is shot around the outsde edges of the aluminum. I suppose it's quite thin between that aluminum and the glass. but there's also some on the outside edge.

As you can see, there's definitely a weak spot where the wire goes in. I've got two of these that need to be repaired since I broke the front sheet of glass on them. So if you'd give me a detailed way on how to seal them up next time, including the construction of bus bars, and materials used, I'd greatly appreciate it.  

[amiklic1]

Hello!

I supposed that you were using perforated aluminium bar with dessicant. We were using that, too, but here is how it's done right now, and it works just perfect:

I use two kinds of interconnection material. For interconnection of the cells I use thin ones, wide around 2.5mm, and for interconnection of the rows and to get out of the panel I use wide ones, much thicker, around 7mm wide.

The butyl rubber is the one commonly used in windows production, double-adhesive one. I just use it to glue the 3x3mm rubber to the glass, and than I put bus bas between the butyl rubber and 3x3 rubber. After that, I put silicone (Sika Tack Drive) between the front and the back glass, to the top. I use 3x3mm rubber just as a spacer. In that rubber I drill two holes (2-3 mm) and apply the gas thrru one of them (lower ones when panel is standing upright) The upper one is just to let the air get out.

You can test the panels so that you heat them with something (or put them directly on the sunlight in summer) and after a while throw alot of cold water. Just like the beer in the summer, moisture allways appears on the hotter side (inside of the panel). The difference in the temperatures is very important.

I hope you could follow that. Glad to help if possible. Maybe I can give some detail pictures, but I'm away from home for two weeks.

Regards.

[tecker]

I guess you 've mulled the options over pretty well by now . I use desicant in my test box with just a surface seal . I looks like you could  cut the jacket with a small knife , pull it out (the jacket)then you could put desicant around the hole and heat it up . When it's hot and you think it's dry put dry argon in from the top .

[tecker]

Most hobby shops sell small brass tube .

[whalechris]

Hi All

Pics here are of panels I bought earlier this year. They were described as "new but damaged" although mounting holes in frames on some had been used. I got 8 panels of 175W, 185W or 200W panels and all had broken glass, mainly crazed but some impact damage.

I purchased them from a guy in Germany who had a stack of them in his lock up (possibly from a factory auction???). He spoke little English but was happy to let me test them before purchase and he did not seem to know much about them. They gave good power and still do, although probably down a little on actual rating, due to crazing and the extra, non specialist glass. I don't know exact figures as I'm waiting on a regulator and meter to start using them properly but they bought a set of 2V forklift truck cells up to excited mode before I had to disconnect them.

I first looked into a plastic sheeting to get a seal over the crazy paving but got very mixed info from manufacturers on how long their products would last, from a UV point of view. Plastic was more expensive than the glass too and by the time I got round to the job, I had moved abroad to where no plastic is available. I fixed a plate of new 4mm glass over each panel. The first one I tried, I used no more nails type stuff to bond the glass to the ali frame (I had some free and it is reasonably flexible) and glazers cheap glass silicone sealant to seal around the outside. I laid panel down on flat surface and ran a bead of each around cleaned aluminium frame, before laying glass on top.

Pic shows No More Nails, silicon and then black adhesive beads

Glass did not touch all of bead without pressure and I did not want it to set with a tension in the joint. So once dry I put extra black car windscreen/windshield  adhesive into gap around outer silicon bead. For the other panels I just used the windscreen adhesive and they have been fine. When just using windscreen adhesive method used was to lay panel on flat surface, put 2 small cork spacers on each edge and lay glass on. Then inject adhesive in gap and when partially set, take spacers out and fill spacer gaps so there is continuous bead around. The exact sealant used is Sikaflex 255-C Primerless Windscreen Adhesive. 2 to 2.5 panels per tube of silicon, with thick bead. Panels are about 1x1.25m in size.

The panels have been outside in sun and rain (a lot of latter this summer) for about 10 weeks now and they are fine with no leaks or condensation. The bonding job was done inside the house but our local atmosphere is quite humid but no problems so far. I am still a little worried that there may be long term greenhouse effect (air heating inside, between panel and glass, not CO2 in the Earth's atmosphere, although that itself is still a bit of a nag!!) from the glass as there is a gap between it and the crazed original glass, of about 2 to 4 mm but so far so good. Two things to note are the glass makes the panels pretty heavy but less that 4mm would not be strong enough. Secondly is that the panel/glass set up does not have enough strength to allow you to pick up panel at a corner. Frame twists and glass will crack (been there, done that, got the T-shirt) so be careful and lift whole edge evenly to keep panel square at all times.

This shows nice wide bead of windscreen adhesive with good adhesion

1330W of rated panels has so far cost about £1150 (1660EURO, 2150USD) to buy, transport, repair and fit so not too bad. It's my first RE project to reach fruition and will power an environmental education and research centre being built here in sunny Horta, Azores 38N, 28W. Greetings from the mid Atlantic.

Any thoughts always welcome.

Cheers

Chris  

[ghurd]

The cells look like Matrix / Photowatt.

What brand is on the panels and were the made in France?

G-

[whalechris]

They say Total Energie on the back so probably. Chris

[Jeff7]

How hot does it get nowadays where you live?

Have a look at the top of them when they are warmest, and again when they're cool. I'm just curious as to how much flexing the front glass pane experiences. On my little markII prototype panel I used polycarbonate on the front, and aluminum on the back. The polycarbonate bows out quite a bit when it gets hot.

I kept getting condensation inside, so I resorted to using about a half tube of Goop, combined with some GE brand Silicone II chaulk. They are both pretty flexible, and both claim to stick well to both metal and polycarbonate.

The panel is back home, I'm at college, so I've just e-mailed a request home to find out how my panel is doing.

The challenge with these homemade panels is considerable - they will need to experience changes in temperature which will go from shrinking everything, to expanding everything again. This will also bring immense changes in pressure within the sealed panel. It'll be trying to suck the seals in during winter, and blow them out in summer. Some day, probably after 2009 when I hope to graduate, I hope to buy a professional solar panel. Maybe then I can get an idea of how they go about sealing them up.

[Volvo farmer]

It's been in the 70's lately. The vents cleared all the condensation out. I'm going to leave it that way for the time being and see what happens.

I hear what you're saying about pressure differences. We often have a daily temperature swing on the order of 40F. None of the other three have moisture in them yet but I sealed up where the wires go in with silicone after the first one failed. In this climate, it might be OK just to leave them vented.

Commecial panels have no air between the front and back. I got one for free that was shot with a bullet and the glass shattered but stayed glued to the cells and the backing piece. I don't know what the magic glue is but it seems rather flexible, like silicone.

[truman]

now this might be off the wall but could you not just expose a contact for each wire so they are permanently sealed in then you would just have to hook up to the contact just a thought.

[Eurapart]

I live in a very hot and humid place. It's either raining hard or sweltering heat. How can I go about addressing these problems? Abrupt changes in weather, temperature, air pressure? Any tips? I am a beginner/amateur at this. And most of the time, my sealants crack.

[Volvo farmer]

I haven't posted an update. I did put very small vents in the top and bottom of this panel and the moisture cleared right up and hasn't returned. Another one of the panels was showing small signs of moisture but it isn't too bad yet. The other two appear to be holding the water out. My climate is normally pretty dry, but it does appear that heat helps drive the moisture out. Hope this helps...