[RE-wrenches] module frame separation

[Joel Davidson]

Brian,

I was general manager of 2 solar factories. There is lots of literature 
about EVA and moisture. For example 
http://www.nrel.gov/docs/fy02osti/30841.pdf

I am sure moisture (H2O) can enter laminates from the edge. EVA does not 
protect the cells from moisture. EVA provides a path for moisture to wick 
into glass and non-glass laminates.

Frameless laminates are laminated the same way as framed modules. The 
laminate seal and the distance that moisture must travel from the edge of 
the laminate to the cell, grid, and interconnects are the only protection 
from moisture. Most manufacturers use a gasket held in place by the frame to 
protect and seal the laminate edge.

Dow 739 and other room temperature vulcanizing (RTV) silicone elastomers are 
good for edge-sealing laminates and fastening and sealing junction boxes.

Joel Davidson

----- Original Message ----- 
From: "Brian Teitelbaum" <bteitelbaum at aeesolar.com>
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Sent: Wednesday, June 24, 2009 5:42 PM
Subject: Re: [RE-wrenches] module frame separation


> Joel,
>
> Are you sure that water can enter the laminate from the edge? My 
> understanding is that the aluminum frame is only needed for structural 
> support, and that the laminate itself is sealed at the edge. I'd like to 
> know if I'm wrong. Maybe a module manu rep can chime in.
>
> How are frame-less laminates edge sealed in any way different than a 
> framed module?
>
> I know that in years past, when we had long and skinny modules, it was not 
> uncommon for installers to remove the bottom part of the frame in order to 
> allow better snow and dirt shedding (although I certainly wouldn't suggest 
> that with today's large glass).
>
> On the silicone sealant: Best to use one that does not outgas acetic acid. 
> Dow 739 is one type, but there are others. These sealants are 100% 
> silicone, and are hydroscopic, in that they draw water out of the air for 
> the curing process, instead of the more usual silicone caulks that cure in 
> a chemical process that outgases acetic acid as a byproduct. It's really 
> nice stuff to work with, since it doesn't have that harsh smell, and is 
> really easy on the skin (mine anyway).
>
> I don't know if acetic acid will damage any of the modern encapsulates, 
> but I used to keep a tube of 739 in my toolbox to seal damaged back skins, 
> and seal module's JB's. I do know that acetic acid can damage metallic 
> parts, including cell metallization and internal JB metal parts.
>
> Brian Teitelbaum
> AEE Solar
>
>
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org 
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Joel 
> Davidson
> Sent: Wednesday, June 24, 2009 2:00 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] module frame separation
>
> William,
>
> The main concerns are physical damage to the unsupported laminate and
> moisture penetration at the exposed edge of the laminate. If the frame can
> be pushed back in place without breaking the laminate, you can fasten a 
> flat
> bar across the back of the module to keep the frame in place. EVA is
> hydroscopic and moisture will wick into the laminate from the exposed 
> edge.
> Run a bead of silicone caulk along the edge of the laminate before 
> securing
> the frame back in place.
>
> Joel Davidson
>
> ----- Original Message -----
> From: "William Korthof" <wkorthof at eesolar.com>
> To: <re-wrenches at lists.re-wrenches.org>
> Sent: Wednesday, June 24, 2009 1:39 PM
> Subject: [RE-wrenches] module frame separation
>
>
>> Recently we've had a few modules (~5 year old) exhibit frame  separation
>> from the glass...
>> in one case, it's minor separation of the long edge of frame on one or
>> both sides of a few modules... the frames seem okay and reasonably 
>> secure
>> when attached on the roof, but were loose during handling.
>> In another case, the customer is located in snow-impacted mountains.
>> Apparently, a sheet of icy snow pulled the bottom (short) edge of the
>> frame apart from the glass and side frame pieces. No damage to the 
>> glass,
>> but the lower edges of 6+ frames are now dangling by a thread.
>>
>> I don't think the module warranties cover this problem---the power 
>> output
>> remains within spec and there is no evident damage to the  glass. But if
>> we don't provide some sort of repair, the modules will  break.
>>
>> Any suggestions for this kind of repair?
>> What kind of glue would we use to reattach the glass to the aluminum
>> frames?
>>
>> Thanks,
>> William Korthof
>> Energy Efficiency Solar
>>
>> _______________________________________________
>> List sponsored by Home Power magazine
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> Options & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> List-Archive:
>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>
>> List rules & etiquette:
>> www.re-wrenches.org/etiquette.htm
>>
>> Check out participant bios:
>> www.members.re-wrenches.org
>>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: 
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: 
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>