Interesting videos, And made me think of a particular silicone that smooth-on started selling somewhat recently http://www.smooth-on.com/Silicone-Rubber-an/c2_1115_1381/index.html?catdept= h=3D1 Slightly cheaper than sylgard 184 ebay 1/2kg kit rates, but not knowing which essential criteria Russel is looking for I cant really say how it would compare, mixed viscosity is lower, so I'd imagine it would flow better. It comes with a primer but they dont give any strength criteria for glass primed, unprimed etc... and how it would compare to sylgard. Any word on EVA vs Tedlar/PVF/TPE vs TPT films as backers? Diminishing returns vs cost? Or is that getting into consultant territory ;) ? On Mon, Sep 17, 2012 at 8:18 PM, RussellMc wrote: > On 18 September 2012 06:54, Joe Wronski wrot= e: >> I look into how solar panels are made from time to time. I formerly >> concentrated on the soldering and tabbing, but today I found >> . >> I killed too much of the afternoon watching 3 parts, but learned a bit >> about encapsulation. This guy didn't use any TPT backsheet, although he >> claims he does for better panels. But the Dow Sylgard 184 encapsulant >> he used is pretty pricey. Probably $60 worth to make a single panel. > > I haven't watched that yet, but (hopefully) will. > > Dow Corning Sylgard 184 is as good a formal PV product as you will > find on the US market. > There may be others but if the manufacturer does not specify certain > essential criteria odds are it will be inferior. > DC do not disclose details of their magic directly but I discovered > (while looking for other things) a patent for one aspect of what is > involved in 184 that makes it especially suitable in this role apart > from the obvious parameters that you can measure. Not a whisper of > this in usual DC literature. > > Note that as far as environmental protection goes you can probably > spread 184 as thinly as you can persuade it to go and it will do its > job. It's role is NOT to keep water vapour out - it is about 10 times > worse than EVA than that, but to keep liquid water off the surface > anywhere. > > Lack of a backsheet is unwise unless he manages an all over 184 > coating - in which case it is largely just a mechanical issue. > > A product which was meant to be superior, also Dow Corning, is their PV-6= 100. > It was introduced with considerable promises and promise a few years > ago, and they were working with an independent company to make > automated PV production equipment, but I strongly suspect something > has gang very aglae, as it has vanished quietly off the distributors > lists and a query I made about a month ago to DC received a "not for > new customers" response. BUT if you follow up the various leads on > PV-6100 and what it did and why you'll learn much. > > For something from somewhere else that appears to work well so far (5+ > years of use)(not by me) and that seems to have many of the the right > characteristics, you may need to talk to me privately. Waving $ > sometimes helps :-). (Not always needed). It's not available to the > occasional Western buyer so I'm not just hiding an available product. > Whether it does as well as it seems it will is as yet tbd. > > I have reports somewhere that detail how to use 184 on the latest very > thin and fragile PV material with good success. In real life PV > material can sometimes be hard to work with. Cold temperatures are to > be avoided when manufacturing as it becomes even more brittle. . > > For an encapsulant - if you had to use something easily available > then almost any silicone rubber that works for you will be a quantum > jump better than any epoxy. Lower modulus helps. Optical clarity will > need to be good, and this varies widely with formulation. Epoxy is > susceptible to UV degradation due to bond energies relative to UV > energy. Silicone rubbers are inherently stable due to single bonds and > Si-O rather than C-C structure. A silicone rubber can provide a 20+ > year outdoor life. Epoxy is liable to be dead in 2 to 3 years and much > less in some places (like NZ with generally high UV levels). > > > > Russell McMahon > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .