> 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?catde= pth=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, I listed them in my 1st email. Here they are again. See above for slightly more detail. .... low modulus (flexible) when set, excellent voidless adhesion to PV material, low dissolved water content, minimal UV degradation, minimal corrosive degradation products with time. >mixed viscosity is lower, so I'd imagine it > would flow better. Could be useful. > It comes with a primer but they dont give any > strength criteria for glass primed, unprimed etc... Adhesion to the PV material matters more. > and how it would compare to sylgard. Those who tell don't know. Those who know don't tell. Build, test in weather. Accelerated test. .. :-) R > > 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 > > wrote: > >> 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-6100. > > 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 > -- > 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 .