Morning Nick, and all--- Best wishes for Peace on Earth , and congratulations for the role we all play in that !
When we were looking, back in the late 80's , for the best caulks for roof penetrations and the occasional crack repair in our EPS foam core covered with reinforced , latex modified, cement plaster, we used silicones , polyurethanes, and the tri and quad polymer caulks like geocel 2300, and OSI Quad. We like black silicone for roof penetrations in asplalt shingles--clear silicones , and tri-polymers, are not UV resistant, black lasts forever ,in our experience . Some folks teaching solar installation have had very negative experience with clear silicone, and we concur. No UV resistance ! Adhesion is not a strong point so be sure to place silicone in the hole and under the foot/ bracket/whatever. That also prevents UV exposure. Also be aware that there are different types of silicone, so do some research. The RTV is probably best. Years ago we got our caulks from C R Laurence Co, a major supplier to the glass trade. They had a great chart listing all the caulks they sold, and their appropriate applications. When we needed caulk for high expansion use , like crack repair , we tried polyurethane but found it to stiff --and messy--although it is certainly sticky and tough. We then switched to the multi-polymers , using Geocel and OSI Quad. We found the Geocel a bit to thin--may be different now-- but the OSI was just right. It is used and sold primarily for vinyl windows/ siding because it sticks tenaciously--even to polyethylene, which we used for 20 years for drainback SHW tanks. The tensile strength is affected by the presence of color agents--it comes in over 200 colors or so. Clear is incredibly strong, and extremely stretchy ! Lay out a bead, let it cure, and pull on it . It can be very difficult to remove from surfaces. Great for installing flashing to thermal collectors so removal for reroofing is not needed. It does takes a while to cure. The tri-polymers will dissolve EPS foam, and react with asphalt at the interface, leaving no bond, in our experience. But a little keresene or your trusty can of penetrating oil is great for cleanup. Caulk is a great tool, but selection of the appropriate type, and application techniques is crucial. Experimentation will be most useful. Take Care Ken Schaal CommonWealth Solar www.commonwealthsolar.com ----- Original Message ----- From: William Miller To: RE-wrenches Sent: Thursday, December 17, 2009 12:46 AM Subject: Re: [RE-wrenches] Geocel 2300 Nick: Read the fine print. Some of these sealants are not recommended on asphalt roofing products. William At 09:31 PM 12/16/2009, you wrote: Aloha wrenches: Do you have experience with Geocel 2300? What do you think of using it for roofing penetrations and roof flashings? Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax: 707-769-9037 _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.716 / Virus Database: 270.14.111/2569 - Release Date: 12/16/09 11:52:00 Please note new e-mail address and domain: William Miller Miller Solar Voice :805-438-5600 email: will...@millersolar.com http://millersolar.com License No. C-10-773985 ------------------------------------------------------------------------------ _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@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@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