Look into commercial-grade sealants, and even consider having them applied by a sealant contractor who will offer a warranty. However, ten years might be the best to expect for most sealants, and isn't that about how long they've lasted? Butyl may be a better sealant for the dome joints, but I'd defer to the opinion of a sealant contractor. At the roof transitions (dome-to-flat-roof) proper flashing and back-flashing are a must. Didn't we use a roofing membrane product at those locations? EPDM or other single-ply membranes should work well there, including flashings. Wish I could be there to help - sorry that I'm not, but seriously consider using contractors for roofing and/or sealants. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Patrick Wiggins Sent: Monday, March 05, 2012 8:06 PM To: utah astronomy listserve utah astronomy Subject: [Utah-astronomy] Seeking suggestions for repairing RH dome The results of today's inspection of SPOC's Refractor House dome are not encouraging. Basically, water sprayed on the outside poured right through to the inside. Leaks everywhere and lots of them. No wide gaps. Just cracks wide enough to let water through. Many located on the vertical seams between the gores, around the door and where the dome joins to the flat part of the roof. We figure at the very least we're going to have to remove the existing cracked caulk and reapply. What a job that's going to be. But looking to the future we're wondering what might be done to more permanently seal the leaks. Strips of fiberglass? Ideas? Rodger is going to speak with Ken about calling another SPOC committee meeting. But until the situation is resolved we'll be without the refractor this year. patrick