Replies

1. 
   Piffin | Dec 12, 2009 09:59pm | #1

   I wouldn't use either at the
   I wouldn't use either at the storm collar. The Rutland is too brittle for there, and the silicone breaks bond after a few years to metal. I use geocell there.

   at the ceiling connection, you probably could use Rutland, but I think it would fall out each year from brittleness too, and the typ location where heat stress will be moving the metal a lot. I think the GE high temp is labeled GE2000, but not absolutely sure. Been a while....

   With the Rutland, read the lable. I think you have to dampen the metal first to use it, IIRC

1. 
   MadisonRenovations | Dec 13, 2009 10:08am | #3

   The Geocel products seem to be low temperature - 200 degF. Is that okay?

   I was having a hard time finding how high of a temperature I need. Most web sites just say high temp without saying how much is enough. One said 450 degF was the minimum.

   And, I definitely do not want to be replacing the sealant every year.

   You mention differences for the storm collar and ceiling firestop - interior vs. exterior?

   And while I'm at it, you had suggested fabricating a firestop with two sheets of metal - is there a minimum spec for the sheet metal?

   thanks,

   ---mike...

1. 
   Piffin | Dec 13, 2009 06:52pm | #4

   26ga metal OK.

   geocell OK exterior. You won't be seeing super high temps there.

   I know there is a GE silicone for up to 2000°F but could not find and verify that. Most showed high end temps of 400-600.

   Which brings us to a discussion of chimney temperatures.

   Wood burns at around 475°F. with one thing and another, you can get a drafting exhaust up higher than that,say almost 700°F.

   But it takes a creosote burnoff chimney fire to really melt the butter! requirements for metal chimney parts are now 2400°F. And believe you me, if you have a chimney fire, you will be replacing some parts. Some will sacrifice themselves to save your house.

   so the exterior of the insulated pipe will realistically never see higher than 450 to 600 degrees.

   The 2000° stuff I used to use was for inserts in fireplaces where the junctions at top of the burn box were linked to the flue, probably the hottest location of all.

   Do use one of the high temp products at the junction of straight single wall black pipe tot he ceiling support box if you need a caulk there, but up on the roof at the storm collar, you might find yourself touching it up every few years.

   I keep a dozen diff kinds of caulk with me in the trailer, but if you are doing a one-off job, one tube is all you want to have to buy.

1. 
   MadisonRenovations | Dec 14, 2009 08:53am | #5

   thanks, Piffin, but you seem to be as intentionally vague as the rest of the web. :-) I have an air-gap chimney, so is 600 deg Rutland RTV silicone (550 degF constant, 600 degF intermittent) the one to use at the ceiling firestop? Or a better brand at a lower temp? Or another brand at a higher temp?

   It sure seems like GE got out of high temp caulk.

   For the storm collar, it seems like you're recommending a Geocel product - which one? The 2300 Tripolymer has a max temp of 180 degF; the 4500 Roof Bonding Sealant goes to 200 degF. You're sure they can, shall we say, take the heat?

   ---mike...

2. 
   Sbds | Dec 14, 2009 06:33pm | #6

   Piffin,
   Thanks for
   Piffin,

   Thanks for http://forums.delphiforums.com/breaktimeclass/start.

   It is so nice to go to something that works so well. I will be there from now on.

2. 
   Piffin | Dec 12, 2009 10:13pm | #2

   http://www.dealtime.com/xDN-building_supplies--glue_and_adhesives-hw_glue_and_adhesives_type_silicone

   this page may help. The search I ran for high temp GE silicone has it together with the Rutland products.

   Looks like maybe GE1200. Look into the spec sheet for it.