I have to put my muffler back in the sled and I was wondering what kind of sealant is used in the joints. Thanks for the info.

Most people use a sealant like Ultra Copper which is rated for up to somewhere around 700-800 degrees, but last year I found a something that works quite a bit better. I cant remember the name but its made to patch small holes in car exhausts and is rated to 1500 degrees and stays totally flexible. I noticed that this stuff didn't blow or wear out like the Ultra Copper did, it was in the exhaust isle of the local tractor supply. If I can find it I will post the name.

If you are talking about the "Victor Muffler Mender", I would stay away from that crap. Gets rock hard when frozen and breaks apart from all the vibrations. It hardened up and fell out completely on my sled, and made a mess of the place.

Doo recommends Loctite/Permatex 17914 Ultra Copper. That's what I use, and have had good luck with it. I normally take my pipes off every year to re-seal them. Doesn't usually need to be done, but there always seems to be some reason I need to take them off anyways (re-gearing, swapping tracks, etc).

I needed to use a grinder to get off all the muffler mender stuff. The ultra copper stuff just comes off easily with a rag, and maybe a wire brush in some spots where it is stuck on good.