Ultra copper RTV for exhaust leaks? (or something better)

Has anyone had any luck with the newer copper rtv's? So I didnt see the need to spend 700 plus on thorleys etc while my engine was out (big old dum dum). After purchasing various cast manifold and cross overs for my year through ebay I ended up with one good exhaust manifold and reused my other. (they would say 96 4wd, single cat but id never get the correct ones, 2 different cross overs that didnt work, 3 cast manifolds where the bolt patterns were off) . The mating area on my original cross over was pretty scaled, the metal ring portion even fused to it; I cleaned it up with naval jelly and some brush wheels (still not ideal but i thought it was okay) its going into a walker down pipe.

I Have the correct gaskets for the walker but the damn things arent sealing correctly. Maybe the extension mating tubes coming out of the down pipe are a little too long, maybe the seal just sucks, maybe since i had to rethread the studs coming out of the cross over its not getting snug enough I dont know. Has anyone used the newer copper rtv's with success. I know in the past the normal copper rtv's were kind of crap but maybe since it has Ultra in front of its name it will hold up, says 700f? I bought a few tubes, just wondering if anyone knows of a better product they have come across incase the consensus is even the ultra copper rtv is doodie.

 

I used it on the turbo header I have..no problems

 

The best by far is Permtex #2 I have been using that for years on exhaust gaskets .

No experience with the Copper RTV

 

I've had a continuous issue with my LCE long tube header to catalytic connection. It seems like the flanges are slightly out of alignment and they OEM crush gasket eventually starts to fall apart. I have successfully sealed it with copper RTV on both sides of a NEW OEM gasket as long as I can get the cat to bolt to the header easily (it's not easy).

It seems I have to redo this every few years though.

 

From what I read it does need redone every year or 2. which isnt a huge deal. As long as it gets you by I guess ill try it. I hate those damn donut gaskets.