Best sealant for thermostat housing?

[05snopro440]

Hey guys, I got my 455 in the 46 fired up yesterday, but I had a massive water neck leak. I had used Ultra Grey with a gasket and it was spraying out like a fountain. Besides using a thicker coat, is there something you've used that works well and cures quickly? I think ultra grey and some other permatex stuff wants 24 hours before fluids touch it.

 

[Tripper]

I usually use Permetex Black but lately I've been using this! It's for water pump sealant!

BoB

 

[05snopro440]

I was thinking of trying Permatex The Right Stuff. Unfortunately the water pump stuff is unavailable at all my local retailers and even Amazon.

 

[Bamamav]

I’ve used both the black and ultra copper with good results.

 

[Old Iron]

Have you checked to see if the mating surface of the neck is flat? Being over tightened and warping the neck is the biggest issue I've found.
60 Or 80 grit sanding paper on a flat surface is a good way to fix it if it isn't flat.

 

[05snopro440]

Have you checked to see if the mating surface of the neck is flat? Being over tightened and warping the neck is the biggest issue I've found.
60 Or 80 grit sanding paper on a flat surface is a good way to fix it if it isn't flat.

It's as flat as a stamped steel thermostat housing mated to an aluminum intake is ever going to be. I got a repop aluminum one but it's clocked wrong and hits my distributor.

 

[Toad]

I was thinking of trying Permatex The Right Stuff. Unfortunately the water pump stuff is unavailable at all my local retailers and even Amazon.

If I'm not mistaken, the Permatex stuff is the same thing as plumbing pipe sealer. I have some in the shop from different plumbing projects & it has always worked fine for me.

Toad