sealing header to block with RTV?

[CorradoPsi]

ok guys, I've never had to do this before but i have a problematic header on my boat. i picked up some ultra copper O2 safe RTV. my question is, should i just smear it on and bolt up? or should i put it on, allow it to partially dry, then bolt up? and if i do the second option do i apply to both surfaces or just 1?

for the guys who say use a new gasket, not an option, they just blow out, its a friggin .32 side exhaust

 

[Diver6127]

smear it on, and mount it with the bolts cinched.

 

[Pinblaster]

Sounds like you header is warped. You may want to get some copper sheet from the hardware or craft store and make a gasket or 3 and use a thin coat of the UltraCopper on both side. You may also want to file the matting surface on the header to make sure it is flat. Just don't file too much. Bolt the header on with the Ultra copper wet and let it set up for 24hrs before you run it. If you can't find copper, you can also make a gasket out of soft aluminum stock that you can find at any HomeDepot or Lowes. :hammer:

 

[CorradoPsi]

filing the header flat is a given, I'm a machinist and can make or get just about anything. just needed to know how to use the permatex ultracopper. thanks for the info guys.

 

[Mr T-Maxx]

I would follow the directions on the package. I beleive they read...Apply sealant and tighten until it begins to squish out (I know it doesn't say squish), let set for X amount of time.....then tighten completely.


Mr T

 

[Pinblaster]

well heck, if you are a machinist, then get some soft copper sheeting the same thickness as the glowplug gasket, to make your header gasket and don't worry about sealer. The copper will seal it self, but if you still want to use sealant, get a can of CopperCote spray and glaze both sides of the gasket and bolt it up tacky. Also if you haven't ported the header to match the outlet on the motor, it's a good time to do it while you still have it off. Cut the gasket to match also. :hammer: