The Stovebolt Site Forums The Shop Area Engine Shop BEST GASKET SEALANT???

What is the best gasket sealant for the water pump and water neck/ thermostat housing? I have used a couple different kinds (including Permatex Super 300) and I always have seep leaks within days. It's driving me crazy. Both surfaces are clean when I apply, I tighten the bolts to the correct tension, I think I'm doing everything right, so it has to be the sealant...

Thanks guys,
Adam

I use the brown gooy stuff that doesn't seem to harden. I wonder if one of your surfaces isn't flat.

Try THIS , you should be able to get it at your local GM dealer.

I use Permatex #2 for that sort of stuff, as truckernix said "the brown gooy stuff that doesn't seem to harden"

Not as a gasket replacement but as a helper for the stock paper gasket.

Also be sure your surfaces are flat, and that the bolts are not bottoming out in the holes.

Grigg

Boy, you asked a question that is like asking what it the best tooth paste. Everyone has their favorites and they all probably will do the job. Some like the silicone gasket makers which I feel are just that, a gasket maker where there isn’t any paper or cork gasket to seal up. Some like the exotic European stuff that the formula one racers use for $40 a tube. Then there are the old timers who swear by Indian Head Shellac, and some don't like any gasket sealer at all.
I personally use only three Permatex products for most of my projects. These are time proven in my book and I’ve been using them for many decades all the way back to the 50‘s.
Permatex #2 non-hardening in the tube for engine sheet metal, water pumps and outlets, transmission and rear axle castings.
Permatex 3H Aviation Form-A-Gasket liquid for threaded connections and very light thin paper gaskets like the steering gear.
Permatex Copper Spray-A-Gasket for a head gasket because the copper helps in sealing and heat transfer.
Denny Graham
Sandwich, IL

Thanks a lot, guys! I'll give permatex #2 a shot and hope for the best. It's probably the only one I haven't used. I'll also make sure my bolts aren't bottoming out...

Adam

Here's another random question: should gasket sealant be used on a composite head gasket (like the one Fel Pro sells)? I'm doing a valve job next week, just got the fel pro gasket set in the mail today, and the head says it needs to be installed dry. This makes me nervous. I was thinking at least a thin coat of Indian Head Shellac on both sides. What do you guys think?

Adam

I would definitely say no to sealant on that head gasket, just as the instructions say. I would also re-torque the head after running it. That is buried in the manual somewhere and on my 216, I always find that some of the values are down some.

i dont use any sealant in those areas and never had any problems with a leak. but if i did it would be what grigg uses, permatex #2. if the surfaces are clean smooth and flat with the proper tightness it cant leak unless its faulty gasket paper.

Thanks for all the great advice, fellas. It's greatly appreciated. And, I will definitely stay away from sealant on the composite head gasket.

Adam