Which Sealer?

Steve_S

Steve_S

Member
Sorry for all the newbie questions but I', getting ready to button up my engine and I'm wondering which, if any, of the sealers I have would be the best for water pumps, front cover and oil pan. I have in the garage:

1. Locktite Aviation (same as Permatex Aviation, non-hardening)
2. Permatex Blue RTV
3. Seals All
 
None of the above!!!!!!!!! If you put sealer on the water pump gasket you can stop up the oil hole. No sealer of any kind was used on the engine when new and none is needed now.
 
You can use sealers in moderation without any problems.That is what they are designed for. Others will chime in here.

R
 
I have been using #2 permatex very sparingly on one side for 50 years and never had a problem. Just remember do not glob it on I useto use a match book cover when I was smoking but that was 30 years ago (I think). :confused:
 
There are many more sealers available now than ever before and some are excellent insurance against seepage or flat out leakage. Blue, red (high temp), black, or white RTV depending on how it sets up, is all good stuff. Anaerobic sealers like Locktite 515 can be used in cases where there is no gasket and it stays plyable for a longer period than we would have ever imagined years ago. Bare gaskets will work fine in most cases except where gaskets join seals or where there is pressure involved. A little RTV in the corners or around a pressure boss will insure a seepless joint in this case. Some folks like to put a quality RTV on one side of a gasket to place it and nothing on the other side in case they might have to pull an item off later. This will leave the gasket intact and in place for re-use in certain situations.

I also use sealers on the bolts and studs where they go into the water jackets. It's just a little bit of insurance. It pays in places where leaks have been a problem in the past. As was mentioned before, you have to recognize where sealant might block a passage that's important to proper function but good common sense will dictate that.

Kerby
 
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Thank you gents, I appreciate the advice and will put the water pumps on dry, or with a very thin coat. Does anyone bother to seal the front cover or oil pan?
 
I was a mechanic in a very large utility fleet. I probably changed a couple water pumps a month for the past 30 years. You won't have this problem on your flathead but on a lot of engines your trying to slip the pump and gasket in behind a bunch of other brackets. Usually it is such a tight fit that you run the risk of accidentally catching the edge of a gasket and folding it over, resulting in a massive leak. You need to glue the gasket to the pump so it will not move. Using silicone on both sides of the gasket is a bad idea because when the silicone squeezes out during the tightening process the gasket can squeeze out along with the silicone.
Gasgacinch is my favorite gasket sealer. This is a contact cement that you brush on, it remains slightly sticky so if you need to lift up the gasket and reposition it you can, and if you need to scrape off the gasket years later you won't destroy the part trying to get the old gasket off.

On a water pump installation I will use Gasgacinch to glue the gasket to the new machined surface of the water pump. I brush on the Gasgancinch on the water pump and the water pump side of the gasket. I let the glue dry on both parts until it is slightly sticky, then I position the gasket on the part and it is not going anywhere.

If the machined surface on the block is real nice you can use Gasgacinch on that side too. If the block has a lot of scratches from the careless use of gasket scrapers then I will use a little bit of silicone instead of the Gasgacinch on this side. The silicone fills in those little scratches which can act like little channels for the coolant which can cause seepage problems. Were not talking about running a caulking gun bead of silicone, just a little 1/8 inch bead. Keep it away from little oiling holes or coolant passages that can become accidentally plugged.

The high heat red silicone is the best silicone to use but on my cars I don’t like seeing red, orange or blue silicone oozing out of my engines. I use the Permatex black silicone which works real well and is not visible when I'm done. Just make sure you get the black silicone made for engine gaskets and not the type for sealing glass.

Gasgacinch is especially useful for gluing intake gaskets to heads when you want to make sure the gaskets stay lined up with the ports. Buy the smallest can they make because once its opened it goes bad in about 6 months.
 
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