General Tech Gasket Sealer and Sealants

[KVH]

I had success with Wellseal on my figure 8s. Do I stick with that? Can I use that on the front engine plate as well? I wish I knew the very best for every application.

My default would be Permatex High Tack for everything, but I like Hylomar for the transmission and, as stated, Wellseal for the figure 8s.

Anyone have a real easy rule of thumb?

 

[TomMull]

I doubt we'll see any rule of thumb here. I've used Aviation Permatex of the FO8s with never a problem. I think it's quite similar to Wellseal. I also use Hightack on paper gaskets. I've also used permatex "Right Stuff" in place of gaskets with great success. I have however been reluctant to experiment with engine rebuilds and use pretty much the same stuff that was available 50+ years ago.
I would add that whether it's due to better gasket goo or better design and machining, many of today's engines simply do not leak.
Tom

 

[TR3driver]

I would add that whether it's due to better gasket goo or better design and machining, many of today's engines simply do not leak.

From what I've seen, it's a combination of all of those, plus more sophisticated assembly techniques. A robot can easily lay a precise 3/32" bead of RTV down the exact middle of a flange, while us poor humans are lucky to even hit the flange without filling the bolt holes and so on.

Sorry, no help on what is "best" for the front plate. I used Permatex Aviation the last time I did one and it didn't noticeably leak; but that was a long time ago and the rear main on that engine definitely marked it's spot. (Probably should have bought a new seal or at least re-centered the old one, but I was broke and in a hurry. Not to mention young and stupid instead of old and stupid.)

 

[MichaelG]

Lately I have been using Permatex "Right Stuff" that comes in a 4 0z. pressurized tube, every application to date such as diff covers, oil pans, etc are completely leak free. Some would say its pricey, but there is no cure time and no mess. I have oil leaking from my fuel pump gasket and I'm going to try it there...might not even have to disconnect the fuel lines......well that is probably overly optimistic. Anyway I think that the "Right stuff" is "Great Stuff"

 

[TR3driver]

I've not tried it (yet). What happens if you get too much in one spot? I presume it squeezes out? Does it form 'strings' like RTV does (that can break off inside the engine and clog important passages) ?

Also, how hard is it to remove later? Does it eventually setup into a rock-like substance, like "non-hardening" Permatex does? I have literally had to use a wood chisel & hammer to chip away old Permatex!

 

[TR-3rg]

Hi,

I have used the Permatex Right Stuff on the differential cover, without a paper gasket, about 6 years ago. Its been drip free the whole time and it's still full of oil! It has a small diameter nozzle so its not easy to put down to much. The factories don't use to many gaskets anymore, so its a replacement for that. I have not tried removing it. The bad side, its a one time use. Don't try 2 weeks later to use what's left in the tube.

I certainly agree with some of the Permatex "non hardening" compounds not coming apart. One time I mixed up the Permatex Aviation "3" for the "300". Anything with "3" is not coming apart. I have used the "300" for head gaskets for years without issue.

RG

 

[MichaelG]

Randall, I have only had to R&R with it once when changing diff fluids....but ISTR just scraping it lightly with a blade to remove the old product. The bead size was easy to control, and I used a small putty knife or razor blade to scrape a bit off if I needed to. No strings like RTV....it is pitched as an elastomeric rubber that stays flexible and resists "compression set"