Sealing cases Options

[Shindog1961]

What are you using to seal the case halves on a rebuild? Any thread lock for case bolts?

[cwpeden]

I've used Permatex or Loctite "Aviation Gasket". Never used thread locker.

[pcar916]

Search the forums with the phrase (no parentheses)

"+case +sealant"

There was a recent thread...

http://www.914world.com/bbs2/index.php?sho...l=case++sealant

Good luck

[Cap'n Krusty]

In the past I've used Permatex Hi-tack, Curil K, Curil T, Yamabond, Hylomar, and maybe a couple of others. I've settled on Loctite 571 and Permatex Ultra Blue. I don't use Loctite "The Right Stuff", but it's widely used in the trade and is supposed to be pretty good. The key in all cases (no pun intended) is to use "just enough", and NEVER "way too much". You want to avoid having it squish out in large quantities into the inside of the engine. I wouldn't use that ancient Permatex stuff that hardens to a varnish like substance, the one that's been in use since flatheads were the hot setup. Another key in obtaining a good, leak free seal, is to get the mating surfaces REALLY clean and to gently flat file the halves to rid them of any burrs or bumps that may have occurred during disassembly.

The Cap'n

[stugray]

Another key in obtaining a good, leak free seal, is to get the mating surfaces REALLY clean and to gently flat file the halves to rid them of any burrs or bumps that may have occurred during disassembly.

Be careful Capn, or you just might bring out the types that think if you even TOUCH a case mating surface, that you should just throw it away and start over:

http://www.914world.com/bbs2/index.php?sho...l=file&st=0

The pics posted are of a spot on the top of the case where a PO obviously tried to pound a chisel between the case halves to separate them.

The pics in that thread are where I needed to take the high spots off of the chisel marks. I cleaned up with a sanding block before sealing the halves. (and the abuse was on the top of the case = minimum chance of leakage)

Stu

[PanelBilly]

I was Also told not to clean up the excess that was squeezed out. I wanted to scrape it all smooth and I guess that weakens the seal.

[Shindog1961]

Thanks for the advice!

[Cap'n Krusty]

I was Also told not to clean up the excess that was squeezed out. I wanted to scrape it all smooth and I guess that weakens the seal.

Pretty hard to wipe off the excess on the INSIDE of the case, where it'll be the biggest problem.

The Cap'n

[Cap'n Krusty]

Another key in obtaining a good, leak free seal, is to get the mating surfaces REALLY clean and to gently flat file the halves to rid them of any burrs or bumps that may have occurred during disassembly.

Be careful Capn, or you just might bring out the types that think if you even TOUCH a case mating surface, that you should just throw it away and start over:

http://www.914world.com/bbs2/index.php?sho...l=file&st=0

The pics posted are of a spot on the top of the case where a PO obviously tried to pound a chisel between the case halves to separate them.

The pics in that thread are where I needed to take the high spots off of the chisel marks. I cleaned up with a sanding block before sealing the halves. (and the abuse was on the top of the case = minimum chance of leakage)

Stu

I prefer t 12-15" long 1" wide file as it can make use of distant case surfaces to assure an even and perfectly flat finish on the work. Gotta let the file do the work, though. Pressing down to speed up the cut is gonna mess up the end result. I took metal shop in 7th grade (yes, they had metal in those days) and we spent a couple of weeks learning how to use a file. Good skill to have, along with patience.

The Cap'n

[pcar916]

I also had metal shop in 8th - 12th grades... for fun. The shop teacher was obsessive about many things but especially about surface preparation. I never found in all of these years any reason to think that was a bad thing.

Most of the sealing problems (in this case) point directly back to poor surface prep. I've taught my girls (now grown) all about files, taps, dies, drills, solvents, coolants, 0000 steel wool, crocus cloth, machine tools, and most everything they need to do life's maintenance/fabrication correctly.

I'm convinced the majority of folks in the USA now don't have a proper set of sharp files and deburring tools in their garage... if they have tools at all!!!

Naturally we in this forum have lots of them.