Thread Sealant for Compressor Fittings?

[Steve Walker]

Hi -

Recommendations please for an air-tight seal when replacing the 4-way valve/switch assembly on my ratty old WolfAir compressor? Three joints are brass to alloy, and the main stem from the tank is steel to alloy.

Browsing the messageboards seems to suggest combining a liquid sealant (Permatex or Loctite 577) with a few wraps of PTFE tape. The "bung it up good and proper" approach appeals to me.

But the factory installation appears to have used a thick, gluey compound, which set hard on the threads. Maybe an epoxy adhesive, it was certainly a bugger to get the assembly apart.

Suggestions welcome. Except angle-grinders, obv... :-)

[Rick Hughes]

Try LSX .... over a number of turns of PTFE tape ....

[Bob Minchin]

I would certainly endorse some sort of liquid sealing compound. I have a similar compressor and trying to eliminate leaks by simply tightening can lead to cracking of diecast parts.

[Nick]

If such things still exist, would plumbers mate or boss white do the job? Just a guess. Nick.

[Jim K]

Liquid ptfe perchance?

Jim K

[Andy Wade]

Hylomar Universal Blue

[harryagain]

Theoretically not required. However when the joint is tightened, the metal work hardens. This means that the ring should be replaced, not easy, (or PTFE used) if the joint is broken, it may leak when retightened. Us what you like/have to hand. Niether here nor there really. Virtually anything works

[Dave Liquorice]

An acetic acid releasing silicone based sealer. I'd be a bit cautious of using that near diecast alloy parts.

Gas (yellow spool) PTFE tape, rather than water (white spool) PTFE tape would be my preference. Just a single turn of gas tape required.

[The Other Mike]

I would have suggested Loctite 577 on its own, but for a one off its a silly price. Second choice, Loctite 55 PTFE cord. Third choice a generic PTFE tape.

[Nightjar]

I put air lines around two factories using just PTFE paste on parallel threads and only had one leak on first test.

Colin Bignell

[Muddymike]

I replaced one of the outlets on mine just using PTFE tape and its been no bother.

Mike

[Steve Walker]

Thanks for all the replies and advice - very helpful.