sealants recommended on here

[David Stepney]

I suspect, Ruairidh, that having tolerably flat faces and threads that are in sufficiently good condition to take proper tightening is half the battle.

And I sincerely hope that the cat referred to is of the miowing variety rather than the other sort mentioned in another thread!

[JonE]

I realise the pros and cons of everything, but just wanted pitfalls/notes on practical use for Threebond 1215 from those that use it or have used it.

[Ruairidh Dunford]

I suspect, Ruairidh, that having tolerably flat faces and threads that are in sufficiently good condition to take proper tightening is half the battle.

And I sincerely hope that the cat referred to is of the miowing variety rather than the other sort mentioned in another thread!

Purrrr…

[JonE]

this is from an old personal email to me which I printed off for my own use as I thought it incredibly useful... I don't think sender will mind me adding - I've been trying to work out how much access I'll have inside to clean things up, but also how many things need to be on the "absolutely double checked" list so you don't need to have to split the joint!

"Re Threebond, I applied it in a 2-3mm bead around all the openings (not just around the outside) and let the assembly of the joint squish it where it wanted to go. Keep it at a respectful distance from internal edges to help avoid bits coming off into the sump.
It has a 1-hour 'open' time so there's no particular rush. It probably wouldn't hurt to spread it with a finger or a lolly stick but make sure you have coverage. I did not use gaskets, but then I have a block spacer plate so different from most A7 engines. I would happily leave them out but I'd do a dry assembly first and check the pistons don't come up too high without a gasket in place. The [racers] set a minimum 20 thou clearance to the cylinder head to allow for crank whip on a 2-bearing engine."

[Charles Levien]

Re head gasket — following excellent advice from Charles P and others I used Loctite 5920
It works best when spread thin — it can get a bit messy so I smeared one side of head gasket, fitted that to block
then put a coating in the head. That way everything seemed manageable

[John Mason]

I do not do any competition, racing, hillclimb or other stuff thar runs an engine hard but for head gaskets I only use a smear on both sides of GP grease. For sealing studs that may leak oil or water I use loctite silicon sealer. I have a silicon sump gasket and on the next strip down will no doubt use silicon gasket for crankcase to block. For all other paper gaskets I use Permatex 80019 Aviation which is protection against oil and fuel leaks. I like this because it is non hardening and comes off easily when cleaning with spirit.

John Mason