Jointing compound

[Ken Wilson]

I am just about to put together my 2T engine after its winter checkover and find that I am almost out of "Red Hermetite"
Before I invest in another tube is there a better modern alternative?

[Kim275]

Hi Ken - personally I prefer to use modern silicon gasket sealant (blue )...especially on my Griff cluch cases - which are rough and battered - seems to be the only one that works...and better than a paper or Klingersil gasket.
Also works well on the gearbox casings.+ on exhaust header + getting a goo d seal on carb intake. ...If there is anything better out there - am sure better mechanics than me will make some suggestions.


Cheers Kim

[riflegreen]

At the factory all that was used was Welseal .

Myself I use Hylomar , Welseal or the Japanese sealer that Rex Caunt sells .

Haven't used Red Hermetite for over forty years .

Silicone sealer has its use for sealing exhausts but that is all .

Chris

[Andy Z]

High quality silicone (eg. threebond) is great for crankcases, but I don't use it for parts which are regularly dismantled. Its messy to remove and if I use it on my MX4 primary case, it makes it difficult to remove. In those cases Welseal is brilliant, very easy to use, and no messy fingers as you paint it on. Its also easy to remove from cases when you need to, as is Hylomar.

If the surfaces are mangled though, silicone may be the only option.
Hope this helps,

Cheers,
Andrew
#190

[stormer254]

A tube of silicone goes a long long way for less than half a crown as the advert used to say. It is very good on Challenger and Starmaker chain cases which always end up bent . Do not use it on any oil circulation type systems,i.e. 4 stroke engines as if any bits break off thy will block oilways with expensive results Ordinary silicone is not petrol proof. Any of the common building grades seem to work very well.
Real engineers will tut tut at the use of silicone but it suits bodgers like me just fine

[ampshire-og]

Engineers use Perma Bond A136, without doubt the Rolls Royce of jointing compounds! The spec says you get 45 mins for it to start to cure, plenty of time to assemble and reassemble and assemble again if needed! Silicone RTV is alright for primary cases and such like but like Stormer says not for delicate areas not needing to get blocked.
Downside to Perma Bond , £20 a bottle! but value for money in my opinion. BTW you paint it on the joint with a small craft brush, so it goes a very long way!

Ampshire-og

[Ken Wilson]

Sealing compound

Thanks for the responses
I guess its going to be a mixture of wellseal and silicon
Regards
Ken