Gaskets- dry or with something?

T> Regular paper gaskets- do you guys assemble them dry, or with alittle T> grease, vaseline, instant gasket etc on them??

T> Tim..

Depends on the joint faces. If they broad and in good, flat, condition I'd just oil (or gease) the gasket. If the joint look slike it needs a little more 'help', I favour blue hylomar.

nickh=== Posted with Qusnetsoft NewsReader 2.2.0.8

Do not use Blue or red Hylomar on Carbs not unless you want more problems :-((

Martin P

Pray explain please Martin. I've used it with no problems.

John

Same here please. We used to build the Rolls Meteors for the Centurion tank solely with blue Hylomar and occasionally the odd bolt

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

So, is green Hylomar OK then?

Julian.

c> Do not use Blue or red Hylomar on Carbs not unless you want more c> problems :-((

c> Martin P

Why's that ? I've found it fine in pretty much all applicarions. Goes wothout saying that no jointing compound should be used in such quantities that it could squeeze out and block things it didn't ought - the RTV silicone rubber 'instant gasket' types are particularly bad in that respect.

nickh=== Posted with Qusnetsoft NewsReader 2.2.0.8

Throw a stone into a pond :-)) As a young lad into bikes we were always told not to use it by the local bike shops as it could get into jets and ports and cause blockages, it was better to get the gasket fitted correctly without the need for sealants and on that basis I have never used it even though mates did and it gave them something to do to clean the carbs.

Martin P.

Same for me Nick - blue Hylomar seems good stuff.

I assume the reason to oil/grease the gasket is to let it move sideways as you tighten up. I can't see any benefit in swelling it up, unless it is to make it more spongy, but it would swell up in service anyway. On this basis I use grease rather than oil . Also I reckon they come apart cleaner if you can avoid using gasket plus sealant. If you have to use sealant, then use as little as possible, especially near oil ways. A glob of sealant can move up an oilway and strangle oil flow with unfortunate consequences (especially for low pressure feeds to rockers etc).

Steve

'Instant Gasket' should not be used 'with' a gasket, it is intended to be used instead of a gasket.

Hylomar is probably the best of the jointing compounds that can be used with or without a gasket.

Red Hermetite was also OK as long as you used it with a bit of common sense, too often it was trowelled onto joint faces to try and stop oil leaks, but that wasn't its purpose, it was supposed to be used with a gasket, not by itself.

In many instances, joints can be reassembled with just a wipe over with Blue Hylomar and no gasket if there wasn't one before.

Lapping joints together before final assembly also eliminates the need for jointing.

If more people took the trouble to clean off old gaskets/jointing compound and then looked at the joining surfaces to ensure that they were flat/clean, Hermetite and their ilk would not have survived so long.

Never buy an engine with Red hermetite oozing out everywhere! Peter

-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk

I use Stag Welseal for almost everything. I make most of my own gaskets too. At least that way I know they fit. Cheers, Scruff.

For all normal applications I use new paper gaskets and blue Hylomar applied with the No1 digital applicator. Allow to dry 5 minutes before closing the joint. This was the practice at Rolls-Royce cars in the mid 79's.

For more difficult applications, I coat the gasket with a very thin layer of silicone RTV - I prefer the clear variety meself. Trapping a blob between finger & thumb, I rub it into the gasket on both sides, setting it aside to dry for 24 hours. You now have a rubberised gasket & any loose shreds can be removed as solids before fitting.

I clean both joint faces with meths (commercial alcohol for our Leftpondwise cousins) & fit the gasket, tightening each fastener opposite another in at least three passes.

I discovered this latter method when trying to seal a Triumph long pattern primary chain case & it worked .... Nuff said, really!

Regards,

Kim Siddorn,