Well seal or blue hylomar

[AdrianS]

What's the preferred gasket cement for the inner timing cover? Blue hylomar or Wellseal on the gasket?

[JulianS]

I use Wellseal applied with a small brush and use SRM gaskets, which fit much better than the more commonly available ones.

[mo goldie]

I agree I use wellseal on all my bikes and works great and you dont see blue squirting out all over the engine.

[Bess]

Hi,

    Blue Hylomar.

Used Wellseal on the engine casings once it was still dripping out a few months later.

Best wishes...

[PeteRae]

I use wellseal  on crankcase halves , both jap and brit, and blue hylomar (sparingly) on other gaskets or sealing faces.
As long as you don't lather it on it's fine.
Works for me....but not for everyone.
Pete

[chaz]

been using Wellseal since the mid seventies mainly on non seperating assemblies as it sets. where covers are likely to be needed to pull off then blue hylomar or equivalent. the Japanese use a product Michel which is grey and soft as they tend not to use gaskets. there is also a product which is oil and petrol proof best for fuel areas.
whichever I do like to clean off after use, so many restos of the late 80's still have red hylomar visible including fingerprints/

Wellseal, as it was a Vauxhall used workshop product when I  rebuilt my first engine , a Viva HB. if it was good for them.... and Ive been GM most of my driving life.

[Richard Mills]

Blue Hylomar was an excellent product until it was changed. I now find it impossible to spread thinly and evenly, it seems to dry in an instant. Anyone had success with a tube bought in the last few years?

[DAVE BRADY]

Hi Richard,

I am fan of Blue Hylomar and I find that as a tube is used it seems to get a bit thicker and harder to spread.  I would imagine that each time the tube is opened some of the solvent evaporates.  I always put the top back on a quickly as possible and perhaps I will buy smaller tubes in future to help to reduce wastage.
It sometimes helps to remove the bit that has gone off at the top and get through to the 'fresher' stuff.

Dave.

[Bess]

Hi Richard,
                 As Dave wrote, plus it has a best before date.

You might be using the bulk standard Blue Hylomar not the original Rolls Royce designed Hylomar Aerograde, a superior product.

Best wishes...

[DAVE BRADY]

Yes!  Definitely Aerograde if you can get it.

Dave.

[Phil C]

Much more expensive though.  Does it have a shelf life like the Blue?   Phil

[PeteRae]

You can buy the aerograde in Cromwell outlets....only had to get some coz i ran out of my "aquired" Rolls Royce aero stuff from the RAF.
Pete

[Bess]

Hi Phil,
          The Aerograde also has a shelf life.

Best wishes...

[Phil C]

Hmmm...

Just been looking at it online. Medium grade.  Says for thickness up to 0.03mm.  So that's just over one thou.  That's a pretty thin layer of compound.  Or am I mistaken somewhere?   

Phil.

[Bess]

Hi Phil,
          Face to face joints such as main casings will be fine. Other joints using gaskets in the world of engineering are designed to be used without products but old casing surfaces can be dire so a light smear of product takes up the discrepancies.

Not saying this is correct, others might have their own methods:

I clean the casing mating surfaces, filing off any high spots with a dead smooth fine (rubbing the teeth with chalk first, stops the aluminum clogging the teeth), apply a thin layer of Hylomar to the gasket, fit the gasket Hylomar side to the engine, once fitted, smear the other face of the gasket with a thin layer grease, let it soak into the gasket, then a thin layer of Hylomar to the other case and assemble together.

If you want a joint without a gasket because the mating surfaces are really bad I would suggest silicone RTV. Again apply a layer of silicone RTV to the engine and grease to the other case then assemble, lightly tighten and allow to semi set before finally pulling together.

There can be issues with product entering the oil, so you need to balance up the quantity of product to stop leaks against the risk of excess entering the oil system.

Best wishes...