Alternator gasket fitting?

[Fallout]

Now I've repainted my alternator cover, it's time to bung it back on. I have a gasket and also some instant gasket and have scrapped and cleaned the two mating surfaces, just as you would clean your own mating surfaces before mating. Mr Haynes is a little bit vague about this bit. I don't know whether to:

a) Just use instant gasket sealant
b) Just use the dry gasket
c) Use a combination of both

I was gonna do C and have a very thin beed of instant gasket on both sides of the paper gasket, but since I've never changed a gasket before, I have no scooby if that's overkill. I'm aware the alternator doesn't see much oil so this isn't too critical, but it kind of is because I had an oil leek from here before and this is why I'm fixing/repainting. Time to get it right! :D

[Sid Squid]

It should go on dry, although typically the maker will specify a smear of gasket goo on the crankcase side of the gasket, on the areas where the crankcases meet, (over the joint of the top and bottom cases), about a 1/2" on either side of the join is loads.

[squirrel_hunter]

Option B.

[Spank86]

Go in dry Fallout, we all know thats how you do most of your mating anyway.

[Fallout]

Alright then. Dry it is, with a bit of goo in the non-gasketed bits. As Spank said, going in dry is my preferred method anyway!

[Bibio]

i'm no doubt going to get flamed for this but many many years ago i was told to very lightly rub grease on gaskets. since then i have always done it and never had a gasket leak.

[Fallout]

Too late now dude. It's on, the bike is full of oil, and it's waiting for it's next ride to start ****ing oil out everywhere! :)

[Sid Squid]

i'm no doubt going to get flamed for this but many many years ago i was told to very lightly rub grease on gaskets. since then i have always done it and never had a gasket leak.
No flaming, clarification: That doesn't help with sealing, grease will not assist as it's soft enough to pushed aside by even slight pressure, and will soften further or even melt if the area in question is subject to heat, so could not overcome imperfections in the clamping pressure, or seal gaps. Some high pressure systems use gaskets that can fail if not fitted to perfectly clean, dry and degreased surfaces as the gasket can move and deform under pressure, and in extreme cases even slide out of the sealing faces.

A smear of grease may help stop gaskets sticking so that the joint can be opened without damaging the gasket.

Your success with sealing is due to fitting the gasket on good condition, flat enough, correctly cleaned and prepared surfaces - i.e. doing it properly.

[Bibio]

yup. i never scrape a seal surface and always use petrol, thinners, turps yada yada to soften then a cloth or tooth brush to remove old gasket bits.

[Fallout]

Right, so I shouldn't have used that gasket scrapper then. Now he tells me! :-P

[Sid Squid]

Right, so I shouldn't have used that gasket scrapper then. Now he tells me! :-P
Gasket scraper is fine - it was the Kango that's a problem.