Re: merc 800 crankcase gaskets need sealant too?
You still need to use a sealer even with cork strips. Use Loctite "518" anaerobic gasket compound, Mercury "Master Gasket" kit, or OMC Gel-Seal.
The "Master Gasket" kit is just Loctite 518 and a small spray can of cleaner/primer. It helps the sealer cure faster. But I've used the Loctite by itself for years with no issues.
One thing, all surfaces Must be scrupulously degreased/cleaned. I use lacquer thinner and a soft-bristled brush.
When you've got the cork strips in place, you'll have to trim the excess length. Note these strips lay 'flat' in the grooves, with the built-in adhesive to the side. Be sure you scrape any remnants of the adhesive out of the crankcase grooves while prepping the block.
Spread the sealer on one side of the block only. Easier to do the block than the cover. This must be an extremely THIN coating, remember it's a metal-to-metal fit and all excess is gonna squish out anyway, so you don't need much. A latex-gloved finger works real well for this and keeps the Nasty Stuff off your skin.
When it's all ready to go, slap that intake on and don't mess around, get the bolts in and torqued down! You don't want to take a break half-way thru; the sealer could start curing before you tighten down all the way, then you have the potential to 'shim' the block. The sealer normally has a pretty forgiving cure time so this shouldn't be an issue, but I'd be remiss if I didn't mention it. It will begin the curing process as soon as it's squashed.
Anyway, that's a quick overview, be sure to consult your manual for the gory details!
HTH........ed
