Gasket Wisdom? (Update to original post)

[scott r bishop]

Hi everyone - long shot here.  We need to replace the gasket to the thermostat housing (getting water spraying out of there), and all the auto shops have is a generic one that doesn't cover the piece correctly (circled in picture).  Marine shops have notoriously bad hours for people like us  , any chance someone near the Twin Cities has an extra one we can buy off you?  It's a Chevy 305/Merc 228.  Still haven't had the 18 in the water and I'd hate to wait until next weekend if there's anything we can do about it.  I can meet you pretty much anywhere, thanks in advance if anyone has one sitting around!

-Scott

[thedeuceman]

Could make one, most auto stores have material

[scott r bishop]

I think we ended up finding one out in Wyoming, MN. How do the "make your own" hold up over time? That will be the next attempt if this one doesn't work out. Thanks for the quick reply, much appreciated!

[Hyperacme]

Set part on gasket material and lightly tap with rubber hammer, should make a indent in gasket material, cut with utility knife.
Save ya trip to Wyoming !

[scott r bishop]

  Thanks for the advice offered!  We did end up finding a gasket, but the leak persists.  It was less, but still there.  We have now taken the full thermostat housing off (the big thing all the hoses go into) and plan to replace both the upper and lower gaskets (before we were just replacing the upper one where the actual thermostat goes).  Upon further inspection with the whole thing off we may not have cleaned the surfaces off well enough (micro-thin pieces of the original gasket were still shaving off with a razor).  So before we reassemble it tomorrow, I was hoping to get some collective wisdom from the group on installing them.  

  Aside from cleaning the surfaces with a razor, using some PBX blaster to remove the gummy stuff, and tightening the bolts alternately to make sure it seats properly; are there any other tips you have for installing gaskets?  Do you use gasket sealer as an added precaution, or is that something to stay away from?  We plan on reinstalling tomorrow morning, and as always any insight you all have would be greatly appreciated.

Thanks again,

Scott

[Rosscoe]

I'd use Permatex gasket cement on it for sure.
You could use some fine sandpaper too. Apply gasket cement to everything. That alone should stop the leaking.

[dorelse]

Yep, I use a fine grit sandpaper to make sure the surfaces are clean.

[scott r bishop]

Success! Put it all back together with some gasket sealer, and no leaks. I would not have used that without the "okay" from you more experienced mechanics, so thank you very much for your input, it is always appreciated.

[Hyperacme]

OK ... You owe us some "On the Water" pictures now ... LOL

[Jerry]

If you go to buy a gasket set for a newer GM (and others I think) you get a tube of silicone.You shouldn't use a gasket and silicone together, but if it works, don't mess with it.