Thin Gasket Material?

[Buccaneer]

What all are you guys using for "thin" gasket material?
The 1940 Sportwin I’m working on has cylinder and
crankcase gaskets .012 thick. The last time I had this
problem I ended up using a paper grocery bag
and some kraft paper that were .008 thick.
There is some 1/64" gasket material "out there", but
that’s almost .016 thick. Perhaps .004 oversize
isn’t too critical regarding compression, but still
maddening that I can’t find what I want.
If grocery bags are used, do you treat the paper
with grease to make them more resistant to
deterioration?
Last time I bought some thin material, it was Karropak,
and it turned brittle and would crack easy while
cutting out a gasket.
Thoughts?
Thanks!

Prepare to be boarded!

[RICHARD A. WHITE]

I use the stuff from Napa, 1/32 thick, never worried about what it did to compression since it was not used on a racing motor…I will admit, it might cause issues with exhaust bolt up on opposed twin motors so beware of that.

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[billw]

Even though I get 1/32" as about .031", are you keeping in mind that it crushes when you tighten the parts together? I mean, if you mic out your old gasket as .012", that’s not what it was when it was new….This may be a stupid question; but I had to ask, just in case you didn’t think of it…

As for splitting, a rule I made for myself is to always punch the holes first, then cut. It keeps the material from splitting when you punch too close to an edge.

Long live American manufacturing!

[chris-p]

quote Richard A. White:

I use the stuff from Napa, 1/32 thick, never worried about what it did to compression since it was not used on a racing motor…I will admit, it might cause issues with exhaust bolt up on opposed twin motors so beware of that.

Learned that the first Ruddertwin I restored. Couldn’t get the damn exhaust on after I installed the jugs! Too thick a gasket.

[RICHARD A. WHITE]

quote Chris_P:

quote Richard A. White:

I use the stuff from Napa, 1/32 thick, never worried about what it did to compression since it was not used on a racing motor…I will admit, it might cause issues with exhaust bolt up on opposed twin motors so beware of that.

Learned that the first Ruddertwin I restored. Couldn’t get the damn exhaust on after I installed the jugs! Too thick a gasket.

Same motor I found out on…LOL

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[twostroke]

Napa and almost everyone else has gone to Fel-Pro gaskets….back in the day, when I had parts stores (and hair…) I sold Victor. Victor had some really nice stuff that didn’t compress much in a variety of thicknesses called "Victolex" if I remember correctly. Usta’ use it to make base gaskets for my Rotax motors when I was racing sleds…..we did some tuning voodoo with port timing with different base gasket thickness. It may still be out there….

Jim

I say "pardon me" a lot. I had a 20H, then raced open mod sleds.

[Buccaneer]

Thanks for the replies. I found some Mr. Gasket 9610MGR
that says 1/64" or .015 thick. One comment
on Amazon says it’s actually .012 thick.
Either way, I’m going to call it close enough!

Prepare to be boarded!

[green-thumbs]

Punch holes first is good advice.
Cut out inside as required next.
After installing gasket trim the excess from exterior.
It is a good practice to cut the blank large so you will not be punching or cutting near an edge.
Thickness of gasket stock does not seem to matter to those who sell gasket sets..
They measure all over the place when checked with micrometer.
Gasket material at auto parts stores seems often to kept "in back."
Ask the clerk to bring out what they have.
Usually they have more than one thickness on hand.
I have had no luck finding suitable material to make heat resistant gaskets,.
Those I have to order as NOS.
Heavy duty paper bags are about the right thickness for water pump to gear housing gasket
used on Early Kiekhafer outboards. Grease the paper before installing.
An antique outboard may have leather seals which also can be made with punch and a little
imagination. Save leather scrap for a new purpose.
The $5 punch sets are good values for the money.
Punch will cut gasket cleanly if you use with end grain cutting block.
Maple is wood of choice. Other wood will work. Important thing is end grain that lets
knife edge of punch to go clear thru the gasket into the wood.
Louis
.

[fifty20ne]

Posting some pices for Lou " Green Thumbs"

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[jerry-ahrens]

Nice work on the gasket making. I like the big wood block too, great idea.

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