That's the stuff - Permatex calls it Aviation Form-a-gasket #3H. It's like
the ever-popular Permatex Form-a-gasket #2 (brown stuff in a tube), but has
more solvent in it, so it is a thinner consistency and spreads more easily
with the brush attached to the can lid. It is not, repeat not the
"hi-tack" gasket adhesive found in all the stores. GM also has their
version of the same stuff.
When a gasket manufacturer like Fel-pro calls for coating of both sides of
a gasket with sealer, they don't mean blue silicone. When an explicit shop
manual tells you to use sealer part number xxx-yyy and gives you a photo
where to put it (yes, factory shop manuals can be that detailed) - they
don't mean substitute any silicone you happen to find on sale at the local
parts store and load it on. For example, if silicone is used on a cork or
rubber valve cover gasket it is highly likely that two things will happen:
1) The gasket will slip out of place on the slick silicone sealer as the
cover is tightened.
2) The sealer will not adhere to the metal because the installer did not
get all of the oil off the parts
With the brown stuff, a little oil film does not seem to affect the seal as
the solvent in the brown stuff will mix with a little oil and still work.
With silicone, it either adheres and it is fine - never to be removed again
without bending the cover, or it doesn't adhere and it leaks badly.
General motors used to make to kinds of silicone sealer for applications
when they were using it in place of gaskets. One was hi-temp and the other
was higher temp yet. Blue silicone is a joke in comparison to either - I'm
not sure why it is so popular (except that it is about 1/3 the price of the
good stuff).
For me, the only place I use silicone is for sealing only water passages in
valley pan type all-metal intake gaskets, frost plug installation, front
seal installation, and in places where two gaskets meet (such as corners in
multi-piece intake gasket sets or pan gasket sets). I buy the good stuff
and use on the tube for years - that's how much silicone I use. I have
never understood why people like to try to stick their engines together
with excessive silicone. I repaired one shade tree "rebuilt" engine that
had so much un-adhered silicone on the inside that it had accumulated on
the oil pickup screen and plugged it - scratch one engine - that extra
silicone cost him about $3.95 + $2500.00 in repairs. I also have seen
silicone users repeatedly ruin oxygen sensors in late model cars by
silicone sealer vapors being sucked into the intake through the PCV system.
Yes, I feel strongly about excessive and unnecessary silicone sealer
usage! Brown stuff never ever caused such problems, seals well, and I use
it wherever possible.
Les
At 08:30 PM 6/17/98 -0400, you wrote:
>It's been even longer for me since I've been all the way into an engine,
>but in my younger years we used a gasket sealant that cam in a can and was
>applied with a swab applicator attached to the lid. Stuff worked great. I
>don't think I'd choose to put the blue stuff everywhere without being sure
>I'd covered all the bases sealant-wise.
>
>Good luck!
>
>Tom Zuchowski
>'61 Bugeye
>
>----------
>> From: J. Adrian Barnes <adrian@icx.net>
>> To: spridgets <spridgets@Autox.Team.Net>
>> Subject: Gasket Techniques
>> Date: Tuesday, June 16, 1998 8:19 AM
>>
>> I am sitting here browsing through my sanitary copy of the
>> Haynes manual (I have two manuals for some reason), and
>> realized I am having a hard time finding my place because I
>> don't recognize any of the pages without all the familiar
>> greasy fingerprints. I can actually READ this one! :-)
>>
>> Anyway, I am ready to start putting the engine back
>> together, and am all the way to the first gasket. It's been
>> 6 years since my first (and only) rebuild and need a
>> refresher course on the proper way to use gasket sealant. I
>> have heard everything from "don't use any" to "use it
>> liberally." Does anybody have any rules of thumb for me? I
>> got that Permatex stuff in the blue tube. And it also
>> appears that you only do one side of the joint with
>> sealant...does it matter which? Thanks!
>>
>> adrian
>>
>> --
>> -----------------------------------
>> J. Adrian Barnes
>> adrian@icx.net
>>
>> icq: 5121878
>> http://www.ravineware.com
>> http://user.icx.net/~adrian/midget/
>> -----------------------------------
>>
>>
>
>
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