GM 1050026 / Delco 10-2018 Sealer Identical Substitutes

I’m putting it in the XJS list because it’s been discussed here in the past (as well as the V12 list) and it has to go somewhere.

GM 1050026 has been suggested for years by various folks on the list such as Chad Bolles for lots of sealing jobs like the cam-covers or even water hose connections. It is, as far as I can tell, pretty much NLA.

The original MSDS on 10-2018 tells us it was made by Perfect Seal Inc in Canada as Perfect Seal #4.

Chemical Name, CAS Number Prefix Value
ISOPROPYL ALCOHOL 67-63-0 = 24.1 %Wt
2-PROPANOL, 1-METHOXY- 107-98-2 = 4.8 %Wt
Silica 7631-86-9 < 71.1 %Wt
CASTOR OIL 8001-79-4 < 71.1 %Wt
Soybean oil, polymd., oxidized 68152-81-8 < 71.1 %Wt

As it turns out at least two other companies who’s products are still available used Perfect Seal #4 under their brand name: - and or have CAS # percentages in generally the same balance.

Evanrude Johnson # 0508235

And also Mercruiser/Mercury Marine 92-34227Q02


The New PN for 92-34227Q02 is 92-8M0170149 and is a Permatex product:

It’s CAS formulation and balance is NOT identical but has some similarities.

And then there may be Permatex aviation Form-A-Gasket PNs that confusingly are different.
E.g. (3H AVIATION FORM-A-GASKET #3 SEALANT) seems more similar to GM’s formula than the updated Mercury Marine Aviation Gasket Sealer:

Supposed additional cross references
MERCURY MARINE * 92-34227Q02

  • 342271
  • 34227
  • FK1151

LOCTITE * 1525607 (Very Similar)

PERMATEX * 80017 (Not as similar)

Paul K.

Hope you enjoyed this little rabbit hole.


Are all of these products intended to be used as gasket dressings, meaning applied to one or both sides of paper gaskets to help hold them in place during assembly and ensure a reliable metal-to-paper-to-metal seal? Or are some of them intended to replace paper gaskets, to be used to seal a metal-to-metal assembly? And are there specs on the size gap they will seal?

Except for when used for sealing or dressing the inside of coolant hoses, I’ve only ever seen it used as a dressing ON a gasket, unlike using silicon AS the gasket. - at least the GM product in question.

Think brown hylomar that’s oil and gas resistant, but easily cleans up with acetone…

~Paul K.

Brown Hylomar?

What is this?

Just an analogy about the circumstances in which you might use the GM sealant (or the other re-brands of it).