Engine/Tranny Case Sealant? Gasoila?

[T. Cotten]

Josh!

Glyptal goes on well with a cheap disposable foam brush. Thorough de-greasing and pre-prep is critical, as with any sealer.

A gentle slow bake is highly desireable; It will turn a darker shade, letting you know it is fully cured.

Last week, an associate brought in an OHV lower end that I performed thirteen years ago.
The glyptal was pristine, indicating that he had a very secure petcock.


....Cotten

[GrandpasHarley]

Thanks Bob and Cotten that information is very helpful

Regarding case preparation before putting in the Glyptal. I washed the Case in paint thinner/mineral spirits. Let air dry, then bead blasted all the grime away with AB size glass beads. Then I placed the case, kicker cover, and top plate, in my mother's dishwasher over Christmas, I did not use soap, just a hot water wash/rinse.

I wasn't able to pull out the parts until later, so they completely dried in the dishwasher. Oxidization started to take place on the inside of the case leaving white residue.

What is the best way for me to clean out aluminum oxidation residue before coating with Glyptal and baking in the oven?

Thanks,

[GrandpasHarley]

Earlier post correction

Earlier post #14....

It also says that when possible the coating should be baked for 2 hours at 125F. Is it necessary to do this?

Should Read "... 2 hours at 125C..."

[larry]

A 10% ethanol/gasoline blend will remove baked on Glyptal overnight. Is this not a problem?

[T. Cotten]

Larry!

Glyptal has excellent resistance againt ethanol alone.
However, USA fuels combine it with highly digestive injector cleaners, detergents, and other un-named additives to form mixes that can even eat powdercoating.

Within your motor, it should only a problem if your petcock leaks, particularly for American OHVs.
Perhaps if the motor develops severe blow-by past the rings, then the coating would be compromised, but the rest of the assembly would be on a short fuse already.

....Cotten

[larry]

Thank you.

[Re-cycleInc]

Ok...sorry for the dumb question, but why do I need to coat the inside of my cases and cam cover? I just pulled apart my 47WL cases, cleaned them, checked the tolerances and reassembled everything without using any sealers except for the normal gasket surfaces. I used the Yamabond on the cases and I'm hoping it holds up, but I guess it doesn't matter since it sounds like I have to take apart the whole thing in order to redo the insides. What advantage does the coating (Gasolia or otherwise) provide on the inside of cases? Is it a seepage/penetration issue?

Thanks,
Scott
AMCA# 13993

[Chris Haynes]

Your cast aluminum cases are porous. In rare occasions oil can seep through the pores. Coating the inside also make a smoother surface so oil can return to the bottom faster.

[T. Cotten]

The next reason is to encapsulate any embedded grit.

...Cotten

[Re-cycleInc]

ah ha...I get it now, thanks. I imagined that oil could possibly seep, but discounted it. I can see how it would give the oil a more slick surface to help it back to the bottom of the case too. My experiences have been mostly with late model Yamaha's at this point and I've never seen it on any of those cases, but the castings are incredibly smooth and non-porous. The same was true for the '70 XLCH that I did a while back. This was the first time I had seen the Gasolia so I figured someone else had added it during a restoration and that it wasn't necessary. I then started seeing it in more and moer pictures so I figures I'd ask the experts here. Looks like I'll be tearing apart the motor I just had just about finished!

Scott
AMCA# 13993