Porous cases fix

[thirdstone]

I was having problems with some older modified Wombat cases failing leak down checks. Air was slowly coming out through the metal near the transfer tunnels . I read up on this and it seems it was common back in the day on other engines even going back to WW2 aircraft.
They use to fix it with a pain like product.
Got me thinking , I used a tank rust repair sealant like that used inside fuel tanks . Worked a treat.

[taber hodaka]

Are you saying air was coming through the aluminum cases?? -----------Clarence

[thrownchain]

I believe they used to use a product called Glyptol, which was red in color, used to seal pourous metals.

[thirdstone]

Are you saying air was coming through the aluminum cases?? -----------Clarence

Yes

[thirdstone]

I believe they used to use a product called Glyptol, which was red in color, used to seal pourous metals.

Yes Glyptol was one of the products used years ago and is still available. From what I could work out it was used in oil pans but I couldn’t work out if it was fuel resistant. One message board thread I read says it wasn’t so I didn’t use it.