Have you given any thought to compressed air underneath and soapy water inside to get the exact spots it leaks so you can focus your effort more?

Old wrote:

 

Yup ... easy and one less thing to worry about.
popped in from working on the shop....
Made the shop out of aircraft anger doors off Elmendorf Air Force Base
"Elmendorf Air Force Base IATA: EDF, CAO: PAED, FAA LID: EDF) was a United States Air Force[ facility in Anchorage, Alaska. Originally known as Elmendorf Field, it became Elmendorf Air Force Base after World War II.It was the home of the Headquarters, Alaskan Air Command (ALCOM), Alaskan NORAD Region (ANR), Eleventh Air Force (11 AF), the 673d Air Base Wing, the 3rd Wing, the176th Wing and other tenant units."
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. dismantled in the 70's and purchased in the 80's

Really appreciate all the advice and suggestions. Thank you to all who have chipped in! Here is where things stand:

As to whether cast iron or steel, I have had experienced folks express confident opinions both ways. When I do a bit of grinding, I will do the grinder spark test. Regardless, it was poorly welded and re-welding is still a long shot option.

At this point I am anticipating trying to seal the interior and the exterior. This will involve cleaning the interior, using repeated cycles of heat and brake cleaner, sweating out as much oil as possible, roughing up the surface, and, if I can get my hands on it, using Glyptal 1201 Red Paint to seal the crack. With the exterior, I will grind down the weld to create a clean surface and, again if I can get my hands on some, seal it with Permatex Spray Sealant Leak Repair.

The challenge is that neither product is available locally. In fact, the Permatex Spray Sealant is not sold in Canada. So working to source. The alternative exterior treatment would be JBWeld with fiberglass. Or at least that is my latest exterior option. But I am working on seeing if I can find someone going between Alaska and the states to pick up a couple of cans, passing them along to me (for appropriate consideration) when passing through Whitehorse on the Alcan highway.

I have at least a couple of weeks before my access road will be dry enough to do any repair work. And I am also waiting on the re-glazing to be completed. as well as for filters and etc. from Cat to do a general oil and filter maintenance.

restore49 wrote:

Have you given any thought to compressed air underneath and soapy water inside to get the exact spots it leaks so you can focus your effort more?
 

Really interesting idea. Will certainly give it a go. Thanks!

Stay away from trying fiberglass - do not flame dry Brake Clean toxic Gas - I know some folks are not keen on JB weld - have done multiple repairs years ago with no issue (not the quick) - if you grind away at the weld bead you can weaken.

restore49 wrote:

Stay away from trying fiberglass - do not flame dry Brake Clean toxic Gas - I know some folks are not keen on JB weld - have done multiple repairs years ago with no issue (not the quick) - if you grind away at the weld bead you can weaken.
 

Curious as to your warning about fiberglass (with epoxy like JBWeld) on the exterior? Mind you, my hope is to get my hands on the Permatex Spray Leak Sealant.
Not to worry about using flame to heat or dry. I have a heat gun and an infrared heat lamp. As for grinding the weld, two master welders who have looked at it thought it would not weaken the weld. My reasoning was that it would make for a more uniform and clean surface. Can you tell yet that I am in no ways have expertise about such matters?

A MASTER welder would have v ground out the inside and outside and melted and joined the inner and outer root passes together. If this weld is not done by a MASTER and you grind away the weld overlap you may expose a crack line. Get a hand held glass bead blaster - find the location of the leak - clean clean clean use a pick glass bead chemically clean heat clean maybe carbide grind where the leak is and epoxy of your choice - forget fiberglass.

If glass bead masked off all around.

The weld that is leaking was clearly NOT done by a master welder. The two master welders who have looked at it are nervous about trying to re-weld. Both have recommended trying epoxy. Will check out glass bead blaster... Thanks!