Gordon_M

I can't weld wood ... There are some similar interests / displays of Red Cross stuff, Clubmobiles and the like, which are worth seeing.

Welcome here, seen you on the tools forum for years and never knew your background - interesting

It does look nice, it's inside, in the dry, and being cared for. A coat of green paint would cure it all ( That wouldn't have been OD originally, or would it? ) If I had my pick I'd go for the Ahrens-Fox pumper beside it, you could REALLY make an entrance in that. 😇

I wouldn't have thought there would be a discussion about coating ... To me it would either have been painted to match or just coated with boiled Linseed Oil

That roof seal strip will cause you grief. The least you need to do with it is a thorough clean and seal externally. If necessary an effective replacement can be made by flattening a section of steel brake pipe. Having had the whole system apart, that seal strip is a sheet of metal folded in a 'Z' configuration, which is then spot welded to the rear of the cab roof, and then that whole assembly is spot welded to the front of the roof. Better avoided unless absolutely essential, about a third of the assembly sport welds on the two I have worked on didn't go through anyway.

I have historical experience with casting like this. Ideally you would have an original link, make up a pattern to match whatever production method the foundry was going to use, and just donate gallons of blood for the cost. Given the way that you have done everything else, I'd suggest that you find or make one track link you are happy with, and then get steel plate and section laser cut so that you can just fabricate them. That would be much easier to fine tune, make small batches, and make extras than actually casting them. Still lots of cost and lots of welding, but you would be doing a lot of it yourself at a rate you were comfortable with. Do you have one original link, or is there somewhere like the Tank Museum that may have one and could give you access to copy?

Interesting, thank you. Several of the companies I worked for back in the day either did galvanising themselves or used suppliers who did it for them. That finish is too fine to be galvanising, so if it is zinc it is probably zinc plating. ( and galvanising would probably still be complete after a mere hundred years or so.)

Jealous, and I wouldn't even have a use for it. What was the original finish, silver paint or plating?

Guesses only here ... The first wheel would be a full wooden rim, just like a buggy wheel, in four sections ( felloes) with the joints halfway between the spokes and a rim bolt or similar at the centre of each section. The second wheel looks like a metal rib with eight turned fello sections, each with a groove that just slotted over the metal rim. Again the through bolt would be at the end of each spoke but the mid point of the fello pair.

At a guess it was cheap, and the block wasn't amenable to being reworked for a full pressure system. You would have to look back to when it was introduced, not forward in time till '53. I'd guess it was introduced in the 1930's when the horsepower and load characteristics were more than enough. Chrysler has the same problem with the 23.5" long block / head on the original Dodge 230. When it was introduced it was 201 cu in or less, and there was plenty of metal between the cylinder pairs. By the time it had been bored and stroked to 217 and then 230 cu in the head gasket width between the two close pairs was only 1/4" or so, they physically couldn't get any more from it due to the original design of the block - I'm sure the Chev problem was similar - inherent in the original block design.

It's good that it has an original engine. I've been told more than once that the weak point of those engines was the splash oil lubrication. ( of the big ends I assume ) which meant they were a lot less robust than the full pressure fed GMC 270 type. Anyone have any more on that?

Weld quality is normally just a question of practice, as long as you are getting some feedback on exactly what you are doing wrong. I have spot, stick, and MIG welders here, but the MIG is my choice for almost all welding. If drastic action is needed just have a socially-distanced open day and invite a few local members with tools. Cutting up an axle over a hundred years old isn't really a sensible option even if you have spent weeks on it.

Send pigeon to welding college or pie-makers immediately. 8-)

Since everything there is hardened, could you get the assembly horizontal under a wire spark eroder or similar, that would go straight through it with little damage and not enough heat to harm wood?

The trailer for the film about Pearl Harbor made ten years back showed a Korean period Dodge M43 Ambulance getting shot up ...

On Dave Engels YouTube channel he commonly cuts these bands on buggy wheels, but it is normally so that he can shorten them and re-install them tighter.

The 'strange aluminium spacer' may be there deliberately as a sacrificial corrosion point, cheap, easily replaced, and preventing corrosion on the tank face. I assume it faces aluminium on one side and steel on the other?

There's a photo of the guilty party up the thread, a Thompson Sub-Machine Gun. If you had a Thompson with the safety off and a loaded magazine, but no round chambered, and you dropped it on its' tail end from a height of a couple of feet, the weight of the bolt was sufficient to slide back, chamber a round, and fire it. You would probably only make that mistake once though.

I can pretty much guarantee that if you try any invasive mechanical repair it'll just get worse. Dab of sealant and running unpressurised would be the thing.

Pores rather than crack I think, it'll flex every time that head bolt is tightened. Clean and cover, but don't be too hard on it as it is eighty years old. 8-) Running the cooling system unpressurised would be the thing.

Yes but not easy. The big problem is finding the extent of any crack, and if it is porosity you are limited to sealer.

It could be a crack, or a small porous spot in the block. One of the things most people don't realises just hollow pressure the cooling systems are on these engines. A new truck and radiator would have a 4psi radiator cap on it, and it would only reach that pressure when working really hard. Clean it and paint it again, maybe with some sort of sealant, then turn your radiator cap back to the first click so it is locked in place but not pressurising the radiator, and just drive it

May be peened over on the back so you may have to grind or file a little.

That's just a blind rivet that has been peened over I think. Should tap out with a fine on the back

Sharp tap sideways will do it. Doesn't have to be a chisel, any solid metal that will transfer the tap without shearing the head off, just go carefully. These sort of rivets are normally used to attach plates to castings, liken engine block.