# 1945 Montgomery Ward air compressor



## OVML915 (10 mo ago)

Vintage air compressor that has been in the family since new. Looking to use this with a new tank. Has a 1/2 HP motor that works. Last time I ran it, the pressure switch was set to 90 PSI and it filled the tank quickly. Slings oil. Anyone know anything about this? Would I be able to find rings if needed? What is the part on the left side and the canister on the back (viewed from front and highlighted in the pictures)?


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## OVML915 (10 mo ago)

CORRECTION - tank made in 1946 not 1945


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## iowagold (Jan 22, 2020)

make sure to have the tank tested for safety sake.
old tanks can be rusty inside.

good old mechanical pressure control system.


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## stevon (Mar 5, 2019)

iowagold,

I think he mentioned he was going to "use a new tank" guess he's sentimentally attached to the old pump

Stephen



iowagold said:


> make sure to have the tank tested for safety sake
> old tanks can be rusty inside.
> 
> good old mechanical pressure control system.


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## OVML915 (10 mo ago)

Yes, I will use a new tank but keep the pump and motor mounted on the old tank for show. I remember my brothers painting car parts with this in the 60's. It was in the same garage from 1949 until I inherited it in 1994. 

I could not find any pictures or description of the part attached to the crankcase opposite of the flywheel. Turns out to be external flywheel counterweights and the unloader valve. The weights are spring-loaded and move the unloader valve actuator like a solenoid. Still not sure what the canister is at the back of the pump. It connects to the check valve and the unloader valve. Maybe part of the unloader valve (which is open whenever the pump is not spinning)





















?


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## stevon (Mar 5, 2019)

OVML915,

The tall "can" looks like a muffler to lower the noise while compressing. That's my guess. They don't build for quality these days, that's for sure.

Stephen


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## sdowney717 (12 mo ago)

yeah, old tanks can explode like shrapnel and kill. A compressor pumps in humid air, and the tanks collect water and they rust out on the inside. How old before such a tank should be replaced? I have a compressor that gets extreme minimal use and it is from the late 90's. The tank cylinder is horizontal, only the forward front of the tank faces the garage doors. I keep it wedged between a red brick wall, the base of the furnace and a heavy built wood work bench.
The backside faces a rim joist and wall
I figure the weakest part of the tank is where water sits, so that is low down on tank bottom facing the concrete floor. I use a very long air hose on a cord reel, so the thing only gets rolled out if I need to work on it. Mine has 2 pistons, typical cylinder model with a belt and electric motor and pullies.

I tend to think though, the rust may form pinholes instead of exploding.


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## stevon (Mar 5, 2019)

sdowney717,

If you are worried about or doubt a tank's safety, a simple hydrostatic test will solve both concerns. You test slightly beyond what you will regularly use the tank pressure at at. or slightly past the working pressure marked or stamped on the tank. Just make sure that you don't go up to the listed burst pressure!

Stephen



sdowney717 said:


> yeah, old tanks can explode like shrapnel and kill. A compressor pumps in humid air, and the tanks collect water and they rust out on the inside. How old before such a tank should be replaced? I have a compressor that gets extreme minimal use and it is from the late 90's. The tank cylinder is horizontal, only the forward front of the tank faces the garage doors. I keep it wedged between a red brick wall, the base of the furnace and a heavy built wood work bench.
> The backside faces a rim joist and wall
> I figure the weakest part of the tank is where water sits, so that is low down on tank bottom facing the concrete floor. I use a very long air hose on a cord reel, so the thing only gets rolled out if I need to work on it. Mine has 2 pistons, typical cylinder model with a belt and electric motor and pullies.
> 
> I tend to think though, the rust may form pinholes instead of exploding.


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