AGM 3927 Lantern

AGM3927

AGM 3927 Lantern as I received it

A few months ago, I was cruising an auction site and saw this sad looking lantern for sale. It was an American Gas Machine (AGM) Model 3927 lantern made in the early 1940s for use by the military. It sat there at the opening price of $10 and nobody bid on right up close to the end. Wondering if it might end up in the trash heap I figured I might take a chance and see what I could do with it. The shipping cost was more than the lantern.

When I received it I discovered that it was in even worse shape than I thought, even after asking the seller some questions. The worst part seemed to be that the top of the fount was caved in a bit on one side. Well, I figured that I didn’t have too much to lose at that point so I dove right in and began disassembly.

Rusted_Frame_support

Many of the steel parts were very rusty

I tried to remove the fuel cap, but it was rusted in place. I tried penetrating oil but it wouldn’t budge. Eventually, I tried a butane torch and it finally came loose. It turns out this was a bit of a no-no as the cap wasn’t free as much as the filler spout was coming unsoldered. Ooops! Things were looking bad and I didn’t even get to the difficult parts yet. I did get the cap off and re-soldered the spout thoroughly.

The pump handle was bent at nearly 90 degrees, but it is made of steel and to my surprise I was able to get it pretty straight. Straight enough to use anyway.

Bent pump handle

The pump handle was seriously bent. Yikes!

I remove the valve assembly as the valve stem and tip cleaner were stuck, especially the tip cleaner lever.

valve assembly before

AGM 3927 valve assembly prior to teardown

With a little coaxing the valve stem eventually came out, but the tip cleaner was really difficult. With a combination of soaking and a torch I eventually freed it  . . . well, most of it. The small bushing closest to the eccentric block was stuck and that took more time and lots of patience. In the end I was able to get all of the parts removed and cleaned up. I had never worked on an AGM lantern before and the parts were somewhat different that a Coleman. Most unusual was the tapered brass with steel spring which mounts opposite the valve stem and is activated by it. I’m still not exactly sure what this is doing, but suspect it helps with the air-fuel mixture and is perhaps AGM’s version of an instant lighting system comparable to Coleman’s Fuel-Air (F/A) tube.

Edit 15NOV18 – I actually understand how this works now. The short air tube is in a different chamber in the valve body. When the valve stem is partially opened it allows fuel from the left tube mix with air from the short right tube. Once the lantern generator is warm the user opens up the valve fully which allows the spring to push closed the tapered pin on the right closing off air-flow allowing only fuel to the heated generator.

3927 valve stem

Eccentric block (top), valve stem (middle), tip-cleaner lever (bottom)

Cleaned up and ready for re-assembly here’s what the valve parts look like . . .

3927 valve assembly

3927 Valve assembly and parts ready for reassembly

The ventilator was in good condition. It is green on top and blue underneath.

AGM3927 ventialator

AGM 3927 ventilator

The fount appears to have been hot dipped galvanized and even though it had the damage to the top, it was in relatively rust-free condition, which was a pleasant surprise. BTW – Don’t place a galvanized anything in muriatic acid. It’s not a good choice.

3927 fount

The cleaned up fount with dent mostly removed (between the valve mount and the fuel filler opening)

As you can see from the photo above the collapsed area on the top of the fount is nearly gone. How did I fix it? Well, I read a bunch of posts on the Coleman Collector’s Forum and some people said they tried compressed air to pop out dents, but most responses said that it was dangerous, because if something comes loose the flying debris could be very dangerous. Others had tried filling it with water and then boiling it, but it appeared that boiling and the resulting steam pressure could be just as dangerous as compressed air. Finally, I read about filling it with water and freezing it. That’s the method I used, and it worked pretty well. The dent isn’t completely gone, but it got most of it out, after . . . four freeze thaw cycles.

The bottom of the fount is labeled US, which indicates it was a military lantern.

3927 fount bottom markings

AGM 3927 markings on the bottom of the fount

I went down to the hardware store and found some paint which match the ventilator really well and painted the fount after some initial pressure testing. But, meanwhile, I was removing the heavy rust from the other parts with the help of some muriatic acid (concrete cleaner and rather nasty stuff), electrolysis (home brew type with a plastic bucket, some re-bar, and a power supply), and a wire brush.

Cleaned_up Parts

The steel parts cleaned up nicely

In the end I was pretty happy with all of the work, and after a little more testing, adding some mantles and globe from American Mantle, I fired it up and all is working well.

3927 complete

AGM 3927 complete

And, of course, one photo of it working . . .

3927 lantern working

AGM 3927 lantern, burning bright

It was challenging project, but I think it came out nice.

Thanks for visiting my blog.

One comment on “AGM 3927 Lantern

  1. […] is a pretty neat design. AGM, as shown in my 3927 lantern blog post , uses an opposing air shut off valve/spring, whereas Coleman used a stainless steel rod in the […]

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