Successful Conversion of a Coleman Picnic Stove

[parnold]

I bought this stove on ebay, and after getting it, discovered that you can't buy the canisters anymore.



It's such a neat looking stove, I just had to think of something.
I had an old primus double burner stove, and it had a hose going to a bar, with two knobs, and jets that blew the propane to the burners. I scavenged the bar from that stove.

The original piping in the coleman picnic stove had the oddball ends on it to connect to the cannisters. Notice the fitting on the right side of the picture.



I cut that fitting off.



I drilled out the jet in the donor bar, and inserted the end of the brass pipe from the coleman into it.



Next I drilled two holes in the support brackets at the back of the picnic stove, noted by the arrows.



I put the pipe back in place, tightened everything and got ready for soldering.



Here's the beginning of my boil test. Two cups of cold water, no wind screen, and a mild wind. The timer is counting down from 15 minutes.



10 minutes later, I had a slow boil!!!!



I ran the same boil test in my house, and the water came to a slow boil in 3 minutes. Now I'm thinking about playing with the hole size on the risers from the jets on the stove, but I have no clue what I'm doing other than adjusting the air/fuel ratio.

My next test will be a bigger pot of water, but I'm thinking a little less heat will probably be acceptable. I usually burn things when I cook anyway!!

[parnold]

Update!

I brought the stove in the house, and without wind, it took 7 minutes to bring the water to a low boil!!

[Alan Wood]

Congratulations on the conversion.

However I sugest you only use that outside. Would not be pretty if anything went wrong and you were using a modified propane apliance.

[High Desert]

A very interesting solution Paul. Thanks for sharing it.

So in the pic is the stove connected to a large tank with a regulator or a 1# bottle?

[parnold]

The stove is connected to a 1lb bottle. I believe the regulator is built into the part that the bottle screws into, it's rather large to be just a connector.

I played with it a little bit more, and tried covering up one of the two holes in the riser above the jet, and it burned very poorly, so less air was a bad thing. I'm very hesitant about trying to enlarge the holes though, it's hard to go back once you've made a hole bigger.



I'll post more pics once I've built the enclosure for it.

[parnold]

However I sugest you only use that outside. Would not be pretty if anything went wrong and you were using a modified propane apliance.

Alan, the beauty of the mod is, the bar I took out of the primus stove, still has both of the shut offs. If one of my solder connections started to leak, I can just turn that one off. There are the two primus knobs on the back of the stove, and the two coleman knobs on the front.

Normal operation, the primus knobs are alway in the on position, and the stove is controlled by the coleman knobs.. but there is that safety factor built in (by accident).

[High Desert]

However I sugest you only use that outside. Would not be pretty if anything went wrong and you were using a modified propane apliance.

Alan, the beauty of the mod is, the bar I took out of the primus stove, still has both of the shut offs. If one of my solder connections started to leak, I can just turn that one off. There are the two primus knobs on the back of the stove, and the two coleman knobs on the front.

Normal operation, the primus knobs are alway in the on position, and the stove is controlled by the coleman knobs.. but there is that safety factor built in (by accident).

Sounds just right Paul. Thats just how the newer stoves are too

[doug hodder]

Paul....good deal on getting if fired up...I'm wondering it's more a pressure issue rather than a fuel/air thing. If you've got a good clean tipped flame, seems to me it would need more OOOOMPH...God forbid...someone operate a stove with some pressure behind the fuel...OH my god...watch out...she's gonna blow!!!!! Sorry no emoticon for sarcasm....Doug

[parnold]

Doug, the flame is all blue, in fact it's hard to see it unless you get down and look across the burner at eye level.

I don't know what that means.

Also, you can hear the hiss of the propane, say at a quarter turn of the knob, but it doesn't light until a full rotation.

I didn't think to look at the number and size of holes in the burner, and the old stove is in the garbage already (maybe I should pull it out). I think it is acceptable the way it is, but it could be better.

Tomorrow I'll fire up my liquid fuel coleman, and see how long that takes to boil water... you know the old saying.. a watched pot never boils.. maybe I was watching too much.

[Zollinger]

Wow! Paul you are really talented. Good job on the stove.

[parnold]

Here's the view from the back, showing the shutoff knobs from the donor stove.



Here is the difference in the burners, the one on top is from the donor stove.



If anyone is interested, this was the donor stove.



I made a box for the stove to slide into, I wasn't particularly fond of the open sides and back.




I may play with the holes in the burner, I'm thinking that by covering some I may be able to get a hotter flame. Anyone have any ideas?

[doug hodder]

Paul...that really came out nice! For blocking the holes you could get a LOT of very small screws ( sheet metal maybe) and install them...it would be a hassle, but would make it adjustable by pulling or adding screws. That way you could make a good flame pattern. Just an idea. Good job! Doug

[parnold]

Just an idea.

And a damn good one!

I'm going to get some foil tape to do a test run, but stainless sheet metal screws would be an awesome permanent solution if it works!

Thanks!!

[starleen2]

Nice conversion

[parnold]

Follow up. With the stove in the box, it didn't draw enough air. I drilled two 1 1/4" holes on the sides by the burners for air. One on each side. It burns like a dream.