Propane bottle question

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Demon
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Thu Mar 05, 2009 6:12 pm

I want to make my first combustion cannon a metered one, so i really need to know how do you attached you propane bottle with the adapter with built in flow regulator to you metering system.

I know there is a special fitting that can do so but i dont have access to a large variety of plumbing fittings. Maybe i could put a hose on the torch end or something like that.

Could you just tell me how do you did it, i would be very thankfull.

By adapter with built in flow regulator i mean this one:

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Hubb
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Thu Mar 05, 2009 6:46 pm

Putting a hose on the torch end is a great idea. In fact, that's what I did. I cut the torch head at the spot just below the bend and I used, I think, 3/8" fuel line with a hose clamp. Also, I scored the brass a bit with a file before I put the hose on, just to make sure it held tight.

The regulator is on the meter. The hose runs and connects to a barb on the meter. Am I making sense?
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FishBoy
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Thu Mar 05, 2009 8:44 pm

actually, with a vice and a wrench, the curved nozzle piece can be screwed out of the base
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sgort87
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Thu Mar 05, 2009 9:04 pm

You can remove the nozzle stem and pop in one of these guys:
http://www.launchpotatoes.com/index.php ... oductId=54

Or you could use one of these:
http://www.launchpotatoes.com/index.php ... oductId=37

(shameless plug :D)
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starman
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Thu Mar 05, 2009 11:19 pm

I prefer using the first method gort describes because the valve that comes with the pencil torch is high quality. Wrench the crooked pipe out of the valve base... pipe wrench or vise grips will be required.
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Combustion Monkey
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Fri Mar 06, 2009 11:16 am

I have cut and threaded a few torch heads using a chasing die. The die cost 5 bucks and does a very nice job.

Also, due to the regulator failures that plague me I no longer use one. I use a gauge on a T fitting just before the meeter. I just open the tank valve until I hit the correct pressure then shut it.

EDIT: added something
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Fri Mar 06, 2009 11:50 am

Demon... search!

I'm not saying this out of meanness or because it's something millions of people have asked, but because doing so will keep you from buying parts online that you could simply walk to the hardware store and get.
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Demon
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Fri Mar 06, 2009 1:03 pm

I 've searched a good 1 hour i think on internet.

But my hardware store is very incomplete and evrything costs a lot. Exemple: If i wanna make an combustion spudgun, i can only make a 2 inch chamber because they dont f%#@ sell the cleanout plug, just the pipe and its cap when its 3 inch or more.

So i dont think they got that piece and i thought that the best place to kow how people make is here.
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jimmy101
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Fri Mar 06, 2009 1:47 pm

Don't really know why people insist upon trashing a perfectly good torch head.

1. Unscrew the mixer (the thing on the end of the bent tube that has holes in it). Usually that can be done by hand. Leave the bent tube attached to the valve body.

2. Get an inch or so of hose and a couple hose clamps. The hose needs to be able to withstand only moderate pressure and almost any hose will work. Garden hose would be fine except it's ID is too big. Any hose that is designed for home water supplies will work fine. Any hardware store should have a variety of hoses, find one with the proper ID. You would prefer an ID a bit smaller than the OD of the bent pipe.

3. Put the hose on the end of the bent tube and hold it in place with the hose clamp.

4. On the other end of the hose; either connect it directly to your meter, or to a short half threaded riser (the threaded end of the riser screws into your ball valve), or put a Hose-barb-to-NPT fitting (use another hose clamp).

5. When you are done you haven't trashed the torch head and it can still be used for it's original purpose.

Since the bent tube (with it's very small vent hole) is still on the torch head the gas flow will be pretty slow. That means you can meter using just a pressure gauge, you don't need a regulator.
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Demon
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Fri Mar 06, 2009 2:06 pm

So its not the valve with the black wheel that regulates, but the torch?

So the propane valve to 1/4 npt adapter wont work with an pressure gauge regulated meter (if i understand)?
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ramses
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Fri Mar 06, 2009 4:23 pm

it could work, but you would need a needle valve or similar (which would cost maybe, $10.

I vote for using a torch head, because it includes the valve, and can be bought for around $12 at just about any hardware store.
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Demon
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Fri Mar 06, 2009 4:56 pm

By needle valve, you mean the valve on the blow torch?
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sgort87
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Fri Mar 06, 2009 5:05 pm

Demon wrote:So its not the valve with the black wheel that regulates, but the torch?

So the propane valve to 1/4 npt adapter wont work with an pressure gauge regulated meter (if i understand)?
The valve with the wheel does the regulating, but the torch tip also provides a resistance. It has a filter tip that slows and evens out the flow. The main regulation is controlled by the valve though.

The propane adapter will work with any regulator just fine.

Jimmy was explaining an alternative to the adapter and rethreading so you can save money and still have a usable torch tip if you needed it. If you're on a tight budget, this work just fine and is the way to go. I used that method on my first launcher. But if you have a large budget and want a tight, sturdy, and clean setup, go with a brass adapter.
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ramses
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Fri Mar 06, 2009 5:20 pm

no, I meant the valve you would need to buy to use with the 1/4 NPT adapter you could buy off the internet. The propane torch includes a suitable valve.
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