Converting torch head to threaded fitting

[Biopyro]

Torch head

So I have this blowtorch head which allows me to get gas from my MAP-Pro cannister. It's great but as you can see below it's not very elegant, because it needs a long, thick hose to prevent kinks.

Fuel meter

I remember when I built it I had a terrible headache trying to go from cannister > BSP as I am in the UK but I wanted to revisit this 5 years later since I thought there might be a new part I could use to neaten this somehow.


Ideally everything except the fill hose would be small and compact, using perhaps 8mm copper or similar to achieve this.

Does anyone know of any examples of fuel meters built by UK spudders? I am open to a total redesign.

[jackssmirkingrevenge]

http://www.ebay.co.uk/itm/100ml-Large-P ... 5af4576005

problem solved.

[Biopyro]

I wish, alas I need it to convert to schrader and have the pressure to fill when I press the tyre-fill fitting to said schrader valve.

I am just thinking about cutting off the torch head and using a die to make a 1/4 BSP thread. This is something I've not done before - what diameter do I need my torch to be for this to work?

[jackssmirkingrevenge]

It needs to be 0.518" dia to be able to cut a male thread.

Alternatively: http://www.ebay.co.uk/itm/BRASS-BSP-Tap ... 3a6563deb1

Drill out the torch head, epoxy the hose barb to it.

Problem solved

[Biopyro]

Awesome, was that number from a public resource or from memory?

It's only 11.1mm (0.437") so I think I might have to consider something along the lines of #2.

[jackssmirkingrevenge]

Memory, I've cut more 1/4 BSP threads than I care to remember plenty of lists online though.

Nothing wrong with option two, use decent epoxy and you'll be fine.

I would still use syringe fuelling though - simple, easy and precise!

http://www.spudfiles.com/how-to-databas ... 22301.html



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[Biopyro]

The other issue with the syringe option is that one of my chambers is rather large and I calculate it would need more than 100 mls of fuel. So it's inelegant and a pain in this case.

[jackssmirkingrevenge]

http://www.ebay.com/itm/Sealey-Oil-Suct ... 589dcf06c9

In the words of Arthur Smith, I'm determined to carry on

[POLAND_SPUD]

You do know you can get such syringes in almost any drug store/pharmacy ??

[jimmy101]

You could just use a couple of right-angle barbs. As you said, the problem with the original setup is the large radius you need to get the hose bend without kinking. Replace all that hose with right angle barbs (or right angle fittings) and short straight pieces of hose.

http://www.smarthome.com/31018/Orbit-67 ... -20/p.aspx
http://www.ebay.co.uk/bhp/barbed-elbow

Or, just get cooper tubing of the appropriate OD and use your blue pressure hose to make the connections.

[Biopyro]

You could just use a couple of right-angle barbs. As you said, the problem with the original setup is the large radius you need to get the hose bend without kinking. Replace all that hose with right angle barbs (or right angle fittings) and short straight pieces of hose.

There must be some good reason why I never did this. I think because I needed an asymmetrical reducing tee and therefore had no call to order from a place with barb elbows.


I will get some and see if the neatening is to my taste, then go from there. Thanks for the suggestion.

I might thread the tip anyway, because I can drop a tee and do some neatening like that too.

[Biopyro]

Does anyone know what the thread is which screws the aerator(?) onto the torch head?

I destroyed the threadlock and unscrewed the pipe but it's the same thread at both ends, neither NPT or BSP. PArallel thread with OD of 11.05mm

[jackssmirkingrevenge]

If you're not comfortable with epoxy, you can always drill the inside of the head to 8.5mm, tap it for 1/8" BSP (all you need is this, female threads are much easier to cut that male threads: http://www.ebay.co.uk/itm/New-G-1-8-28- ... 25747e9738 )

Then use one of these to attach to your fittings: http://www.ebay.co.uk/itm/1-4-Bsp-Male- ... 19e2a25c4a

Side note, this turned up on google, ouch: http://bernzomaticinjuries.com/index.html

[Biopyro]

Yeah I might tap the inside to a female thread but I don't know if there is enough material to do 1/8"

I've just found this: (How-To) Basic Propane Meter which is useful, it suggests that there is a compression fitting which will screw in... decisions.

[PeteS]

Another option is to find a fitting a suitable size and solder it on. I typically turn a part on the lathe or drill one out if I don't have something that fits properly. If the fit is close soldering it together is really easy, just like sweating copper pipe.