Torch problems

[Parm]

Regs are only about three years old

 

[bambuko]

...yes got brand new flash backs and hoses....Regs are only about three years old

just doing sanity check

 

[Parm]

No it's good to check, it wouldn't go down very well if I blew my self up if you knew what I did for a day job!!

 

[bambuko]

let me guess - you are fireman

 

[Parm]

Propane regulator if it had a gauge fitted it would only be one (out), bottle pressure remains more or less exactly the same from the beginning to the end (the only way to gauge how full it is, is by weight).
Oxygen might have two gauges (one for the bottle pressure, one for out).
Forget the gauges for the minute - let's establish you are using the regulators correctly:
I suggest close both of them (by unscrewing them totally) and just crack a bit of a turn in
then see if you can light propane OK?

ps
how old are these regulators? (you know they are "lifed"?)
are you using flashback arrestors?

Hurray

Getting somewhere now, I opened up the torch to full on propane and then cracked reg so I could just hear gas comming through then closed off at torch. Did the same with oxy and guess what the propane lit first time and when given oxy it produced a nice tight cone about 5mm long.

The flame seemed to be very under powered and there was no roar, is this normal?

 

[Parm]

let me guess - you are fireman

Nah, H&S consultancy in heavy industry

 

[bambuko]

that's even better

 

[Parm]

Flame

 

[bambuko]

Hurray
Getting somewhere now, I opened up the torch to full on propane and then cracked reg so I could just hear gas comming through then closed off at torch. Did the same with oxy and guess what the propane lit first time and when given oxy it produced a nice tight cone about 5mm long.
The flame seemed to be very under powered and there was no roar, is this normal?

Now you can start adjusting and playing with it to your hearts content (and yes, that's what propane alone will look like) - notice it's not lifting away from the tip.

 

[Parm]

Flame with oxy

 

[bambuko]

and who says it cannot be done?

 

[Parm]

The controls on the regs seem to be very coarse. Just a light touch is the difference between working and not working

Is this normal or do I need something with less range and finer control?

 

[Parm]

and who says it cannot be done?

Cheers fella, I'm a complete novice with anything gas and oxy. First time ever

 

[bambuko]

and to quote the guy I learned from:

"...I carefully watched the flame change color from greenish to blueish as I added oxygen.
The right blend of propane and oxygen was just at the colour shift when the green became blue.
Of course as I continued to add more oxygen it got even bluer.
I measured the inner cone and it was 16mm at that adjustment with a Victor #2 (UK #7) tip.
Of course in addition to the balance between the 2 gasses you have to have the right volume.
That depends on the thickness of material being brazed and I go by the sound of the flame.
It is a bit louder than the gentle hissing of an oxyacetylene frame..."

As for your regulators, notice their max output on propane - 5bar (72 psi)
which means it is likely to be coarse where you need it (i.e. around 5-6 psi)
The other thing to watch (particularly with small propane bottle) - pressure will initially drop as you start drawing the gas, so you may have to tweak it after the initial light up.

ps don't forget that you have both regulators and your torch valves to adjust things

 

[Parm]

So far so good. Propane is 19kg and full, oxy is 20l bottle and also full.

If I get 0 - 3.5 bar regs will this give me finer control at the lower range and also if I go for a bigger tip say 7 or 8 will I get a longer and more powerfull cone?

 

[Parm]

Should have said both torch controls were fully open to get the flames in the pictures

 

[brightspark]

i wouldnt bother getting more regs with gauges . at worst u may run out of oxygen on a sunday propane u can get .they will do all the pressures u require i was using burning regs for a few years till i scored a new ish set that was 35 years ago .and still going strong

 

[brightspark]

Should have said both torch controls were fully open to get the flames in the pictures

up the regulator pressures slightly then and u will only need to open torch controlls half way

 

[Parm]

Right gents I cannot thank you enough

I have taken on board all advice, particularly that of Bambuko.

I can now light the torch, set the gas and control the flame as I was expecting to. It does a beautiful job on heating up some 5mm plate I've got and melts some brazing rod like a teat. Just need to get some brazing flux and I'm good to go.

Technique was as suggested above and I can now get a cone about 30mm long if required.

I'm so happy

Thanks again chaps

 

[Jan]

Don't forget that LPG is stored as a gas which has to evaporate to be used. This takes heat drawn from its surroundings. As such this means a drop in liquid temperature with a corresponding reduction in the rate of evaporation. A gas cylinder stored outdoors in cold weather will often start to frost up at the level of the liquid inside it. This why Winter caravanners often move from butane to propane to take advantage of the lower 'boiling point' of propane. Although a little dearer by volume/weight it also burns a little hotter at a slightly lower output pressure, so the economy works out almost the same.