LPG torch problems

Jewelry Discussion
1

I am posting again about my LPG torch - it is the same problem I
posted about a short while ago. The problem was that I’d had a
contaminated gas supply which caused the flame to get very weak and
eventually die. I figured out that it must have been a
contamination in the gas supply when I removed the hose from the
bottle and a large quantity of liquid spilled out and had to be
mopped off the floor rather than vaporizing.

First of all, I mentioned in my original post that I now had a new
supply of gas but the gas still didn’t seem to be getting through.
I had figured that the contaminant had caused a blockage in the hose
and/or handpiece. I posted here and on another forum and received
some suggestions on how to flush the blockage out - the suggestions
were varied and some of them didn’t really sound right or safe to
me. In the end I put the problem on the backburner while I took up
several different office work temp jobs and was not in my studio
much anyway.

This brings me to today - I am back in my studio this week and now
back to the problem of my torch. Unfortunately all of the posts
from this forum and the other I posted to that I had saved to my
computer were lost when my computer crashed recently. I just tried
doing a search of the archive but the search engine seemed to not be
working properly - it kept coming up with no results… or perhaps I
was just putting the wrong words in - so, please forgive me for
repetition and not being able to recall properly the suggestions
that people made.

Of the suggestions I had that were of how to flush the hose and
handpiece out I was told by different people to use compressed air,
alcohol, water and water and soap - there may have been others, or
variations on these but I’m sorry - I can’t remember. As far as I
know compressed air is very dirty, however my father said that if I
used a filter and blew compressed air through it would be fine. I
think compressed air would move hard blockages fairly well, but what
if it is some kind of greasy buildup? Would it still do a good job?
Water sounds a little strange to me - I had thought that gas and
water could be explosive - or am I thinking of something else?
Alcohol sounded more strange than water as if any residue remained
it would be a fire hazard - or would it not? I think it was
suggested to clean with soap and water and then follow with alcohol
to make sure that no water droplets remained. In any case -
mightn’t alcohol dry out the hose and make it more prone to
cracking?

I’d had a thought - back in high school when I played clarinet - my
teacher taught me to clean it by taking a soft cloth and attaching a
length of string longer than the clarinet with a weight on the end
to it, then dropping the weight down the clarinet and grabbing it at
the other end to pull the cloth through. Maybe a similar method
with a much smaller cloth could be used for my torch? However, what
if remnants of the cloth became attached to the inside of the hose?
This could cause more blockages - right? If not blockages, would it
become a safety hazard?

I have emailed my supplier asking for advice who (very predictably)
told me that the problem couldn’t be fixed and that I’d need to
purchase a new torch.

A bit of discussion on the safety and effectiveness of various
methods of flushing the hose and handpiece out would be very useful
to me. I am one of those people who took YEARS to get comfortable
with using a torch as it was so difficult for me to shake the
feeling that it was dangerous… and now, I am nervous about
fiddling with my torch in case I really do make it dangerous.

Thanks everyone for your continual help, support and understanding!

R.R. Jackson

2

I wound try to back flush the hose with something like dry nitrogen
or dry CO2. This can probably be done by reversing the ends of the
hoses; the torch hand piece is another issue. Either of these gases
is pretty non toxic and readily available. I would be extremely
cautious about using any kind of a solvent or water to flush with.
You may be able to take your torch handle into a good welding
supplier and have it refurbished. We have one locally here in
Indianapolis that sells refurbished torches and regulators. I
probably wouldn’t use the LPG supplier for this however.

Dan Wellman

3

Hi,

If I were you, I would replace the hoses and the torch, just to be
safe and certain of not contaminating my air or my metals. Do you
have any way of finding out what that stuff was?

Daniel Ballard

4

RR, why don’t you just take your entire torch w/hose back to where
you bought the gas and have them test it for you. You might just
need to buy a new hose. Cheap enough if it solves your problem.
And definitely safe. Call them first to be sure they will do it for
you.

5

Good Morning,

First Water and either fuel or Oxygen is not explosive or

dangerous.

In reference to cleaning your hoses I like the clarenet idea I

would pass a cord long enough to be at least double the length of the
hose then knot in the middle a swab of cheese cloth( or other lint
free fabric) and start with a dish soap / hot water , then plain
water then finally dry swabs top remove any possible contamination by
pulling the swabs back and forth, much as a rifle user will clean the
barrel. If the hoses are short enough and you have access to a rifle
cleaning kit you could use that.

In reference to the Torch You have a few choices. 

1- Return it to the manufacturer for cleaning and a rebuild.

Expensive but sure, and will take time.

2- Go to an electronics supply store and buy a can of Electronic

cleaner and a can of compressed air. You want the Freon type, not
the type that contains lubricants. I would then (while wearing safety
glasses) use the cleaner to clean out all internal passages and
valves in the torch. Once you are satisfied that the passages are
clean flush and dry them with the canned air.

3- Dish Soap and hot water followed by clear water, then dry with

canned air (note you can get canned air at photographic stores as
well).

For the regulator I would only go with option 1 or 2 above or

replace it altogether.

For the tank I would replace it Period.

General comment #1: for Fuel hose (Propane or bottle gas) almost any
cleaning method (except using compressed Oxygen that is) is safe.
For cleaning a hose carrying Oxygen never use a petroleum based or
flammable solvent as it is almost impossible to remove every trace.
For a compressed air hose almost any method will do.

General comment #2: If you just want to blow it out with clean
compressed air, go to a place where they paint cars. They will have a
compressed air setup with both oil and water filters so has to yield
pure compressed air, as any contaminant would ruin a paint job.

General Comment #3: If you call around to places that supply
Acetylene and Oxygen to garages etc. they will be able to refer you
to a place that repairs Regulators and torches for the trade. They
will have the tools and Knowledge to fully repair and recondition
your torch, Regulator and Hoses.

General comment #4: Grin if your LPG supplier so cheerfully says
can’t be repaired buy new, send them a nasty letter (in full legal
form of course) holding them responsible for the damages and asking
them to replace the equipment as they were the source of the damage
and thus in breach of contract to supply pure bottled gas and it is
their recommendation that the equipment should be replaced.

Hope this helps and if you have any questions feel free to contact
me offline.

Kay
@Kay_Davis

6

Hi there

I recently had not dissimilar problems with contaminated gas supply
in our workshop. An oily substance was coming from the pipes into the
the torches and dousing the flames. I blew out the pipes with a
normal air compressor and soaked my torches in Methylated spirits for
an hour or so and then let them dry out.

That worked for me… hope it works for you.

7 
    If I were you, I would replace the hoses and the torch, just
to be safe and certain of not contaminating my air or my metals. Do
you have any way of finding out what that stuff was?

It’s not an actual contaminate, but a deliberately introduced one. I
can’t remember what it is, but it is added by the LPG companies here
in Australia as a “smell” in case of leakages. It doesn’t case any
problems - except to jewellers, as out torch head outlets are not
big enough to burn off the additive, so it accumulates as an oily
gunk in the hose and will end up blocking the torch head, too. It
can be burnt out of the head,just flame it with another torch, but
the whole thing is a bit of a pain really.

Christine in S Aust.