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Lampwork => Common Problems => Topic started by: helenfc on March 03, 2010, 10:47:14 AM

Title: Methane?
Post by: helenfc on March 03, 2010, 10:47:14 AM
I think I know what the answer to this is already, but here goes...is it possible to hook a hothead up to methane gas? It sounds a bit dodgy to me, but I was hoping to take my torch into uni for the week and the workshop has oxygen and natural gas (nearly all methane), and something tells me they aren't going to love me bringing in my propane tank...
Just thought I would check anyway, don't really fancy resorting to mapp... ???
Title: Re: Methane?
Post by: Bluebottle on March 03, 2010, 10:54:25 AM
Hi, natural gas hasn't got enough pressure to operate a hothead you can get equipment to raise the pressure but it's mainly made for industrial use and would be prohibitively expensive for this type of use  HTH

Mike    ;D
Title: Re: Methane?
Post by: sparrow on March 03, 2010, 11:56:21 AM
Sorry, I can't resist.......I thought you were trying to run a HotHead on farts..... ;D
Title: Re: Methane?
Post by: Lush! on March 03, 2010, 12:08:58 PM
Quote from: sparrow on March 03, 2010, 11:56:21 AM
Sorry, I can't resist.......I thought you were trying to run a HotHead on farts..... ;D

Cheap ... but smelly  ;D
Title: Re: Methane?
Post by: helenfc on March 03, 2010, 12:35:10 PM
 ;D ;D ;D ;D
i had a horrible feeling someone was going to say that sabine! :D
ok, i thought that would be the answer, I was just wondering since it is powerful enough to run the big blowtorches in the workshop? if it can power one of those maybe it has already got pressure raising thingys? hmmm
our technician is new and not sure either...is there any way of telling whether it has the pressure raising equipment already?
thanks :)
Title: Re: Methane?
Post by: fionaess on March 03, 2010, 01:47:55 PM
Quote from: sparrow on March 03, 2010, 11:56:21 AM
Sorry, I can't resist.......I thought you were trying to run a HotHead on farts..... ;D

And me Sabine.... ;D ;D ;D ;D
Title: Re: Methane?
Post by: Zeldazog on March 03, 2010, 02:34:34 PM
Quote from: helenfchalmers on March 03, 2010, 12:35:10 PM

our technician is new and not sure either...is there any way of telling whether it has the pressure raising equipment already?

Ever so slightly disconcerting that the technician isn't sure what equipment is the workshop - isn't that what a technician is there for.....
Title: Re: Methane?
Post by: Zeldazog on March 03, 2010, 02:35:55 PM
Do you know, I think there was a thread ages and ages back about hooking up torches to household gas.... did I dream this??   :o
Title: Re: Methane?
Post by: Bluebottle on March 03, 2010, 02:41:54 PM
Quote from: helenfchalmers on March 03, 2010, 12:35:10 PM
;D ;D ;D ;D
i had a horrible feeling someone was going to say that sabine! :D
ok, i thought that would be the answer, I was just wondering since it is powerful enough to run the big blowtorches in the workshop? if it can power one of those maybe it has already got pressure raising thingys? hmmm
our technician is new and not sure either...is there any way of telling whether it has the pressure raising equipment already?
thanks :)

The simple answer is to ask the head of dept what the gas pressure is if the answer is in inches water gauge it will be normal natural gas but if the answer is in P.S.I ie pounds per square inch then there is a chance it may work
what would be wrong with using one of the authorities torches? but I really think it is too much trouble, and the rest of you dirty girls can get your minds above the belt line  :D :o ;D :o

Mike   ;D
Title: Re: Methane?
Post by: Zeldazog on March 03, 2010, 02:45:41 PM
I knew I'd read about using natural gas somewhere - unfortunately, it doesn't mention using a hothead on it

http://www.frit-happens.co.uk/forum/index.php?topic=7089.0 (http://www.frit-happens.co.uk/forum/index.php?topic=7089.0)

Title: Re: Methane?
Post by: sparrow on March 03, 2010, 02:46:13 PM
Quote from: Bluebottle on March 03, 2010, 02:41:54 PM
and the rest of you dirty girlscan get your minds above the belt line  :D :o ;D :o

Mike   ;D

Nope  ;D ;D
Title: Re: Methane?
Post by: Bluebottle on March 03, 2010, 02:57:27 PM
Quote from: Zeldazog on March 03, 2010, 02:45:41 PM
I knew I'd read about using natural gas somewhere - unfortunately, it doesn't mention using a hothead on it

http://www.frit-happens.co.uk/forum/index.php?topic=7089.0 (http://www.frit-happens.co.uk/forum/index.php?topic=7089.0)


Almost any torch can be made to work on any gas and any pressure but in this case the modifications to a hot head would be irreversable. if indeed it's possible. In Japan all torches work on natural gas as they are not allowed to have gas cylinders on residential premises but they have to use a low temperature glass and boro is out of the question.

Mike   ;D
Title: Re: Methane?
Post by: helenfc on March 03, 2010, 04:04:28 PM
thanks for that link dawn very helpful :)
mike what sort of modifications would need to to be made to a hothead?
its interesting to see people work minors off it though.
Title: Re: Methane?
Post by: Sulis (Hazel) on March 03, 2010, 04:44:50 PM
Quote from: fionaess on March 03, 2010, 01:47:55 PM
Quote from: sparrow on March 03, 2010, 11:56:21 AM
Sorry, I can't resist.......I thought you were trying to run a HotHead on farts..... ;D

And me Sabine.... ;D ;D ;D ;D

I think I have finally found my teenage son a part time job.... ;) :P
Title: Re: Methane?
Post by: llewennog on March 04, 2010, 08:58:39 AM
I think Seans Barracuda is setup to run on Natural gas, You can conver most decent torches to run on either, personally I prefer Propane as it has more BTU's but can be a little harsher on glass.
Title: Re: Methane?
Post by: Hamilton Taylor on March 04, 2010, 09:12:00 AM
We run all our torches on natural gas in the studio - but only because we can - some torches need to be altered to run on natural gas.
The barracuda will run on propane or natural, with no modification. Minors and midranges are the same. I don't remember any GTT literature saying they will only run on propane, and I've certainly run a bobcat on natural gas without a problem. Propane is hotter, and will keep a bigger gather molten and workable, but there is always more natural gas in the tap. Horses for courses....
:)
Sean
Title: Re: Methane?
Post by: helenfc on March 04, 2010, 11:33:27 AM
thanks sean...the only question now is would it work on a hothead? will eventually save up for a minor I hope, but bringing in a propane tank to the workshop is out of the question (unsurprisingly) i just dont want to ruin my wee hothead... also it would only be for a week and back to running on propane after that. maybe i should just forget it for now!  :D
Title: Re: Methane?
Post by: Bluebottle on March 04, 2010, 01:05:50 PM
Quote from: helenfchalmers on March 03, 2010, 04:04:28 PM
thanks for that link dawn very helpful :)
mike what sort of modifications would need to to be made to a hothead?
its interesting to see people work minors off it though.

Hi Helen, the injector orifice ( the part that the gas goes through in the burning head ) would need to be drilled out to allow more
gas through as would possbly the rest of the torch as the valve openings will be very small HTH

Mike   ;D
Title: Re: Methane?
Post by: helenfc on March 04, 2010, 01:12:25 PM
aaah isee :)
thanks mike, much appreciated, guess I will just resort to mapp for a week then  :'( :'( :'(
;D
Title: Re: Methane?
Post by: Bluebottle on March 04, 2010, 02:02:29 PM
Quote from: helenfchalmers on March 04, 2010, 01:12:25 PM
aaah isee :)
thanks mike, much appreciated, guess I will just resort to mapp for a week then  :'( :'( :'(
;D

I'm glad someone understands, it took me a while  :D :o :D :o

Mike   ;D
Title: Re: Methane?
Post by: helenfc on March 04, 2010, 03:09:06 PM
yes my techno jargon comprises of 'thingys' and 'stuff'  :D takes a wee while for the penny to drop sometimes!
Title: Re: Methane?
Post by: stuwaudby on March 18, 2010, 04:32:06 PM
Must add the fact that I'm a gas engineer to my profile....

MAPP is a mixture of highly reactive gases, predominantly propene. It is less stable than propane or methane so therefore breaks apart more easily releasing more energy in a smaller volume of flame.

Methane will theoretically burn at similar temperatures in air but the temperature glass can reach in a flame depends on a number of factors:

First the science:

When heating glass there is a balance of heat input and heat loss, sufficient heat must be input to overcome the dilution of the flame by the surrounding air and radiant loss from the glass. The velocity of the burning gas mixture increases the heat input rate. A greater sized flame reduces air dilution.

MAPP has a vapor pressure of 97 PSI @ 70F (the pressure in the can) which is equivalent to 6.7 bar. This means the velocity of the gas is very high in the burner (which is why they are so noisy).

UK domestic gas is typically delivered at 20 mbar  = 0.02 bar

A hot head could be modified to burn domestic methane by modifying the mixture hole sizes, however:

Using Bernoulli's equation for oriface plate flow the mass flow rate is proportional to the root of the pressure. The MAPP will deliver 18 times more heat than domestic methane. Considering that MAPP can hardly manage to melt thick rods, domestic methane would stand no chance.

It is feasible that domestic methane could be pressurized to 7 bar and would work great in a hot head. The cost of the equipment would be far in excess of Oxy propane, probably illegal and not something I would want near my house.

My advice is take the plunge and buy an oxy propane set up. After two bottles of MAPP I switched. You also get that advantage of being able to listen to trance music while creating :)
Title: Re: Methane?
Post by: helenfc on March 18, 2010, 04:41:24 PM
thanks stu, but i already have a bulk propane set-up, my question was actually because its a breach of health and safety regualtions to have a propane tank in the workshop at college, and I wanted to take my hothead in for a week. fortunately i took the plunge straight away when I started and never had to use mapp! :) turns out I can melt glass with the natural gas at college, but it makes it cloudy and dirty.
welcome to fh by the way! :)