Gas welding revelation

[dp]

I´m a few weeks into a welding course and until last night, never really liked the idea of gas welding because of the two big ticking bombs (oxygen and aceteline cylinders) that are part of the deal. However last night while waiting for a Mig to become free I thought I´d have a go. What a revelation, I thought Mig was a doddle after arc but gas seems as simple as working with plasticine in comparison.

Out of interest, is it allowed to have gas cylinders in your back shed\garage and is it expensive? How much welding do the cylinders allow?


TA

[alanworland]

90% of my Morris welding was done with gas - I 'aquired' a bottle of oxygen a used it with a product I know as MAPP gas, an lpg product which burns very similar to acetalyne - these were only available in small bottles and I used to get them through the post!
I totally agree with your discovery, the process seems so civilised! I believe you can only hire the cylinders and this is quite expensive - about £250 a year I think?

[Alec]

Hello DP,

My small cylinders are about £70 P.A. to rent each, and refills are about the same (I''m not sure exactly as it keeps going up as does the gas price). They last for a very long time just gas welding cars, as you are using very small nozzles. I can understand why the MIG is so popular purely on a cost basis, but it is nowhere near as useful or as good in some circumstances as gas. I'm particularly thinking of outer panel repair sections which can be welded and need little or no grinding and a softer weld so dressing the weld is easier.

Alec

[bmcecosse]

Gas welding is lovely - one snag being it does create a lot of heat - and tends to set the car on fire.......... I've had my bottles for so long I can't remember the source now - and I managed to get refills at cost through work, although now retired - I have enough contacts there and elsewhere to get refills if I need them . The acetylene is v expensive - oxygen not so bad. I did take the precaution of moving my bottles into the greenhouse when the Fire Brigade came to inspect my house.........
TIG welding is very similar to do, and more localised heating - but unfortunately uses prodigious amounts of v expensive Argon +2% Hydrogen, so not ideal for DIY.

[marcusthemoose]

mmm. what a most sensible idea- moving compressed gas cylinders into a nice hot greenhouse..... i hope they weren't in there long roy!

[chickenjohn]

Another big thumbs up for gas welding. Lovely, peaceful, soft weld, as said above with minimal grinding needed (almost none if you manage to accurately butt up the repair piece). I learnt how to gas weld on the Mid Kent restoration course. Unbeatable for visible panel repairs. I have been making up repair sections at college and gas welding them into Minor wings to improve my skills at panel forming and gas welding. Yes, total waste of time in pure financial terms as panels are readily available but very enjoyable nonetheless![frame][/frame][frame][/frame]

repair section tack welded in place with gas. I fully seam welded the piece in after completing the tacking, using minimal filler rod.

[les]

I thought someone might have mentioned distortion by now! You lot must be good

[bmcecosse]

Just do a little bit at a time - and cool with damp cloth. Fortunately - Fire inspection was during the winter .......

[chickenjohn]

I thought someone might have mentioned distortion by now! You lot must be good

Thats what the hammer and dolly are for in the first pic. Gas welding does give some distortion but the weld is soft and about the same thickness as the original steel and so can be planished back to shape with hammer and the proper shape dolly.

[kennatt]

was waiting for the distortion to come up,mig is without doubt much quicker,you can weld long runs with very little if any distortion and no need for heat sinks etc. gas can be done with little distortion if you do a bit at a time but very slow process,and just try gas under the car upside down and watch the molten blobs form and drop down your sleve been there for years untill mig came allong .don't think the fire brigade or your insurance co would be very favourable if they knew you had full gas bottles in you garage or shed

[bmcecosse]

More worried about SWMBO finding them..........

[chickenjohn]

was waiting for the distortion to come up,mig is without doubt much quicker,you can weld long runs with very little if any distortion and no need for heat sinks etc. gas can be done with little distortion if you do a bit at a time but very slow process,and just try gas under the car upside down and watch the molten blobs form and drop down your sleve been there for years untill mig came allong .don't think the fire brigade or your insurance co would be very favourable if they knew you had full gas bottles in you garage or shed

It's not an either/or situation. I use Mig on the main structure of the car, (chassis legs, floorpan, sills etc) and use gas at college for panel repairs. Gas is far superior for anything that will be visible once the car is finished. Almost no grinding needed and any distortion can easily be planished down. Cant do that with Mig as the weld is hard and has a proud bead.

Each has their place.

[Alec]

Hello Kenatt,

I've been welding underneath for years (no MIGs when I started car welding, at least not the cheap machines now available), and don't have molten blobs. You only need to melt the steel enough for it to fuse. To me, looking at many posts of MIG repaired sections with heavy blobby welds (partly due I think to the use of CO2 rather than an argon mix), gas tends to be a much neater weld.

Alec

[les]

It seems to give a nice finish, but with distortion comes stretching and it's not too easy to 'shrink' the metal back, well not too easy for me!

[plastic_orange]

Fire Brigade would only point out that if you had an 'incident' with the cylinders, there would be a 200 metre exclusion zone set up around your property for 24 hours. This would be a great opportunity to meet your neighbours in the rest centre
There are no specific regulations stopping you from having them, but make sure they are properly stored, all safety devices are working properly, and that you can easily remove them from a fire if one occurs (store near exit).

Pete

[bmcecosse]

I was waiting for your response...........knowing you are a Fire person! I would imagine it would be the whole village evacuated - not just 200 yds........ I do move the bottles outdoors when welding - and yes the flashback arrestors are in place! And they are stored just inside the door when not in use, beside the Argon bottle. There was the occasion when I was welding a patch on daughter's Mini rear subby - with petrol tank directly above - and the waxoyl lit up like a Christmas tree with flames stretching up and out of the wheel arch and across the boot floor - now that was scary....

[alanworland]

A friend of mine used to do 'MOT repairs' and was working on a car on ramps in his garage, the fuel pipe was located inside a box section which he was welding underneath when the fuel pipe was burnt through with instant ignition - not recommended!
He managed to get out from under the burning river of petrol and somehow pushed the car off the ramps and out of the garage - the garage survived, but the car was a right off!
He gave up working on cars!

[bmcecosse]

[plastic_orange]

Up until about 2001(I think), we had less onerous procedures when dealing with acetylene, but since then the 200 metre exclusion zone for 24 hours has arrived. I had the misfortune to attend possibly the first one in the country when we had no option but to close the main east coast railway line at Carnoustie. When I was on a course at the Fire Service College (just after the incident), we had a seminar with someone from the Home Office, and I mentioned the new acetylene procedures as I felt they were too inflexible. She then asked if I was from Tayside
She did admit that they were working on a revision, but to my knowledge this has not happened.
Remember, if you have an 'incident' the costs to you, or your insurance company may be huge (think revenue lost by Scotrail as an example).
As I was the Emergency Planning Officer for the Brigade at the time, I kindly gave my oxy acetylene equipment to my mate (didn't want to tempt fate )

Pete

[dp]

90% of my Morris welding was done with gas - I 'aquired' a bottle of oxygen a used it with a product I know as MAPP gas, an lpg product which burns very similar to acetalyne - these were only available in small bottles and I used to get them through the post!
I totally agree with your discovery, the process seems so civilised! I believe you can only hire the cylinders and this is quite expensive - about £250 a year I think?

I´ve got a plumbing torch which takes disposable mapp gas cylinders (and plain propane and possibly butane). That´s lasted for ages. What do you use as a torch and is oxygen buyable too? Ta?