Still on welding: O/A (oxyacetylene)

[kogatana]

Hello

Below is Ed's reply to my inquiries regarding MIG, TIG and plasma cutter. I thought I would start a new thread, because now following his advices I might begin with an O/A torch.

In Taiwan I have had a short introduction to the basics on using an O/A torch, I cut a piece of railtrack with it.

Now, rather than asking my wife to ask her friend's husband to lend me his torch, if I want to acquire one what should I look for?
In Taiwan most brands are imported from Japan. I have checked some auctions also from the US, and there seem to be a quite popular "Victor" brand, so much so that it is being copied. Does anyone knows if a kit (torch, regulator,...) from the US is 100% compatible with oxygene and acetylene tanks usd in Taiwan? Is there an international standard regarding the matter?

Now for my needs: cutting (up to quite thick: still haven't finished my small railtrack anvil), welding (iron, steel).

Thanks for any advices.

Ludo (Taiwan)

Ludo: Yes, I really think an O/A torch is a better first tool than a MIG welder for a blacksmithing shop. I have a MIG and use it fairly often because it is a convenient tool, but it is quite one-dimensional... all you can do is weld. A good MIG will definitely cost at least as much as a good O/A set... in my case it was much more. The torch, on the other hand, just continues to increase in usefulness as you grow as a blacksmith.

I routinely use the torch to locally heat for setting tenons and rivets. I often heat pieces that need shaped a particular way. By using a rosebud, you can heat and bend as you go, which makes complex bending with varying thicknesses a piece of cake. With cutting tips, you can cut rough shapes in MUCH thicker steel than a plasma cutter. It is nothing to cut a 2" bar of mild steel with a typical medium duty torch. With practice you can cut patterns in thick or thin sheets. I have used the O/A welding tips on site to tack pieces in position to get a pattern for railings. By making a mockup with scraps that I can bring back to the shop, there isn't any guessing on slopes and dimensions. The O/A set doesn't need an electrical outlet to do that sort of work. Welding sheet metal is actually easier with a torch than anything but a TIG. When I am all done forging, cleaning, and sanding a piece, I can use the rosebud on the torch to warm the work before applying a finish, and then use the torch to speed the drying or alter the look of the finish.

Be aware, though, that this is assuming you are going to be working with iron and steel. Other metals present different problems and the torch isn't always the answer.

[HWooldridge]

There is a national standard in the US but I do not know if it is observed internationally. If I were you, I'd talk to your local distributor for the gases and let them guide you on the torch for compatibility and support. The Victor clone is a good choice. A basic kit with 3 welding tips and a cutting attachment will do 95% of the work you are apt to try. Maybe get one larger tip for the cutting torch to allow you a cleaner cut on the rail track.

[Ed Thomas]

Ludo: As mentioned in the other thread, the O/A torch is a powerful tool and can be very dangerous if not handled correctly. I didn't take a course, per se, but a friend was a welding instructor at a VoTech school back when I first used my torch, and I made sure I was doing things safely before I started. Every two years or so, our monthly blacksmith meeting demonstration is an O/A torch safety and use refresher by him. That is how important we all think O/A knowledge is here. Acetylene in it's free state is unstable, so containing it and using it requires diligent attention and no fooling around. The work you can do with it is well worth that attention, so don't be afraid of it... just respectful. A formal torch course would be best, but at the least make sure you are completely comfortable with all the operation and safety information from your dealer before you take off.

If you don't have a knowledgeable friend as a resource or a timely night class, then I strongly recommend you buy all your equipment from a dealer rather than online or catalog. The small difference in price will be more than offset by the assurance that you are getting compatible and safe equipment for the work you intend to do. In fact, you can waste a lot of money trying to chase bargains which are incompatible with each other or are unsafe.

Very often used torches leak or have defects, which is why they are being discarded. Used and cheap gages/regulators are very often faulty also.

The Victor torches are very popular and good.

Good luck. It is exciting to have someone from your part of the world with us in the forging community. I hope it works out for you.

[habu68]

Here is a story about someone who had a "little" knowledge of O/A

Strange-Looking Car Leads To Explosives Charges - News

O/A is a tool, like a car, a knife or a gun, they all can be misused and cause harm. education is the key.

[J W Bennett]

Ludo,
Ed is right. Lacking a votech or smithing group then your next resource should be a welding supply company. Not only can they advise you on what equipment is best and the basics of how to use it but they can probably point you in the direction of a source for good knowledgable instruction.

JWB

[Paragon]

One of the main things to understand with acetylene is that you can only use it at a rate of 1/7 the volume of the tank. What I mean is that if you have the smaller 40 cubic foot tank, then you can only withdraw up to 1/7th that per hour (about 5.7 cubic feet per hour)
I bought a Victor SuperRangeII kit and got a #00 tip instead of the #2 that comes with it.

Using Aceylene is all about numbers..

If you look at the documents below, you can see what size tips you can use by looking at the SCFH figure for Acetylene. The #0 cutting tip I have I may be able to use if I keep the settings down but I will only be able to cut around 3/8" plate with the 40cf tank I have. If I wanted to cut anything thicker, either I would have to manifold tanks together or get a 80cf Acetylene tank.
The Main use in cutting is your oxygen. You can see that an 80cf oxygen will last for about an hour of cutting 3/4" steel. The acetylene flame is for your preheat only so it may be possible to cut thicker plates with patience. I have not tried any cutting yet so I do not know for sure.

Same goes with the welding. In order to get the heating and penetration of weld, I would probably have to get a larger tank if I wanted to do anything over 1/8" thick. From what I gather, this is assuming a complete weld all the way through in one shot. You can weld one side and flip the piece over and weld from that side to get the full penetration. I have welded 3/8" square solid to a few thing around the edge but I know it is not a deep weld. Only for a shelf so it doesn't need ot be strong.

http://www.thermadyne.com/victor/literature/pdfs/B_WeldNozzle_info.pdf
http://www.thermadyne.com/victor/literature/pdfs/D_Performance_Data.pdf

As for tanks.. Not sure what fittings you have over there. (would almost assume it is the standard over here so the companies can easily sell equipment there) but I have been welding for a month now, so all I know is from reading.

Any questions, let us know.