Framebuilders - Small O/A sets

Anyone have thoughts on small O/A sets like this one? Seems like a good way for me to go because of space restrictions, etc, but I'm worried about running out of gas every ten minutes.

http://sfbay.craigslist.org/eby/tls/3154754197.html

I have the same size bottles because I have to move them through a crowded area to get them from where they are stored to where I use them. The portability is nice and the tanks last a reasonable length of time. That looks like a good price too.

I have a set too, and it works fine.It is my only O?A welding rig. I use it for brazing and fusion welding.

The portability and easy storage is great too.

One more advantage is that is is very convenient to transport the tanks to refill them.

Mine even came with a cutting torch, which works very well, but will drain a O2 tank in a hurry.

Awesome! I can't really store full tanks at my house (two family, top floor... could store it on the deck, but can't move the full size ones up and down the stairs). This way I could keep it on the deck, out of harms way, and then work in the driveway. Not ideal I know, but it'd work. Would you get through a whole frame without re-filling? Are the regulators the same kind you'd use for a big tank if I switched later?

Thanks!

p.s.
Looking around I'd probably just spring for this version:
http://www.amazon.com/Victor-0384-0936-Genuine-Portable-Cutting/dp/B0019RO22K/ref=sr_1_1?ie=UTF8&qid=1343497141&sr=8-1&keywords=victor+brazing+set

there is a turbotorch setup with a J28 clone that you might have better luck with. The only problem is that J28 tips are expensive.
turbotorch 0386-1321 cst-pt
There are a batch of them on ebay, unfortunately many are selling without tanks

there is a turbotorch setup with a J28 clone that you might have better luck with. The only problem is that J28 tips are expensive.
turbotorch 0386-1321 cst-pt
There are a batch of them on ebay, unfortunately many are selling without tanks

What is the advantage? (I believe you, I'm just not seeing it yet)

" Are the regulators the same kind you'd use for a big tank if I switched later?"
You will need adaptors to attach these regulators to larger tanks. I bought a set like that long ago.

What is the advantage? (I believe you, I'm just not seeing it yet)

the J28 and clones are an aircraft style torch that weighs quite a bit less than the 100FC that comes with the set you linked. This is a big advantage for heat control and comfort. On thin sections, an experienced brazer constantly flicks the flame away from the workpiece. It becomes second nature. With a heavy torch, that is much harder to do. It's also nice to have the controls at your fingertips instead of down where you are gripping the torch. Not a big deal, but definitely convenient.

I learned to build frames with a torch as big as my forearm, and built a number of frames with that. At Trek, we used a variant of the Smith AW1A, which is quite a bit lighter (AW6, I think). Now I have a couple of AW1A's and the TurboTorch that is in the kit I mention. I don't think I would go back to a heavy torch. The only thing is if you are doing any gas welding on heavier sections, the light torches will get warm.

There is a limit to the rate of acetylene flow that is a function of your tank size. It's 1/7 of the tank's capacity per hour. If you go any faster than that you start flowing the acetone carrier and bad things can happen.

I have much bigger tanks, and the largest tip that is recommended is a Smith 207. I found that brazing lugs with brass was much easier with that tip size.

One thing you might consider if your concerns in the first post are something you would be willing to pay up front to overcome, would be to go propane with an oxygen concentrator. You won't run low, will be easily able to refill the propane, and will not need to have oxygen, other than the air around you. Puts you in the same risk cat as a person with a BBQ, maybe less when one looks at it. There are threads here on this kind of rig. By pay up front, I am assuming you will recoup your costs soon enough, and have a saleable rig down the line.

Thanks guys, a lot to think about!

the propane and oxygen concentrator idea is pretty attractive. I have never managed to find an oxygen concentrator, although I will admit to not looking too hard. With propane, there is no issue with burning it as fast as you want either. I have also thought that just getting a oxygen cylinder and burning propane isn't a bad way to go.