Brazing/fuel question

deereman75 · May 11, 2012

Gary Fowler said:
You will have a hard time using the acetylene tip even to braze with as they wont put out much heat and tend to pop and go out really bad. I would keep my acetylene tank if you plan to use the welding tips for anything at all. For cutting, you have to have all new tips to use propane or MAPP or any other gas other than acetylene. You have to have a lot more gas with them than acetylene so the tips have to be a different design. Initial cash layout to switch over is going to offset the cost of cheaper propane, but for just cutting and heating (you need a different head on you rosebud also) propane is going to do you a good job.
Maybe you could buy a small acetylene tank just for your welding. AS for hoses, I have seen people use the same one on both gases for years with no problem with deterioation. The worst that could happen is you have to buy new hoses after several years, so use what you have till they go bad (if ever)then buy the ones rated for acetylene and propane as replacements. Just make sure you check them for blisters etc before you use them and never leave the bottles on when not in use. I shut mine off after each use anyway and back out the regulator screws.

I think you would have to use a heck of a lot of gas to justify the change over if you have to buy new rosebud, all new cutting tips of varing size and new hose and still want to do gas welding which means you still need the bottle. I own my bottles so there is no demerge cost or minimum monthly fill etc. I might use one bottle per year of gas

I just have a little b size acet tank, so I can only use the smallest cutting tip to begin with, not many to upgrade. (plus since I almost only work with stuf in the 1/4 inch range, I can make do with 1 for now) Never had a rose bud, but I found a place that sells cheep ones that go in the cutting attachment. I guess I might just keep the b size tank for gas welding. (until I get that mig that is :drool

The other thing is we just have a little 40cf o2 tank, and I am thinking of selling it back, and leasing a big (120cf+) tank. Think that would be a good idea? Or should we just get the biggest owned bottle. (80cf)

monckywrench · May 11, 2012

I go with owner cylinders since leasing is painful.

I like small and large cylinders for different jobs, so I wouldn't give up a small oxygen, I'd just add a larger one at leisure. Keep any eye out on Craigslist.

Gary Fowler · May 12, 2012

I prefer to have 2 tanks rather than one large. With one large one when you run out, you are still out and no one takes them back till they are empty. I have 2, an 80 and a 120. At least that is what I think they are, but none of the dimensions listed show their exact size. I keep the 80 as a spare and so I have plenty of time to get a refill when I run out. Then finish the 80 before hooking up the 120. Unfortunately I only have one gas bottle though. I may buy a couple of propane tips to use as emergency as I always have propane bottles for my BBQ pit.

deereman75 · May 12, 2012

Gary Fowler said:
I prefer to have 2 tanks rather than one large. With one large one when you run out, you are still out and no one takes them back till they are empty. I have 2, an 80 and a 120. At least that is what I think they are, but none of the dimensions listed show their exact size. I keep the 80 as a spare and so I have plenty of time to get a refill when I run out. Then finish the 80 before hooking up the 120. Unfortunately I only have one gas bottle though. I may buy a couple of propane tips to use as emergency as I always have propane bottles for my BBQ pit.

With as cramped a space as I have, 1 set of tanks taked up enough space.

Sublifer · May 15, 2012

crash325 said:
#1 best solution - Try brazing with your propane before getting rid of your Acetylene tank.

I recently changed to propane for cutting. There is a learning curve there as it works a little differently. Lift the bright blue flame back 1/2" to 1" from the cut. Propane heats a little slower, so give it a little more time. In my case, once I got the technique correct, cuts were cleaner, with a lot less slag.

I've done a fair amount of heating using my old rosebud. It is pretty temperamental, very fussy to adjust and blows out pretty easy. Heating is much slower and again hold the tip back about an inch. When the first heating a lot of moisture forms right around the area where the flame is at.

In 1962 I was working in a small plant and doing a lot of high temp silver brazing / soldering. Tried propane, it seemed to form a film that no amount of flux or scratching would help. Silver just wanted to ball up, nothing would get it to flow out.

Actually your heating problem is cuz you're not far back enough still. Propane's flame has the majority of the heat at the tip of the outer cone. It is not near the inner cone like acetylene. So when you are preheating to cut, start about 3 inches back then bring it in some when you are about to cut. Rosebuds too, then need to be further out. And if you don't have alt gas tips you will have issues because the burn rate of propane is slower (though it has more BTUs than acetylene) but because it burns slower the oxygen needs to be aimed further into the flame rather than right at the base. That is why you can have trouble keeping it lit too.