Framebuilders - Anyone run Oxy/Propane here?

I've been shopping for my first torch setup and was thinking of maybe doing a Oxy/Propane setup over the normal Oxy/Act setup. I know it's the why fix which isn't broken type thing but I'm always the non normal kid in class and always had to be difficult and even in my framebuilding class...just ask Mr Fattic. He brought up the setup for use in his Ukraine Project as Propane is cheaper and easier to find in remote areas.

Now mind you I haven't pitched a tent and reside where the Unibomber once lived and have limited access to acetalene but the stuff still kinds of freaks me out. I'm even able to buy my needed items with a student discount at our local Airgas being in a metal fab/welding course.

I'm just wondering if any folks here run this setup or have sticked with the normal tried and true Oxy/Act setup? I'd be just using this for just brazing and no welding or cutting. Would there be anything I couldn't do with it or limiting myself with running this setup. I wouldn't mind trying to do run a oxygen generator/concentrator and propane and really cut my longterm expenses.

I'd say you need a lot more torch experience if the main reason you want to go propane is that acetylene "freaks me out". You can blow yourself up and burn down the house with oxy/propane too!

nothing wrong with Oxy/Propane. Airgas should be able to set you up with everything you need to use regular propane tanks. Acetylene is more energetic than propane, but you still have to be careful with propane. And I don't think propane is quite as user-friendly.

I did my framebuilding course with Doug Fattic two months ago would stay after class by myself and braze by myself and now in a metal fab and welding program but I'd rather try propane. So I guess I guess the "freaks me out" comment wasn't the right term.Hell even my instructor right now doesn't really care for acetylene. I'm not saying that I can be less careful with Propane but I'd rather I don't need that extra heat that Acetylene has over Propane and if I ever run out I can refill for just a few bucks any time at nearly any place around town.

We used oxy-propane at Trek. It was well-suited for a manifold system, since the manifold could be run at a fairly high pressure (acetylene can't be safely run at over 15psi) and regulated down at the individual work stations. Propane burns cooler than acetylene, so you need to use a larger tip to get the same heat output but practice makes this easy.

Acetylene is less dense than air, and thus tends to disperse more readily than propane. If you do decide to use propane, good ventilation is essential to prevent it from accumulating in low-lying pockets and becoming an explosion hazard.

You might also want to think about MAPP/Oxy. More heat output than propane mix, little faster, but the smell of the gas draws flies al the way from Timbuktu.

Propane apparently gobles up a lot of oxygen for it's output. You might consider setting up with a concentrator so that you can keep the bills under control.

Anyone have a recommendation for a lightweight "injector" torch for propane brazing. From what I have read, an injector type torch that sends the O2 through a venturi that "sucks" low pressure propane results in better mixing and better performance from propane.

I use propane and an oxy-concentrator. Works fine, but I kinda wish I could gas-weld (or at least try eh?). Like was said propane blows up pretty good, just like acetylene can be used safely. Propane is easier to obtain, that's about it. It's nice not to have to worry about a pressurized oxy canister and a gas supplier.

Since it consumes more oxygen, you need more oxy flow, and my light-duty torch bottoms out when using my largest tip (no. 6 Victor), necessary for brass and BB/crowns. Just ordered a bigger handle/nozzle, we'll see. The flame has higher BTU, while burning cooler, and the big flame from the bigger tip englobes lugs nicely. So far so good, still learning.

I really can't gas weld anything I would want to gas weld using my oxy/acetylene. Anything beyond sheet metal is a real problem

You might also want to think about MAPP/Oxy. More heat output than propane mix, little faster, but the smell of the gas draws flies al the way from Timbuktu.

I built my frames (a looong time ago) using MAPP/air. I was a starving college student at the time, and the torch was dirt-cheap. I see that MAPP ceased being produced in 2008, but there is a 'MAPP substitute' being sold.

Katmandu, where in SE MI are you located? It seems that there are quite a few of us from this area on C&V....

You might also want to think about MAPP/Oxy. More heat output than propane mix, little faster, but the smell of the gas draws flies al the way from Timbuktu.

There is no more real MAPP gas. Propadiene is worth more to the plastics industry than it is to anyone who wants to burn it. It has no industrial advantages over other fuels, and fell out of favor with underwater cutters (where its far superior to propane, and acetylene isn't usable because it can't be delivered at greater than about 1 bar) with the introdcution of exothermic cutters which are faster and can cut things you can't with a torch. The stuff that's sold as MAPP these days is propane and propylene, and totally unsuitable for anything more intensive than plumbing.

Since it consumes more oxygen, you need more oxy flow, and my light-duty torch bottoms out when using my largest tip (no. 6 Victor), necessary for brass and BB/crowns.

Tuz,

Did you try a larger diameter oxy hose yet? Going from 3/16" (typically recommended for J-28), to 1/4" and you'll see a noticeable increase in volume at the same PSI. A shorter hose also helps.

With no tip on the nozzle, I disconnected the hose from the handle, and the flow jumped from about 4 LpM to off the chart on the oxy-concentrator... Is your experience different with the J-28? But yes no doubt it would be best to have the shortest hoses possible.

With no tip on the nozzle, I disconnected the hose from the handle, and the flow jumped from about 4 LpM to off the chart on the oxy-concentrator... Is your experience different with the J-28? But yes no doubt it would be best to have the shortest hoses possible.Hummm?... interesting.

I just ran a couple comparative tests with two of my torches (J-28 & an older, aircraft J-50) using the same UN-J mixer & 4-TEN tip. With the OC warmed and pumping out 9 PSI, I can easily max the flow gauge above 5 LPM. I did no testing without the tip because I already max the gauge. Also, the tests were using Smith's kevlar hose - a tiny sucker that is what?... 10-12 ft. long? My OC is a DevilBiss 505DS (5 LPM).

Which begs the question, are you using a UNN-J mixer?

Interesting indeed! Here is my chain: UN-J mixer -- J-28 -- no check valves -- kevlar hose -- flashback arrestor -- long std hoses. My OC is also 5 LPM, perhaps lower pressure? (can't remember).

Interesting indeed! Here is my chain: UN-J mixer -- J-28 -- no check valves -- kevlar hose -- flashback arrestor -- long std hoses. My OC is also 5 LPM, perhaps lower pressure? (can't remember).Ok.

It appears that your OC isn't putting out the volume you need, because other than the FB arrestor (which I no longer use), our systems are closely matched.

Checking Victor's reference data, the largest J series alt-fuel tip is #5. However, the Victor J series O/A tips goes up to a #7. This indicates to me that the J-28 handle will permit the higher flow rates. I'd try it without the FB arrestor first (just to eliminate the variable). But again, your problem seems to indicate the OC's limitation. I assume that you checked/changed the OC filters? yes?

Tuz,

Something else to ponder...

Toronto's elevation is about 3500 ft. lower than mine.

Haha perhaps eh? But my OC is capable of maximum flow, just not when the torch handle is in line... As for the filters, apart form the gross particle one, I wouldn't know where to look!

But my OC is capable of maximum flow, just not when the torch handle is in line.Indeed. When you disconnected the torch, pressure went down... and volume went up. Unfortunately, flow (volume) can only be referenced at a specific line pressure. That said, what was the line pressure (measured at the OC) when the torch was disconnected? Probably well below usable.

Yes, there may be a restriction somewhere downwind of the OC, but I don't yet have enough data to agree with you that the J-28 isn't capable of the flow desired. Mine doesn't have the same issue - so what else can cause it?

I'll be happy to loan you one of my torches and/or tips to try, if you wish. Just say the word. My treat.

Thanks! I'll investigate the pressure-volume situation tomorrow when I visit my shop.

I built my frames (a looong time ago) using MAPP/air. I was a starving college student at the time, and the torch was dirt-cheap. I see that MAPP ceased being produced in 2008, but there is a 'MAPP substitute' being sold.

Katmandu, where in SE MI are you located? It seems that there are quite a few of us from this area on C&V....

Sorry, haven't been following this thread. Downriver, on the banks of the Huron River, Wayne & Monroe Coubty line.

There is no more real MAPP gas. Propadiene is worth more to the plastics industry than it is to anyone who wants to burn it. It has no industrial advantages over other fuels, and fell out of favor with underwater cutters (where its far superior to propane, and acetylene isn't usable because it can't be delivered at greater than about 1 bar) with the introdcution of exothermic cutters which are faster and can cut things you can't with a torch. The stuff that's sold as MAPP these days is propane and propylene, and totally unsuitable for anything more intensive than plumbing.

Okay, wasn't aware. Have not needed to go to weld supply in a lot longer than I thought. So does that mean my Mapp bottle that is now past due for insp. is a collectable?:rolleyes: