Feeding a scarfing torch?

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I wanted a rather large cutting torch that I may take advantage of scrap deals I run into. Have a refurb Oxweld C-59 on the way (it was cheep, prospective buyers must have freaked out at the retail cutting tip prices) and am looking for advice:What general setups have ya'all run to feed propane and gaseous oxygen to large capacity torches? I'd want to be able to slay old heavy equipment etc. Thanks in advance!
Reply:Hello farmall, mainly, if at all possible look at the manufacturers recommendations for their specific equipment. Most of the large size/capacity torches require 3/8" hoses, pay attention to any flash-back units when using them, some de-rate the flow capacities and could cause problems with properly supplying the torch with the correct amount of gases. Pay close attention to the type of tip that you are using, especially when using propane or natural gas, the tips for these two gases are not the same, although the differences are slight. Those are just a few items that I can think of off the top of my head. Good luck and best regards, Allanaevald
Reply:Thanks for the reply. I downloaded all appropriate factory manuals.I'll match the flow rate of the recommend regulators, though I'll be hunting Victor or Smith instead of the very nice but (usually) expensive factory units. Nice thing about Ebay though is while the popular stuff goes high (Victor Journeyman etc parts) but heavier duty gear is often quite inexpensive. The torch was under 150 shipped, and appropriate Victor regs are often well under 100 bucks each (likely because they don't have the common CGA fittings).Draw rate:Is a single 100lb propane tank sufficient? I can always do "tees and whips" to get more propane or O2, but having an idea would help me plan.
Reply:Farmall - Sorry to say I don't think it's going to work as you're anticipating.This torch is probably designed to use a huge volume of medium pressure oxygen supplied through a large hose. Is there even a conventional cutting tip listed as available for the torch?If it's the torch I'm thinking of, the seat in the head is so huge that any available conventional cutting tip would have to be a costly odd-ball. And even if a tip were available I don't believe the handle is up to the pressures used in heavy scrap cutting.Back when the mills were humming, used scarfing torches and other jumbo oxy-fuel stuff used to show up regularly at the Chicago flea market.Good LuckLast edited by denrep; 11-24-2010 at 03:45 PM.
Reply:Hello again farmall, without doing some investigating I would say that a 100lb. propane would be more than sufficient, expecially for cutting purposes. As to heating, I believe that would also be sufficient. Definitely check and don't take my word for it. Draw-off rates, safety wise, are much more applicable to acetylene fuel gas.     Burn rates can tell you whether you are safe or not regardless of fuel/oxygen combinations. Whenever the fuel gas velocity and flow being supplied aren't sufficient to exceed the burn rate of that fuel gas you risk burning inside of the torch or supply lines, hence, UNSAFE. Whenever you have enough velocity and flow to allow the burning of the fuel gas/oxygen combination at or beyond the tip you will not have that sort of safety issue. Well I did a little checking and it's interesting that there is not a ready source to determine a draw-off rate for propane, at least I'm not saavy enough to find it right now. I have included a link that might explain a bit about this, here again, it didn't give me specifics, but then I didn't search the entire 420 pages. Look at page 39, it explains about the draw-off process and it also involves ambient temperature and cylinder size as being contributing factors. Best regards, Allanhttp://www.propanesafety.com/uploade...de_Low_Rez.pdfaevald
Reply:Get the terminoly right, "scarfing" refers to a bent tip, ideal for cutting off old welds, or cutting out,,,  gouging out  cracks.   For the purposes designed for, very good.  For scrapping, not so good,   haven't yet seen a scarfing tip designed to work with propane.   In any case, if you are scrapping, much more efficient using a standard tip than a scarfing tip.Last edited by jsfab; 11-24-2010 at 04:06 PM.
Reply:Originally Posted by aevald. . .Well I did a little checking and it's interesting that there is not a ready source to determine a draw-off rate for propane. . . .
Reply:simple and effective, Denrep. Regards, Allanaevald
Reply:And in subfreezing temps the propane won't boil off as fast, hence a pressure drop. Been there, done that thawing frozen 6" Drisco pipe w/ weed burners.                                                     MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:When the supply line freezes shut, propane's maximum withdrawal rate has been reached.
Reply:Mama mia Well let's hear the magic number, how many CFH?      If you "feed" this baby it from manifold connected HP bottles, it'd probably "swallow" a 300cf bottle every minute. We are definitely looking  forward to the fire show. Good Luck
Reply:You are correct on consumption, so after testing it won't be cutting anything that won't pay for itself.   My anticipated use wouldn't require long cutting sessions unless someone else is paying to feed it.The absurd max capability is a hoot, but the very large tip size (nozzle nut = 1 3/8" thread!) means that there is ample room for a tip adapter for somewhat smaller tips. It will be fun to play with.