Setting/technique for welding 1/2" steel

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I'm trying to weld some 1/2" steel plate to some 1/4" steel tubing and I'm not having just a whole lot if success.  I've read the posts that explain the reason that oxy and acet should be set the same and that they don't need to exceed about 5 or 6 psi and I understand. I'm using my biggest tip and I'm turning up the acet until the smoke quits and then matching that with O2. It doesn't seem to be hot enough to phase it. Should I keep upping the acet and then matching it with O2 until it does the job or try something else?  How far should I open up the valves?(on the torch, not the tanks) Can I literally keep going until the torch valves are wide open or is that dangerous(this is all assuming that the tank regulators are set at 5-6psi each. Is 1/2" just too much to ask of an oxy/acetylene torch?
Reply:chad, you do realize you have to pick your tip size based on metal thickness right? For 1/2" your going to be using a tip with an orfice over .100" and gas pressures to suit. I would go with some form of electric welding as its going to be more effecient in that heavy of material.
Reply:Originally Posted by makoman1860chad, you do realize you have to pick your tip size based on metal thickness right? For 1/2" your going to be using a tip with an orfice over .100" and gas pressures to suit. I would go with some form of electric welding as its going to be more effecient in that heavy of material.
Reply:ive seen fotos of oldtimers welding large pipe with a torch..and it was a bigaasss torch. you wont get puddle withtoosmall a torch.
Reply:This is a SCARY post, I don't care what anyone else says.Oxygen/Acetylene is NOT something to be "messing around" with, if you don't know what you're doing.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIThis is a SCARY post, I don't care what anyone else says.Oxygen/Acetylene is NOT something to be "messing around" with, if you don't know what you're doing.
Reply:Chad, Tips in the size range you need arent in a common set, and are usually reserved for high output torch models like the Oxweld W-17. Another thing you MUST watch for is that your fuel draw rate does not exceed the limits for your cylinder size. As far as setting your torch, having too high of a gas flow at the tip will just blow the flame out, you should not need to push the tip much harder than the "initial" setting. As an option, could this part be fillet brazed instead of welded?
Reply:Originally Posted by sn0border88Your a smart guy, but sometimes you need to get off your horse.  He's not messing around, and has obviously done some research to understand what pressure the tank reg's should be set at, how to set the flame and what different size tips do.  Nothing dangerous, just not sure where the limit for his torch is which I would think is a pretty reasonable question.I would make sure your reading the tip charts right and have them set at the right pressure for what your trying to do.  Here is information for  victor torches, page 61 http://www.thermadyne.com/IM_Uploads...20guide_lo.pdf
Reply:Originally Posted by makoman1860Chad, Tips in the size range you need arent in a common set, and are usually reserved for high output torch models like the Oxweld W-17. Another thing you MUST watch for is that your fuel draw rate does not exceed the limits for your cylinder size. As far as setting your torch, having too high of a gas flow at the tip will just blow the flame out, you should not need to push the tip much harder than the "initial" setting. As an option, could this part be fillet brazed instead of welded?
Reply:Here's a handy tip chart:http://www.hoopersupply.com/tipchart.htmlIf you go to the middlechart, and look at the Victor #6, you would see that at 45CFH (the maximum draw of a #6 tip), NO single acetylene cylinder can support its draw rate safely.What size Acetylene tank do you have.  I'm guessing that after you upgrade your torch (which probably isn't large enough to work with a #6 tip), and tank (which should actually be a manifold with several tanks to draw from), and possibly regulators (that flow rate is pretty large for a smaller regulator), hoses, and get that #6 tip, you'll find that you've invested more than what a stick welder would run you (especially if you find one used).Besides, I've got a Victor #4 tip, on my 315FC torch (that's their larger body torch which lets your fingers stay a little farther from the work), and I found the heat from that too objectionable to use again.
Reply:Recommendations for tip sizes and flow rates are based on efficiencies. A smaller tip will do the same as a tip a size or two larger, but with slower travel rates. A larger tip will do the same as a smaller tip, but with lower pressures, and, or faster travel rates.  It doesn't hurt to use the maker's recommended settings, but bear in mind that advised pressures are not what you may experience at the tip; length of hose, diameter of hose, flash-back arrestors and check valves all create friction loss.The setting of pressures should be done with the torch valves all the way open. Acetylene should not be used at a pressure greater than 15psi. If you can run a puddle on the 1/2" plate you are close to having the right setting. Take the time to strip off the mill scale. If your puddle has a layer of scum the acetylene is too high. If you have excessive sparking then the oxygen may be too high. When you have a nice shinny puddle, with a nice little bright dot floating on it you have a neutral flame. It would be a good idea to preheat the assembly to about 350 degrees before welding.
Reply:rlitman, good point.  It definitely wouldn't make sense for me to buy extra tanks, etc. at the same price as a mig welder.   Also, thank you for the chart.maarty, based on all the things you said, would you think I should be able to run a puddle on a 1/2" plate with a #4 tip?  Also, and I realize this is a newbie kind of question but... we are talking about being able to run a puddle of only the parent metal or of the filler rod(or both?)Thanks for the input, guys.
Reply:Originally Posted by chadmw7rlitman, good point.  It definitely wouldn't make sense for me to buy extra tanks, etc. at the same price as a mig welder.   Also, thank you for the chart.maarty, based on all the things you said, would you think I should be able to run a puddle on a 1/2" plate with a #4 tip?  Also, and I realize this is a newbie kind of question but... we are talking about being able to run a puddle of only the parent metal or of the filler rod(or both?)Thanks for the input, guys.
Reply:This is a Victor "style" #4 so I'm assuming the bore sizes must be similar.  I need to verify that though.  I'll give it a try with the preheat.  I can live with the slower travel rate.  Any advice on how long to preheat, what to look for, etc.?
Reply:Originally Posted by chadmw7This is a Victor "style" #4 so I'm assuming the bore sizes must be similar.  I need to verify that though.  I'll give it a try with the preheat.  I can live with the slower travel rate.  Any advice on how long to preheat, what to look for, etc.?
Reply:That's funny. Slow? Didn't seem like it. Nonproductive?  Felt that way. Interesting. I figured there was a way the guys "in the biz" knew how long to preheat. Didn't know it was going to be that precise.  You mentioned a cutting tip. I also have a #6 rosebud if that would be any better. Should I use that or is a cutting tip the ticket?  I assume with either one, I need to use a neutral flame, right?
Reply:A half inch of steel isn't very thick. You don't need a precise heating time because the variables are too many to have an exact time. Rose bud or cutting tip are fine, and yes, neutral flame. The reason for preheating is that when you are welding less heat will be sucked into the surrounding metal, and will stay where you are putting it with the torch; it also reduces distortion and the possibility of stress cracking. It is always better when everything expands and contracts evenly. Preheating also makes for a more refined grain structure in the steel.Make sure to grind clean the weld zone beforehand. No mill scale!!!
Reply:Makes sense.  Sounds like preheating is never a bad idea when something needs to be structurally sound anyway.  I'll give it a try.
Reply:Chad,Just how large is your acetylene tank anyway?Don't have a Victor tip guide handy, but a Smith AW209 tip (recommended for 3/8 material) has a consumption of 23 cu. ft./hr (SCFH).  This means that you would need a minimum of a 160 cu ft tank of acetylene (using the 1/7 rule).  If you go to the new withdrawal standard of 1/10, you would need a 230 cu. ft. tank.Sn0 may not agree, but an internet message board is NOT the place to learn the basics of ox/ace welding.  Often times, it's the question that wasn't asked that gets one in deep kimshe.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIThis is a SCARY post, I don't care what anyone else says.Oxygen/Acetylene is NOT something to be "messing around" with, if you don't know what you're doing.
Reply:I have criticized sundown numerous times for being rude here. However I don't see where any part of his post was rude at all. Sometimes you gotta tell it like you see it and he is right an internet forum is not the place to learn how to use an oxy/ace setup.
Reply:Originally Posted by down19992000I have criticized sundown numerous times for being rude here. However I don't see where any part of his post was rude at all. Sometimes you gotta tell it like you see it and he is right an internet forum is not the place to learn how to use an oxy/ace setup.
Reply:by the way, just to clear up any confusion, I started that reply before I saw sundown's most recent comment.  I wasn't referring to that one being rude.  It was his earlier comment that contained the smartassness.
Reply:Oh boy.
Reply:Originally Posted by chadmw7So how wasn't that rude?? Just because he didn't actually come out and say DUMBASS?  In all seriousness, you guys need to post a sticky or something that spells out which questions are below the level that's worthy of an answer on this board.  You also should lay off the guys asking questions if you're that concerned about their safety.  At least they're ASKING.  It's not as if you have to buy a license to purchase one of these setups.   I'll bet that for every one like me trying to find out as much as he can, there's three of another guy opening the box and letting it rip "figuring it out as he goes".  I don't normally get caught up spending time with side comments like this but I thought I'd throw out some food for thought before the next guy comes along trying to learn.Thanks again to the guys who are willing to help a new user learn how to do it right and safely.  ... and having said all that, I do appreciate the question about the tank size.  That's helpful.  I'll check on that.  I don't remember but I'm sure it's probably not big enough for that kind of flow.alright chad simple and short, everybody keeps talkin about acetylene, your good there. Dont forget O2, they both need to match! Its called a Neutral flame... If Acetlyene is set at 7-8, then set your O2 the same!  Opening your valves on the torch all the way wont affect anything. Last but not least of course is tip size, use a chart to determine that... personally i would stick weld it!!
Reply:chad,You may not like what I say or how I say it but understand that it was for your safety, not to belittle you.If you'd been torch welding as long as I have (over 55 yrs) you'd recognize little signs that the poster doesn't have the necessary background to be taking on the task (welding 1/2" plate) originally discussed.  Little things like "do I just keep turning up the ox/ace on the torch".  Experienced guys know that the tip size determines the material that can be welded.Most home welders (hobbiests) do not have sufficient size acetylene tanks to run the larger, welding and cutting tips and surely not a rosebud.  If you don't understand this, then you need more study, not more questions on an internet board.You try to run a larger welding tip/cutting tip/rosebud off an 80 cu ft. acetylene tank, the first sight something's not right, is when acetone starts spitting out the tip.  Next is a trashed regulator, followed (potentially) by the big boom.Don't get me wrong.  I'm not a big supporter of Big Brother keeping us all safe, but if there's one area in welding that probably should have some form of certification, it is ox/ace welding.  I don't think you should be able to get a tank filled without demonstrating that you know how to use it properly.  It's (certification) is required to get a scuba bottle filled, and an acetylene bottle has a lot more potential to do harm to others than a scuba bottle.As far as "learning to weld on an internet board", I've seen as much bad advice, given freely, as I have good advice.Guess I never been very good at "political correctness", especially when safety is involved.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:hey chad, welcome to ww..sundown  sometimes rips asssss  but hes often right to do so. your question in my opinion was completely appropriiate , intelligent, just fine.  sometimes we get a newb asking"i want to weld. what do i need, how do you do it, what will i get paid ." as complex as welding/fabricating is, theres a ton of reading that must be done, and when a newb asks us to do it for him and puke it back into his head  like a bird with a gut full of worms, he is reminded to go read on his own. my 2 cents.ps something i found is that the flame needs to come out "soft"; if its blowing the puddle around you got nothing. basically  you cant use a toosmall tip and crank up the regulators...the  tip  needs to be large enough and flame low  enough velocity to creat the kind of puddle  within a few seconds  that just kind of sits there  waiting for the filler......i didnt explain that  too well but hope the idea comes across..