chamfering heavy plate

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By way of introduction, let me say that I'm not a welder; I'm a hobby blacksmith who bought a used Lincoln AC-225 because arc welding is sometimes a whole lot more convenient than forge welding.  It was a great buy and I'm really happy with it; it's come in handy many times.  But I'm still a hack welder by any reasonable standard.Here's my problem.  I have several piece of 1" thick plate that I need to bevel -- heavily -- for fillet and edge welding.  I don't have an O/A torch or a plasma cutter to do it with.  I do have an angle grinder, but that'd be a time-consuming way to go, and my hands get numb just thinking about it.  I haven't ruled it out, but I'm looking for better ideas.  My first priority is getting the work done in a reasonable time, but a close second is keeping the cost low.  Would carbon arc gouging/cutting with my welder work, with or without compressed air?  (I know very little about this process, but I get the impression that it usually involves uses DC, and higher current than my AC-225 can produce.)  I could rent an O/A torch -- or maybe even borrow one -- for a day, but I have very little experience with them and have never cut with one.  How steep is the learning curve?  Ditto for a plasma cutter.  Or are there other options I'm not considering?  One thing to bear in mind is that I'm pretty well limited to 230V/50A, single phase power.Thanks for any suggestions you might be able to offer.
Reply:Looks like it may be possible to carbon arc gouge with 225 amps AC.see this link, I'm sure there's a bunch more info out there, this was just the first one I ran across.http://www.weldwell.co.nz/advice/arc_air_info.htm
Reply:Unless you want to try this with a sawzall and about a case of cutting oil, the torch is the way to go, we'll talk you through it!  "This is a cutting torch, it gets very hot..."ok, just kidding!Plasma is very easy to get started with, but limited in thickness unless you have very large machine capacity. Look into the link on air arcing that Pulser gave, other wise the torch can handle this, we use a track burner at school for this purpose, just a torch on a track with a motor, simple.You should learn to use the torch, me thinks.City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Thanks.  Since I already have the welder, maybe I'll see if I can find some AC carbon arc electrodes and try those out.  If I can't find any around here, or if they don't seem to be working so well, I'll see about getting ahold of an O/A torch for a day -- in which case I'll probably be back with more questions.
Reply:Considering what you can buy a decent O/A setup for I would STRONGLY recommend going ahead and getting yourself an O/A setup.  For bevelling plate a torch is your best bet, and I'm not sure about carbon arc gouging on an AC 225.  Depending how much you have to bevel I think you might run into duty cycle problems with that machine, but even if you don;t I personally would much rather have a torch to bevel it with.  Also, how are you cutting the plate to start with?I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:They're already the right size.  Good thing, too!I'd love to have an O/A setup, but even the small, cheap ones I've seen run around $300.  That's is a bit steep for me at the moment.  (I got my Lincoln for $105.  There's no way I could've swung a new one.)  But I may be able to get ahold of one for a day.5 minutes later: D'oh.  Now I see there's some guy on Craigslist selling a Craftsman set for $100.  No bottles, though.Last edited by MattHB; 08-27-2007 at 02:26 PM.
Reply:If you don't need full penetration, then the angle grinder would be the way to go.  I wouldn't suggest purchasing a torch just for this job.  Though a torch setup would be beneficial in your shop.  If money is an issue, then note that the purchasing of the torch is only part of the expense you have gas also.   What are you doing with the plate?  How large are the plates?  Do you use propane?  I use propane/oxygen because and also use it for my forge.  On the one hand that might save so money, however you have to purchase the proper cutting tip. Depending on how much you have to do, a large grinder and some discs might not be a bad option.
Reply:"Your best bet would be with an O/A setup, It will do a cleaner job. If you really think you want to gouge you will still have to shell out a few bucks. Gouge torches can get pretty expensive, though you can pickup cheap models for about $100, but you will get what you pay for. I just got done with testing from several manufacturers. ArcAir wrote the book on gouging and is the best known for gouging torches, but you will be in the ball park of several hundred dollars depending on the model. I tested a torch called a Superton ST-4 recently. It is a torch capable of up to 1/2" carbons and rated for 1000 amps. This is overkill for you, but you may be able to find a smaller model. It was a Arc Air K4000 knock off, but was priced at about $150 and performed very similar to the Arc Air.However, I think your biggest problem will be the limitations of your machine. Air carbon arc gouging is done at relatively high voltaqes and amperages. For example Arc Air recommends 1/8 inch carbon     60-90 amps.5/32 inch carbon   90-150 amps3/16 inch carbon   200-250 ampsI don't know if your machine will be able to give those kinds of amperages and still maintain high enough voltage to keep it light for a 3/16 carbon. Voltages of 40 volts or more are not uncommon using this process. You might be able to get by with a 5/32 but you will probably be working the duty cycle of your machine pretty good.In addition to Pulsers link, here is the address for ArcAirs gouging guide for anyone interestedhttp://www.thermadyne.com/twecoarcai...89_250_008.pdfLast edited by reddoggoose; 08-27-2007 at 08:31 PM.Arguing with a Welding Engineer is like wrestling with a pig... after a while you realize the pig likes it
Reply:I'm gonna vote angle grinder.Cutting with a torch takes some skill. You will get aggravated quickly trying to learn how to cut by beveling these plates for your project. It would be quicker to just use a grinder. You don't have to bevel them at a large angle, only 20* or so. That would be pretty easy with a 4 1/2" grinder and some good disks.Miller EconotigCutmaster 38Yes ma'am, that IS a screwdriver in my pocket!
Reply:If its a narrow angle to be used with something like 6010, bevel it by hand.  If you need a steep bevel, borrow a torch.To make a relatively smooth cut with an OA torch isn't too bad using your fingers as a guide.  If you were to attempt to air arc a bevel on heavy plate, even if you're relatively well versed in it, you're going to do just as much if not MORE grinding making it smooth and removing the dross than you would having ground it by hand in the first place.
Reply:I've air-arced 1" test plates without problem. Chuck'em up in the vise and knock the dross off with a chisel...grind to desired finish.Anything worth doing is worth doing RIGHT
Reply:I didn't have time to read this entire thread so I don't know what was been suggested already, but you have several options, here are two that you can do with what you have on  hand.You can Air arc itOr you can get some 3/32" or 1/8" 6011, turn up your welder as high as it goes.  Turn that plate on a 45 degree angle so you are cutting straight down.  Stick it in and dig it out.  Then clean it up with a couple grinding disks.  This method is dirty, nasty, and hot.  But it works.  I'd recommend the air arc, but you do what you have to do.Either way will need some grinding afterwards unless you have a OA torch and a track setup.
Reply:Thanks for all the additional thoughts.  Strangely enough, last night I discovered that in a couple of weeks I'm going to inherit not one, but TWO O/A rigs.  The uncle who owned them wasn't the sort of guy who tended to take good care of his things, and I'll have to get everything checked out, but hopefully when all's said and done I'll have at least one full set of working O/A gear.  Since this project can wait a few weeks, if it comes down to cutting I'll probably go ahead and use O/A.  I'd rather not overwork my welder with arc gouging or the 6011 idea if I don't have to.  (Welderboy, I used that trick with the 6011 to bore a hole in a piece of 8" Schedule 80 pipe recently.  It worked.  But I'll be happy if I don't have to do a lot of cutting that way.)As for what I'm doing, what sort of bevel I need, and whether I could do it with an angle grinder, those last two are actually questions I should probably be asking you guys.  Should've thought of that before.  What I'm doing is building up an anvil.  Here's the basic idea, with a few details left out.  Don't laugh until you've priced a few decent quality 300 pound anvils.  (The plate is about 50 points carbon, so I'm going to have to preheat and post heat everything.  That'll be interesting.  So will the heat treat, which I haven't fully worked out yet.)So you tell me: to get the best possible fusion between the face and the plates, how steep should those bevels be?  And the seams between the plates? I'm counting on not having a perfect mechanical fit (I wasn't planning on having the plates or face machined or surface ground), and getting enough penetration in the welds for it not to matter too much.  The shallower the bevels the better, since steeper bevels mean more to fill in, and more electrode$ to do it with.  But the number one priority is getting the best possible fusion between the upright plates and the face of the anvil.While we're at it, any recommendations on preheat/post heat, and preventing warpage?  Warpage could really screw up the plan.
Reply:I'd say you want as much penetration as possible.  If you really heavily use the anvil, then cracked welds might become an issue.  Cracks caused by vibration.   Might even consider putting some bolts through the plates to keep them compressed.  Remember, as you grind welds you are actually thinning the weld, hence you want much weld below the surface.  I am assuming you are going to smoothe the welds.I would use a grinder for beveling. As stated with the other methods you will end up grinding.If you really want to use your welder, then can't you just "hard surface" the top and beak with the appropriate rod. Might even eliminate the top plate and hard face the acrose the top of the welded plates.   You really need to know the top edge of the plates is machined flat otherwise the top plate will have dead spots.   I think that vibration will your main concern.
Reply:I thought about hard facing the top, but I was worried that getting it thick enough would require an awful lot of hardfacing sticks.  On second thought, though, since the 1050(ish) underneath should also harden, maybe the hardfacing wouldn't have to be that thick.The bolts through the anvil are a good idea.
Reply:Well since you've bought the plate then you might as well go ahead with your plan, but I will throw out a suggestion.  Look around for an Old anvil. It doesn;t really matter what condition it is in as long as it's not busted.  I have seen old ones at sales, or even flea markets for little of nothing.   All you have to do is run it buy a machine shop and have them regrind the top surface and you are good to go.  Just an idea.  ~JacksonI'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:See, the thing is that I didn't buy the plate: it was free.  So I'm starting well ahead of the game on cost.  If I'd had to buy the plate it would've made more sense just to put the money toward a commercially made anvil, as you say.