Henrob/Dillon/Cobra for Aluminium

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Hi there,I need some advice on the above torches. I am a half decent welder using oxy/acetylene and stick welding on steel, but now I want to do some Al welding for a motocycle project I'm working on.I was planning to save up and buy an AC/DC TIG, but over here in Australia the cheapest I can find is AUD2500 for a Chinese 160Amp (240V) through a guy on Ebay, brand name machines start at AUD4500 (200amp/240V). I've read some articles on the Henrob torches (I think they're called DHC now, made in the US by Cobra) and they claim to be able to weld Al and Stainless Steel. Now I don't believe everything the Sales Reps say, because they all sound like they're from the Shopping Channel on TV (but wait! there's more....buy now and receive a free set of steak knives!) but I have come accross some independent reviews which say you CAN get good results welding Aluminium with these torches.I can get one here for around AUD650, about the same price as a top quality standard torch kit with cutting attachment and regulators, but this is a lot cheaper than the TIG.Can anyone let me know if they've used one of these for Aluminium and what were the results.And before anyone tells me to bite the bullet and splash out on the TIG, I will eventually, but there are lots of other tools on the wish list that I could get with the price difference (lathe & mill to name 2)ThanksJDH
Reply:The Henrob will work just fine.   But it's big drawback is it takes lots of practice and then some more practice to get it to do what you want.However someone with the patience and skill (a suitable replacement for funds under most circumstances) can use a Henrob and do quite well.I would recommend finding someone who's got one and had success with it before purchasing if possible.My biggest problem with it and aluminum is the way aluminum welds, not changing color etc.  Not the torch's problem, just mine.life is good
Reply:I don't have one, but I'm pretty sure that there's nothing special about the Henrob torch other than the fact that it's a nice form-factor for OFW.  One can definitely weld aluminum with the OFW process, but it's difficult and I don't think a Henrob or a Meco Midget or any other torch is going to make it that much easier.
Reply:http://www.cut-like-plasma.comA reseller but the videos in the site clears a lot of things up. Good reading.i bought the Meco midget torch form http://wwwtinmantech.comi know, i know. the thread is 3 months old!
Reply:Thanks for the reply Laserjock, I think that website was one of the ones I came across when I was looking for the torch. I was going to buy from them, but I found a local supplier here in Australia and bought one with the necessary adaptors to fit our OA cylinders.I'm quite happy with it, haven't mastered aluminium welding yet, but getting there - got some really good results in both appearance and strength. Like some of the other replies mentioned, I'm not sure if the flame is THAT much different from a normal torch, but the design of it makes it a lot easier to control the heat and puddle.It's definately a useful addition to the toolbox, and I'm sure the light gauge cutting attachment will come in handy some day.Did you buy the Meco for aluminium or just general welding?How well does it perform?
Reply:Originally Posted by halbrittI don't have one, but I'm pretty sure that there's nothing special about the Henrob torch other than the fact that it's a nice form-factor for OFW.  One can definitely weld aluminum with the OFW process, but it's difficult and I don't think a Henrob or a Meco Midget or any other torch is going to make it that much easier.
Reply:Cool! This thread is not dead. I just got my Midget<strike that Meco. Trying hard to be PC here.  I too need to swap my Acetylene fittings. Had to dig up some info on CGA's. I bought the Meco with a set of Victor/Thermadyne regs. The Oxy reg was fine but the Acetylene reg apparantly uses the CGA 510 OR CGA 300. I just ordered the correct fittings and it should be here in 2 days. I already bought the cylinders and did not anticipate this. I'll soon have both styles if the welding shop decides to change the fittings around on me again.My reasons for getting the Meco:I will be welding up some Al tubing for an intercooler setup. I'll post pics when I get some practice and the project finished.I like the smaller size. When I opened the box I thought the torch was not included in the shipment  I was not looking to cut thick material with it. Have a bandsaw at work for that.I am gonna be working with small projects and thin gauge metals. A larger torch (not a big possibility) is a drive away. The shop had a selection of Victors.BIG FACTOR! A TIG outfit (the one I'm interested in buying) would have set me back almost double what I spent on this. Not knocking TIG at all. I can apply the OA technique on other types of welding. Welding speed-prolly eqaul or close enough not to matter. I am not going into production with this.Exit! long post-just excited I'm not alone here. Last edited by Laserjock; 10-09-2005 at 09:49 PM.
Reply:Good to see this thread is alive again! Thanks Laserjock!Just out of curiosity, how many different standards are there for welding equipment fittings stateside? Here on Oz, welding gas supply is dominated by one or two big companies. I don't think you can even buy your own cylinders legitimately, all of them are leased. The upside is you know the cylinders are always certified and up to scratch, you can get them filled anywhere, and all the fittings are the same Australia-wide.Cluna,You mention the flare from the flux when welding aluminium.......the DHC websites talk about a blue lens to eliminate this. Is it worth the $$$? I have some trouble seeing the puddle with my standard goggles, but will it be that much clearer with the blue lens, or will the puddle always be hard to see when welding aluminium?My other question is about preheating. I'm doing fine with the thin stuff, as Cluna said move fast and heat control (I find frequent dipping of the filler rod helps as well). But when I tried to weld the thicker stuff, the weld puddle and heat affected area grew huge and made a bit of a mess. I understand that Al really sucks up and dissipates the heat, so I'm assuming thats why I can't maintain a neat weld puddle. Would pre-heating help here and whats the best way to preheat smallish (but thick) pieces of Al?I haven't done any stainless welding yet, but are there anymore tips 'n' tricks you can share? I've been avoiding it up until now because it's a real b**stard to cut and drill (if you don't have a plasma cutter), but I will be using it on some 'cut-to-size' bits.Laserjock,Like you, I had to choose between an expensive AC TIG and a lot less for this setup. I won't be doing production work either, so speed is not a major concern. Still want one though, its still on the wish list, but would rather wait a bit for a decent setup. From what I've read, you can't scrimp on the Amps when welding Al.I have a "full size" torch for any heavy duty cutting/welding/bending/brazing with OA, plus a stick welder for the other heavy stuff, but I really like OA for some reason, probably the total control you have over the weld.Post those pics when you get a chance, and if any one else has pics of what a gas welded Al bead should look like, it would be good to compare against.
Reply:I'm only aware of the 2 for acetylene. I have the links at home. That's because I ran into that problem and needed to research a solution. I bought my cylinders outright. I think each has a 5 year DOT stamp before needing hdrostatic testing. I guess I will find out in ~5 years when I go to refill and they accept/reject my tanks.As for the sodium flare/blue tinman sells the TM2000 lens. When I got my outfit, it included the headgear wuth a supplied green lens and the TM2000 lens. I compared the one that was included in the headgear and the TM2000. The TM2000 was better optically. It had almost no distortion, brighter and better contrast. Visit the tinmantech website for a better description.
Reply:Yes the special glasses are worth it. Without them, you cannot really see the puddle or wrinkle effect. Flux melts and it looks like apuddle without them but it is obvious with the lenses  Supposedly there are some cheap ones around that work just as well. I found them on google groups wth a link once but it has been a while. I have the Cobras but I've been told the TM2000s help you see the puddle better ?? I don't know if it can be much better but I'd rather have the TM2000 headset now. You just have to filter out the sodium flare and then you will be amazed at the control you gain over the puddle.I've found that hot and fast is the game. Too small of a tip and the whole thing will be at melting temp before you will get a puddle. I still fight myseld to use larger tips. You want to tune the flame to the hot side of safe and let speed and larger filler rod be the heat control. If really thick, do the old acetylene soot heat test for preheat (when the carbon burns off, the al is ready) . The lens will help and so will well cleaned aluminum (the oxide really hides the puddle on thick stuff--even with flux--to thepoint it is on the verge of collapse before you recognize it. Brushed and cleand with wheel cleaner/al etching/phosphoric acid will solve that problem. Of course lotsa prctice and cursing. Sometimes you will think it is impossible before you figure it out.Stainless is easy, just use a bit of flux (backside also) and less heat than you think you will. It isn't as clean as a tig weld but it cleans up well
Reply:CGA info:http://www.thermadyne.com/victor/lit...ts_Connect.pdf
Reply:http://tinmantech.com/html/aluminum_...g_article.htmlhttp://tinmantech.com/html/welding_a...ody_sheet.htmlSome pics of welds.
Reply:Hey thanks guys!The information you've provided has been really helpful! The Tinmantech site is full of useful info, I didn't realize he actually supplied the TM2000 lens, I will see if I can get one shipped over here. Some good comments and views on the Henrob torch, although he seems to prefer the Meco.Oh well, I like it.Everyone I had spoken to previously (mostly reps trying to sell me an expensive AC TIG setup) said TIG was the only way to go welding Al, but reading through posts here and the Tinmantech site, OA welding is not only a viable alternative, but has some advantages if you're prepared to put in the practice.Cluna, I've got more questions!  When preheating the Al. (I'll try the soot method, thanks) do you clean with the stainless brush before or after heating? (or both). Is preheating just a matter of running the OA flame over the piece before I start welding, or is there something else to it? LaserjockI see you've got a thread going with your OA - Al welds, I keep on eye on that from now on, and post mine when I've had a bit more practice.Thanks for your help. JDH
Reply:I've found you only need to preheat the thicker metals with the soot method. I only clean at the beginning, preheat then add a little flux while hot.On thin stuff I put on the flux and  just lightly preheat the water boils softly from the flux. Just barely run the flame over the metal (NOT THE FLUX).Tiggin Al is cleaner and in some circumstances necessary (O/A Al lap joints risk flux inclusion and the inability to remove flux makes it a poor choice). If you have the money then TIG ing AL is never a bad choice.
Reply:You might think about getting a high freq unit and a cheap ac welder with continuous amp adjustment.  You could tig with that on a budget.  No squarewave or other goodies, but I do it without the goodies and for most stuff it works fine.  My high freq unit is by dayton.  It was around $200 new.  Some folks have even built their own high freq units for like $25 in parts...they are really simple inside.  There are several other cheap add-on hi-freq units, but not from miller or lincoln.  If you already have an ac welder, just get yourself a high freq unit or build one, a tig torch with compatible connectors, a flowmeter and argon...and you can tig.  Remote amp control is nice, but optional.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Originally Posted by JDHLaserjockI see you've got a thread going with your OA - Al welds, I keep on eye on that from now on, and post mine when I've had a bit more practice.Thanks for your help. JDH
Reply:Whats the story wit TM Technologies (Tinmantech). I want to buy a Meco Midget Torch and have emailed TM Technologies about 5 times (over the last 2 weeks) now but they haven't replied (apart from the auto responder) once.Why do companies behave like this?....It's just so stupid.All the best.Neo
Reply:Originally Posted by NeoWhats the story wit TM Technologies (Tinmantech). I want to buy a Meco Midget Torch and have emailed TM Technologies about 5 times (over the last 2 weeks) now but they haven't replied (apart from the auto responder) once.Why do companies behave like this?....It's just so stupid.All the best.Neo
Reply:I have one disagreement with the Tinman video I have.  He claims you can use any bottled water to mix with your aluminum flux ... not so.  Bottled water has minerals added to improve taste and they can affect the flux.  I have better luck with distilled.Dynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:Hi, for what it's worth.....I saw a demo of the Dillon at out model club back in the late 80's, and one of the points strongly stressed was the lack of preperation or cleaning required when welding alluminium.The demo showed a car's gearbox that had been left to rot in a field for years and was completely covered in that whitish grey powdery oxide coating as old and weathered alluminium does get.The first test was to fill in a blind bottom bolt hole in the gear box side, and the demo guy took an ally filler rod, heated it and coated the end with powdered flux, next he heated the area round the bolt hole and stuck the torch tip down into the hole.......normal torches go out when the flame blows back, but the Dillon is designed to have complete combustion within the nozzle and tip and so no blow back occurs.The hole was welded up WITHOUT FIRST CLEANING OUT THE HOLE OR BRUSHING THE OXIDE COATING OFF OF THE HOLE.The hole was progressively welded up to the top.The second test was to build up a piece of the bell housing bolting flange by welding that had broken off.Same again, no cleaning or weld preperation......welding filler rod coated with powdered flux and the broken area built up layer on layer.Normally you have enormous trouble with dirty alluminium but in the demo this did not happen.There was another test and that was on stainless steel, a piece of .025mm (.010") thick stainless steel shim about 20mm (3/4") wide and 75mm (3 ") long.First the demo guy cut the shim with the cutting torch attachment, then he laid the two pieces of shim on a fire brick with the two cut ends butted together and using no clamps or weights to hold the pieces down, welded the two ends back together.....there was no clean up between cutting and welding.I thought this was quite an amazing torch, and at the time it was selling with a pair of low pressure regulators for A$500, which was out of my range.Ian.
Reply:Originally Posted by NeoWhats the story wit TM Technologies (Tinmantech). I want to buy a Meco Midget Torch and have emailed TM Technologies about 5 times (over the last 2 weeks) now but they haven't replied (apart from the auto responder) once.Why do companies behave like this?....It's just so stupid.All the best.Neo
Reply:Originally Posted by makoman1860Neo, I think it must be an issue with you. I get my orders within a couple days every time. I know they are around as I talked with Kent last week. Did you try just putting an order in or did you have some questions??
Reply:Neo, Kent might be out doing trainings or something of the like, and so if it is a tech question it might be waiting for him in his inbox. Just so you know, it is a very small company, basicly Kent and a couple staff people to help take and ship orders, his primary business is still using the tools he makes on restoration work, and teaching classes all over the world. It would be worth a call to them.
Reply:there is a sculptor named tom gingras , his website shows him using a cobra torch..i believe he is a rep for them and quite skilled and innovative with it, might help you to look it over..
Reply:I've been playing with the cobra DHC2000 for a week or so.  I think it might work fine for quick repairs in the field.  I was getting frustrated with the aluminum until I added more flux, then it seemed to lay down a very strong, ductile bead.  Steel welding means you have to totally relearn your technique if you already torch weld.  It's a high skill process, I think I will like it after many hours of practice.  It's main advantage is 4PSI on gas and Oxy, which means I can use it with one of the little totes for extended periods. Two video links that might help are:http://www.cutlikeplasma.com/video_library.htmhttp://www.cobratorches.com/demo-videos/Pressure has nothing to do with flow rate. The Dillon torch uses the same volume of gasses as any other torch with the same tip orfice size, and same flame size.
Reply:Hi all, I have a great interest in the Dillon torch, but the Oxy/Acc bottle rental kills the enthusiasm, so having also had a great interest in generated gas for welding etc, I always wonderd if it was at all possible to use one of these torches (with some modification) with an Oxy Hydrogen (Hydrox)  gas producer, the type that produces the oxygen and Hydrogen from water using the electrolysis principle.There is a huge following on Utube showing various DIY "Hydrox" gas producers and also a torch made to work with the gas, which is pretty simple for DIY useage, and extremely hot as you can weld stainless with it same as a regular Oxy/Acc torch.One of the big advantages is there is no stored gas, rented bottles or gas buying ever......the gas producer runs direct from the electricity mains supply and breaks down the water into it's basic constituents of Hydrogen and Oxygen, ratio of 2 parts of hydrogen and one part of Oxygen, switch on the unit and you get gas , switch off and it stops working, no gas stored so no safety problems with large volumes of gas under pressure.Jewellers use these type of torches, and some years ago I went on Ebay and got outbid for a Kronos jewellers torch running on Hydrox.Ian.
Reply:[QUOTE=blackbart;2283161 Steel welding means you have to totally relearn your technique if you already torch weld. [/QUOTE]In what way is the technique different than using a Smith or Victor, etc? JimDynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:Originally Posted by 4sfedIn what way is the technique different than using a Smith or Victor, etc? Jim
Reply:@4sfed,     I am still getting used to it, I have to admit, it was an "Impulse" buy after playing with it at the farm show.  That being said, I have started to have some success with aluminum after figuring out the flux issue.  It has a narrow, smaller, heat zone than my victor. The soft pressure from the cone prevents it from aluminum being blown through.   For steel, they want the cone ahead of the puddle, washing in the filler, using capillary action to pull in the puddle.  It feels wrong, but the welds are testing good.   As far as PSI not being related to flow, that is correct, but I would assume it is using less gas, since they are the same regs I use with my victor. I may hookup a flowmeter to be sure.    I have access to TIG,MIG,OA,plasma,Stick etc, and have been welding for 35 years.  The main reason I bought it was some of my jobs are WAY out on the water.  If I can master it, I figured I can just take a small bottle "tote" kit instead of loading a boat with a full welding setup, which is what I do now.    A fair judgement on the system?  Not totally 100% convinced yet.  It seems to work, the learning curve is high, especially if you are already a welder.  You have to unlearn certain OA techniques. It is a high skill process.   Cutting with it requires that you remember steel burns with oxygen with out any added heat. If you just watch the oxygen tip, you can do some fairly presice cutting when compared to a standard victor.  Also your PSI is much less, 4 PSI acytelene, 8-12 PSI on the O2.    The selling point for me was gas usage.  Not the expense as much as the time.  If I can cut and weld with a "Tote" for 3-4 hours, then it will be worth it.    I still would choose TIG for most aluminum boat repairs, Or MIG for bigger repairs and fabrication.  However, I am still open minded on the cobra (DHC2000), but I have to master it first. I have played with it for several hours.  I'll repost after I master it.
Reply:BB, Again, not understanding what you are having to re-learn?? Unless you had poor welding habits to begin with?? Just so you know, victor is about the worst torch out there for mixer and tip design, so I am not supprized that you are liking the dillon a bit better. Aluminum with the dillon is as straight forward as with any torch, as the same process is used. Good Luck!
Reply:I forgot this post was mostly for Aluminum. For welding steel 1/8 and up, you're right, for thinner they want the torch ahead of the puddle, insted of in it.  Also you don' occisalate the torch as much.  I have never tried aluminum with any other OA unit yet, so I can't comment on that. I usually tig or mig it. Cutting steel is quite a bit different, the torch tip is almost riding on the steel, where a normal set up would be 1/4 to 1/2" off it.  I provided links the their  video instructions for people to copare. It does have a smaller but very hot flame.  Adjustments are the same, neutal, except they want a carburizing flame on stainless. Raising PSI above 4 makes no difference in the heat, you have to go to the next size tip. So I guess most of the technique differenced are when it come to steel, not aluminum.
Reply:Originally Posted by makoman1860The dillon uses what I call a hybrid flame shape. Somewhere between a full pointed, and bulbous flame. Soft enough to prevent puddle agitation and oxidation, yet focused enough for concentrated heat. Good all around tip for steel and aluminum, but a little too pointed for stainless in my book. The outer envelope is well done. My hybrid meco tips have a similar flame shape, but a bit softer for 4130 work, and an outer envelope a tad wider.Whoever thinks o/a welding is simple.....never studied it! There is much more going on than probably 99.8% of welders would understand or appreciate.
Reply:Originally Posted by 4sfedMakoman, Do you have any references that discuss the nuances of the different flame shapes?  I have several of the old standards that discuss the process and techniques, but you've alluded to flame characteriztics that remind me of the discussions on the advantages and uses of variable frenquency and pulse with inverters.  Thanks
Reply:Could be, I rarely use OA.  The thinnest steel I remember welding was probably 16 ga.  I alway let the puddle melt the rod before where the directions for the cobra wants the flame to wash it in. I also always used a circular motion with the torch where they seem to want very little movement.  Their samples were on much thinner steel, like you said. Probobaly 20 gauge or so.
Reply:Originally Posted by makoman1860 The information I have comes from some burner design handbooks, older torch design literature, and a Russian gas welding engineering handbook from the mid 1960's. In the end what I did was machine a series of tips from a fully pointed flame, to a fully bulbous, all the same orfice diameter. I then used them on sample coupons, noting and recording the results for myself.I also sectioned a tip of every manufacturer out there.
Reply:Hi, when the guy selling the Dillon at our model club in the mid 80's demoed the Dillon torch, one of the characteristics strongly put forward in a comparison to other OA torches was that complete mixing and hence complete combustion occured in the flame AT THE TIP, which prevented outside air getting to the weld zone and causing oxidation of the weld area.A "normal" OA welding torch has a large over spill of burning gasses and this causes blow back when you get near the job, also drawing in outside air to the weld zone........the Dillon uses LESS gas due to the characteristics of it's design and the tip is where the heat is and not in the over spray of burnt gas.This was demoed by the action of the alluminium weld where the torch tip was inserted RIGHT DOWN INTO A BLIND HOLE, without blowing out or cremating the copper tip.Several sets were sold that night purely on the results of the demo and the ability to do what other torches were totally incapable of.It is a highly specialised torch and can do wonders if you take the time to study the method and aquire the expertise.If you don't understand the characteristics or bother to study them you willl just dismiss it as just another gas torch.Ian.
Reply:Originally Posted by puddytatHi, when the guy selling the Dillon at our model club in the mid 80's demoed the Dillon torch, one of the characteristics strongly put forward in a comparison to other OA torches was that complete mixing and hence complete combustion occured in the flame AT THE TIP, which prevented outside air getting to the weld zone and causing oxidation of the weld area.A "normal" OA welding torch has a large over spill of burning gasses and this causes blow back when you get near the job, also drawing in outside air to the weld zone........the Dillon uses LESS gas due to the characteristics of it's design and the tip is where the heat is and not in the over spray of burnt gas.This was demoed by the action of the alluminium weld where the torch tip was inserted RIGHT DOWN INTO A BLIND HOLE, without blowing out or cremating the copper tip.Several sets were sold that night purely on the results of the demo and the ability to do what other torches were totally incapable of.It is a highly specialised torch and can do wonders if you take the time to study the method and aquire the expertise.If you don't understand the characteristics or bother to study them you willl just dismiss it as just another gas torch.Ian.
Reply:just purchased one at the CBA swap meet this past weekend. having trouble with the aluminum also. gonna try more flux