bending aluminum tubing

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I mentioned this in another thread, but i wanted to be more specific here with it...I have a JD2 model 3 bender from trick tools and i want to use it to bend 1.75" aluminum tubing with a wall thickness of .080I have been told by a few people that bending 6061 is tricky. So i would like to know how i could do this with my bender. I know its possible to bend 6061, because plenty of companys sell U-bends made from 6061. Is there a way to anneal it or a trick to bending it without crakcing or damaging the tubing, or should i be fine when using my bender?Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Use lithium grease in the forming grooves of the dies so the aluminum will slide rather than get stuck and kink.  This works on the bender I built from plans on http://www.gottrikes.com/.   The lithium makes all the bends smooth and troublefree.  Good luck.DougMiller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:thanks for the tip...you reccomend a wall thickness that works nicely?Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Originally Posted by sen2twothanks for the tip...you reccomend a wall thickness that works nicely?
Reply:I have successfully annealed and subsequently bent  6061 T6 and it is quite easy with an O/A torch if you have one. The only hitch being that now it is annealed and needs to be re-heat treated if the part requires full strength, of course if you regularly weld it and don`t post weld heat treat then it is the same thing or pretty close. The process I learned was to use an acetylene flame to deposit a small amount of soot on the part where it is to be annealed and then proceed with a neutral flame and heat until the soot begins to burn off then stop and let cool. Always worked nicely for my purposes and did not crack and break like T6 always does.
Reply:Originally Posted by BrianNye Welding guyI have successfully annealed and subsequently bent  6061 T6 and it is quite easy with an O/A torch if you have one. The only hitch being that now it is annealed and needs to be re-heat treated if the part requires full strength, of course if you regularly weld it and don`t post weld heat treat then it is the same thing or pretty close. The process I learned was to use an acetylene flame to deposit a small amount of soot on the part where it is to be annealed and then proceed with a neutral flame and heat until the soot begins to burn off then stop and let cool. Always worked nicely for my purposes and did not crack and break like T6 always does.
Reply:Originally Posted by BrianNye Welding guyI have successfully annealed and subsequently bent  6061 T6 and it is quite easy with an O/A torch if you have one. The only hitch being that now it is annealed and needs to be re-heat treated if the part requires full strength, of course if you regularly weld it and don`t post weld heat treat then it is the same thing or pretty close. The process I learned was to use an acetylene flame to deposit a small amount of soot on the part where it is to be annealed and then proceed with a neutral flame and heat until the soot begins to burn off then stop and let cool. Always worked nicely for my purposes and did not crack and break like T6 always does.
Reply:Yes it works for Tube and Pipe as well....from my search anneal temp is somewhere between 650 and 800 or so depending on the alloy. I found on 6061 the so called torch soot method works just fine.No, I`m not the science guy from TV.
Reply:one more question about the soot technique, or annealing in general. Do i wait for the aluminum to cool or bend it hot?also, if im supposed to bend it, or work it cold... does that mean i can anneal it today and bend it 3 days later. by this i mean, does it retain its workability after being annealed, or does it return to its natural state?this will be for an intake manifold on a car, structual strength is not a concern since it will only be holding up maybe 1lb of material with four of these 1.75" tubing.Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Once is has been annealed it will retain those characteristics until it is heat treated or work hardened depending on the alloy.
Reply:I might add that .080 might mot yield the best results without a mandrel but it may get adequate results for the application. When I did this it was on .125 x 1" 6061 T6. On steel thin wall stuff is difficult so .080" may be a little more of a challenge. Maybe try the lube as Doug suggested. I was using a rotary draw bender as well so I can`t really compare from experience how the two benders may vary in results having not used model 3. Good Luck.Last edited by BrianNye Welding guy; 10-29-2009 at 02:11 PM.Reason: f d up
Reply:thanks for the help!Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Annealing as BrianNye Welding guy described, works well.   I used the same method to bend 1" x .060" wall 6061T6 using a PT105 bender.   I've not had much luck bending past 90deg though.
Reply:How to keep this from happening when using the soot burn off technique...?(near the end of the video)[ame]http://www.youtube.com/watch?v=QPe6rBPOnx0[/ame]Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:It depends on whether or not your tube is "6061 T6" or "60-61 T6 511" The 60-61 T6 511 will crack often with a startling bang if you go to bend it. Even if you anneal the 60-61 T6 511, it will crack or fracture, and show huge distortion in the surface. It will be ruined. If you have your hand on it when it breaks you will remember it till the day you die. Ha-ha. They still make 6061 T6, however this tube can anneal in sunlight to 60-61 T0 material. So it is more then tricky it is just plain crazy. What you want is 50-52, H42 or H52 hardness. Your bender will bend it very nicely. I prefer the H52 because if you over bend just a bit, you can just grab the pipe and open the joint a half degree, and not bend the straight pipe connected to the elbow you just bent. If you use the H42 and you go to open a joint the straight pipe just bends over the whole length. It can be very hard to work with. On the upside the H42, does maintain a slightly rounder shape right at the elbow and through the elbow. The H-52 tends to misshapen, slightly near the end of the bend. You can sand this out though. You have to use a lubricant or a disposable plastic patch, between the shoe and the H-52, to protect the pipe. Or it will draw to much and collapse the outside of the elbow. The H-42 is more forgiving. All of the below rails were bent with a Hausfeld bender. You can still see a slight distortion in the elbows done in H-52. I can anyway. A slight hollow on the inside of the elbow. You can sand that out. If you can see it before the paint goes on.This is how I make the railings. Myself and a fellow from Australia made the program that calculates the length of the pipes, in a Cadd program. These are all also made with 50-52 H52 material. From Yarde Metal. It will bend sharply but this is as far as I would go. And only for handrails. Not for high stress moving objects.        Sincerely,             William McCormick
Reply:The soot works fine, but we use a heating tip or a cutting tip. We keep the blue tips just touching the work. I have never come close to melting a piece, while annealing. But I do have many years of experience. A new guy might melt through a plate though.I usually do not warp the plate though either.        Sincerely,             William McCormick
Reply:Very nice!also, for you that have bent .080 wall aluminum tubing (or thinnner/similar) with success, whats the CLR of the bend you were using. i know this can have a huge effect. trick tools offers 5.5 and 6.5 i think for 1.75" OD. i would prefer a tighter bend and go with the 5.5, but im not sure if this is to tight and cause a problem and maybe ripple or break the tubing...Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:My DiAcro #4 bender uses a follow block to capture the tube firmly in the die. This allows a tighter radius than a Hossfeld or JD2 type bender, along with reduced distortion. The drawback to my machine is being limited to 1 1/4" OD material.The tube in the pic is 3/4" X .065  6061 T-6, the die is 2" CLR, no annealing was done to the tubing.RexTest pretzel:
Reply:Originally Posted by sen2twoHow to keep this from happening when using the soot burn off technique...?(near the end of the video)
Reply:^ahhhh... very true wise one. Just a ploy to sell those temp markers...Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Originally Posted by sen2two^ahhhh... very true wise one. Just a ploy to sell those temp markers...
Reply:so just for future knowledge, about what degree does the soot technique get the aluminum to where it anneals it properly. as in, if someone only had a MAPP gas torch, propane, ect... what temperature would be optimal for annealing since there wouldnt be any soot to burn off?Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:did some searching and found this...http://www.suppliersonline.com/prope...61.asp#Generalmy guess was 750*, so i was close...Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:RexOn smaller diameter tubing you can bend a radius like that. As you go larger in diameter, it gets very bad very quickly. Because of the amount it stretches. The harder tube cannot stretch that much. I bend solid bars and tube that size myself, and I have no problem at all. But as soon as you hit that 1 1/4" pipe mark you have to go to something else. I use a little Parker Hanifin crank bender. I know that a 5 inch center line die will not work on a  60-61 T6 and a, one and a  quarter inch pipe. I would suspect that a six and a half inch die would not work as well. As far as heat treating, I was told that it depends on how the pipe was made. If it was either extruded or drawn. One way allows for annealing the other does not. They give the one that cannot be annealed the 511 designation. I have been unable to anneal the 511 aluminum. I believe the extruded stuff marked 511 cannot be annealed. When I was younger you could anneal all the 60-61 T-6 aluminum there was. But it also turned to 0 aluminum in strong sunlight. So I do not know if the drawn 60-61 T-6 aluminum would be a good choice.        Sincerely,             William McCormick
Reply:One other thing you might want to consider. As you go larger even with a mandrel bender. You are going to cause, a certain amount of porosity in the metal. As you stretch it that much. You certainly can harden the material substantially as well. I used to make and repair stainless steel pipes about three and a half inches in diameter. They were bent with a mandrill bender. And you could tell the metal in the bend had been affected by the bend. I used to polish newly bent pipe as well. And again there was a definite degrading of the material that had been bent.        Sincerely,             William McCormick...Well....the soot......I've had good luck learning that from a couple guys, put it on there with base metal cold, very, very thin layer, just a few small spots......no need to paint it on like the dude in the video, and use a MHA for the heating....single point tip is not the thing for this....actually I found the video a bit insulting....keep the heat moving all around, no problem.....anyone can melt a hole like that guy did.  Soot, again....it seems to me it burned off around 550-600 degrees...a good preheat for the castings we were doing...usually 356-T2/6 alloy. Engine and transmission stuff...I've used the soot method also for die castings before TIG work...which usually are 6-10% magnesium....they don't bend very well though...  Temp sticks are about $10-12 each...or a kit for couple hundred $$ with holder and a bunch of small pieces a variety of temps...although I've done a lot of welding on all kinds of materials....usually about 6-8 different sticks is all you'll need....couple for aluminum, magnesium, couple for chrome-moly, 3-4 for carbon steel/pipe work....in addition to touching the work like in the video, the other way is to draw the line on the material while it's cold, or warm....then heat it up, the line liquifies and changes color when at the correct temp...  Bending tubing...most of what I've bent in aluminum was 1100 or 3003, 6061 is a little hard...as it's usually for tooling....most #6000 extrusions (which all aluminum tubing is) I've used are more like 6063 aren't they??  Either way....I'd say anything over about 3/4" you'll need a lot of support everywhere to bend it....like in the picture there....especially for the thinner wall stuff.Dougspair
Reply:...Is there paper or oily stuff in that blue barrel right below the grinder??? Well, at least I can see he's got the fire extinguisher....nice dustpan too...I like those....I have one at home...one at work...Dougspair
Reply:...Oh...I see, after another look...the bender is a DiAcro....they know their stuff for bending and punching.....I have a small manual DiAcro turret punch at work...pretty sturdy....1/16" up to 1-1/4" in 16 gauge alum...or 20 gauge steel....50+ years old...still works fine...if not abused...  I believe DiAcro is/was owned by Strippit...a division of Houdaille...who at one time made the Burgmaster 3-axis turret machining centers....back in the 60's and 70's....when I worked for Burgmaster....punched paper tape controls....before the CNC and micro-processors....  Burgmaster was great machine....which is why you hardly ever see them for sale....people don't like to let them go...Dougspair
Reply:Question for those who have experience annealing and heating aluminum tube/ stock: Any experience in burying a piece in vermiculite or coke to keep in the heat, and allow for slower cooling, or for more consistent heating?? Any benefits or drawbacks? It's always good to understand a new technique, and sometimes a small change in process makes a huge diffrence in product quality/ durability/ workability.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Dougspair you are totally correct. I was mistaken, my sheet material is 50-52 H-32. My tube is 60-63 H52 hardness. One thing about the diameter of a pipe is that as you increase the diameter of the pipe by one inch. If you bend both diameter pipes around a die of the same inside diameter of four inches. Not center line radius. The larger pipe will stretch 3.14 inches more on the outside wall and shrink 3.14 inches more on the inside wall. If you bend a full circle. The smaller pipe will stretch 1.57 inches on the outer wall, and shrink 1.5 inches on the inner wall. On a ninety degree bend, that means the larger pipe stretches on the outer wall 7/8". And shrinks on the inner wall by the same 7/8".The smaller pipe stretches on the outer wall by 7/16" and shrinks on the inner wall by 7/16". You can see that is why the larger diameter pipes have to have such a huge sweep in order not to collapse or get stretch marks. Even the mandrill benders will damage pipes. By stretching them an extreme distance. Although the larger pipe is 10 percent longer then the smaller pipe in the bend. You can see that there is a 100 percent increase in stretch from the smaller diameter to the larger diameter pipe. That is why you can bend smaller diameter 60-61 T6 material in a fairly large radius bender.        Sincerely,             William McCormick