bending aluminum

i'm working on building a wakeboard tower for my boat and yesterday i took my aluminum (6061) tubing (2" 1/8wall) in to have bent. well needless to say it peeled leaving me with 2 pieces. is their a certain way to bend 6061? otherwise the guy at the shop told me to get some 6063, that stuff bends like butter he said. which brings me to my next question, is 6063 going to be stong enough?

I don't remember the exact ratios, but there is a certain wall thickness you need relative to the tube diameter to get good bends in AL pipe. Are you sure it is an alloy issue and not a wall thickness problem? Just curious, why are you using aluminum? Beside bending it, how are you at welding it? I've never been able to get good welds without burning through at least once.

i don't believe it's a wall thickness problem. it seems that most people who are building their own towers are using this type of material, it's cheap and light. as for the welding, i have a buddy that welds aluminum day in and day out so that's not a prob. i just don't have a buddy that bends al...

Keith,
Yes there is a special way to bend 6061 or any type of aluminum. You may need to find out if its drawn or what type of process they made the pipe in but you will need to bend it by using mandral bending this is where the pipe is captured when bending. I buildt my own tower its on the boat in my profile. Let me know if you have any other questions. I paid a bender a few hundred to bend my tower and have around $400.00 in it total.

Good Luck,
Steve

Bending aluminum is very difficult with thin wall material. The elongation is typically 14% which in most bending applications of 90 degrees is borderline the limit. We currently purchase material prior to tempering in order to take advantage of the lower strength and larger elongation properties. Once we are finished we temper in order to increase the strength. The big problem we have is the lower temper is subject to age hardening and if it sits around too long (more than a week or two from the time it was extruded) we might as well send it back for remelt.

By the way we purchase 6105-T1 material and temper it to 6105-T5 material. Wakeboardin is right in that you may have to use a mandrel in your bending process to keep it from collapsing too much.

Also used a mandrel system.
My tower is strong and only weights
35 pounds. It folds but not far enough
to get in the garage. I can take it off
by myself. Its all 3 inch. Phat uh?
Check my profile.

(Message edited by sandbag on May 29, 2003)

6063 is what handrails are made out of. Its softer, so its more easily bent. Still should be strong enough for a tower. I cheated - I used buttweld fittings so I didn't have to bend it. I also used 1 1/2 sch 40 6061 pipe right off our shelf.Pipe is measured on the ID. So the OD of my pipe is close to 2". Tubing is measured on the OD and would be 2"
Scott

scott where did you get those buttweld fittings at? sandy that is definitely a phat tower, and wakeboarding that tower is sweet also... thanks for the info fellas

Bending it in full T-6 condition is going to be tough, it's certainly possible but it can get complex. It's a lot easier to get the tubing without any heat treat and then do the heat treat after all the welding and bending are done. You also end up with all the residual stresses of the bends and welds being removed by the heat treat.
Bill

Keith - how far is Fond Du Lac from you. Just kidding. Most metal supply or more specif. pipe places sell fittings. Almost all alum fittings are t-6061 so you should have no problem. Tell your buddy NOT to grind the welds. Paint the tower or powder coat. Once thats done the welds are less noticable. Brenner Tank is in Fond du and the make tanks there. I know they have fittings.
Scott

fondy is about 30 min from me, i was actually up there last night. i'll check out brenner, thanks.