Aluminum Tube?

[Cahdealme]

I'm wanting to build an aluminum tower for my boat. I've got friend with the jd2 model 3, will this bend the tube without kinking? Is there a minumum wall thickness to work with, compared to steel for the dies. I'm not beyond buying a bigger radius die if needed. Any tips on not scratching the hell out of the polished surface? Thanks for any help.

[Pook]

grease the hell out of the pipe or it will gouge bad. make sure you buy bendable aluminum tubing...can't remember the # right this second but make sure whoever you buy it from knows your bending it, if not it will crack.

[DanB]

yup the al material needs to be 5XXX something.. i forgot the other 3 numbers.. make sure u get those type not common 6XXX alumium peices you can buy..

[SCOTTS_4X]

yup the al material needs to be 5XXX something.. i forgot the other 3 numbers.. make sure u get those type not common 6XXX alumium peices you can buy..

and this is where you and everyone else that's never bent aluminum tubing is wrong.

contrary to popular belief, you can bend 6061 aluminum tubing. how do I know you ask? I used to bend the stuff by the truckload. I worked for a company called pro-flight towers, and all we ever used was 1 3/4", .125 wall 6061 t-6 aluminum tubing. sure every 200-300 bends we would get one that would split, but not a big deal.

about not scratching the tubing, good luck. aluminum is soft, it will scratch. we used a bender that had a following die, that slid along with the tubing, so no worries of gouging. also we made towers out of polished tubing that had been hard anodized. for bending stuff like that we had special dies cut out of delrin.

-Scott

[Kavik]

Try parafin wax. It doesn't stain or get all over everything. Clean the die after every bend. The aluminum will gall a tiny bit, stick to the die, and make it worse. Try to design your tower to minimize the degree of bend, i.e. (2)45deg per leg instead of (1) 90 deg. They have less headroom that way, but minimize cracking at the bend.

If you are buying pre anodized tube, practice welding on it alot. It's really tough to make the welds look pretty. If it is pre polished, make sure there is no coating at the joints to foul the welds.

.125 would be minimum thickness. .156 is perfect, .188 works but will be a royal bitch to bend.

Good luck!

btw - I've built a couple of towers too....

[DanB]

ok i never bent the tubes but i have bent some flat stock and stuff like that and flat sheets.. cracking always happen for me.. im glad u corrected me.. i just assumed it will behave the same for tubes.. thanks for letting us know..

Dan

[Pook]

and this is where you and everyone else that's never bent aluminum tubing is wrong.

contrary to popular belief, you can bend 6061 aluminum tubing. how do I know you ask? I used to bend the stuff by the truckload. I worked for a company called pro-flight towers, and all we ever used was 1 3/4", .125 wall 6061 t-6 aluminum tubing. sure every 200-300 bends we would get one that would split, but not a big deal.

about not scratching the tubing, good luck. aluminum is soft, it will scratch. we used a bender that had a following die, that slid along with the tubing, so no worries of gouging. also we made towers out of polished tubing that had been hard anodized. for bending stuff like that we had special dies cut out of delrin.

-Scott


does the radius of bend make a difference? I only have experience with bending a few dozen pieces for parts for water parks... first tube we were sent cracked, some pieces didn't but more than enough to make it a big deal, second batch of different tubing bent easy with no problems.

[SCOTTS_4X]

we were using a 12" die. so 6" radius. likle I said there were very few breaks. few enough that we wasted maybe 6 feet of tubing every 1000-2000 feet. once in a while we would get a bad batch and send a bundle back, but for the most part we had very few troubles.

-Scott

[LuckyPabst]

I used to work here:http://www.fishingboatsunlimited.com/catalog/default.php

We built towers and wakeboard arches out of SCH 40 anodized aluminum pipe, either brushed or polished. It's what all the boat shops use down here, very common at the marine suppliers. We also did canopy frames from 16 ga. SS tube, but that's a different subject I suppose.

We used a bender like this but with an electric pump (that also powered the tube bender):
http://rampac.thomasnet.com/ImgMedium/HyPipeBenderProdImage.gif

They had replaced the two outer "things" (not sure what to call them) with nylon or some such plastic to protect the pipe and used the stock cast aluminum dies.

Welding is a PITA, they had developed a technique that used only an on/off button on the torch, no remote amp control of any type, just leave the machine set somewhere around 215 amps or so. You'd go around the joint once with rod and while it was still hot, around again "bumping" or pulsing the weld with the button to get a nice even bead and to kinda float the anodizing to one side of the weld. It takes a litte getting used to!

All tube copes were done in a cheesy bandsaw with a 1/4" blade. Real easy once you get the hang of it. They also use a roll bender to get large radius bends so the tops would have some shape to them.

Chris

[SCOTTS_4X]

Welding is a PITA, they had developed a technique that used only an on/off button on the torch, no remote amp control of any type, just leave the machine set somewhere around 215 amps or so. You'd go around the joint once with rod and while it was still hot, around again "bumping" or pulsing the weld with the button to get a nice even bead and to kinda float the anodizing to one side of the weld. It takes a litte getting used to!

Chris

I don't mean to hurt anyones feelings but if you can't weld it in the pass that you are adding filler with, you need to either take a different approach or go back to be basics and brush up on the old tig welding skills. it's not very hard to get a nice looking bead in one pass.

-Scott

[Kavik]

Take two pieces of aluminum that are anodized, TIG them together, then check back in...

[SCOTTS_4X]

Take two pieces of aluminum that are anodized, TIG them together, then check back in...

I guess you must have missed the post a little further up that said I used to do that for a living? :rolleyes:

-Scott