bending aluminum?

[wheelsucker]

I bought an aluminum plank about an inch wide and 1/8 inch thick, I'm trying to bend it around the stock mufflers to make customer exhaust hangers, I've got it bend almost all the way around but am having trouble bending it the last little bit to make it form around the muffler better. Does anyone know how to bend aluminum so as not to break or scar it? I've got a heat gun but am not sure it will make the aluminum hot enough to be any more bendable than it already is.

[BRENTTODD]

Go buy a bottle of map gas to heat up the stock and bend it around the cans put palstic shims around where you need to hit it if you have to. Keep in mind the heat will discolor the alu a little bit so i hope u plant to paint them. I no pro but thats my idea good luck dude

[Guest Nogbad]

Anneal the aluminium as follows to render it soft for further bending.

 

Heat gradually with a gas torch to about 400°C. A good guide to the correct temperature is that a matchstick wiped across the surface smokes but does not ignite, leaving a whitish line on the ally.

 

After you get it to this temperature, quench into a bucket of cold water.

 

The material will now be soft and can be further bent.

[Guest ratchethack]

FWIW, commonly available aluminum 1/8" x 1" anodized strap extrusion stock is easily bent to any shape without heat, including sharp 90 degree corners, without fracture or undue loss of strength. I've used it to fabricate brackets countless times for decades, and most of my moto's (including one I'm riding today) sports many examples.

[wheelsucker]

FWIW, commonly available aluminum 1/8" x 1" anodized strap extrusion stock is easily bent to any shape without heat, including sharp 90 degree corners, without fracture or undue loss of strength. I've used it to fabricate brackets countless times for decades, and most of my moto's (including one I'm riding today) sports many examples.

 

Ok, is there a trick to bending it? I've got it bent for the most part to the shape around the exhaust canister but its still a little stiff. I'm looking to make the fit a little closer.

 

Oh, and thanks a lot for the heat suggestion....especially telling me that the aluminum would be hot!!! Way to be there for me

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

J/k. I haven't tried it yet and may have to pick up a torch as a last resort.

[lavrgs]

I'm sure it's too late but my first thought was that I would go with thinner material. Both for weight and ease of bending. Aluminum is pretty forgiving and is easily polished and can also be anodized which would provide a cheap durable finish with multi color options.

[Guest ratchethack]

Ok, is there a trick to bending it? I've got it bent for the most part to the shape around the exhaust canister but its still a little stiff. I'm looking to make the fit a little closer.

 

Oh, and thanks a lot for the heat suggestion....especially telling me that the aluminum would be hot!!! Way to be there for me

 

J/k. I haven't tried it yet and may have to pick up a torch as a last resort.

No real tricks to it beyond the obvious, Wheelsucker. The commonly available anodized 1/8" x 1" alu strap stock may easily be formed around a diameter smaller than the muffler so that it springs back to a close fit.

 

Sorry, I haven't a clue about wot y'er talking about WRT "heat suggestion" and that it would be hot, since I had no such suggestion??

 

Nog's suggestion to quench in water after heating is not a safety tip. It's a heat treatment method to make the metal soft again after its been heated. This would not occur if you let it cool on its own.

[wheelsucker]

Yeah, I was joking about the suggestion to heat it with a torch and it burning me. I think I figured out a way to make the bend, I'm just going to have to go buy another aluminum plank from Home Depot. My other thought was to use the clamps (the ones with the slots and tightenting screw) that are used on pipes, but I like the inch wide AL better and would probably look much cleaner.

[Guest ratchethack]

Just a word to the wise. If you ask y'er Homey at Home Depot for an aluminum plank, you're bound to get a more vacant look than you generally want in reply. If you ask for anodized aluminum extrusion stock, they usually know exactly wot y'er lookin' for, and nearly every HD has a nice display stand with different dimensions and different cross-section shapes.

 

Wot you're looking for is generally referred to as "strap", but can also be referred to as "bar" stock.

 

The stainless steel hose clamps you refer to may also work, but HD isn't likely to have them in the size you need. They are available in sizes that large, but you might have to find an industrial supply outlet.

[wheelsucker]

Yeah, I bought the AL bar stock/strap today. I was trying to be too cute with it and can't bend it to the proper degree. I figure I'll get one piece for each side, bend them in the middle around the pipe so that the bar overlaps itself. After this, I will have the basic shape of the bend I want and can modify it a lot easier.

 

As for the straps, I bought some that were too big from Home Depot in the plumbing section w/ the pvc pipes. I mocked them up on the pipes, and while they don't look too bad I do like the look of the one piece better. Plus I don't know that the bolt on the hose clamp would look all that good or be as clean looking. I will keep this alternative as a bakcup though.

 

I'll take some pics when I'm done in case others want to see/know.

[Ryland3210]

If the aluminum is the common 6061 T6, it is not very ductile. Typically, it will bend somewhat, but then fracture if deformed too far.

 

Nogbad's annealing to soften previously heat treated material sounds reasonable, but the water quenching afterwards gives me pause. Many alloys will precipitation harden with such treatment. They will get harder, obtain higher yield strengths with with lower ductility with such fast quenching.

 

I used to heat up tools with a torch, plunge them into a carburizing powder for several seconds, then plunge them into water. This resulted in a very hard surface.

 

I don't recall ever hearing of fast quenching used to soften an alloy. However, in the case of work hardened material which does not have precipitation hardening elements, I suppose perhaps the mechanism might be that crystal grains will grow larger when heated, and fast cooling prevents them from developing finer grains. Generally, the finer the grain structure and more dislocations, the higher the yield strength and hardness.

 

Here's an example of precipitation hardening I used in a pinch to make a special purpose screw driver to remove a stuck fastener. Grind it to the desired shape, heat it just shy of red hot, plunge it quickly into water.

[Guest ratchethack]

If the aluminum is the common 6061 T6, it is not very ductile. Typically, it will bend somewhat, but then fracture if deformed too far.

John, the anodized extruded aluminum stock WS is speaking about is very soft aluminum. Its ductility is a requirement for all extrusions and it is fairly malleable. T6 (6061), on the other hand, is aircraft grade alloy, brittle and hard, has a tensile strength of 42,000 psi, yield strength of 35,000 psi, is neither ductile, as you mentioned, nor at all malleable. Standard stock aluminum such as extrusion stock at Home Depot will not have properties anything close to T6.

Here's an example of precipitation hardening I used in a pinch to make a special purpose screw driver to remove a stuck fastener. Grind it to the desired shape, heat it just shy of red hot, plunge it quickly into water.

Properties of steel alloys with regard to heat treating methods are entirely different than that of aluminum alloys, and I would not expect those used in making a steel screw driver, (which I have also done) to apply to any alloy of aluminum.

 

BTW, the air filter bracket I sent you gratis, postage paid, at your request many months ago (photo below) was made of the same anodized extruded aluminum strap we're speaking of, and is the stuff you get from Home Depot. It has strong, 90-degree bends with no loss of strength. Like I said above, I use this aluminum strap for lots of things. Never heard a single word back from you, John -- not as much as an acknowledgement that you received it. I guess you never received it, but then, since you were expecting it, after all the coordination on shipment -- not a word??

[Guest george in vancouver]

Here's a handy guide to aluminum alloys and their characteristics from Aircraft Spruce.

 

Too bad the charts at the end are too out of focus to be of any use. They're in the print catalog and a handy thing they are. Referred to them a week ago re: selecting the right material for hand-forming a rear splash guard tire clearance "bump".

 

BTW, here's what I use for temp indication when annealing aluminum while forming.

 

Here's a place that has a bunch of aluminum forming resources. I got my slappers and shot bags from them.

 

GD

YVR

[rossoct]

WS, the alum. you want to use is 5052 thats bendable.

 

I would also think 1/16 to 3/32 thick is plenty good for that application

 

Chris

[dlaing]

BTW, the air filter bracket I sent you gratis, postage paid, at your request many months ago (photo below) was made of the same anodized extruded aluminum strap we're speaking of, and is the stuff you get from Home Depot. It has strong, 90-degree bends with no loss of strength. Like I said above, I use this aluminum strap for lots of things. Never heard a single word back from you, John -- not as much as an acknowledgement that you received it. I guess you never received it, but then, since you were expecting it, after all the coordination on shipment -- not a word??

Nice work, Ratchet! Better than FBF's