Customs sheetmetal forming question..

i need to form some U shaped sheetmetal pieces,,approx 4 inches in diameter,,18 ga. steel,,about 4 foot lengths,,,,,,,,,would a sheetmetal roller give me a tight enough roll?..
basically, im looking to end up with pieces to tie the quarters of my kustom shoebox into the deck area,,,,,i have access to a friends roller,,but wanted to post here and make sure there wasnt a better way to accomplish this,,,

 

Jim----is this a half circle or is there any straight on the end.
Old retired tinner

 

basically just half a circle...maybe less than half in some spots...
i may also have to make some for the doors that have some straight though...

 

If it's just a half circle, couldn't you get some 4" exhaust tubing and just cut it lengthwise on a band saw? Or am I missing something?

I don't think a roller will roll that tight, a piece that's 4' long would have to have huge rollers.

 

i thought of doing that,,but wouldnt the metal be too thick?

 

I can do that small in my roller, i don't think you should have any problems. Im also a fan of the exhaust tube idea as well tho.

 

just did a search...found some 4" dia 16 ga steel (not aluminized) tubing in 5 foot sections..seemed a little pricey at $102..ill keep looking

 

is the aluminizing just a coating that can be ground or sanded off,,or is the metal actually treated in some way?

 

You can always bend it over a 4" piece of pipe.

 

I would think someone manufactures some 4" diameter tube with sheetmetal thicknesses, although I could be wrong. Should ask someone who makes exhaust if 4" diameter exhaust tubing is availible and what the thickness is.

I'm just thinking to get U-shaped bends into a piece 4 feet long on a roller, you'd have to have rollers no more than say 3" diameter, and they'd have to be 4 feet long. I can't say that I've ever seen a machine that could make those.

It might turn out sloppy, but have you considered clamping a 4' long sheet on one end and then heating and bending it over a piece of 4" diameter heavy pipe? Probably would be difficult to keep a consistent temp over that distance, but now I'm just thinking out loud.

 

Looks like some new info came up as I was typing, I didn't realize you could roll something that long that tight, but I stand corrected.

You can take the coating off of aluminized tubing, probably by sandblasting it, it's just a coating, not an alloy.

That tube is kinda pricey, if you can source a piece cheap enough I still think that'd be the easiest way. And if you can cut it clean enough you'll only need one stick.

 

You can do what you are looking for in slip rolls but the rolls can't be any bigger than the diameter you want in the sheet. I have a set of rolls that have 3" diameter rolls 50" long. When you roll the "U" there will be a flat on each side of the "U" that you would have to trim off. The easiest way to make that shape is in an english wheel with a go cart slick on top and a shaped lower roll made to the shape that you want on the bottom. Used that setup today.

 

I've done the pipe thing before... works fine.

 

yes-not having any straight ,you have to back roll it
that means put the metal in from the back and roll
to the front.this will help eliminate a crease line,`
start loose and tighten a little at a time.go about
a 1/3 of the way swtich end sand repeat.
Having that small of a dia the ends will roll tighter
TwoChops

 

If anyone in your neighborhood is junking one of those freestanding basketball poles with the plastic base filled with sand, the big upright of those is about 4" diameter ~16 gauge tubing. The powdercoating comes off easy in a sandblaster.

 

My basement has all kinds of drain pipes around there, Ive used that for forming a ton of times. Just enough off the ground to form some goodies.

 

Go to a farm store and check out tractor mufflers. Lots of 100 mm (4") pipes are used in the exhaust industry.

I could probably get you something through work but it is all SS 409 alumunized and it would be hard to work with.

 

Try a truck part store. I am thinking it is around $10 a foot. I bought a foot and a half for my truck and I think I gave between $12-$15 for it. It didn't seem to be that expensive

 

That would be worth it just for the story! Probably could score one of those off of Craigslist for less than $50. Then you could sandblast the tube with the sand that was in the base! That hoop is like a custom car kit from ikea with everything you need included.

 

You should be able to use your friends slip roll, if the rolls are smaller than 4".

 

Glass pack mufflers are made of 16 gauge tubing too, in case you have a few junky ones lying around somewhere.

 

I'd try the rollers,you'll have to trim the ends though.Breaking your piece into 2ft lengths will make life easier

 

thanks for all the great info guys,,,you definitely have given me some great ideas,,,
i love this place,,,,,,,,,,,,

 

i could definitely do that,,,it would just be a tiny bit of extra welding,,,,,ive already got so much welding ahead of me,it wouldnt make that much difference...haha..

 

What about furnace duct work?

 

Yah, furnace flue pipes are fairly thin, thinner than exhaust tube. Probably cheaper too.

 

You could go to a local rain gutter supplier. They make 4" Downspouts in 10 foot lengths. The typical thickness for this is 26 ga., but there is 16 ga. out there. I have installed rain gutters at schools and they always want 16 ga. downspouts so the kids don't kick the pipes in.

 

IMO,,,,,I'd roll it,lot cheaper, a 2 or 4 foot piece can be formed around a 3" pipe and it would spring back to approx 4".
Make the piece wider than you need so it can be clamped good,then trim excess.
Maybe you have a driveshaft layin around to roll it around. Clamp it good.

 

I made this attachment for my English wheel to form simple rolls.I can use different anvils to form different radius or make special anvils to shape different shapes.

 

Johnny, how's that working out for you? I need to make one of those myself.

16 is probably too thick anyway. 24-26 is too thin. Get some 19 (or at least 18) and head for the slip roller!

Just my opinion.................