Bending brass sheet 1/32 inch thick at 90 degrees.

[Deleted]

I have two pieces of 4 inch wide 21 swg sheet 5 inches long that needs to have a 90 degree bend at each end to give me a 1/4 inch upstand, if that makes sense.

The bend needs to be a very sharp 90 as per the equal angle that you can buy.

I have asked several sellers of benders on ebay but they all say it has to have a small radius which I do not want.

Advice please.

Happy to buy a bender or alternatively if anybody can recommend a fabrication firm that can do it for me as quite happy to pay for the service.

It is for the end plates for a firebox for a small steam plant.

Thank you.

Rodger

[ejparrott]

I think you'll struggle. The tin smiths I use for my bending and stuff can't achieve what you're asking. If you really want it that sharp, fabrication from two parts is really the only option

[Deleted]

I don't think what you ask is possible Roger, the very act of bending will put a small radius in the material, if you need a dead sharp 90 degree corner then I'd suggest the best route to be silver soldering separate parts together..?

Pete

[Roger]

Maybe you can fabricate that by leaving a small overlap when Silver Soldering, then filing back to get the edge you need?

[Deleted]

Thanks replies.

Silver soldering a butt joint would work if I could find some 1/32 by 1/4 angle to put on the external corner. I have only been able to source 1/16 inch which looks too heavy.

[ejparrott]

Don't bother with angle, just butt the two plates at the corner

[Roger]

Feb 8, 2016 18:07:06 GMT ejparrott said:

Don't bother with angle, just butt the two plates at the corner

Or rest a thin Brass rod in the corner if it needs strengthening.

[SteveW]

It occurs... A conventional bender will always leave a radius. An alternative is to use a couple of steel plates either side of the sheet and the lot clamped in a vice. Then using what I would call a drift and a Mk1 persuader to push full width over to 90 degrees and perhaps beat it down a bit.

The steel plates could provide a sharp-ish internal angle but always a radius on the external edge.

If you need a sharp edge you could simply silver solder a piece of brass wire along the edge then file to sharp edge. Simply file a 'v' each end of the bend at the 45 degree point and wrap a piece of pre-stretched (to get it straight) wire from 'V' to 'V'.

Edit: Maybe a good idea to use silver solder paste for this one if you can get it else you'll silver plate the whole thing.

It occurs to ask... Why do you want/need a sharp external edge?

[jma1009]

hi rodger,

i dont know if this is any help but B&Q do brass angle less than 1/16" thick as do KS (racks in model shops).

cheers,
julian

[weary]

Eileens Emporium
www.eileensemporium.com/index.php?option=com_virtuemart&category_id=82&page=shop.browse&Itemid=9&limit=20&limitstart=0
supply brass angle down to 0.15mm thick.
Clicking on the description gives you the thickness, so 4 x 4mm is 0.5mm thick for example, 6 x 6mm is 0.7mm thick, which is just under your desired 1/32" thickness.

Regards,

Phil

[cupalloys]

If silver soldering, I would suggest you rough up one edge of the upstand to create a gap for capillary flow. Rest a simple weight (a file) on it to hold it in place. Apply a stripe of silver solder paste to the inside of the joint. Heat externally and draw the silver solder through to the outside. If the very small fillet produced is unacceptable use your file again.

Dependent on the service conditions of the assembly you could replace the silver solder with soft solder paste. Use in the same manner as above.

Both products readily available from CuP Alloys.

[Deleted]

Thanks for replies to all.

SteveW - I should have said that I needed the sharp bend on the inside and radius on outside. just tried your suggestion on some scrap and it works a treat and gives me just what I was after - thanks.

Julian and Phil - thanks for info which is most helpful as needed for another small project as well.

Rodger.

[mutley]

Am i confused or are you using these plates in a boiler?

[SteveW]

Guys,

I think I should add that fifty odd years back at school we didn't have such exotic kit as a bender. It was either the mark one vice or bending bars. I think we've all seen bending machines and vices at the shows but I've never seen my bending bars.

The bending bars were like a huge hair pin made of 3/8" by 1-1/2" steel bar at just over a foot long. At one end a was the 180 degree return bend on (as I recall) something like a 3/4" internal radius and re-entrant to bring the two bending faces out parallel with just enough gap for the sheet metal to be inserted.

I recall there being a 1/2" bolt hole at one end to clamp to work, the other end used a bench vice to clamp and hold the sheet. Once the sheet was lined up it was all clamped up and then the bend completed with a hammer and/or a second bar to spread the load.

These things were much better to use than having to juggle two bits of metal and a bit of sheet material to pull off a bit of bent metal.

So, simple and handy bits of kit for the sort of bending we do. Why can't I find any?

(346)

[jon38r80]

We had bending bars of a very similar design at school. I think they were made by some schoolboy as part of an exercise in annealing and bending metal to a shape to practice using an air gas torch and hearth. I don't have a hearth so make do with two bits of black angle with a bolt through one end clamped in a vice. Not as good as the school workshop kit though.

[ejparrott]

We had bending bars at School and at Uni, rarely used though. I make my own when required from barstock with a pitch of holes to clamp the material as close as possible.

Try looking at Blacksmith supplies

[uuu]

For small jobs at the Pump House we use a fly press - pushing the plate into a vee block. You do need enough overhang to bridge the vee in the first instance.

Wilf

[johnthepump]

Feb 10, 2016 17:34:10 GMT uuu said:

For small jobs at the Pump House we use a fly press - pushing the plate into a vee block. You do need enough overhang to bridge the vee in the first instance.

Wilf

From the Pumphouse


Fly press angle bending by John The Pump, on Flickr

[jma1009]

john helps (johnthepump) very kindly guillotined up the brass sheet for the tanks of my first loco (5"g Railmotor) and then bent them up for me. saved me an enormous amount of work!

john is one of those rare individuals in ME who spend more time helping others than on his own projects!

cheers,
julian

[Deleted]

Hi John


Warco's 3 in 1 formit folds 90 degree bends using the same principle, add it's shear and rollers and it's a very versatile tool, saves me a lot of time that's for sure. www.warco.co.uk/sheet-metal-bending-rolls/302933-formit---universal-sheet-metal-machine.html

Pete