I have done it with pipe filled with dry sand, not lead and also the coil spring method. (springs are available at hardware and plumbing suppliers, internal and external types).

What radius bend are you trying to achieve ?

Paul.

Edited By Paul Lousick on 15/01/2019 21:17:08

Where can I buy Cerrobend ?

It is listed on ebay in USA, 1/4lb stick costs $16 but $66 for postage.

Paul

One of our plumbers at work has a small set of pipe benders for 6,8 and 10mm pipe mainly for central heating work I think. Quite small hand held benders.

8 & 10mm is a popular size in microbore ch systems….or…..

Try your local garage, they may have suitable benders for brake piping….take your pipe along and bobs your uncle…

Edited By John Rudd on 15/01/2019 21:47:39

I had a similar requirement with 1/2" pipe and a 1" radius bend a few years back for the blast pipe on my traction engine. Bend needed to be tight to get the blast nozzle in the centre of the chimney! The pipe was thin walled AC copper pipe also which made it worse. Did a bit of research and salt was recommended rather than sand as it is finer and packs tighter. In order to get the salt to pack down tight it was recommended to hold an engraver or similar against the pipe to induce vibration to pack it down (didn't try that as I didn't have one!). Was told there was no way I would get a bend that tight! Red rag…….. I annealed the pipe and packed it with salt, crimping the ends. Got a lump of hardwood and filed a profile of half the diameter of the pipe into it and the radius required. Then clamped the pipe to it with a horseshoe type bracket and used the back former from a commercial bender (straight lump of ally with a u groove milled in it, half the diameter of the pipe) and worked it round by hand. On completion it was a pretty fair bend, the pipe had gone a little oval but removing the salt, another anneal and some careful dressing with a planishing hammer sorted it. Polished up quite nicely. Subsequently I was advised to put a cork in one end of the pipe, fill with water and put in the freezer (after annealing) instead of filling with salt or sand. Not had a need to try that yet but it sounds plausible and it's cheap and clean. Would allow a second anneal during the bend without having to un crimp the pipe to empty the filling medium and clean it out before annealing again. I have a similar job to do with 1" pipe this year for the latest engine so may give the ice method a shot.

Paul.

AJW,

If it is of interest, I re-plumbed the heating system in our current house 18 years ago in 10 mm microbore pipe. For the bends, I used one of the commercial hand held pipe benders directly on annealed 10 mm bore copper pipe, no fillers or springs were used. As a result I was able to get tight bends of 90 and 120 degrees without any further treatment such as annealing. Really tight bends are best done with fittings.

The bender I bought was from the plumbing merchants and it will handle 6 and 8 mm bore pipe as well. A neat little gadget and easy to use.

Regards

Brian

One advantage of Cerrobend is that it expands slightly on freezing making a tighter packing. Lead shrinks. Water expands too, maybe too much.

Street elbow as in my link above only has one end swelled out, so it won't foul your bolts

.

excellent point, and why I wanted to top-up my pitifully small stock

Following FMES's link, I asked for an indicative price, and they replied promptly:

We can offer as follows,



1 kilo Bend alloy £68.00 + VAT



Delivery: From stock

Carriage: UPS £16

Terms: Payment against a pro forma invoice, by bank transfer.

.

MichaelG.