Wanted – Brass tube bending

[nick mordinParticipant @nickmordin]

Hi there – for a small project I'm working on, am wondering if someone has the skill and kit to bend 1m brass tube (12mm diameter with 0.5mm wall thickness). It isn't precision work that is required, just don't want it to kink.

I have the brass tube already and a simple picture is as follows:

**LINK**

thanks in advance, Nick

[nick mordinParticipant @nickmordin]

[egaParticipant @ega]

nick mordin:

Forgive me for not wanting to click on an unrecognized link from a first-poster, but could you put your drawing into JPG format (if not already so) and post it?

Requests of this sort are more likely to bear fruit if there is some indication of where you are – say, UK county.

I note you naturally want to avoid kinking but can you tolerate a slight necking effect? Those more knowledgeable than I would want to know the type of brass you have in mind.

[pgk pgkParticipant @pgkpgk17461]

12mm is within microbore plumbing size and the pic shows a decent radius (as opposed to many of the tight and weird shapes used for steam engines). It may well be more expedient to ask a local plumber to bend it for you for a drink.

pgk

[Werner SchleidtParticipant @wernerschleidt45161]

I think you have to fill it with fine sand and close the ends. It should be on the bended end for 10 centimeters longer to span it. And then you can bend it.

Werner

[Bob StevensonParticipant @bobstevenson13909]

There are five methods used in the brass musical instrument business;….

1) anneal the tube and then use finger pressure to bend around a plywood profile of the bend shape…best if the curve is not too extreme.

2) Fill with soap solution and freeze then bend as above.

3) Fill with molten lead, bend, then melt out the lead.

4) use a spring the closely fill the pipe while bending as does a plumber.

5) use a dry medium such as fine glass granules or sand, as mentioned….stopping the ends can be tricky.

[Martin ConnellyParticipant @martinconnelly55370]

I have seen another method used in brass instrument tube bending. After the initial bend form is made the part is put in a mould and ball bearings are pushed through to push the tube into the mould walls. The first ball is to maximum size and subsequent ones are slightly under size so they fall out easily.

Martin C

[bernard towersParticipant @bernardtowers37738]

Just fill with woods or fields metal , bend and melt out filler ,job done.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Nick, this might just do the job 12mm internal bending spring however, your pipe will need to be in the annealed state before you bend it by any method.

Regards Nick.

[John ReeseParticipant @johnreese12848]

Most brass tubing I have seen was hard drawn. Annealing would be in order before bending. The radius of the bend looks large enough to allow bending without the need for filling with sand, ice, Woods metal, etc. As the radius of the bend is not specified tbis is my best guess.

[RobinParticipant @robin]

I made a few bassoon style crooks at college, we used Wood's metal, worked a treat.

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