Exhaust Bending.

[spectrum]

I need to make a new downpipe for DT100 I'm doing up for the other 1/2.

I' ve not done any bending with thin wall tube before so couple of questions -

Can I bend it ok in my cheap tube bender (may have to get dies the right size made) ? Will exhaust tube (mild steel) bend ok cold or do I need to warm it ?

Assume I' ll need to fill with sand and then bend ?

If I can get pre made bends is that an easier route than bending my own ?

[Richy]

It kinks in a cheap bender (?) what dia. is it? you can get premade bends for making your own car exhausts. I think Demon Tweeks list them but you will get them cheaper elsewere.

[4tgp]

Hi, I would buy mandrel bends of the nearest dia. you can get. Just get a couple of 90's or a 180 and cut off what you need. The cutting blade or disc must always point to the centre of the bend.

I don't think you will get the tight bends you need by filling with sand and heating.

Here's what I did in stainless. really easy to do.

http://pbmagforum.co.uk/index.php?/topic/1203-supermono-project/page-6

[Superdunc]

Pre made bends are a lot less faffing about. Maynot be so readily available in your part of the world. Try a Dairy suppler, they use a lot of stainless pipe work, though it might be bit on the heavy side for what you want.

You can get very could results, with practice, from sand bending. Sand needs to be tightly packed, and kiln dried,else when you heat the tubes any moisture will turn too steam and be hazardous.

[VanWinkle]

Pre made bends are a lot less faffing about. Maynot be so readily available in your part of the world. Try a Dairy suppler, they use a lot of stainless pipe work, though it might be bit on the heavy side for what you want.

You can get very could results, with practice, from sand bending. Sand needs to be tightly packed, and kiln dried,else when you heat the tubes any moisture will turn too steam and be hazardous.

do they still use springs for bending pipe work nowadays or are they a thing of the past?.

[Superdunc]

do they still use springs for bending pipe work nowadays or are they a thing of the past?.

On gentle bends on thin wall stuff maybe. Resin is more common, or if you want really tight bends, 1 to 2.5 d centre line radius, they use metal donuts threaded together.

[VanWinkle]

how does the resin thing work then?.

[coppersaucepipe]

We used to bend plenty of 25mm steel conduit cold. That has a thicker wall though.

[spectrum]

Thanks guys. I'll look at the pre - made bends route 1st ( or get a selection made up). I'll have a play about bending some pipe as well just to see what happens.

[lorenzo]

As someone with brightly coloured trainers on to do it foryou. When I wore those pupurple trainers all of you lot said I was a bender, so someone should be able to sort you out.

[kaighn80]

piggin pipes can do most things youll need done to tubes, and its mail order, if your in blighty then motex, exhaust unlimited, motorparts direct etc do pre made bends and deliver.