Metal to use for mandrels

Beansprout · December 17, 2011, 10:05:41 PM

I want to make some of my own mandrels, and I'm wondering which kinds of metals would be ok to use.

I know that normal mandrels are stainless steel 316. This gets a bit expensive though. I know that copper doesn't work (tried it a year ago and still can't get the beads off the mandrel!)...

What about Stainless Steel 303 or 304? What about mild steel? I could try and get some samples from my neighbour but I'm pretty sure they won't be identifiable

Have you guys tried anything other than 316?

Redhotsal · December 17, 2011, 10:06:45 PM

Stainless steel welding rods. Don't use steel as it will go rusty.

MangoBeads · December 17, 2011, 10:38:48 PM

Other steels can be very hot to hold too

Hamilton Taylor · December 18, 2011, 01:11:27 AM

316 is expensive, but it will last the longest. This is marine grade stainless, designed to resist corrosion at sea for years. Little did the designers know that we want to heat it to around 1000C, repeatedly, and still expect it to perform! But, it does fine, better than any other steel.

Don't use 303 or 304 - the minimum you should use is 308 (which we use for our 5mm mandrels). But 316 is still the best. I don't think they're that expensive - we sell them at about 23p per (2.4mm) mandrel. And I reckon you can get a hundred beads off that mandrel, at least, before it needs replacing. That's 2.3p per bead. Not bad, surely....

in the (really, very very) olden days, copper was used - to get it out of the bead, stretch it - for this, your mandrels need to be disposable. but, these days, your mandrels will cost a lot more in copper than in 316.

Sean

Lush! · December 18, 2011, 09:35:05 AM

Quote from: Hamilton Taylor on December 18, 2011, 01:11:27 AM

in the (really, very very) olden days, copper was used - to get it out of the bead, stretch it - for this, your mandrels need to be disposable. but, these days, your mandrels will cost a lot more in copper than in 316.

Or dissolve it, like they do in Murano!

Hamilton Taylor · December 18, 2011, 10:03:55 AM

Oops, I forgot that Julie - they still use copper in Murano!
Also, I spot a roaming decimal point - it works out to 0.23p per bead, of course...but only if you stop at 100 beads before you replace the mandrel.
And me doing a physics degree....

Krysia@No98 · December 18, 2011, 10:23:53 AM

Quote from: Hamilton Taylor on December 18, 2011, 10:03:55 AM
it works out to 0.23p per bead, of course

Assuming that you only do one bead per rod

These should do the trick

http://www.ebay.co.uk/itm/STAINLESS-STEEL-WELD-RODS-10-RODS-1-6mm-DIA-GRADE-316L-FREE-P-P-/260857643599?pt=LH_DefaultDomain_3&hash=item3cbc53c24f#ht_500wt_715

You should get about 30-40 mandrels out of that. (depending on length)

A few yeas ago I bought 100 rods and got three mandrels out of each. I put 200 in the pot and still have 100 that I've not used yet. Of the 200 I think I still have most of them though some rods are a little shorter.

Redhotsal · December 18, 2011, 06:23:41 PM

Quote from: Hamilton Taylor on December 18, 2011, 10:03:55 AM
And me doing a physics degree....

I've got one of those - doesn't help with the mental arithmetic. When I first started dating Adam and had car trouble, I remember him saying "you ought to be able to fix your car - you've got a Physics degree......." Um, no, that's because I have a Physics degree and not a Mechanical Engineering degree.....can't cook either.....

Anyway - 100 beads off of one mandrel, eh? Nope not me.......at least - not the skinny ones. I'd pay a decent sum of money for non bendy 1.6mms. Any suggestions - apart from don't make gallumping great big beads that stick to the mandrel.........?

Krysia@No98 · December 18, 2011, 06:53:29 PM

It's not cheep, but have you tried Brass?

One of the guys at work has got a brass rod. He won't let me have it though

Apparently, it's a standard British finger and he uses it to poke into electrical items to find out how safe they are, so he says I can't have it...

Pauline · December 18, 2011, 07:32:18 PM

Quote from: Krysia on December 18, 2011, 06:53:29 PM

It's not cheep, but have you tried Brass?

One of the guys at work has got a brass rod.

does brass work??? you can buy brass 5mm rods in B&Q

lyzzydee · December 18, 2011, 08:24:06 PM

I like my collection of decorated mandrels !!!!

Beansprout · December 18, 2011, 10:18:57 PM

Oohh lots of laavly replies

I've got tonnes of 1.6 and 2.4mm mandrels... It's the Ring mandrels I'd like to make really, nice thick 16mm chunk. I've emailed my local Steel Supply company to see if they have any cut-offs I can have

OR even to buy a length or two... cus postage must be a bastard buying from the interwebz. I'll let you guys know if they reply

I'd even like to make a cabochon, if I can find some 316 sheet? And also convince my dad to tidy his garage so he can get to his welding gear ^^

Hamilton Taylor · December 18, 2011, 11:10:06 PM

Brass melts around 900C - don't use it!
Yeah, I reckon you can get at least 100 beads off a 2.4mm 316 mandrel - don't know about the 1.6mm tho' - don't use em, 'cos I'm ham-fisted, me....

ETA:I would have thought that making ring mandrels and cab mandrels was more expensive than buying them, if you're only doing a couple. Incidentally, don't forget that the larger the mass of metal you have, the more it'll take to get it hot, and the more conductive it'll be. If you try to make a mandrel from a 16mm dia. bar section, it will probably get too hot to hold - unless you weld a skinny (5mm?) handle on to it.

Krysia@No98 · December 19, 2011, 12:12:21 AM

Quote from: Hamilton Taylor on December 18, 2011, 11:10:06 PM
Brass melts around 900C - don't use it!

Good to know

I won't try that then.

Gaud yeah those thicker rods don't half hold the heat! The 5mm rods that Amanda (mango) does are great as they don't hold the heat as much

Redhotsal · December 19, 2011, 08:54:05 AM

If you want to make BHBs and especially if you're working on something like a hothead you'd probably be better off with tubing rather than solid rods. Stainless, of course.