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 :D
Have you guys tried anything other than 316?
Stainless steel welding rods. Don't use steel as it will go rusty.
Other steels can be very hot to hold too :)
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
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!
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.... ::)
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. ;)
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.........?
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...
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
I like my collection of decorated mandrels !!!! ;D ;D
Oohh lots of laavly replies :D
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 :D 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 :D
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 ^^
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.
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. ;D
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
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.
^^Wot she said...
Quote from: Hamilton Taylor on December 18, 2011, 11:10:06 PM
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.
This is why I'm asking for cut-offs, then maybe buy straight from the supplier. Ring Mandrels cost like.. £10 each? A meter length of 16mm bar costs about £20ish, I think you can even get 10cm lengths for £7, and you can get a few 3-4cm cuts out of those, which I'd then weld to a 4-5mm handle. I'd much rather have the hassle than spend the extra money!
Quote from: Redhotsal on 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.
Tubing is 2x or 3x more expensive :( And yea, I'll be welding it onto a handle so it shouldn't be too hot :D
Yeah - so, it's more expensive.......so you'd rather be sitting waiting for your glass to heat up as the solid lump of metal that's pulling all the heat away from your glass slowly heats up and burns your hands? No contest in my book - pay the extra and buy the tube, I reckon.
If you're trying to heat up a solid bar ring mandrel, and then you want to get your glass to form a nice even ring around that then you must be the sort of person that really appreciates a challenge......!
Plus, if you don't weld the handle on straight and right in the middle it'll be a royal pain in the arse trying to even up your glass.......
Do you have a kiln? pre heating them a bit in the kiln might save you some time... Mind you on a hot head that is going to be mighty painfully slow...
Quote from: Redhotsal on December 19, 2011, 08:37:21 PM
Yeah - so, it's more expensive.......so you'd rather be sitting waiting for your glass to heat up as the solid lump of metal that's pulling all the heat away from your glass slowly heats up and burns your hands? No contest in my book - pay the extra and buy the tube, I reckon.
If you're trying to heat up a solid bar ring mandrel, and then you want to get your glass to form a nice even ring around that then you must be the sort of person that really appreciates a challenge......!
Especially on a hothead!
Words that would never come out of my mouth (or the mouths of one or two of my pals, they know who they are ;)) ...
Quote from: Beansprout on December 19, 2011, 06:38:23 PM
I'd much rather have the hassle than spend the extra money!
Good for you, Rebecca!! ;D ;D
;D ;D
I hate hassle! ::) :D
I tried to make some threaded mandrels for doing ring tops, not because they are especially expensive but because I kept mangling them and that made it expensive. I've since managed to stop mangling them all now though!
So I looked at welding rods threaded all the way down, quite expensive but still worth it but hard to find in 2.5mm, then tried a plain mandrel in 2.4 with a die set, cost about a tenner to get set up which seemed ok, but just couldn't get the start straight enough to get a good thread going. I had 2 vices but it wouldn't hold the mandrel tight enough and so I would need an expensive vice...say about £30, tried all sorts of ways to hold the mandrel tight, gripping the bottom with vice grips, using a gripping material in between, nope, didn't work. Gave up.
Like I say...I hate hassle! ;D
One of the tubes I use to make very large BHB's is 25.5mm in diameter. I cut off about a three inch lenth, hold in hot fingers and dip in bead release to make the bead. No problem,
about metals for mandrels - you can use tungsten welding rods for the very thin stuff, they come in boxes with 10 pcs down to 1 mm thickness, but they are stiff and durable as you will know from your tungsten picks...I have seen them on ebay for about £7 for a box.
In stead of brass you can use bronze, it has a melting temperature at about 1200 C. But it is quite conductive, so make sure to have some sort of isolating handle.
I buy my steel in full length from a steel and iron company (they don't sell to private people, but the local blacksmith helps me out), in full 3 or 6 meter lengths.
Right now I am looking for some 1/16 steel, welding rod or other - something very stiff like spring steel, it is to be used as a wool comb (not being heated). I need at least 6 meters, but in Denmark 2mm is the thinnest I can get in straight rods.
I wonder if anybody here can help? Imperic measure stuff is not normally sold in Denmark.
I have pianowire, but it only comes in rolls, and straighten it out without heating it is beyond me. Am going to try that for mandrels though!
Kathe, Denmark
Quote from: Redhotsal on December 19, 2011, 08:37:21 PM
Yeah - so, it's more expensive.......so you'd rather be sitting waiting for your glass to heat up as the solid lump of metal that's pulling all the heat away from your glass slowly heats up and burns your hands? No contest in my book - pay the extra and buy the tube, I reckon.
If you're trying to heat up a solid bar ring mandrel, and then you want to get your glass to form a nice even ring around that then you must be the sort of person that really appreciates a challenge......!
I'll probably go for the tube then! I'm all about trial and error so I'll try anything that *might* work :P I am concerned my HH won't be able to keep up with me so I'll make it a little easier on myself and little old HH. With the welding-on-straight thing, my dad has got all that holdy/keepy-inplace.. stuff.. I'll let him figure that out xD
Thanks Julie!
Ah thats what I need, a holdy/ keepy- inplace thingy! :D
The welding of the handle is actually probably the most crucial part. You want to be able to rotate the handle so that there's no wobble in the tube. If it's not aligned it'll still work but it'll be a pain to center anything. Ideally your tube will have a closed end and you can weld the handle to that. Make sure the tube doesn't flare out in any way, or that you leave any weld marks on the outer wall of the tube as you'll have a hard time getting the final bead off. And don't make the handle too thick as you want it to be easy to turn. :)