Mandrel research - the final frontier!

[ajda]

- - - EDIT 04/05/2015 - - -
OK... deep breath... I'm ready to roll. If you have read what follows and would like to join these trials, please pm me for PayPal and other details... Just to reiterate, I will be "marketing" this through my Etsy shop, as a not-for-profit venture, where it will cost £5 plus postage (x2), but if you contact me direct through FHF, are in the UK and can pay by PayPal gift, I'll do it for a flat £5 - you save postage, I save seller fees.

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Actually, an ongoing obsession, so probably not the final frontier, just another chapter...

I'm calling for lampworkers to help me out with a new phase of mandrel testing - not quite ready to launch, perhaps another week or so. But if anyone wants to register an interest, or make a suggestion or comment - even if just to tap your head in a knowing way - please feel free.

I'll be opening this on FHF, also "marketing" the experiment through my Etsy shop so as to reach a wider audience. However, this is not a profit-making exercise. I can't afford to give hundreds of mandrels away free, but would like it to be good value so as many as possible participate. If I can get 100+ on board, the exercise might have real validity - and I'll just about recover my costs. I will make the results available to anyone who's interested.

For those of you who weren't around at the time or haven't followed the story since, there follows a bit of background - between the two rows of dashes below. If you are only interested in the new experiment and how to take part, just scroll down to the lower line of dashes and continue reading there.

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About 2 years ago, getting fed up with rapidly deteriorating mandrels, I started looking into which grade of stainless steel might be the best for lampworking. I focused initially on 2 main issues: melting point and softening. In fact, the difference in melting point between one grade and another is pretty insignificant - if you blast any mandrel with a hot enough flame you can melt it... But, assuming you are careful not to go that far, repeated exposure to very high temperatures affects the steel in various ways - causing softening, pitting, etc.

I talked to several experts in the field and tried to get my head around a lot of physics and chemistry while running trials. Apart from performance, important considerations were cost and availability and I ruled out more than one specialist alloy on that basis. For example, RA330, theoretically one of the best for high temperature work, is difficult to get hold of and is around 3x the price of others - even if it were much better, it's unlikely any of us would want to pay that much more for it.

I settled eventually on 310 grade stainless steel which seems to offer the best balance between performance, cost and availability. After trials I had quite a bit of surplus so started selling it in my Etsy shop and have continued stocking it since. Quite a few FHFers had mandrels from me in the experimental phase and have bought from me since.

Almost all feedback on 310 has been positive - most recently I heard from someone who has had a bunch of 1.6mm mandrels, in constant use 3-4 times a week, still going strong after 18 months. In fact, only one user has reported a negative experience, with mandrels apparently breaking up in the flame. Maybe there are others who have had similar experiences who have not reported back so as to spare my feelings - I hope not! Could this person somehow have got an odd batch, or could it be that there there is something else that I've failed to take into account? While no grade of steel has yet been formulated to cope with the kind of abuse that lampworking mandrels get in practice, it is worth remembering that there are lots of different variables - it may be that one particular combination of equipment, materials and techniques suits one grade but not another.

Whether I'm selling mandrels or simply talking about stainless steel, I don't want to make claims that I can't substantiate. And anyway I continue to have (and probably always will have) a niggling sense that there might be something better out there!

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I now have a stock of 4 grades for blind testing against each other and the plan is to focus on three problem areas:
1. softening, bending
2. brittleness, cracking, breaking up
3. surface pitting, scaling, corroding
(Other issues may become evident in time.)

In order to keep costs down, and because thin mandrels should show up weaknesses more rapidly than thicker ones, the only size used in this test will be 1.6mm x approx 220-230mm.

Anyone who wants to participate will need to invest £5 (plus postage in some cases - see below*). For that you will get:
1. 16 coded mandrels to be used and abused for beadmaking in your normal way
2. a very simple information and feedback sheet
3. on return to me of used mandrels + feedback, 10 new mandrels in the best grade (your choice - or mine if you don't specify) to keep.

The 16 don't need to be kept apart from your other mandrels or given any special treatment - the coding marks will allow you to separate them out and me to distinguish between them when the time comes. You won't know which grade is which, though I hope all 4 will at least be fit for purpose. I would not expect a high failure rate, rather to see gradual differences appearing over time - one getting softer, another more pitted, etc. If any mandrels become unusable put them aside and continue with the rest, then eventually send all 16 back to me and I'll send out your new ones. That's your part done.

Looking at the mandrels and feedback that come back to me, I can start to build a picture of how each grade is performing and compile an ongoing report. I don't want to fix methods or time scales for working with the test mandrels because people work in different ways and at different rates, but I'd suggest using the whole batch of 16, more or less equally, until significant differences begin to show up or, if nothing much shows up, a period of 6-12 months. I'd hope to have a basic report available within about 6 months, updating and refining it over the longer term as more evidence comes in. I'll keep the test open to new participants as long as stocks last - and the results, as I said, available to anyone who's interested.

*Postage for UK = 2 x RM Large Letter 2nd Class. I will charge for that at cost on my Etsy shop on top of the £5. However, if you contact me direct through FHF, are in the UK and can pay by PayPal gift, I'll do it for a flat £5 - you save postage, I save seller fees. Actual postage rates may be prohibitive for those outside the UK, but I'd like to go as wide as possible so will offer international postage options too. (The other cost to bear in mind will be return postage of used mandrels.)

[flame n fuse]

Hi Adja
Sounds interesting! Count me in.
Julia

[ruth]

count me in please.

Ruth

[marklaird]

Hi Alan,

Yes please. I love the idea of doing a more scientific study on Mandrels (is that sad or what).

Happy to pay via paypal gift.

Mark.

[ajda]

I love the idea of doing a more scientific study on Mandrels (is that sad or what).

Join the club. Perhaps we just don't get out enough...

[Nicknack]

I love the idea of doing a more scientific study on Mandrels (is that sad or what).

Join the club. Perhaps we just don't get out enough...

I don't think you do...... must be a man thing!

Please count me in.

Nick

[Calico Cat]

Yes please - count me in

I have some of the originals - you kindly cut them extra long (35cm) for me - they have been in use for about 18 months.

I had my very first "casualty" two weeks ago - foolishly tried to make a very large bead on a 1.6mm and it proved too much - the mandrel snapped . . . .

[richardnash666]

Don't mind helping out always game for a scientific test especially if you need someone with a not so light touch with the flame. I am improving but for this sort of thing I suspect you should also need people of variable skills

[Carefulkate]

Happy to help with this but my set up has just been packed away so depends when you need the results for we are hopefully moving house 

[Angie]

Count me in, your original ones are still going strong

[Rascal]

Count me in aswell. I don't understand the science but will happily use them and provide feedback. Also can pay via PayPal just let me know when you are ready.

[Rob Bending - Chemical Brother]

Oooh, experimental design.  Like that idea, although I may not work hot enough to excite the failure modes.

Had you considered the bead release chemistry as an influence here?  First thing that bounces into my mind is whether there may be a high level of soluble chlorides or sodium in the slurries, which would have an impact on the surface chemistry of the steels.

Did get to Flame off - does that count as getting out 

I'm in.

Rob

[ajda]

I have some of the originals - you kindly cut them extra long (35cm) for me - they have been in use for about 18 months.
I had my very first "casualty" two weeks ago - foolishly tried to make a very large bead on a 1.6mm and it proved too much - the mandrel snapped . . . .

Sadly no stainless steel mandrels are going to be indestructible, especially thin ones... I've managed to kill quite a few making boro beads with a Bravo torch - to be expected, I suppose!

Don't mind helping out always game for a scientific test especially if you need someone with a not so light touch with the flame. I am improving but for this sort of thing I suspect you should also need people of variable skills

Definitely, Richard - the more range and variety in the test group the better.

Happy to help with this but my set up has just been packed away so depends when you need the results for we are hopefully moving house 

I hope to keep this running for a year or more... Good luck with your move.

Count me in, your original ones are still going strong

Good to know! Thanks.

Count me in aswell. I don't understand the science but will happily use them and provide feedback.

To be honest, I don't think even those experts who claim to understand the science can always predict how an alloy will perform in practice outside its normal limits - and lampworking is way outside the normal limits of any grade of steel. That's why I think practical trials like this might reveal more than any amount of theoretical understanding.

Oooh, experimental design.  Like that idea, although I may not work hot enough to excite the failure modes.
Had you considered the bead release chemistry as an influence here?  First thing that bounces into my mind is whether there may be a high level of soluble chlorides or sodium in the slurries, which would have an impact on the surface chemistry of the steels.
Did get to Flame off - does that count as getting out 
I'm in.
Rob

Actually, not so hot is probably still too hot for most stainless steels - you may not get catastrophic failure, but you'll still get deterioration over time - such as "creep" and "scaling" in steel-boffin-language.
Yes - bead release chemistry could well be a factor. I'm hoping to include it as one element in the feedback - I doubt whether one type will stand out significantly against others, but it's possible.
I don't think Flame-Off does count - too much of a busman's (or beadmaker's) holiday...

[Margram]

Count me in too, please. I'm all for the advance of science

[ajda]

OK... deep breath... ready to roll...
I've added a note at the top of the original post, so anyone coming new to it will see that the trial is now running. I'll be in touch with those who've already expressed an interest - if anyone else would like to join, please pm me for PayPal and other details... Just to reiterate, I will be "marketing" this through my Etsy shop, as a not-for-profit venture, where it will cost £5 plus postage (x2), but if you contact me direct through FHF, are in the UK and can pay by PayPal gift, I'll do it for a flat £5 - you save postage, I save seller fees.