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stu_clouds
03-03-2010, 02:11 PM
hi,

just a quick question, does anyone here roll silver from ingots into sheets? does it take long?

Also what thickness do people use for cuff bangles both self rolled or bought in sheets?

regards

Stuart

ps_bond
03-03-2010, 02:47 PM
just a quick question, does anyone here roll silver from ingots into sheets? does it take long?

Also what thickness do people use for cuff bangles both self rolled or bought in sheets?


Yes, yes, 0.9mm generally for simple constructions.

:)

Oh, and I use a geared rolling mill - I don't think I'd enjoy going back to rolling out ingots without it!
Forging the ingots out initially saves a lot of effort though.

stu_clouds
03-03-2010, 07:54 PM
how i wish i had a geared rolling mill, sadly im still at my parents and i dont think they would take kindly too me attaching the stand too the tiled floor, so i have to use the smaller mill attached to my workbenches.

thank you for the advice iv nearly rolled a sheet down to .9mm finally.

Lindyloo
04-03-2010, 01:25 PM
I have a question about the mills. The Durstons seem to have two descriptions of gears. They all seem to say they have spherical helical drive gears. But some (the more expensive ones) say they also have a gearbox with a reduction of a particular ratio. What do these mean?

Also, if you melt down metal, and then pass it through the mill. In my limited experience, it seems to crack and split. So what have I done wrong? A tutor once told me that each time you melt the metal, it becomes more brittle, and needs to be melted with some casting grain included to improve the purity. Does this help?

ps_bond
04-03-2010, 01:46 PM
I have a question about the mills. The Durstons seem to have two descriptions of gears. They all seem to say they have spherical helical drive gears. But some (the more expensive ones) say they also have a gearbox with a reduction of a particular ratio. What do these mean?

We could do with a Durston rep to answer these... :D
Helical gears are sort of an angled version of "normal" (spur) gears - they offer better power transmission than spur gears (and run quieter at speed, but that's not relevant for hand-driven rolling mills!). They're spherical if the gear teeth are cut onto a spherical body, or slice of a sphere. These gears drive the rollers from the input shaft (the handle for non-reduction rolling mills).

Adding a reduction gearbox onto the input shaft reduces the output - so every time you turn the handle, the input shaft turns 1/4 of what it would without the gearbox - BUT it has 4 times the torque, so while you have to turn it 4 times as many turns, you use 1/4 the effort.


Also, if you melt down metal, and then pass it through the mill. In my limited experience, it seems to crack and split. So what have I done wrong? A tutor once told me that each time you melt the metal, it becomes more brittle, and needs to be melted with some casting grain included to improve the purity. Does this help?

There's a bunch of possible problems, not least of which is the potential for contamination (solder, oxides, hydrogen embrittlement etc. etc.). Many of the casting grains have additives to improve flow at pouring temperature and modify grain formation characteristics as they cool - I think the Cooksons literature goes into some of this - so adding a small amount in to scrap does help.

There's other issues at work regarding alloy segregation & the likes, but I'd need to refer to Brepohl to be sure of my facts.

Lindyloo
04-03-2010, 01:58 PM
Thank you Peter. That answers my questions. The mill we used at college must have been a non-reducing one, because one turn got the metal through, and sometimes it was a bugger to move if you turned the rollers down too far. I am just considering buying one. Really can't justify the dearer ones, but I'm a bit worried that I may wish I had, if I struggle with the non-reducing ones.

stu_clouds
04-03-2010, 03:26 PM
i wish i had bought the larger ones, trying to roll out a good size sheet of silver is a nightmare, but it saves me going too the gym i suppose :). the smaller one is fine for reducing wire though. i shall certainly be purchasing the larger one as soon as trade picks up for us.

regards

Stuart

Lindyloo
05-03-2010, 12:58 PM
Would you consider the cheaper brands, or is it only Durston for you Stu?

stu_clouds
05-03-2010, 02:51 PM
Durston all the way, you get what you pay for really. i just wish i had held out for the geared one grrrrrr. ah well we live and learn.

CDW Designs
01-04-2010, 04:21 PM
Hi Everyone
Talking about Durston rolling mills I have recently bought one and want to know how strong are the rollers for 'thinning' silver sheet and for making bangles or heavyish pendants what is the best thickness to use? Also should they be kept covered when not in use? Mine is a new one and luckily geared but I am anxious not to ruin it by using it wrongly. I am not an expert jewellery more experimental and 'learning amateur'. I still havent got round to uploading any photos yet as I dont know how to>>>>>>>

Dennis
01-04-2010, 05:48 PM
Hi Christine, I have had the smallest Durston rolling mill with reduction gears for about fourteen years, and have tried to look after it by wiping it down with a clean cloth and a trace of lubricant after use and keeping it covered. Even so it now has a few small pits on the rollers. The big enemy is moisture from annealing and small specks of grit.
The Cook Book says you can pass 6mm of sheet through the smallest of these mills, but that could be quite tedious with pauses for annealing. Also the repeated annealing is likely to build up firescale on sterling. The thickest I have rolled down was 4mm. I try not to close the rollers too much at one time as this results in wavy or curved metal which is difficult to manage. I aim to turn the mill with just one hand. If you take too big a bite you can in fact get completely stuck and need a stronger person to rescue you.
There will also be hours of fun experimenting with the grooves for wire.
Hope this starts you off, Dennis.

CDW Designs
01-04-2010, 05:53 PM
Thanks Dennis
I will have to get going. Its been a big investment and I want to make sure I look after it.. It is well greased and I have covered it too. How strong are the rollers themselves to not getting marked or scratched????
Thanks for you help though that does help.

Dennis
01-04-2010, 07:20 PM
Some clever clogs at the college I attend started a craze for roll-texturing silver sheet with sandpaper. It's never been the same since. Most of these problems arise with multiple users,when the tutor is busy. Care for it as you would care for £600 in crisp new notes. Roll only base metals which will not contaminate silver or gold. Briefly this means copper or brass. Avoid stainless steel and hardened steel.
If in doubt do nout. Dennis.

CDW Designs
02-05-2010, 06:02 PM
I've been told you can only use 'soft' metals so as you say, copper or brass. The trouble with texturing I dont wont to use up an excess of silver but will experiment.....thanks again.

Dennis
02-05-2010, 07:15 PM
Hi, I now use fabrics almost entirely, partly because they give me a quick result and partly because if you put them all the way round the metal, so that they cover the top and bottom, the metal comes out flat. Favourites are lace curtains and net curtains, the kind the neigbours twiitch when you go out. Also the squared fabrics for embroidery, because you can cut out random squares in the metal afterwards. Sometimes you get even better effects if you do it a second time with a new piece of material. Hope you are still pleased with your mill, kind regards, D.

Tabby66
02-05-2010, 09:44 PM
Hi!

Dennis - you are a font of knowledge! I always read your posts with interest.

A rolling mill is on my wish list, I'm hoping for one for my birthday . . . . . in October :-(

So got to use college one until then. I've been collecting leaf skeletons whilst gardening this week. Do you have any advice regarding texturing some silver with them? What thickness of silver works best, leaves are a bit irregular and broken, can I do anything to improve regularity of pattern? Should I texture both sides (for earrings/charms on a bracelet, for example)?

Any help appreciated.

Tabby

Dennis
03-05-2010, 09:38 PM
Thanks for your confidence, but I have not done much with leaves as they are brittle when dry and break up under pressure.Your best chance is to put the veins on the under side next to the metal and then wrap right round with paper. A metal thickness of 0.7mm is about right. One thing to note is that when you heat and pickle silver a fine layer of pure silver forms on the surface. Do that about three times in a row and you have a softer surface for roll printing. The down side is that with each subsequent soldering operation you loose a little sharpness. The way to finish is either with a largish glass brush, a cm or so unpealed, and lots of soap(satin effect), or a brass brush and lots of soap(more shiny). Brass brushes for cleaning suade are ok at a pinch.
When you get fed up with this, send some leaves and other fragile items to an electroforming company and they will come back fabulous. Kind regards, Dennis.

mizgeorge
03-05-2010, 10:42 PM
I've never had a good result with 'real' leaves. If they're not completely dried out they leave a horrible gunky mess on your rollers, and when they are completely dry they just crumble.

However, craft packs of skeleton leaves (sold mainly for papercrafters) are excellent and give a very good, clear impression on both copper and silver.

This was done on 0.5mm sterling sheet, and has been oxidised and polished back to highlight the texture. The T bar was printed onto 1mm sheet.

http://farm4.static.flickr.com/3395/4575852241_2c3755be74.jpg
(http://www.flickr.com/photos/mizgeorge/4575852241/)

Dennis
04-05-2010, 05:36 AM
Good morning, thats beautifully done,George . Also we have not yet mentioned the silver leaf pendant shown recently by a new member. This was made by pressing a leaf into silver clay. Dennis.

emroyjewels
04-05-2010, 09:05 AM
George - that's gorgeous!

I have to stop reading this forum - every time I do, I get serious tool envy and I don't know if hubby will let me fill my studio with any more stuff!!! Rolling mill now definitely added to the list :Y:

ps_bond
04-05-2010, 09:09 AM
However, craft packs of skeleton leaves (sold mainly for papercrafters) are excellent and give a very good, clear impression on both copper and silver.


I had some lovely little nylon leaf skeletons that made for fantastic impressions - probably from a similar source. Never seen any quite right since - possibly I've been looking in the wrong places (Hobbycraft, for example).

griffT
04-05-2010, 10:53 AM
Rollers on rolling mills seem to gain sort of stain type marks whatever you do. Perhaps if you oiled them every night and polished them....

I wonder if Durston has considered the idea of supplying reduction gearboxes as a later fitment when it can be afforded?

I've noticed also that when the mill is operating at maximum throat capacity, the helical gears that Peter refers to, are engaging by only a few millimeters and there is a terrific load applied to the teeth.

Nick.

Tabby66
04-05-2010, 07:30 PM
Thanks Dennis and George for your advice. That necklace is lovely George and has exactly the type of finish i'm trying to produce - think i may need to take a trip to my local art suppliers! I will also try the annealing and pickling and see how I get the best effect. The leaf skeletons I collected are headed for the compost heap!

Thank you!
Tabby