Cutting Shaping Cabochons

[snowdrops]

I'm loving the pendant shapes that come out of the kiln, round, rounded square, oblong rounded etc.  However, I'm really interested in pieces I see online sometimes that are very obviously shaped with something after fusing, ie no rounded corners, no sloping edges.  I've read around Lap Glass Grinders, tile saws etc.  Does anyone know exactly what is used in this process ?  I've got a few pieces where the clear glass cap has formed a little clear strip on the side and a few I'd like to look a little different.  Thanx.

[Zeldazog]

You've answered your own question - they are usually done on either lap grinders, or maybe a tile saw (and then probably a grinder, or a wet belt linisher which will do the same thing as a lap grinder.... someone with plenty of spare time on their hands, and a lot of patience  may use diamond hand 'lap' pads.... oh and of course there are band saws and ring saws.....

They could be done on any number of these things, there is no singular method of taking back glass to create the faceted edge look.

There's even the possibility of tack fused glass so the edges haven't rounded off properly.....

[Pat from Canvey]

Dawn has covered it well but there's also the possibility of shaping a cabochon on a cabochon mandrel if you have a torch. You don't have to stick to a circle shape when applying glass to the top of the mandrel. I've found a photo now,

[snowdrops]

Thanks Dawn, wow, they just all look a little daunting, lots of money to spend if I get the wrong thing and they all look like they need a fair amount of space. So they all basically cut into the glass and make a hard line ?   Maybe try to find a tutorial online that shows the machines actually working.   

I've made 6 attempts at tack fusing, all have fully fused.  The first few were because I had the timer set for 30 hours instead of 30 mins !!!!!         I will have another go I suppose.  There's so many different schedules around and they all vary with how many layers you use and your own kiln temps.

Pat I don't use a torch, I use my kiln.  It's not so much that I want to make heart shapes, but I'd  like to salvage some of my pendants that have a clear line at the ends where the cap has been longer on one one side or slipped slightly.  I suppose I thought I could just chop those off and do the same the other side to make new cabochon doh !!

Thanx again both x

[snowdrops]

Oh my gosh Dawn, I've never seen a ring saw, just looking at a video now, looks amazing 

[Moira HFG]

If you just want to tidy pendants up, taking off a mm or two, it's worth going for the cheap option: diamond abrasive pads like this:
http://www.pearsonsglass.com/Studio-Essentials/c1/index.html

I have a ring saw and still use these for small jobs. The 60 grit is coarsest and removes material reasonably quickly. Then you can either fire-polish them in the kiln, or if you prefer, buy the finer grades to smooth them down. Dip the pads in water often as you work, if you try to use them dry you'll rub the diamond coating off!

[Pat from Canvey]

The simple option is to visit a local studio that has a ring saw, flat lap or diamond band saw for hire. Maybe someone here who is local to you and has either of those will allow you to have a play. Where are you based? I go to Glass Studio Supplies in Wickford, Essex when I want to hire their large ring saw to cut large chunks of glass. When I want to change the shape of a fused piece or use a bit as a cabochon, I use my 8 inch flat lap.

[snowdrops]

Moira I think that's what I'll try to begin with.  It is just approx 1 mm of glass that's slipped over here and there.  Well worth a shot, I've got a few there to sort, not bad tho out of over 100 cabochons which look lovely.

Alas Pat, I make jewellery as a hobby, (I work 40/50 hours a week in the day job )   and make a little back selling them.  If I started hiring equipment it would be even more of a loss, also live in a part of Wales where you'd be lucky to have anyone know what a cabochon is, let alone own or hire that type of equipment lol. 

Think I'll until I sell a few more pieces, (hopefully my pendants in Wells should go quite quickly) and then put them towards the Taurus 3 ring saw.  Probably after chrimble as a treat.  Trouble is,  I'm always torn between new kit and drooling over pretty glass lol.  One day, when I've won the lotto or written my book, I can give up work and just play all day with lovely glass and silversmithing 

[Moira HFG]

What a lovely idea! 

[Margram]

For a lowtech solution see Avril's post about halfway down the page here: http://www.frit-happens.co.uk/forum/index.php?topic=37927.0

This works quite well if you only have a little to grind off, and have a bit of patience!

[Pauline]

If I started hiring equipment it would be even more of a loss, also live in a part of Wales where you'd be lucky to have anyone know what a cabochon is, let alone own or hire that type of equipment lol. 

living in the same county, I could take offence at that!  I have grits and diamond pads and a dremel with grindy thingies that you could come and have a go with if you like to see how you get on.

[snowdrops]

Lol Pauline, fair comment, tho you know I'm mostly right 

I have a Dremel and think your idea of pads to go with it sounds very feasible.  I've got an assortment that came with the drill and a set of 20 diamond tipped I bought of various shapes and sizes.   What type do I need for removing approx 1-1.5 mm of 6mm glass ?  Would be great if you could send me a link please  

Hand pads would be no good to me currently as I've only very recently dislocated my dominant shoulder.  Can only just about stir coffee let alone rub forcefully. 

I think I will eventually get the Taurus 3 ring saw, tho will be sometime after chrimble.  It can double up to aid with my silversmithing too. The one thing I've learned, is that the word lap does not refer to a machine that is portable and fits on your lap    !!   

Thanks very much everyone.  xx

[snowdrops]

As an update, I decided to try using the diamond bits I have for my Dremel.  It took a little while, tho not too long.  I managed to salvage 5 cabochons !!!       So pleased.  I can see where a grinder would be a lot quicker and easier, however, still planning on the Taurus 3 at some point. For now tho.......... result    

[Metal Monkey]

Hi,
I know this is far too,late coming in, but hopefully it will be useful. I occasionally need to cut small stone slabs for inlay. I do this by using a diamond disc or slitting saw in a flexible shaft drill (pendant motor). If you saw, then gring underwater, it gives a smoother finish, the tools last longer and they cut more efficiently.

I think this would be the most economical route. For various diamond coated or sintered tools, try www.eternaltools.co.uk