how do I remove grinding marks from a slumped bottle

[loulabelle]

Hi
I am relatively new to glass fusing and recently I bought a glass mould which holds bottles. I am able to do a full fuse in the mould but this often leaves spikey bits, which need to be ground off. After I've ground them they are smooth but need to be polished . I've heard of fire polishing but understand that this happens at temperatures higher than slumping and as the bottles have already been slumped can I fire polish them in a mould as otherwise they'll lose their shape. If anyone can help that would be great. I have a skutt hot start  and would welcome a fire polish  programme .
thanks Louise

[Katerina]

hi
I thought fire polishing made on the open flame.....like hot head?

[julieHB]

Here are a couple of good links for you:

http://www.glass-fusing-made-easy.com/fire-polishing-fused-glass.html

http://www.glasscampus.com/tutorials.htm

I have only fire polished small pieces, so cannot really give much advise. Soak the bottle in water and washing up liquid as soon as you have ground off the sharp bits, let it dry, then fire polish. The fire polish is a much shorter cycle, so there is little time for the bottle to slump any more. If you put it in the mould it shouldn't be be a problem anyway.

[Stephen Richard]

Hi
I am relatively new to glass fusing and recently I bought a glass mould which holds bottles. I am able to do a full fuse in the mould but this often leaves spikey bits, which need to be ground off. After I've ground them they are smooth but need to be polished . I've heard of fire polishing but understand that this happens at temperatures higher than slumping and as the bottles have already been slumped can I fire polish them in a mould as otherwise they'll lose their shape. If anyone can help that would be great. I have a skutt hot start  and would welcome a fire polish  programme .
thanks Louise

The low tech way is to use progressively finer wet and dry sandpapers.  As you have used your grinder, you probably are at 80 grit now.  So get some 160 - 200 grit, some 400 grit and some 800 grit wet and dry sandpapers and work from coarsest (lowest number) to finest, keeping them wet throughout the process.  Dry off the bottle where you are sanding from time to time to see if you have removed all the scratches from the previous grit yet.

One thing you can do to help is to use a paint pen on the dry ground surface, let the paint dry and then begin sanding.  When absolutely all the paint has been removed you are ready for the next finest grit.  Does not actually take very long.

The next most expensive way is to get diamond pads to do the job.  still need to be wet though.

[Angie]

 glass also sell a devitrifying liquid called kiln spray 'A'. Is has finely ground glass in it so you have to mix it each time you use a brush to apply it. It will also leave your ground areas shiny after refiring although sometimes you can detect an edge if you don't paint the whole item. Very useful for small items.