Monday, 5 November 2012

Rods in Glass


Inserting large rods into glass

Normally large diameter rods are incorporated into a glass piece for display supports. However, rods over about 2mm will break the glass when incorporated in the fusing. This means that rods to support the glass that will be of sufficient diameter for the strength required cannot be fused into the glass.

You can use a rod of the same - or slightly smaller - size if you wrap it with thin fibre paper to cushion the differentials in expansion and contraction. When the glass has cooled, pull the rod out and clean out remaining fibre paper with water and a pick. 

Alternatively, you can use fibre paper to create a void of similar size to the wire or other metal support that will be inserted.

If you find that you do not like the hump that the rod or fibre paper create, you can use a third layer between the top and bottom.  Cut the glass to leave a channel of the length you want.  This means that the intermediate glass will need to be in at least two vertical parts, with half the channel width taken out of each side.  You can cut the glass in three parts horizontally.  The main piece is cut to a length minus the depth of the channel.  Then two strips are added to the bottom which leave the desired width. Finally, put the top layer on.  

Alternatively, the middle layer can be the design, with the bottom and top being clear or any other colour desired.

Once fired, clean out the channel and glue the rods into the glass. Silicone is a good all purpose adhesive that will allow a bit of movement.