Making frit

Frit

Frit describes fine particles of broken glass.

Glass frit one buys from the merchant is made from compatible sheet offcuts smashed in mills and grinders and sieved for size. In the studio, one can perform similar operations on a small scale.

It should be stated here that making frit in the manner described can be an extremely labour intensive operation.

Sorting the glass

The first step is to carefully segregate the glass offcuts.

As the ultimate objective is to use the frit for decoration on fused objects, then the provenance of the offcuts must the impeccable.

Prepare by carefully segregating all offcuts, at least by maker or COE. Ultimately it will need to be sorted by COE and colour.  

Unless one intends to throw away all offcuts, with no intention of them being put to another use, it is good practice to put them in separate containers segregated by COE. 

Some go a step further and sort by broad colour clusters; blues, reds etc within each COE group.

It is NOT an economic operation to use good glass (glass purchased for the purpose of making frit) to make frit. It is less costly to buy it ready made.

The equipment

Fig 82-01

Fig 1 shows the essential equipment. It comprises;

• A piece of heavy truck tyre inner tube
• Some clothes pegs
• A heavy hammer
• One or more sieves of varying mesh size.

The operation is simple;

• Fold one end of the inner tube on itself, secure with clothes pegs.
• Close off the other end of tube.
• Go to town with hammer. Shake up the glass frequently.
• Remove the glass regularly and sieve. There’s no point in pounding it too small.
  

It is best done on a firm base, such as on a concrete floor, but this can be quite uncomfortable, so a verrry solid bench is next best.

Sieves

An ordinary kitchen sieve will give a reasonable particle separation, passing everything smaller than the opening size, including dust. The mesh size will tend to be of a standard size, with little range or option of choice.

A wider range of mesh size can be found at the suppliers of fossickers and prospectors equipment.

Fig 82-02

The home made set shown in Fig 2 use a mixture of woven wire mesh and perforated stainless steel sheet in wooden frames.The openings in the frames are about 160 x 140mm and they all nest nicely on top of 4 or 5 litre ice cream containers.

It is very much up to one’s personal preference as to what sieve size is used. Within a certain range they all tend to flow together with little variation in colour density. That will be more influenced by how high one piles up the frit.

 Fig 82-03

Fig 3 shows the distribution of particle size made from a few minutes pounding with a hammer.