reticulated hydro sponge

These hydrophilic foams are relatively dense sponges with a high tensile strength and elongation at break.

These characteristics make them ideal for cleaning, smoothing and fettling ceramics during the casting process, as they are tear-resistant. This means that the sponge does not disintegrate during use, which is very important.

Cheaper and lower density sponges can disintegrate during casting, which causes small pieces of sponge to stick to the ware before it is glazed. If this happens, then the sponge burns off during the firing process and causes pin-holes in the surface of the ware, which renders the finished product to be un-saleable.

Therefore it is better to spend more money on high quality sponges, rather than to purchase low quality sponges and risk losing money on potential product losses.

The most popular types of these sponges that we offer are the following qualities, photographs of which are shown in our gallery:


A small-pored sponge type used in the tableware industry


Medium pored sponge which is probably the best sponge for general use on all types of ceramics


This sponge quality has medium/large pores, which offer an abrasive quality that is popular in the sanitaryware industry


This sponge quality also has medium/large pores and similar characteristics to the HR sponge above

The standard characteristics and specifications of the Hydro sponges are shown in the below table:

Standard Tolerances

Foam Type HM HF HR HN
Density (kg/cbm) Min 32 27 28 28
Max 38 31 32 32
Compression Load Deflection (kPa) Min 4.0 2.5 2.5 2.5
Max 6.0 4.5 4.5 4.5
Tensile Strength (kPa) Min 140 120 120 120
Max 140 150 150 150
Elongation at Break (%) Min 140 210 150 150
Max 140 230 200 180


IMPORTANT: Please note that these specifications are correct as of November 2013, but can be altered at the manufacturer’s discretion subject to revised test results.