Epoxy Systems, Epoxy Resin

To strengthen marble or granite slabs a two-component epoxy
system is used – consisting of an epoxy resin (“A” part) and a
hardener (“B” part) that bind together and form a chain system.
The amount of hardener to be mixed to the resin is a percentage
depending on the material to be treated and environmental
conditions (generally, 25%, 30% or 50%, to say, 25, 30 or 50 grams
of hardener should be added respectively to every 100 grams of
resin). Mixtures can be obtained either manually by using ameasure
or a precision balance or automatic devices consisting of metering
pumps and blenders. For the epoxy system to catalyze, a
temperature above 15-16°C is required. The higher the temperature,
the faster is the drying time. By using today’s tower furnaces (35 to
40°C), the catalysis needs 150 minutes to occur on the average, then
the slab can be polished 24 hours later.
For marble applications, a clear, quite fluid resin should be used (25%
hardener); for granite applications, a more fluid system should be
used (30% or 50% hardener) as fissures are thinner Using this new
two-component epoxy system offers a great advantage in stone
processing because even defective slabs or blocks can be processed
and successfully marketed. Meshing is another step in the slab
renewal process. A glass fibre is applied on the rear of a slab
impregnated with the epoxy system. A strengthened slab will not
break when hand-led. The mesh is available in a range of wefts, weights
and heights. Generally, rolls are 100 or 300 linear meters