With the recent interest rising for sulphur free clays I contacted the new office of Kolb America Inc. via email asking about their offerings for a sulphur free clay. Mark Malewitz was kind enough to forward the link of the website, although I was hoping for a little more in depth account of how the product is actually working in the real world. As we all know the brochure can spin the best product in the world but reality has a way of bringing everything into perspective. On paper the TecClay looks to be everything you would want, sulphur free, light weight, good bonding capabilities, easy to mill. OK, let’s look at all the product highlights as stated from the website.
- TecClay is 100% sulphur free.
- TecClay has 40% less weight than normal clay.
- TecClay temperature stability is better than ordinary clay. Working temperature is 52 degrees Celcius.
- TecClay gives a perfect finish, no more irritating stroke traces or scratches.
- TecClay has edge stability, ideal for interiors with high detail.
- TecClay is perfect for CNC milling. The clay chips are dry and do not stick to the model.
- TecClay is oxidation free, homogenized and absolutely odorless.
- TecClay has excellent bonding capabilities.
Mark states that TecClay has been perfected over the past eight years giving it plenty of research history. My main concern as with all sulphur free clays is, they tend to be too dry and they do not adhere too well when having to make major model changes. Maybe it’s the change in oils and binders to make them mill friendly and light weight. The clay may not stick to the model when milled but by the same token the clay also doesn’t want to stick to itself unless an outside heating source is being used. I know that Kolb offer a portable clay heater that heats the clay to a depth of 20mm ( 3/4″ ) and this is obviously the reason for this particular piece of equipment. To heat a large area for a minor change can also have an adverse effect on the surrounding area, maybe even causing additional correction. Localized heating with a heat gun may be the answer but I am not a firm believer in this style of clay modeling.
With the majority of large corporations having to use sulphur free clay sooner than later, extra time will be needed to bring the clay up to a working temperature before adding additional clay, be it for changes or packing in preparation for milling. Preheating the clay on large models will be the only sure way of blending the clay for a seamless surface so as to avoid the likes of delamination and aerated surfaces.
In my working environment I have not used the Kolb TecClay and to become more familiar with the product I would be interested to hear from anyone who has. What is your experience with using this product, what are the good points, does it have any bad points?