> I'm looking for suggestions on formulations to produce lighter plastic
>holds. I came from europe and I spent last summer is USA. I saw there
>holds which are more than twice lighter than holds here in europe. Does
>any have any experiece to make lighter holds?
> P.S I seen all the past post on Deja News.
>>The reason U.S. holds are lighter is that there is less silica sand in
them.Some are almost pure resin.There is a cost however.Low sand ,low
durability and wear resistance.Why go with low sand?People are hooked on
light.Why is beyond me.Unless your carrying a bucket full of holds up a haul
line what's a few extra grams per each.From a commercial gym perspective,
holds are considered an investment.Length of service would then seem
paramount over the slight extra burden on your course setters.It's
interesting to note that silica is not only the most wear resistant and
strength promoting filler you can add to holds ,but is also the
cheapest.However from a commercial manufacturer's point of view,a low ratio
of sand will make your matrix easier to mix(i.e.less wear on your equipment
plus speed)and you can produce those vivid stringy swirls everyone digs.
And to set the record straight for those led to believe otherwise,neither
sand or it's grit size have much to do with the texture of the holds
themselves.That (texture)is transferred from the molds themselves and one
would be hard pressed to tell a feel difference between a pure resin hold
and one which contains sand.
I'm not sure of the process,but the urethane holds available seem to offer
great weight characteristics and incredible durability.The down side is
possibly the cost relative to resin.