Matt surface - Paving slab from pu molds

[arek]

Hello

I use polyurethane moulds . The problem is that the ready products are very shiny. I don't know if it is ok but the moulds themsleves are not matt they are aslo shiny. I have seen ready products made in Numold moulds but produce by some other companies and they are matt. What may cause this shiny effect?. Are there any relase agents or plasticizers which may cause the ready products become matt? I have aslo noticed that ready products in other companies when you take them into hands are powdering. They leave a very thin film of dust on hands. Maybe has someone faced to such problem?I am waiting for any clues.

thanks

Arek

[matt h]

polished surface is caused by smooth mould and release oil, powdery is just cement dust...u windin us up?

[arek]

I am very serious. Whay are u thinkin I'm widing u up?I' m just tryin to find out why other companies which use the Numold moulds have matt products and I don't. I really don't know what cause such situation. Thanks for any suggestions.

[Tony McC]

It's most likely to be a combination of the mould release oil and the method of curing that determines the finished appearance. Try experimenting with different brands.

[mouldmaker]

Dumb question, maybe, but have you tried asking numold themselves?

Your best bet, like the boss says, is try different mould release oils. Fuchs used to do a water based emulsion called Renocast 601 (still do I think, but I believe they were planning to change the name) which is not unpleasant to use and usually gives a matt effect. Also if you're spraying mould oil, try using less; set your sprayguns to a very fine mist and don't overapply. And if you're painting or ragging it on, stop.

Also plasticisers can cause shine - if you use them, try a batch without and see if that makes a diference.

[arek]

>Dumb question....

Mr. Mouldmaker,

Stand behind a dog. Below a tail a dog has two balls. Look at them, the products shine like them.

Arek

[Dave_L]

Your dog has shiny bollocks? :rock:

[Suggers]

Yet another weirdo - where does the pic mob dig 'em up from ?

[Dave_L]

Yet another weirdo - where does the pic mob dig 'em up from ?

It must be the fumes or summat from the 'crete, sends 'em crazy!