Sorry for the slow response to this everyone.
In most cases, we are pouring parts out of the clear into a closed mold. The standard process we use is to mix, degas, pour the degassed resin in our mold, and then pressure it (easily achievable within 5 minutes but obviously no dilly dallying during the process). The reason we recommend both in this instance is that often times there is not enough volume in the gates and sprews to displace all of the air bubbles that get crushed in mold and we end up with a short shot (not completely filled).
However, as Curtis mentioned and as we have shown in one of our How To pages, you don't need to vacuum before pressure casting if you don't want to. You also don't need to vacuum the two individually before mixing them together but these steps do help reduce the amount of air you will pour into your mold that will require you to crush under pressure. In a second How To page we show how we mix, vacuum, and then pressure cast when making an old '56 Ford pick up truck tail light lens.
Links to the two How Tos are as followed:
http://www.alumilite.com/index.php?page=show_info&type=HOWS&id=47
http://www.alumilite.com/index.php?page=show_info&type=HOWS&id=52
(you might have to copy and paste these)
The reason our material needs to be either vacuumed or pressure cast is because of the fast cycle time. The air bubbles simply don't have the time to float to the surface and pop on their own as many extremely slow epoxies systems do that may take overnight to cure. Our material gels at the 5 minute point and the work time or open time is then set at 5 minutes because that is the point in which you must have pressure on it in order for the bubbles to be crushed. Once the material gels, the air bubbles will not be crushed under the air pressure due to the material solidifying and maintaining its shape under the pressure.
Regarding the black website, you will not be looking at that much longer. A new Alumilite site should be up within a few weeks. Will let you know when it is up and for the record it is a white background.
And yes, you can add the metallic powders directly into the resin as Curtis mentioned. When we cast, we want the concentration on the outside of the part because we typically don't machine it once we remove it from the mold. Therefore we brush it on the mold and do not fill it. The resin flows into the coated mold, picks up the powder and you remove a perfectly looking metallic piece. However if using it in the clear, add it to the resin, pour, then pressure cast it to achieve dynamic effects in your blanks.
Hope this info helps.
Mike
Alumilite
800 447-9344
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