Friday, May 15, 2015

Castaldo Quick-Sil Instructions

Castaldo Quick-Sil is a two-part room temperature vulcanizing (RTV) silicone molding putty that produces tough, strong, long-lasting production jewelry molds for lost wax casting with 0% shrinkage. 

Castaldo Quick-Sil is safe, non-hazardous and non-toxic. No unpleasant fumes or odors. 

Castaldo Quick-Sil is easy to use - merely mix equal parts of part A and part B by hand ( Figure 1 ). There is no need to measure precisely or vacuum in order to achieve optimum results.

Working time: 1 to 2 minutes.  
Cure time: Approximately 15 minute.
Important Notice — Do Not Over-Mix!

• Mix quickly - a uniform color is not necessary.
Over-mixing will result in non-cure!!.
• The total molding process must be completed within the 2 minutes working time.
• Rubber can be worked beyond 2 minutes but weak or defective molds will result.
• Apply as much pressure as possible with a unheated mold press, vise or clamps for best results.
Rubber exposed to cold during shipping or storage will remain cold for extended periods and should be warmed to 70o – 100o F/ 20o- 40o C before use.

Castaldo Quick-Sil is designed to make molds for lost wax casting, but it can also be used for direct casting of low temperature metals such as lead, tin, pewter, etc.  

Because Castaldo Quick-Sil produces finished jewelry molds in a very short time, working time is also very short. This requires a rapid technique of mixing so that working time is not exceeded. 

The easiest way to achieve this is to make thin pancakes of part A and part B on a table top or similar work surface. ( Figure 2 ) Once the two pancakes are formed, place one on top of the other ( Figure 3 ) and then mix them rapidly by pushing down on your thumbs ( Figure 4 ), kneading with both hands or rolling between the palms of your hands, ( Figure 5 ) or any combination of these techniques. 

Press the mixed rubber compound into a mold frame, push the model into the rubber and then cover the model with more rubber compound. ( Figure 6 ) A mold press, vise, clamp or heavy weight is essential to ensure that air bubbles will be driven out of the mold and one uniform piece of rubber is created.

If you notice creases, fold lines or "knit lines" in the cured mold, you have exceeded the working time and the mold has begun to cure before the mold was fully packed. These areas will be weak and subject to tearing. 

The cure rate for new Castaldo Quick-Sil is affected by small temperature changes. Warm hands will cause shortened work time and cure time and cold hands will produce longer work time and cure time. Please note that the more vigorously you mix part A and part B, the more heat will be generated in the rubber itself. Working time (and cure time) will be reduced. 

Please also note that placing Castaldo Quick-Sil in cold mold frames will result in longer cure times. We suggest warming the mold frame slightly to approximately 90° F / 32° C before beginning the process. 

The oily residue on your hands after making a mold with Castaldo Quick-Sil is ordinary mineral oil, also commonly known as "baby oil" and used in child care. It is harmless and will not stain clothing, etc. Occasionally Castaldo Quick-Sil molds will “sweat” oil for a day or two after being made or if not used for a while. This is harmless and normal. It can easily be cleaned off with soap, water and a soft brush. 

Mold frames, plates and sprue button formers that have been used with White Label®, Gold Label® or No Shrink Pink® rubber will have a surface film that contaminates Quick-Sil and must be washed off with any common solvent. If the mold frames, etc. are to be used for White Label, etc. again after Quick-Sil®, washing is required again. The effects of such contamination are a surface layer that is gooey, gummy and easily scraped off.

How much silicone is needed to fill a mold box

A mold box may be a glass or plastic container, a milk carton or constructed from Styrofoam, wood, metal, Lego blocks, glass or acrylic sheets. 

Measure the box dimensions with a tape measure to calculate the volume of silicone required to make your mold. First, the box size should allow for 1/2” clearance over the top and all sides of the model. The formula for determining the required volume is: V=WxDxH 

V = volume in cubic inches 
W= width 
D= depth (front to back) 
H= Height 

Multiply your dimensions to get the total volume in cubic inches. Divide this number by 25 (the cubic inches of LiquaFast-Ice per pound) to give you the  number of pounds of resin to fill the box.  

This formula can also be used to determine the volume of resin required to make a 2 part mold.

Make your dimension measurements for the first pour after you have laid  a clay base, then do the same for the second pour after the clay has been removed (with the model half-way embedded in the cured resin). Add the resin required   for both pours to give you the total volume required to make your 2-part mold.
A helpful hint for you is to make several different size and shaped pouring gates for later use. A preformed, hardened pouring gate when placed in the second mold half prior to pouring will eliminate the need for cutting in the gate later. Making a gate is easy. Just roll several size funnel shapes out of an air drying clay such as Das Pronto, Kneadatite or an oven drying Sculpey. Sand off any irregularities.

How to Cast into a Homemade Silicone Mold

How to Make a Two-Part Mold using LiquaFast ICE