Tuesday, April 7, 2009

Pouring Your Cultured Marble Molds Four Times a Day

I am often asked if I can turn my cultured marble molds four times per day. Of course the molds are capable of being used four times per day but the question is, is it humanly possible or even likely. The answer is no, it’s not. Even if you could, it has nothing to do with the molds but everything to do with the raw materials and equipment you use in manufacturing. A mold’s lifespan is determined by how many cycles you turn the mold and how hot you pour them.Cultured marble is made using a polyester resin with a promoter, and various kind of fillers such as limestone, granite and onyx. A catalyst is added to the mixture which reacts with the promoter in the resin, making the cultured marble cure.Several factors determine how fast your cultured marble hardens and how many times per day you can turn your molds.Promoters: Promoters are generally added to the resins by the resin manufacturers. There are different kinds of promoters, so not only the amount of promoter but what type of promoter they add will affect the cure time. The more promoter that is added, the faster the cure time will be.

Catalyst: The more catalyst you add the faster your marble will cure. There are also several different brands of catalyst and some of these are designed to give you a faster cure time. There are some products, such as bathtubs, where you don’t want to catalyze too much because over calalyzing can generate too much heat.

Climate: Heat is your friend in manufacturing cultured marble. Your cure time can be shortened a great deal with some heat. The warmer your climate is the faster your cure time will be. The faster the cure time, the sooner you can get your part off the mold and start the process over. Under ideal conditions (like a hot summer day) you may be able to get a marble product cured sufficiently to demold in a couple hours but in the wintertime, you may have to let the product sit on the mold four hours or more to cure enough to remove it from the mold.

Equipment: A heat tunnel (Equipment) is an important factor in turning your molds more times per day. You have to spray gel coat on your mold prior to pouring your cultured marble matrix on it. This gel coat has to be cured prior to pouring your cultured marble. Running this gel coated mold through a heat tunnel as you see in the photo below, drastically shortens this gel coat cure time. Heating this gel coat can cut the gel coat curing time by half or more, especially in a cold climate. In a cold climate, it is not uncommon to have a gel coat cure time of 45 minutes to one hour, and a heat tunnel can cut this time down by 50 to 60%. Having the mold warmed up during this process will also cut down your cultured marble gel and curing time considerably.

Now that you have learned some tips on how to ‘work towards’ turning your molds four times per day, let me say that it is unlikely that you will ever turn your molds four times per day regardless whose molds you use or how much experience you’ve gained working with the raw materials. It’s just not realistic to expect that in an eight hour day, you can setup a mold (divider bars), wax it, wipe off the wax, spray your gel coat, let the gel coat cure, pour your cultured marble, let the marble cure, de mold your part, and go through this process three more times in a regular eight hour day. Pouring your molds two times a day is feasible, so when you’re putting together your business plan, figure the maximum times you turn your molds will be two times per day. When you have all the facts and details, you will find that you can put together a very attractive P/L statement by planning on turning your molds only once per day, as most cultured marble factories do. If you have more questions on this, give me a call at (408) 230-3616 or e-mail me at doyle@culturedmarblemolds.com.
There is also a lot of facts on the Frequently Asked Questions (F.A.Q.) page at:http://www.culturedmarblemolds.com/cmmfaqs.html.


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