Dan Does IT!
Mixing Plaster by the Islands Method
Picture yourself on a sandy beach, the early morning sun bathing your face in a warm blanket of golden light, palm trees rustle to the relaxing breezes. The island natives dance in grass skirts around a huge fire in preparation for the evening's meal of roasted wild boar. Flames lick the pale blue sky and the air is scented with smoke and wild jasmine flowers.
This is the world of all those who mix plaster by the islands method. It affords the opportunity to live free off the land and never have to ...
Oops, where was I? Oh, I was daydreaming again. Okay, back to the real world. In actuality, you will have your hands deep in buckets of plaster slurry, swishing them around to break up the lumps of unmixed particles in the bucket. A much more worthwhile endeavor than lying around on a pristine white beach, sucking down pina coladas.
This is down to earth serious stuff. You can't lay under a palm teee all day and be a worthwhile plaster caster. OK my limbo rocking friend let's dive into this sea of entrepreneurial information.We'll ease into it gently until you get your sea legs.
Let's start out with just the basics. Here are some items you will need to start your plaster mold and casting business
You will need plaster. (No kidding. Really?)
The following types of plaster will be good for beginners to start with: Casting plaster, pottery plaster, molding plaster or art plaster. They fit into the category of Beta Hemi Hydrates. They are generaly softer than Alpha Hemi Hydrates and require less mixing time. The type of plaster to purchase depends on the project you have in mind. The types of plaster mentioned above are good for carving, plaster molds, and all around art projects. You could go to an art store and purchase a few bags of plaster, they sell it in 5 or 10 pound bags. These retail marketers are a little too pricey for my blood. Your best bet is to call building supply companies in your area to see if they carry plaster in 100 lb bags. You'll get 100 lbs for the same price as a couple of small bags from an upscale art store. Buy one or two of the 100 lb. bags.
If there is a ceramic hobby mold manufacturer in your area, you may be able to purchase a bag or two of pottery plaster from them or you can find a supplier of United States Gypsum plaster in your area by calling 1-800-621-9532.( or go to gypsumsolutions.com) They have reps on staff that are paid to help you set up your plaster casting business. While you are on the phone to U.S.G, ask for the rep for your area. They can be of tremendous help in deciding what plaster to use and how to use it.
You Need A Level Table to be a level headed plaster caster
Mold shops use tables with marble slabs on top of them. Some shops mount a marble slab about 3' x 3' on a 1" steel shaft so that it turns. I have also used a Lazy Susan with a marble slab on it. This makes mold making so much easier. You just turn the marble to get to the back side of the mold.
Make sure your table is perfectly level. If it is not level, everything you make will lean toward the peach orchard.
Deep Flex Molds
Learn about Deep Flex Molds in my YouTube videos. Merlin's Majic and Deep Flex Molds.These are inexpensive plastic molds, great for beginners to learn plaster casting
5 Gallon Bucket
This is a bucket of water for cleaning hands and tools. Since we already discussed on the previous page the hazzards of wasahing your tools and hands in the sink we need not be reminded of that situation again.
A two gallon plastic pail or Tupperware bowl would serve for small batches.
One way to clean up
The small plastic pail or bowl will be easy to clean. When you are through pouring, dump out the unused plaster and let the remaining plaster in the bucket harden up. You can then beat the bejeepers out of the bucket with a stick like Mama used to do to me to get me out of bed on cold winter mornings. (you think I'm kidding.) You can use Tupperware or other similar plastic tubs. Just squeeze the sides together and the hardened plaster will come right out. It is actually easier to clean buckets if you swish the last remains of the plaster around to coat the sides of the bucket and let it harden rather than try to scrape and clean every bit out befor it hardens.
I have seen mold shops use stainless steel buckets which cost $100 or more. They wash the buckets out as soon as they are done pouring a mold. There are also buckets with removable plastic inner liners. This saves wear and tear on the outer bucket.
Or Try This
If you want to wash the bucket out rather than wait for the plaster to harden, dump out any remaining plaster slurry into a box or an old USG plaster bag. Then take your bucket and befor the plaster hardens, fill the rascal half full of water. Use a rag to vigorously wash all plaster from the sides and bottom of the bucket. Quckly dump this cloudy white water into a waste water bucket. After an hour or so, all the plaster will settle to the bottom leaving the rest of the water clear. Dump out the clear water and stop when you get to the plastery goo on the bottom. Dump that plaster waste in the trash.
You will need an apron or coveralls or clothes you wish totally ruined.
You be the juidge of how much water you will need.
The temperature of the water is very important. It will determine how fast the plaster will set. Water that is about 70ºF works well for average jobs. Don' go over 85° f. Colder water slows the set, hot water speeds it up.
That's a short list of things you'll need.
Now it is time to get down and dirty.
Preparing a batch of plaster.
Here it is. Are you ready? Roll up your sleeves. It is time to dig in and let the good times roll. To start out you will need to estimate how much water it will take to fill your molds. If you want to you can actually fill the plastic molds with water for your first couple of attempts. This is just to measure how much water it will take for your mix. You actually only need 2/3 of that amount but mold makers always mix a little extra. Plaster is relatively inexpensive and the problems caused by running short are not worth the few cents saved. The first time your mold springs a leak or you realize you figured wrong, you'll be glad you mixed a little extra.
Plaster manufacturers recommend that you always weigh out the materials to achieve what they call the use consistency ratio. The use consistancy ratio is always based on 100 lbs of paster to the required amount of water. The use consistancy ratio of no.1 pottery plaster is 100 lbs plaster : 70 lbs water. Weighing each component is the best way to get the optimum results from the plaster you're using. After saying that, I'm going to go against all the rules.( Just keep this between you and me. I don'twant to end up in plaster prison! The food is terrible . I hear they feed you oatmeal.)
Here's how it's done. You will achieve a similar to manufacturers recomended ratio, but not the exact same ratio of plaster to water without weighing out the materials. This method works best for the types of plaster mentioned at the beginning of this article (Beta Hemi Hydrates).
Other plasters (Alpha Hemi Hydrates) will not achieve the optimum results by the islands method.
If you can work near an exhaust fan that is great. A dust mask can be worn otherwise. Put the amount of water that you have so diligently estimated you need into your mixing bucket. Never put the plaster into the bucket first and then dump water on top! Always put the water in the bucket first, then add plaster to the water.
With a dry hand ( or scoop) reach into your big plaster bag and scoop up a hand full of beautiful white plaster. Good plaster should feel smooth and free of hard lumps. With your hand full, wiggle your fingers and shake your hand to make the plaster fall through your fingers into the water in the bucket below. This process prevents large clumps of plaster from falling into the water.
Keep sifting the dry plaster into the water with your hand. Work quickly and spread the plaster all around the surface, evenly. The process is similar to when Mama used to make a cake. She didn't just turn the flour sack upside down and smack the sack on the bottom like a newborn baby. She sifted it in slowly to get a fine, lump-free flour mix. That's what you are going to be doing, sifting slowly and carefully. Plaster should fall like gentle rain on the water surface, then sink out of sight.
Mama didn't want a lumpy cake.
You don't want a lumpy plaster mix. Let's not make Mama angry!
Build yourself an island
Do not mix the wet plaster or disturb it in any way while sifting it in or this system of measurement will not work. Keep sprinkling plaster into the undisturbed water. Eventually you will notice little islands of plaster forming above the water surface. When the islands stay at that level and get damp and do not sink below the water, you have the proper amount of plaster in the water.
Now let your island paradise set for 2 minutes. This allows water to penetrate the molecules of plaster. This slaking prepares the plaster for the mixing process.
You have just prepared your plaster mix by the islands method! congratulartions! Try to control your excitment.
The next page continues this article with Beer for My Plaster. You will at last understand the PlasterMaster saying 'Beauty is in the eye of the beerholder. '
Don't miss " Beer for my plaster" on the on the next page.
Lots of secret information.
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