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Miniature Reef Ball Mold Instructional Manual

Reef Ball Mini-Mold Instructions

Materials you will need:

Tools Needed

Optional: (These concrete admixtures are available at concrete supply stores)


Take the mold out of the plastic bucket. Use the butter or silicone spray to completely coat the inside of the mold. WARNING: Failure to put a releasing agent on the mold can make removal of the models difficult or impossible and can DESTROY THE MOLD.

Next, put talcum powder on the outside of the mold so that it can be easily removed from the plastic bucket.

Step 2: Mold Set-Up

Make a water balloon that fits the inside of the mold so that it touches all of the top "knobs" in the mold. A little practice and you will make it just the right size. Too much and it will be hard to get concrete into the mold. Too little and the "holes" in your mini Reef Ball will not go through to the center.

Place 4-6 "Squishy Balls" in the bottom of the mold, try to avoid putting them on top of the Reef Ball copyright notice. Now place the water balloon in the center of the mold. Finally, put the whole mold into the bucket and seal the lid.

Step 3: Mix The Concrete

Add 1 Quart of Water and one pint of sand to your mixing bucket. If you have microsilica, add a cup of this to at this time. WEAR PROTECTIVE MASKS WHEN ADDING MICROSILICA OR PORTLAND CEMENT AS THE DUST IS HARMFUL TO BREATH.

Start the drill mixer and continue mixing while someone else slowly adds the Portland cement to the mix. Keep adding cement until the mixture has the consistency of a thick soup. Liquid enough to pour into the mold, but not too liquidy or the concrete will be very weak.

[If you have superplastisizer, mix the concrete until it is thicker than needed and then add 1-2 tablespoons of superplastisizer and continue mixing. The superplastisizer will make the concrete liquid enough to pour into the mold. You must use this method if you are hand mixing because you will not be able to hand mix concrete that is liquidly enough to pour and still have strength]

Step 4: Pour The Concrete

Add the concrete to the mold until you can just see the top of the balloon sticking out. Place the bucket in a warm place (65-85 degrees) for 12 hours.

Step 5: Opening The Mold

Remove the mold from the plastic bucket. If this is difficult, a butter knife and dish washing soap around the edges will help. (But the next time don't forget the talcum powder!)

Over a sink, puncture the balloon and let the water drain out.

De-mold your Reef Ball from the mold by slowly separating the Reef Ball from the mold.

Next, find all of the squishy balls and remove them. Be sure to count the number of squishys to make sure you have found them all. If you can't find one, place the mini-Reef Ball in a dry place for a few days and you will see a wet spot where the squishy can be found.

Step 6: Curing Your Reef Ball

Rinse your Reef Ball Model in water and place it in a plastic bag and seal it up to retain the moisture. Leave it in the bag for at least a week . Your Mini-Reef Ball is now complete.

Step 7: Long Term Storage of The Mold

If you are not going to use your mini-mold for awhile, first make sure they are dry, then put cellophane across the mold seams before storage. (Urethane tends to stick to itself if left in contact for a long time) Newer molds are more prone to this problem. Store in a cool place away from direct sunshine.

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