Averaging Plaster Weights

Now that I have figured out the perfect mix to use when I’m making plaster magnets, it’s time to start figuring out their actual costs so I can get all the prices in the Etsy store updated! 🙂

Per my plaster mix experiment post 20ml plaster = $0.28

Since most of my magnets are tiny, my attempts at measuring how many ml of mix went into each were a dismal failure. So instead, I went with an average weight.

I piled a bunch of the casts onto a postal scale and then calculated the average. Once I’ve worked through all the bodies I have, I’ll make a few 10 item batches of each small mold to measure how many ml are used.

The kittenloaf used 20ml and the average weight is 0.7oz, so I’m using a 1oz = $0.40.

Magnets will be added as I work out the costs, so not all of them will appear here at first…

Last updated: 05/11/2017

	Kittenloaf (Sleeping Cat) Average oz = 0.7 Plaster cost @ 0.40 per oz = $0.28 Primer, paint, and sealer $0.15 0.7 inch Neodymium = $0.53 or 1 inch ceramic = $0.33 Total materials = $1.11/0.91
	Leaping Horse Average oz = 0.04 Plaster cost @ 0.40 per oz = $0.012 Primer, paint, and sealer $0.15 Ring Neodymium = $0.33 Total materials = $0.45
	Flat Cat Head 0.03 average oz @ 0.40 per oz = $0.12 Primer, paint, and sealer $0.15 3 inch tape magnets @ 0.04 per inch = $0.12 or 1 inch ceramic = $0.33 or 0.7 inch Neodymium = $0.53 Total materials $0.39/0.60/0.80
	Large Horse Head Average oz = 0.06 Plaster cost @ 0.40 per oz = $0.24 0.7 inch Neodymium = $0.53 Total materials = $0.77
	Heart Horse Average oz (head+mane) = 0.08333 Plaster cost @ 0.40 per oz = $0.03 Primer, paint, and sealer $0.15 Wooden Heart = $0.19 Tape magnets 2 inches @ 0.04 per inch = $0.08 Total materials $0.45
	Corgiloaf (Sleeping Corgi) Average oz = 0.5 Plaster cost @ 0.40 per oz = $0.20 0.7 inch Neodymium = $0.53 Total materials = $0.73
	Clydesdale Head Average oz = 1.0 Plaster cost @ 0.40 per oz = $0.40 0.7 inch Neodymium = $0.53 6 inches of Tape Magnet = $0.30 Total materials = $0.93/$0.70
	Small Horse Head and Mane Average oz (head+mane) = 0.08333 Plaster cost @ 0.40 per oz = $0.0333 1 inch Tape Magnet = $0.04 Total materials = $0.07
	Small Bird Head Average oz = 0.0333 Plaster cost @ 0.40 per oz = $0.012 0.5 inch Tape Magnet = $0.02 Total materials = $0.04

Cost of Magnets

• 07004 1 inch diameter ceramic magnet $1.98/6= $0.33
• 07090 3/8 in. Neodymium Rare-Earth Magnet Discs $3.98/12 = $0.33
• 07046 1/2 in. Neodymium Rare-Earth Magnet Discs $3.98/6 = $0.66
• 10102256 ArtMinds Wood Hearts $3.89/21 = $0.19
• 0.7 Neodymium Rare-Earth Magnet Discs $3.98/3 = $1.32
  Or on Etsy from MinkusMargo for $26.43/50 = $0.53
• N40.  0.125″ (3.175mm) dia x 0.0625″ (1.587mm) thick, magnetized through the thickness. from SuperMagnetMan for $20.00/100 = $0.20
• Magnum Magnetics Pro Mag Round Magnets 0.75″ dia for $6.99/50 = $0.14

The magnetic tape I am using is this one from Home Depot (1/2 in. x 10 ft. Iron Ferrite Magnetic Tape @ $3.98). Which breaks down to roughly $0.04 an inch. One 2.5 inch strip is enough to hold three pieces of paper and for most of the forms I’m using multiple strips.