Climb Hold
Cost Breakdown:
The specific cost to manufacture a hold
depends greatly on the size, design, and volume of the hold
itself. But we can
get a very good estimate off of using the following calculations.
Lets start, take a medium sized hold that
is approximately 3”x3”x1.5” that
requires 7 fluid oz. For starters we need to calculate
the amount of silicone rubber the hold will require. An
ideal rubber mold will use as little silicone as possible. Using
Dow Corning’s high tear strength silicone rubber (HS II
or III – the III is just a little softer than the II which
is a little better for removing extreme undercuts or negative
drafts designed in your holds), you can get away with only ¼” wall
thickness which will reduce the amount of rubber needed in making
your mold. So if we add ¼” to each side of
the hold and say ½” to the top to include a little
as a fudge factor we will get a good idea of how much rubber
will be required. So our mold box dimensions will be 3.5”x3.5”x2” deep. We
then calculate the volume of this box and subtract the volume
of our hold we will determine the amount of rubber needed to
make the mold. So the mold box requires 24.5 cubic inches
and the rock is 13.5 cubic inches. When you subtract the
two you come up with 11 cubic inches of volume the rubber will
need to fill.
So if our rubber required to make the mold
is 11 cubic inches and the hold requires 7 oz, we can now begin
calculating a close cost estimate for the hold.
There are 21 cubic inches per 1 lb of silicone
rubber. So
if we need 11 cubic inches of rubber we simply divide 11/21 to
come up with .53 lbs of rubber. If we take a gallon kit
price for the HS II of $165.00 for 10 lbs we come up with a cost
per lb of $16.50. This is kind of a worse case scenario
for many climbing hold manufacturers because the economy of scale
is not with you purchasing only one 10 lb kit vs the 50 lb (5
gallon) or drum quantities but from this example you should learn
how to calculate your cost per hold. So we then take $16.50
x .53 to calculate our mold cost of $8.75. If this mold
yields 100 holds out of it before breaking down, you then need
to divide the $8.75 cost by hundred to know the mold cost per
hold. In this example it would be $0.0875 or basically
9 cents per hold you remove from the mold.
Now let’s calculate the resin cost per hold. A gallon
kit of RC-3 (gallon of each side of our preferred rock climbing
hold resin: 128 oz of A + 128 oz of B = 256 total oz) costs
$90.00. Once again this is a worse case scenario because
your economy of scale or price per gallon drops dramatically
when purchasing larger 5 gallon kit and drum kit quantities but
you will learn the process for accurately estimating your cost
per hold. The cost per oz would then be $90.00/256 oz which
equals .35 cents/oz. We then multiply that .35 cents by
7 oz required to fill the mold cavity (your hold) to come to
a $2.45 total cost for the resin.
We then add the mold cost per hold of 9 cents to the $2.45 resin
cost to come to a $2.54 per hold cost for a medium sized 7 oz
shape.
Other cost factors that have not been included
that will add to the cost per hold. Mold box materials, glue/clay for
sealing the mold box down, foam to make the original shape/hold,
dye if you choose to color it, washers, mold release to help
extend your mold life (help make sure you get to a 100 pulls),
and labor. All of these should be factored in to give you
a more realistic idea of where your real cost per hold stands.
Mold box material is typically very inexpensive
but should be factored into the equation. I personally recommend purchasing
4’x8’ sheets of corrugated plastics which you can
cut to make quick and easy mold boxes with. It typically
runs about $10 per sheet and will make a ton of mold boxes and
bases. It can be cut or scored using a simple Exact-O type
knife.
My other preference is to use hot melt
glue to seal and bond the mold box walls to the base. Hot melt is an easy answer
to making mold boxes very quickly. Inexpensive hot melt
guns and glue sticks are found at a local craft store. Larger
industrial sticks can be found online.
Our reactive dyes (meaning they actually
chemically crosslink with the resin and will never bleed out)
are very concentrated. To
effectively color the resin you will only need approximately
6 oz per 5 gallon kit of RC-3 (preferred resin for making holds)
which costs $19.20. 10 gallons of colored resin will
make approximately 182, 7 oz holds. If you divide the $19.20
(cost of the 6 oz dye) by 182 you come up with a dye cost of
$0.11. Add this $.11 dye cost to your $2.54 mold and resin
cost and your new colored hold cost is $2.65.
Using a filler can dramatically decrease
the cost of your holds. Using
either dry playground sand, microballoons, calcium carbonate,
or any other dry filler will reduce the cost per hold of your
raw materials because it requires less resin and replaces that
volume with a less expensive filler. Lets take a microballoons
as our example. 5 lbs of microballoons costs $22.50. 5
lbs of microballoons is approximately 3 gallons of volume. To
calculate a cost per oz of microballoons we take 3 gallons times
128 oz per gallon to get 384 oz. We now take our cost of
$22.50/384 oz to come up with a cost of $0.06 per oz of microballoons
which is much less expensive than our $0.35 cost per oz of resin. Now
to fill that 7 oz of volume we can use 5 oz of resin and approximately
3 oz of microballoons to yield us a total of 7 oz. This
would give us a 60% microballoon fill percentage. You can
take this all the way up to 100% but would not recommend going
over 100%. Physical properties will not be dramatically
affected when using less than 50-60% microballoon fill in RC-3. In
our 7 oz hold example we would then have 5 oz of resin at $.35
each plus 3 oz of microballoons at $.06 each. This gives
us $1.75 worth of resin and $.18 worth of microballoons. Add
these together and your new resin cost is $1.93 rather than $2.45
previous unfilled resin cost. You would then add in your
$.09 mold allocation cost per hold as well as your $.11 dye cost
for a total of $2.13 total cost for resin/filler, mold, and dye
rather than your previous $2.65 when using straight resin. This
is an approximate 25% savings in cost when using the microballoons.
Once again these are price estimates off
of small quantity list prices for starter size material kits. They do not include
mold box material cost, glue cost, cost to create or purchase
masters to make molds off of, or labor. This is a simple
walk through on how to generate a cost estimate for making your
own climbing holds. As you were to purchase larger quantities
your pricing would decrease dramatically decreasing your cost
per hold.
To discuss any of this information or if
you would like help using larger volume pricing to accurately
calculate your costs, please give us a call and we’d
be more than happy to assist you. |