Pen Casting and is it worth it?

[David Cramer]

Hello

A few questions about alumilite.

Does anyone know how many ounces it takes per 3/4" by 3/4" by 5" casted pen blank?

Where is the best source to buy the stuff and is it the best stuff?

A guy at my Local Woodcraft said it's like $175 ($160 plus $15 for shipping) for 16 pounds (2 different containers part A and part B).

Just wondering "approximately" how many pen blanks that will make and is it worth it?

I already have an 80 Gallon Compressor for my work and a 2.5 gallon pressure pot, so that's not the issue. Still wondering if it's worth it and how much each blank would end up costing as I can't find the ounce total anywhere.

Thanks:)


David

[David Cramer]

Sorry, I better clarify. They weren't selling it at Woodcraft, he was just telling me what he remembered it costing. Just wondered if it's the best casting material to use and how many, about, that I can expect to get out of the total (256 ounces if I recall). Thanks:)

[Marvin Hasenak]

Do you have a local Hobby Lobby? Ours sells the Alumilite and dyes for it, not sure on the total cost, but the dyes will dye a lot of Alumilite. They sell it in smaller containers that volume wise is a more expensive, with no shipping costs. You will have to do the math, a gallon holds X amount of cubic inches, and then figure your blank's cubic inches.

It also isn't all about cost, making your own blanks and being able to come up with your own designs will become an art in itself. Also you will have the ability for casting worthless wood blanks, another new adventure.

[Shawn Pachlhofer]

I would suggest you visit the "Casting and Stabilization" page on the IAP forum.

I'm not a caster, but I do turn a lot of pens.

best deal on Alumilite is to buy direct from them. Many casters use mica powders from www.coastalscents.com (http://www.coastalscents.com) for coloring.

your other option for casting is polyresin (PR) - I think Silmar 41 is what I remember reading is used a lot.

all of your questions can be answered easily on IAP

[Bruce Pratt]

I've had good success with Silmar 41 (about half the price of Alumilite). Doesn't need a vacuum or pressure pot, unless you are casting very porous objects within the plastic. You can use almost any solvent-based pigment or dye for color. If you are using two different colors, the challenge is to get the density of each colored plastic the same. If you don't, the more dense will sink to the bottom of the mold. You can make casting molds either out of UHMW PE, or PVC pipe.

[David Cramer]

Thanks for the responses as I truly appreciate it. I'll be checking out the links today to see if it's worth even making them...Alumilite is expensive:eek:

David

[Paul Gilbert]

Let's do some math-

Look up the MSDS for the alumilite. It will give you the specific gravity of the compound. Then:

(spec. grav)*8.34 = Weight of one gallon of alumilite. ---- One gal. of water = 8.34 lbs.

a 3/4 x 3/4 x 5 blank would be (3/4)*(3/4)*5 = 2.81 With a little waste this is about 3 cubic inches. A gallon is 231 Cubic inches.

231/3 = 77 A very good approximation of the blanks you can get from one gallon of resin.

Example:

If the specific gravity of a resin is 0.8 then a gallon of that resin would weigh 8.34*.8 = 6.67 lbs.

16 lbs. of resin would be 16/6.67 = 2.4 gallons

2.4*231 = 554 (the number of blanks you will get from 16 lbs of resin.

175/554 = $0.32 each.

Factor in some waste and your blanks would cost you less the 50 cents each.

Note: in the above example I took a blind guess at the specific gravity. I think that plastic floats, so the specific gravity would be < 1.0

[David Cramer]

Hi Paul,

Umm...thanks:):):):) Someone knows their math:) Thanks for taking the time to do that!

Gratefully,

David

[Paul Gilbert]

WOOPS!!!!
I just looked at my math and there is a BIG error in the example ----

2.4*231 = 554 (THE NUMBER OF CUBIC INCHES AVAILABLE)

Now 554/3 = 184 (the number of blanks available)

175/184 = $0.95

Big difference! Sorry about that.

[David Cramer]

WOOPS!!!!
I just looked at my math and there is a BIG error in the example ----

2.4*231 = 554 (THE NUMBER OF CUBIC INCHES AVAILABLE)

Now 554/3 = 184 (the number of blanks available)

175/184 = $0.95

Big difference! Sorry about that.


Nah, it's not a problem at all Paul. Thanks for correcting it, but it's still not too bad at .95 each. I appreciate your efforts. Thanks again Paul:)

[guy laizure]

I get about 90-100 blanks from 2 gallons of alumilite.I make my blanks 7/8 square and 5.5 inches long.There will always be some waste as it is impossible to get every drop out of the mixing cups in order to get the mold in the pressure pot before setting up.