My calculations say that I have between 1.5 and 2 ounces of resin in a 3/4" x 6" pen blank. Using a gallon of resin as an example and 2 ounces as a blank size, I can get 60-64 blanks out of a gallon of resin. (Assuming I have very little or no waste) Currently, US Composites (USC) (http://www.uscomposites.com) has gallons for $37 each and to Kentucky the shipping is about $20. Total is $57.
My goal here is to show you the cost per blank of the resin. $57 divided by 128 (@ two ounces per blank times 64 blanks to get the 128 number) equals $.45 per ounce; multiply that by 2 ounces equaling $.90 per blank for a gallon of resin. I took all the numbers on the high side so $.90 is high.
Like many people, I started with casting resin I purchased from a craft store. Most of them have 40-50% off coupons for a single item. Last time I looked at Hobby Lobby, Casting Craft (CC) quarts of resin were $29.99. Using the same formula, 50% discount on the resin and not adding tax, Casting Craft resin cost around $.94 per blank. I'm not putting Casting Craft resin down. I'm just showing the cost is really higher than ordering a gallon online. I made acceptable blanks with CC resin. I feel the Silmar 41 resin makes a much better blank.
Be aware when you purchase 5 gallon buckets, USC has to add a hazardous material fee from UPS. I break the resin into gallons. I purchased some empty gallon containers from USC. Generally speaking, I can get the per blank cost of resin under $.75 per blank with 5 gallon purchases.
iLLSTREET Composites is another vendor that sells Silmar 41. The polyester resin is shipped with methyl ethyl ketone peroxide hardener. If you aren't sure how to use the resin, check out my video channel on YouTube. (http://www.youtube.com/user/fool4peppers)
In the blog, I have only discussed polyester resin. Another casting resin that can be used is Alumilite. I have used this resin before but have more experience with Silmar 41. I will not attempt to debate the pros and cons of the two resins. With Alumilite, you must use a pressure pot to remove air bubbles. In a later blog, I'll discuss pressure pots and air bubbles. Stay tuned.
Next blog, I'll discuss coloring.