PDA

View Full Version : Calculate blends recipes for MINIMUM cost!



Flintlock Hokie
03-28-2012, 07:57 PM
I made a spreadsheet that will choose from up to six different materials to make your favorite alloy blend AT THE MINIMUM COST! A sample calculation is given in the picture below. I chose six common ingredients, but you can choose your favorite and modify the composition of each.

Enter the cost of each alloy. (I used the purchase price from Rotometals.)
Enter the maximum and minimum amounts for each component under "Specifications."
Enter the amount of the blend you want to make in the upper left.

To calculate the mix, choose Tools/Solver from the Excel menu. In the Solver window, click "Solve." If a solution is possible, you have the option of keeping the solution or reverting back to the previous values. If a solution is not possible, Solver will tell you that. In that case, look at your specifications. You may be calling for a minimum composition that adds up to more than 100%. Or you may be asking for more tin (for example) than any of your ingredients.

http://home.comcast.net/~flintlock.50/pwpimages/blend%20calc%20picture.jpg

Since antimony and tin are the most expensive ingredients, the cheapest blend is usually the one that just meets your minimum specifications for these elements.

If you only want to calculate a blend from your favorite ingredients, eliminate the ingredients you don't want by setting their cost to something exorbitant. (Only three ingredients are needed to guarantee a solution, if you choose the right ones. Example: Don't choose 4-6SbPb, WW and Linotype if you want a blend with 5% tin because none of the ingredients have that much tin!

I've gotten some surprising results. For example, even though tin ingot costs $16.69/lb, it seems to be the ingredient of choice for meeting the tin specification because you need so little. To get enough tin with other materials, you need lots more of that ingredient.

I'll be happy to share this file with anyone. I don't know how to post the file for sharing, but I can send it to you if you are interested. Or if someone can tell me how to make it available I'll try that.

Flintlock Hokie

HangFireW8
03-28-2012, 10:06 PM
The problem for me (and many others here, I suspect) is that I use primarily mystery metal. Stuff of known composition, like 60/40 lead solder bars, I usually get at lead scrap prices, not tin prices. Pewter and rolls of electrical or plumbing solder I get for pennies at yard sales.

For a while I used spreadsheets to track and carefully blend for BHN. I was stuck on Lee's assertion that I had a follow a pressure/BHN formula for good loads. After being disabused of this notion here, I realized it just doesn't matter. Now, I add some tin to medium BHN WW for pistol, add soft sheet lead derived ingots and some solder to lower BHN WW for 45 Colt or BP 45/70, and add a little magnum shot to WW, a little tin and water drop for rifle. Size to bore size plus .001" and the results are always good.

ku4hx
03-29-2012, 08:28 AM
I made a spreadsheet .....

I've had one for a while, my only problem is knowing the exact composition of the stuff I bring home. Truth is, I haven't used mine much at all in years for that very reason. Early last year I did get 20 pounds of diving weights that I called pure lead and mixed with certain amounts of 50/50 solder and Rotometal's high Antimony alloy to give me something that worked. I'm still unsure of the exact composition, but boolits cast from it do so well in my 9x19 I try not to obsess too much. Been so long since last used it I need to change the 750F note; that was a pure guess that eventually proved less than accurate.

badgeredd
03-29-2012, 09:53 AM
I like several aspects of both spread sheets and believe they are useful as a tool. Like Quickload and other software, they can be used as a guide to get us close to our goals with cast boolits.

I recently made up a spread sheet calculator to get a fairly good idea of the contents of different alloys I want to mix up for my experiments with alloys.

We all know that pistol boolits at their relatively slower speeds are far less critical in most cases than rifle boolits are, mainly because we often try for high velocities with very good accuracy in rifles. We can achieve good accuracy with cast boolits reasonably easily with pistol boolits if we do our part with fit and good loading practices. Therefore I really don't worry much about the actual alloy I use in most pistols as long as it is of the appropriate hardness for the job. I do use my alloy calculator to try different alloys and hardnesses to try to get the most accurate high velocity boolits I can get for rifle loads. My goals with rifle boolits are to get as close as possible to original jacketed loads as possible and still have reasonable hunting accuracy. While the spread sheets are interesting and useful, I view them as a tool that we can use to improve our shooting, but they are by no means a gospel for cast boolit making and shooting.

Just my opinion...

Edd

ku4hx
03-29-2012, 10:35 AM
We all know that pistol boolits at their relatively slower speeds are far less critical in most cases than rifle boolits are, .....

+1 If I ever really get into rifle boolit casting I'll be a great deal more fastidious concerning alloy composition. I did some rifle work years ago but just never really "got into it".

HangFireW8
03-29-2012, 02:36 PM
+1 If I ever really get into rifle boolit casting I'll be a great deal more fastidious concerning alloy composition. I did some rifle work years ago but just never really "got into it".

The first time you shoot as much rifle cast ammo in one range trip as you did handgun... with no barrel overheating, and the bore cleans up real fast and easy... you'll be hooked!

HF

ku4hx
03-29-2012, 03:00 PM
The first time you shoot as much rifle cast ammo in one range trip as you did handgun... with no barrel overheating, and the bore cleans up real fast and easy... you'll be hooked!

HF

Oh I know that's true! But I'm in the process of doing something I believe all parents should at least consider: passing along certain possessions (long guns in this case) to my children while I'm still alive. By doing this I get to enjoy them using the guns and maybe even get my son hooked on loading and casting.

I guess I should have said getting "back into" rifle boolit casting in the other post to be perfectly accurate. I have done it, just to no great extent.

popper
03-29-2012, 04:17 PM
Zip it, go to advanced(bottom of page), manage files and upload it.

Flintlock Hokie
03-29-2012, 09:54 PM
Since a given blend can't usually be made from only two ingredients, but requires three, I first wrote the spreadsheet for three ingredients to eliminate all the algebra of solving three simultaneous equations. Then I realized I could add as many ingredients as I wanted. But with more than three ingredients available, there are multiple ways to make a given blend. That's when I realized I could make Solver not just FIND a recipe, but find the minimum cost recipe. So my project grew.

The original goal of simply finding a recipe to get close to the desired blend is the more practical of the two objectives. Admittedly, finding the cheapest blend is a bit of overkill UNLESS you don't have any ingredients on hand and are trying to figure out what you should get.

I hadn't had much luck finding WWs. By playing with various ingredients and prices, I saw that WW can be turned into just about anything and STILL be the lowest cost recipe. So I kept looking. No need to buy Lyman #2, pure lead, etc. as my base. Today I visited six tire stores and garages. One wanted $50 per 5 gallon bucket! (Keep looking!) I ended up with 157 lbs of WW at no cost. It will be hard to find a minimum cost recipe that doesn't use my WWs as the base.

But WW apparently isn't what it used to be. I happen to have access to an X-ray fluorescence machine to analyze my ingots (it takes about 10 seconds per ingot). So far, they don't contain nearly the antimony or tin I've seen advertised in various articles. It will be nice to know how much tin or Superhard to add to get close to a desired blend.

Anyway, I've attached the spreadsheet. Holler if you have any questions.