# Copy the Gamekeeper John "PPSG (pocket poacher super grip)" reproduce



## unkraut (Feb 1, 2014)

Moin moin,

Reproduce in Alu...






Thanks

;-)) Unkraut


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## Can-Opener (May 11, 2013)

That looks like fun  I have a bucket of aluminum scraps I am saving for doing this someday  What is the crucible you use made of? It looks like a tin can? Very cool project  Way to go


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## derandy (Dec 28, 2014)

Very cool...


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## unkraut (Feb 1, 2014)

Moin moin,

Yes, the pot is a tin can, correctly identified,
Aluminum melts, depending on the alloy at around 800 degrees, tinplate at approximately 1000 degrees well!
With the gas flame, to reach the heat at the location not that melts the tin can. However, it holds only 2-5 Castings, then gets the holes ...
Have fun imitate ....
Greeting

-

see my earlier videos, including alternatives for molding sand .... which unfortunately is not always Mr. exhibited to be suitable































usw...


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## Chuck Daehler (Mar 17, 2015)

An inspiring video! Nice work too..they look almost the same size as the Gamekeeper models.

Casting metal from an original results in a slight reduction if size due to the fact you used cold metal to make the mold impression and hot metal to pour. As the hot metal contracts as it cools you'll get about 1.8% less size in the cooled copy, depending on the aluminum alloy or if it's pure Al. Also you must finish the piece, that means removing metal to get a good finish. Count on at least 5% less dimension in your finished piece, depending on how much metal you have to remove to get the desired finish. That's not too much difference, but it's less. If you have a partial fill or a glitch in the casting you can't repair it unless you have an aluminum welder guy handy.

Be ready for a very long and arduous finish process. First you use a rotary wire brush in your grinder to remove scale and uglies. Next you file (and file and file) to get the metal surface down from the pock marked casting state. Next you go through at least five sanding steps same as wood but aluminum will be slower to respond. Wet sand of course so buy the proper sand paper. If you have a commercial buffing unit (and most folks don't) then you use Tripoli to work down the last sanding (1200 grit minimum) to a pre polish then rouge for the final polish. You will need two cotton buff wheels..one for Tripoli and one for rouge. Or, if you don't have a buffer and/or can't or won't buy wheels, a lot of hand work with automotive rubbing compound then Brasso and using rags, and black fingers if you don't use rubber gloves. But your finished slingshot will glisten in the morning sun! You can impregnate a wheel with aggressive automotive rubbing compound if you don't use Tripoli for the pre polish.

For contraction of cast metals... http://www.calculatoredge.com/charts/mshrinka.htm

Many "tin cans" are plated steel which has been lead-tin soldered together..the bottom and side seam, and will fall apart when heated to the melting temp of Al. He said, "Properly intenfied" and meant it. First do a dry run with the can in the furnace to make sure it'll take the temperature. If it does, fine, if not, you learned something about cans without having a mess. If you can't tell the difference between an aluminum can (which would melt) and a steel one, use a magnet off your refrigerator..aluminum isn't magnetic whereas steel used in cans is.

Melting and pouring molten metal...been there done that 100s of times I the gold foundry biz.

A cast iron melting pot for lead bought at a plumbing supply would be my recommendation if you can't find a real ceramic crucible. Unfortunately they are pretty heavy and unwieldy to manage. The proper crucible to use is a graphite/ceramic crucible or a ceramic crucible and they are not particularly expensive and can be used with care, many times. You will need a set of long strong tongs to pick it up out of the furnace and pour it. The tongs should have a right angle jaw as well to make pouring possible...you pick the crucible up by the lip by putting one jaw inside the crucible and the other outside and pinch it like that. Second method is to pick it out of the furnace with the right angle tong, set it down, then change tongs to a set that has jaws that fit around the crucible body and pour it. If the crucible drops out of your tong jaws it will splash molten metal everywhere including you, so this is a delicate and touchy operation.

Caution, make sure the mold is absolutely dry. Any water or even slight moisture in the mold compound will turn to steam and explode, spewing molten metal everywhere including you. I would use a face mask or at least decent eye protection lest you post a picture of yourself with a charred face here. Dropped crucibles and splashing metal do a damdam on skin.

Old caster's trick. To make an item 5% fatter so as to compensate for a 5% smaller finished product, dip the original in paraffin once or twice or enough times before making a mold of it to make it about 5% fatter. That works only when compressing the mold compound (sand) doesn't mess up the paraffin.

P.S. I liked the fluorescent police vest and hat and police camouflage...good to wear work clothes when casting alright!

End of dissertation.


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## unkraut (Feb 1, 2014)

Moin moin,


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## alfshooter (May 11, 2011)

:thumbsup: :thumbsup:


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