How to cast a round-shaped tin figure

by Hans Chr. Wolter

Although you have not had any appren­tice­ship in pro­fes­sion­al mold­ing, it is afford­able to under­stand how fine­ly con­struct­ed molds can throw a mul­ti­tude of ben­e­fits. The ben­e­fits of mold mold­ing and mod­els them­selves are nat­u­ral­ly asso­ci­at­ed with mold build­ing. When using own molds, the cast­ings become items that can­not be pur­chased on the mar­ket, they can meet exact­ly the desired needs, and one can dis­pose of mass effects of fig­ures with­in an afford­able framework.

Mate­r­i­al require­ments:

Sin­gle met­als or alloy
heat­ing Source
Wood or masonite plates
melt­ing pot
talc
Screw fin­gers or elastic
Cleans­ing with hole
gloves
Wire cut­ters

Process

If a lot of time has been sac­ri­ficed on the con­struc­tion of the mold, and sub­se­quent­ly the self-cast cast­ings have to be care­ful­ly paint­ed, it will be a very short-term pol­i­cy to save on the met­al quality.
Too lit­tle met­al qual­i­ty gives poor and inac­cu­rate mold­ings, and it will bring a risk that one day sud­den­ly, oxi­dized rash­es break through the paint­ed sur­face of the figures.

A stan­dard alloy that both meets the require­ment of “draw­ing fine” in the details and at the same time incor­po­rat­ing a form of guar­an­tee against “pest” in the fig­ures can be com­posed of 3 parts 60% tin and 1 part print metal.

The print­ing met­al, also known as print­ing lead or typeats, con­tains anti­mo­ny, whose prop­er­ties are instru­men­tal in mak­ing the mold­ings fine and durable. Now one can of course vary his alloys — for exam­ple, it is not nec­es­sary to use as much tin as when the body is very sol­id. How­ev­er, if you stick to this stan­dard alloy and if you hit a tem­per­a­ture of 300 degrees Cel­sius, the cast­ing can only be good. With an unsuit­able alloy and at too high a tem­per­a­ture, the fig­ure qual­i­ty will sim­ply be too small.

The alloy can be made in advance or the ingre­di­ents can only be pre­pared. One approach is to use an old cast iron apple slice pan to pre­pare the alloy com­po­nents. This can be done in such a way that a large por­tion of 60% tin is melt­ed in a spa­cious iron pan. Then the tin is poured with a pot spoon or the like into the apple slice pan.
Sim­i­lar­ly, the type met­al is made. The hemi­spheres are kept sep­a­rate in the two types and assem­bled in the right ratio 3: 1 when desired.

Some wood or masonite plates are formed in appro­pri­ate dimen­sions so that they can be held firm­ly on the out­side of the two molds.

A dessert dish is drilled in the mid­dle and is cut flat at the tip, thus pro­vid­ing a suit­able clean­ing tank for skim­ming impu­ri­ties in the liq­uid metal.

 
Heat­ing

Sev­er­al sources of heat­ing are pos­si­ble: nat­ur­al gas, primus and elec­tric­i­ty are the most read­i­ly avail­able. For exam­ple, nat­ur­al gas is suit­able when, for alloys, larg­er amounts of met­al are to be melt­ed in pots. Basi­cal­ly, there are sev­er­al ways to heat the met­al up before it is poured into the mold. It can be heat­ed in a pot, in which case a spoon can be used for pour­ing into the mold. A cru­cible of, for exam­ple, iron or cop­per can be placed direct­ly on the heat source.
Or an elec­tric cru­cible may prove to be the solu­tion because of its con­stant tem­per­a­ture per­for­mance.

When one is unable to cal­cu­late the tem­per­a­ture, it is advan­ta­geous to invest in a ther­mome­ter that can mea­sure tem­per­a­tures up to 400 degrees Celsius.

Prepa­ra­tions

In order to pro­tect the mold and at the same time obtain good mold­ings, the two molds are sand­ed with talc before each mold­ing. Prac­ti­cal­ly, it is for the pur­pose of using an old lunch box with a lid or the like and fill­ing it with talc and a cot­ton wool for use at the powdering.

The formed wood or masonite plates are laid on the two sides of the mold, the mold is held togeth­er by either elas­tics or clamps. But of course, it must not be tight­ened so hard that the mold is deformed and thus gives an unsat­is­fac­to­ry cast.

The mold is placed firm­ly with­out the risk of tip­ping over dur­ing the pouring.

Safe­ty

With a met­al tem­per­a­ture of about 300 degrees Cel­sius, one must of course use his com­mon sense. The work requires appro­pri­ate cloth­ing, includ­ing gloves and dis­ci­pline with regard to chil­dren’s presence.

Shapes can become very hot when used repeat­ed­ly. They can eas­i­ly hold onto it and usu­al­ly do not require cool­ing. In any case, you have to be warned against exper­i­ment­ing with water cool­ing. If there is only one drop of water inside the mold when met­al is poured down, the water will look into some form of explo­sion movement.

Cast­ing

When the alloy is brought up to the work­ing tem­per­a­ture (for exam­ple, 300 degrees Cel­sius), it is well stirred with the formed clean­ing cloth and the impu­ri­ties from the sur­face are con­tin­u­ous­ly removed.

To ensure qual­i­ty, it is very impor­tant that the met­al is kept as clean as possible.
With good weight, the met­al is poured into the mold, which is prefer­ably vibrat­ed, while the met­al is still liquid.

It is advis­able to have sev­er­al molds run­ning when mold­ed. Thus, it is self-evi­dent that the indi­vid­ual form is allowed to stand for a long time before it is opened. If the mold halves are sep­a­rat­ed from each oth­er too quick­ly, when the met­al only appears to have solid­i­fied, the item will have a vul­ner­a­ble con­sis­ten­cy and may break more or less.

The bidet can be used to grasp the cast­ing cone, lift the fig­ure out of the mold and bite off the excess met­al that can return to the crucible.

More­over, the abra­sion resis­tance of a mold well treat­ed with talc and not exposed to tem­per­a­tures far in excess of 300 degrees Cel­sius will be sig­nif­i­cant; and sev­er­al hun­dred casts will be able to be tak­en with­out putting their mark.