Resin molding of figures

What is Resin?

Resin is a mate­r­i­al formed by blend­ing 2 liq­uids (also called an A and a B com­po­nent). It will cure as a chem­i­cal com­pound when A and B come into con­tact with each oth­er

How Dan­ger­ous Is It?

Because Resin con­sists of Iso­cyanate, which emits tox­ic fumes in the liq­uid state and is relat­ed to var­i­ous oth­er epoxy mate­ri­als — MUST — before you even start, make sure you have the fol­low­ing 3 things at your dis­pos­al.

1) Rub­ber gloves

Remem­ber too!
You should not wear the same rub­ber gloves for a long time at a time, as the vapors from the mixed resin over time will also pen­e­trate these. Ie that gloves should be thrown out after use.

2) Very! - Very! - Impor­tant!
A good and prop­er ven­ti­la­tion! - due to the tox­ic fumes of Resin while it solid­i­fies

3) If your ven­ti­la­tion is not suf­fi­cient or you work with resin in larg­er quan­ti­ties, always use a res­pi­ra­tor fil­ter mask.
And if it’s real­ly bad (Yeah Baby, we’re talk­ing saftey­out­fit mod­el “Out­break” star­ring Dustin Hoff­man)

Impor­tant!

When you have fin­ished work­ing with resin, remem­ber to wash your hands thor­ough­ly with warm water and soap, even if you have been wear­ing gloves. The use of sol­vents for this should be avoid­ed.
If one is unlucky to get the liq­uid resin on the skin, it is almost impos­si­ble to remove again. One can pre-empt the prob­lem by using a skin cream before start­ing to cast. In such a dish soap or a good hand clean can han­dle most of the clean­ing — oth­er­wise the resin must be worn off.
The prob­lem is that resin hard­ened on the skin sticks to it and is water resis­tant. So the soapy water can­not enter between the plas­tic and the skin and sep­a­rate them.
If the acci­dent has occurred, the best solu­tion is to make the skin sweat so that water (sweat) comes between them. A trip in sauna is an effec­tive means and in the absence of bet­ter, 10–15 min­utes with the hands in a dish of very hot water can also solve the prob­lem (but it is always bet­ter than get­ting liq­uid tin on your fin­gers!)

How to mold with resin?

Gen­er­al­ly, it is cast in resin, which one would cast with tin, ie. by pour­ing the liq­uid mold­ing mate­r­i­al into the mold and then allow­ing it to cure. In most cas­es, it is there­fore pos­si­ble to use a mold in which tin is cast, also to cast resin.

You start by mix­ing the two com­po­nents A and B togeth­er in a plas­tic cup, glass or the like,
In most cas­es, the ratio between them must be fifty-fifty (A 50%, B 50%) or what­ev­er the man­u­fac­tur­er indi­cates.

Impor­tant!

Be care­ful with dos­ing and stir­ring, as oth­er­wise the result is use­less.
It is a good idea to use 2 syringes (with­out nee­dles) (one for A and one for B) to make as accu­rate a dosage as pos­si­ble. These are avail­able at phar­ma­cies in var­i­ous sizes.
You can choose to mix fillers if you mold very large items. But here I will, how­ev­er, refer to what the man­u­fac­tur­er indi­cates in the instruc­tions for use

Impor­tant!
Com­po­nents A and B are sen­si­tive to mois­ture and there­fore mold­ing in damp rooms is not pos­si­ble

Once the two liq­uids have been thor­ough­ly stirred up with one anoth­er, one can either choose to pour the thin liq­uid resin direct­ly into the mold, or if the sit­u­a­tion requires it to wait until the resin is of a thick­er hon­ey-like sub­stance, which it begins to stay in a few min­utes after the stir­ring has start­ed.

Note! - The time you have a thin cast­ing mass is thus very short — there­fore, small por­tions. On the oth­er hand, a mold can be filled sev­er­al times. It is impor­tant to avoid air bub­bles in the resin if you want the best pos­si­ble cast­ing result.

There­fore, by using either a tooth­pick to prime / dab the air bub­bles or with vibra­tions (e.g. with the aid of a shak­ing brush), these air bub­bles can be removed while the liq­uid is still in a thin liq­uid state. This pro­ce­dure should usu­al­ly be done when the resin is just poured into the mold.

Once the liq­uid resin has been poured into the mold, it must stand and hard­en, prefer­ably in a rea­son­ably ven­ti­lat­ed room tem­per­a­ture room.
The cur­ing of the mate­r­i­al — in con­trast to tin — must take place for some hours depend­ing on the tem­per­a­ture and what the man­u­fac­tur­er pre­scribes. I myself pre­fer to leave it for 24 hours. (Then I can kill time play­ing Jack Bauer while I wait).

Var­i­ous cast­ing tech­niques

As with tin cast­ing, trav­el cast­ing has dif­fer­ent cast­ing tech­niques. And I will there­fore briefly describe four dif­fer­ent trav­el sup­port tech­niques I know of.

The first, which is the tra­di­tion­al and most com­mon method of back mold­ing, is to pour the mixed liq­uid into an open sin­gle mold

The oth­er is to pour the mixed liq­uid into a 2‑part mold as in the case of tin cast­ing

The third is to pour the mixed liq­uid into each half of a 2‑piece mold, allow it to hard­en for a while and then squeeze the two halves togeth­er.

The fourth is to pour the mixed liq­uid into the deep­est half of a 2‑piece mold, and then squeeze the two halves togeth­er.

 

Pro­cess­ing of mold­ed items.

When the resin is cured, it does not release more tox­ic fumes. But when pro­cess­ing the mate­r­i­al, its dust par­ti­cles are just as dan­ger­ous. So, it is rec­om­mend­ed to wear a dust mask when it is fil­ing in it.

Larg­er holes in the work­piece can be filled with poly­di­ene or oth­er filler. If you cut it, it is impor­tant to note that it can be a brit­tle mate­r­i­al, depend­ing on the type of trav­el, to work with and there­fore can eas­i­ly break. But usu­al­ly this is no prob­lem unless you work with small thin sub­jects.

To bond items with one anoth­er, you use super glue or con­tact adhe­sive

For paint­ing, ordi­nary craft paint (oil or water-based) is used with­out prob­lems

 

Advan­tage

The long cur­ing time and the ini­tial high vis­cos­i­ty of the resin make it eas­i­er for the mold­ing com­pound to run out at all ends and edges of the mold.

This means that the use of air ducts in the mold is not nec­es­sary to the extent that it is for tin cast­ing (per­haps in cast­ing tech­nique 4)

One can much eas­i­er make small thin and com­plex items.

Do not stand with 300 degrees of hot tin

Plas­tic pipes / rods / parts can be cast into the work­piece such as gun pipes for a gun tow­er

Dis­ad­van­tages

Unfor­tu­nate­ly, a mold cast­ing can­not be remod­eled or restored (unless the air­craft is sup­posed to have a detached wing)

The num­ber of mold­ed items in one day is lim­it­ed

Improp­er mix­ing ratio and agi­ta­tion can result in poor mold­ing results

Only super glue and con­tact adhe­sive can be used to bond

(and yes, as men­tioned before — very tox­ic)

 

Wish List

Work­ing Mate­ri­als:

Resin A and B com­po­nent
Pla­si­crør / rods / parts
Mold­ing tools: 2 syringes (one for A and one for B)
Plas­tic cup and the like for stir­ring (prefer­ably with pour­ing spout)
Studs (prefer­ably with a flat end)
Tooth­pick (or shake pow­der)
and one or more molds

Tools and oth­ers for prepa­ra­tion:

Scalpel / hob­by knife and the like.
File / sand­pa­per and the like
Pol­ly­fyl­la and the like. (only need­ed for bad casts)
Super glue or con­tact adhe­sive

Safe­ty equip­ment:

Rub­ber gloves
eye Pro­tec­tion
Breather
Skin cream
Dust mask (res­pi­ra­tor for longer / larg­er cast­ings)