Making Rubber molds

Here we start to see how I make the rubber stamps so I can make resin copies of my model parts. The first thing to do is find materials to make your work. Unfortunately I don't know where to find this things out of Italy but with the help of some search engine you may find something. Attention that there are various type of Rubber and Resins, to start I say you that there are two main rubber type , the first is the RIGID (red color) that is used mainly for metal parts. The second is the FLEXIBLE (fleshly color) very soft and flexible used mainly for resin cast, but nothing stops you by usingtha Rigid one for the Resin parts (the pieces may be flat as details). Here is the list of things you may need:

Wooden plastified plane (50x60cm)
Clay
Sheets of plasticard or other similar material
Artistic Spatula
Spatula for sweets
package tape
Plastic Jug where you prepare the rubber
Talc
hung
big syringe
Silicon rubber

To start we may place a layer of clay on the plastic surface smoothed with a color can as a roller. It must not be too big (you have to use too much rubber at one time if so) and we have to cut away a side as you can see on the next photo. Now we have to make a hard choice , you may decide how to put the piece to replicate on the clay base. I make this way, i look the side with the less end easiest details and I put it down on a hill of clay on the layer and as you see on the next photo I smooth the borders (the clay is the to be the cap of you rubber stamp so you have to push it down easy). Remeber to see also the parts that go downside as a U (look the design)

You have to put some pieces on the same layer as you can see on the next photos , they have to be not so close to each other.

After you have made 2 or 3 layers (do not make to much at the same time, it's easier to do a good job so) you may use the plastic sheets (or other similar material) to make a wall around the layer leaving almost 1cm of distance (look at tho next photos). I have made some standard measure sheets to use with all kind of pieces to copy. I only have to take the best for that layer , looking also on the height of the pieces plus 1cm .

To make the sheets stay togheter I use the package tape and after this I place the little wall around the layer putting also a round of clay at the base so the rubber doesn't go out under the sheets base (look at the photo up and down here). Now you have to prepare you rubber mixture (you may see on the boxes for the percent of catalizer for 100gr. of rubber) and mix it well. After you have a homogenous mixture you may strain to the box taking attention to not move the pieces on the clay as you can see on the next photos.

After you strain the rubber you may leave rest so the air bubbles go out of the block.

After the time signed on your rubber confection for the drying you may turn upside the boxes and take of the clay as seen on the next photos . You may take off all the little pieces of clay (I use a little hard toothbrush , not my personal offcourse ) and after having pushed up the sheet borders and putted some talc on the rubber (so the new rubber you strain on may not glue with other part) You can make a new download of rubber (almost 1 cm of thickness to be very good).

When the second rubber mold is hard you can take out all the original pieces and try with some resin how good has gone you rubberstamp. See the next photos for the resul resin cast copies. (The gray piece is the original one - Kondo Sazabi 1/220 BClub original)





Go to the next part where you see how to puor the resin and make your pieces. GO ==>

M