Making a mold with RTV Mold Silicone, incl. 5 super tips!

The casting process has been discussed here before. In this Blog I will show you how we make a mold with RTV Mold Silicone.

The starting point is a ready-made shad or a self-invented one made from clay, for example. I like the latter the most. The first is recommended to start with. I make the masters Fimo Clay  This is a type of clay that does not harden on its own. This must be baked for 30 minutes in the oven at 100 degrees Celsius. You can then sand it or edit it with a knife.

Step 1 Glue the master(s) to a piece of aluminum foil.

Step 2 Build a suitable frame around it with LEGO

Step 3 Attach the bottom of the mold to the foil.

I do this with Fimo Clay or with Plasticine. I wouldn't use glue. This does not improve the shelf life of the Lego.

Step 4 Press the clay onto the foil.

I use the back of a teaspoon for this. There is often not enough room for fingers.

Step 5 Prepare the required amount of LUPA RTV Mold Silicone.

You can easily calculate the quantity in ml by calculating length x width x desired height of the mold. In this case that was 13x 8x 2.5cm = 260ml. I pour this into a measuring cup and then add 5% activator. Then stir well again. I use a fork for this.

Step 6 Fill the mold and wait 24 hours. The Silicone mold should now have hardened.

Step 7 Remove aluminum foil

Turn the mold over and carefully peel off the aluminum foil. The mold is now ready for use.

Step 8 Break down mold and carefully remove clay masters..

Step 9 Remove clay edges

Carefully remove the clay edges. For example, you can use a knife for this.

Step 10 Ready for action!

All details are in the mold. Ready for years of use!

The family together :)

The first castings. For this I of course use the LUPA Plastisol / dye and glitter from our range

Tips & Tricks 

1. 'I didn't produce enough silicone…' : Don't panic, make new silicone. Even after several days, the second layer will simply adhere to the first layer of silicone.
2. 'The silicone runs out from the bottom of the container through the cracks' : Wipe away the silicone with a paper towel, take a piece of plasticine and spread it over the 'leak'. It is a good idea to also carefully seal the outer edges of the Lego container with plasticine or possibly. with fimo clay before filling the container with silicone.
3. 'How much silicone should I make?' Suppose your container is 4cm x 20cm x 4cm (lxwxh), then you need 4x 20x 4 ml = 320ml silicone to completely fill the container.
4. 'Can I reuse the Silicone?' You can't melt it down again, what you can do is cut old molds into small pieces and mix them with the new silicone.
5. 'My workplace is a mess, there is sticky silicone everywhere' Wait until the silicone has hardened, then you can remove it straight away. So don't use a cloth if it hasn't hardened yet!

How cool is it if on the first test day an asp box (87.7cm) makes a mistake in your shad!

If you are interested in experimenting yourself... Follow the link and you will automatically find everything you need: https://www.lureparts.nl/nl/alle-onderdelen-per-kunstaas/softbaits-shads-maken.html

also look at this article where you can learn how to make soft baits with an injector

If you have any questions, please let us know: info@lureparts.nl

Catch and build them,

Oscar Wissink

Lureparts.nl