Formula 4 Steering Wheel Grip Moulds and Mould Stand

Moulds and Moulding stand for the SimbaSim F4 Steering Wheel 

Contains the 4 moulds (two for each grip) and a moulding stand. You'll need to attach the stand to the wheel plate with a M5 25mm bold and nut.

Moulding Grips with Polyurathane Resin

I use the 'Polytek Poly PT Flex 60 Liquid Casting Rubber' which is available here: https://www.mbfg.co.uk/pt-flex-60-rubber.html - you will also need the black dye (which is available here: https://www.mbfg.co.uk/polytek_pigment.html). This has a pot life of around 4 mimutes, so make sure you have everything prepared before you mix up the rubber.

You will need:

• Water washable resin

• Cornflour

• Sanding paper from 180 to 1000 (sanding sponges are ideal for this - https://alishort.com/CUJ6 )

• Hot glue gun

• Spring Clamps

• 2x 500ml plastic measuring jugs for part A and Part B

• 300my syringe

• 2ml syringe for the dye

• Weighing scales

• Rubber mallet

• Demoulding wedge or car trim removal tools

• Silicone spatula for mixing

• Scalpel

• Side cutters

• Kitchen Paper

• Mould release silicone spray

How To Cast Rubber Grips tutorial

Prepare the Moulds

• Print off with 4 walls, 15% infill

• To fill in the layer lines, use a mix of water washable resin and cornflower (mixed 1:1, just paint it on and put on a window ledge to cure in the sunlight)

• Sand up to about 400 grit

• Apply high build primer and sand to around 1000

• Sand the mating faces flat to about 1000

Prep for moulding with Polyurethane rubber

• Spray with mould release silicone and allow to dry

• Mount onto the plate and stand upside down (the moulds fill from the bottom) and ensure the front moulds are on the countersunk side of the plate

• Use spring clamps to hold them moulds on, and make sure they are aligned correctly

• Use a hot glue gun to seal the edges of the mould

Mixing and injecting rubber (for one grip)

• Pour out 200g of mixing rubber (100g of part A in one container, 100g of part b in another container)

• Add 2ml of black dye to part B and mix (check the instruction for whichever dye you buy - different colour require different ratios)

• Add part A to part B and mix for no longer than 30 seconds. Mix at a steady pace, if you over mix the pot time will reduce

• Draw the rubber into a 300ml size syringe

• Wipe the nozzle of the syringe

• Inject steadily into the mould

• Allow it to set

• Use demoulding wedges or car trim removal tools (you can 3D print these) and a rubber mallet to remove the moulds

• Trim the flash off of the grips with a scalpel and side cutters