[munter]

Lots of us have done it. During lockdown I opened my two pots of Smooth on Vytaflex that I had purchased some twelve months earlier and got out some old moulds and made some new ones.
I began casting using my experience from two earlier episodes.

1) It is messy
2) The one part (yellow pot part B) starts slowly going off as soon as you open the pot.
3) Use a syringe to inject the mixture, I used a 10 ml one mainly due to what I had and the nozzle size.
4) Choose tires to repop you like and use a lot. 
   I wanted tall profile narrow vintage tires, tires to fit the Slotit 14mm rim, high profile wide, F1 wide donuts, SCX Escort and Fiat Abarth replacements.
5) Clean the rim and lids carefully after use because any residue on the rim starts to cure and getting the lid off the yellow pot will have you speaking bad words before all the contents are used. 
6) You will have failures which is disappointing after waiting twelve to sixteen hours for demoulding. Some failures can be repaired when you mix and cast next time but some will go in the bin....my success rate improved as I learned my syringe technique.
7) The black pigment is extremely strong so take care not to get it on you, your clothes or anywhere it shouldn't be.

This pack cost me about 40GBP. I have given a few sets away but now have a supply that should last me a while.

Pictures can now speak

[JasonB]

They look good.

What do you make the moulds out of?

[munter]

They look good.

What do you make the moulds out of?

Thanks Jason...for moulds I use a 20 shore hardness silicone

[HelioMagalhaes]

Hi Jason, thank you for sharing your experience and good results. It's hard to find some detailed information about this as you did. That's why I wanna discuss a little bit more: 
- How did you make the mould?

Here's what I am about to do it.....

MY GOALS
- Replace the Carrera's melting tyres (pure fast UV decomposition) to have my cars running (it's hard to find in Brazil Carrera tyres, and buying NSR/Slotit tyres it's expensive because you have to buy the rim together because the tyres don't fit on Carrera original rims).
- I don't need a super ultra grip, because I like sliding on the curves (so does my kids), and I don't and ultra high velocity...the faster they go, the hardest they crash and destroy.
- I might try make urethane tyres for testing after I make my silicon rubber tyres.

MY FIRST TEST
Use silicon rubber shore A 10 for the mould, and silicon rubber shore A 55 for the tyres.

THE MOULD
I was inspired by this video https://www.youtube.com/watch?v=fHz4-ErV..._rel_pause
But the tyre this guy uses (3D print) has a really wide flat face so it's easy to glue it at the bottom (to avoid the tyre floating as you said).
My first try will be to cut off the bottom of the plastic cup, and use a not so strong tape to cover it, and them place the tyre inside. well, let's see if it can hold down the tyre.

SYRINGE
After mixing the catalyst for the tyre silicon ruuber, I will use a syringe to inject in my mould, but before injecting it, I will position the tip of the syringe upwards, use my finger to shut the syringe hole, and pull the syringe to create a vacuum inside. All the air will go up as if it were a vacuum chamber. Then I am going to slowly release my finger on the hole.


I will update my results soon.