Thanks for all the advice, guys. It gave me a lot to think about.
My original plan was to just use oogoo and some "Friendly Plastic" or the like for making small pieces, but after your words, I think I'll just have to bite the bullet and buy some reputable silicone/resin starter kits instead.
Thanks.
Absolutely going to be worth your time and money to buy proper stuff and have a play.
A while back I watched a heap of YouTube videos where these guys were "cheating the system" using caulking silicone for making a mold. I was inspired and decided to give this a go given 300g Clear Silicone is $4.95 at Bunnings Verses the $60+/KG for a proper molding silicone.
Yeah sure, at $4.95 a tube x 4 gives 1.2 KG for less than $20. Then you need a solvent to get rid of the adhesive or it will stick to your part and be total bi-otch to demold, it even lets go at all.
On the videos, they used caulking silicone mixed with Benzine which is basically a lighter fluid - which Bunnings does not sell. A tabacco shop maybe? Anyway, so then I tested various chemicals that will mix with this. Out of Kero, Metho, Turps and Acetone, the two that worked for me were Turps and Acetone. Turps is cheap, Acetone, not so. Turps leaves the silicone feeling oily and smells really bad. Acetone leaves no smell or oily feel, but also costs $11.00 for a litre bottle (now you are up to $31 for DIY 1.2KG kit).
After a heap of experimentation, it turned out that caulking silicone + Acetone (mixed at 10% of the weight of the silicone) worked pretty good. You can use more acetone, but there is no gain as it just takes longer to evaporate and the condensation of the evaporation is what sets the silicone. Potlife was about 6min MAX, which is pretty short, about the same as PinkySil. The problem is that I ended up with a heap of waste - usually about half the tube at a time. The best way to mix it was in a glass jar, so you add the silicone, add the acetone, put the lid on and shake the jar like a mad man. The silicone goes from a glue to thick but paintable gel, but it does not pour very well so it tends to trap air. Given the 50% wastage, I was basically back at $60/KG, so decided to save myself the grief of hit and miss and just buy the real stuff that I know works.
Other videos show them tip silicone into soapy water and mold it with their hands. The water prevents the air from curing and the soap apparently breaks down the adhesive. They can then make a one part mold but the cure time before demolding can be as long as a week. There is also a heap of videos showing them mix silicone into baking powder or corn starch. The end result here is a moldable putty at also takes days to cure.
Using the real products and you have a good idea of how it will work out.
Here is my stash I picked up today. A combination of silicone and resins at about $500 here, but enough to last the next month. Because these products are for commissions, I know I will get a positive return here.
