by mattb » Thu Apr 30, 2015 6:15 am
Making good tires is really not too hard. I happen to like silicone over urethane, but the process is somewhat similiar. Urethane tires are the easiest, use some silicone to glue a tire in a small disposable cup. Back side of tire the part you glue down. Cover the tire with Oomoo or some similiar low shore hardness 2 part silicone rubber. Allow to cure and pull the silicone plug out of the cup or just cut the cup away. The tire may stay in the rubber or may come out with the bottom of the cut. Next mix up some urethane rubber, and spread the new tire mold open and pour urethane in. A coffee stirrer helps to spread the rubber in the mold and get the air out. Let cure and flex it open to remove your new tire. This is as easy as it sounds. You can get all the rubbers and the dye to make the rubber black from smoothon.com. There are nice articles with pix on youtube and all across the web.
Making silicone is a little more involved, if you try to make a mold from silicone or urethane, the silicone you would pour in that mold will either not cure when in contact with urethane or it will stick to the silicone mold. There is a mold release/sealer for two part silicone molds, but it must be painted on completely, 2 coats and allowed to dry overnite. Not sure if it would have to be replaced every time or not. My tire molds are actually machined from aluminum and I put the wheel in the mold with an axle out the back side 1/8 inch hole and a nut to pull it tight. Then I pour silicone in the mold and get a nice tire. Instructions for this are on the internet, also. I have made molds with plastic from the tire only. The tires are hard to get out of this type mold, but it will work, I do use plenty of mold release with the plastic molds. None of this is very hard, but the outlay in money will be $70 or more to get started.
If you like urethane, it is easy to just order up a variety of tires and have some stock on hand!!!