Here's a summary of events in the dramatic sense. Used smoothon 321 urethane.
Right after I got home from work my wife went to pick up some dinner because she wasn't in the mood to cook. So I figured I had a good half hour. Just enough time to mix up some urethane and set up a few wheels. So she gets in the car, takes off and I hustle off to the garage, grab the urethane and start mixing up a batch. Everything looks good. I had the molds all ready and this just was too easy. So I pour the urethane into the molds and stand back like a fool admiring his work. Then it hits me. Panic !!!!!!! Fool !!!! You skipped the mold release spraying part !!!!!
Now it starts looking like a "I Love Lucy show" as I pour the urethane back into the bucket from the molds. Then I drain the molds on a towel by tipping the molds upside down. In a panic, I grab some other molds I had waiting and quickly spray mold release into them. Sloppy and quick .... Not to mention all the urethane that slopped out the side when I picked up the molds to pour them back into the bucket. I of course had the urethane up to the lip. What a mess !!! Plus I didn't have rubber gloves so I'm getting this stuff all over my hands and it's hot. It just keeps getting worse. I quickly pour the urethane back into the other molds and had a lot left over but no time to dump it. I then grab a pack of paper towels and start wiping the slop out of the molds that I didn't have any mold release in. By this time it was the consistency of snot. And it's all over me !!!! I was able to get most of the stuff wiped out of the molds but not everything. I fear those may be ruined. I can always make more but ... Then I rush to the bathroom to clean the formulating snot like substance off my hands. Everything is in chaos as my wife pulls up to the garage with our food. She walks in as I'm staring at the hardened mess of urethane in the bottom of my good bucket that I never did get to dispose of properly. Plus the mess on the table. She shakes her head and walks into the house with our food.
I finally pull the wheels out of the molds and they are all bubbly. They actually came out ok other than the all the bubbles in the urethane. I must have done something else wrong too. Maybe pouring it out of the rubber mold and back into the bucket did that. The stuff gets hot. I guess this is how you learn stuff.
After dinner I slowed down and after cleaning up the mess, tried again with much better results. However the pieces I really wanted (Brain cup and neck bracket) didn't come out very well. I may need to create better molds. The 2nd batch of wheels came out fine though. Some bubbles but not as many. This time we did them indoors because the humidity is one of the reasons for bubbles.