I think the first time anyone asks about cleaning a yoyo bearing, they’re always offered the warning: “make sure you’re bearing is totally dry before you put it back in since mineral spirits can damage plastic yoyos.” Sounds familiar, right? Anyway, the more I heard that, the less convinced I was that this statement had any real science behind it. I set out to test the statement myself.
Here is some unnecessary chemistry to make me look smart:
Many plastic yoyos are made out of either Delrin or Celcon. Celcon is a copolymer of Delrin, which means the long polymer strings that it’s made out of have Delrin bits (monomers) interspersed in some way (Wikipedia didn’t say which way) with some other monomer. I think in Celcon the other unit is cyclic ethers and even I don’t know what that means so I’ll stop talking science here. (woohoo!)
Anyway, the test subject was a yellow YoYoJam KickSide with a bent axle. Since I couldn’t test the tiny imperceptible damages from teeny drops of paint thinner that might affect play in a standard bearing cleaning situation, I decided to make pretty darn sure the damage to my yoyo was perceptible.
In my first trial, I filled the cup side of the non-axle half of my KickSide with about a 1.5-2 tbsp. of mineral spirit based paint thinner and let it sit around for 20 minutes. When I compared it with the untampered half, I found no difference. Second trial was the same deal, but I totally forgot about it for 2 days. Again, no difference.
Initially, I’d planned to do more than 2 trials, but 2 days is a freakin’ long time and I think that’s pretty darn conclusive in terms of evidence. It’s a shame I didn’t have a Delrin yoyo to test this on too since that conceivably could be more reactive since it doesn’t have those cyclic ethers in it.
I guess though, the point is: don’t worry about getting mineral spirits on Celcon yoyos.
Interesting thoughts, I always though that by letting the mineral spirits soak into the yoyo it might make the yoyo brittle and thus more likely to shatter if the yoyo were to hit the floor or anythig solid.
You should try this experiment with other cleaning solvents such as the lighter fluid that some people use and if you can get your hands on some isopropal alcohol.
I know for a fact that with the alcohol it can damage some plastics such as perspex it makes the plastic look as if it has thousands of cracks through it.
All of those are good ideas. I need some lighter fluid anyway! It makes sense that alcohol could do some damage since it’s polar and according to wikipedia, Delrin’s vulnerable to oxidation and stuff like that. Plastics are nonporous though, so the mineral spirits couldnt’ve soaked in (in the regular sense), but there might’ve been some diffusion. I’ll test the strength with a hammer next.
I’ll test the strength with a hammer next.
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Only if you dont want that yoyo any more.
If you could try the alcohol and the lighter fluids tests before attempting to hammer it would be better
yeah destroying the test subject before you can do all the tests could be a backwwards step. Also just an after thought with only using the one yoyo with all these solvents how can you tell which solvent has done the damage, some of the effects may not present themselves immediatly after the initial treatment.
yeah that would have been easier but, where the fun in looking up some facts on the net when you can experiment and find out the info by actually doing it.
Yeah dude! I just did science! Besides, I wanted to prove that Delrin wouldn’t react and I don’t know enough chemistry to explain what was happening. Without an explanation, it really wouldn’t have looked like solid proof: just speculation.