home-built bushings?

[bucksaw87]

so i got some old rollerblade wheels at home just sitting around collecting dust. i was thinking of melting them down and building my own bushings. my question is, does urethane lose its springiness and elasticity when it's heated to that extent?

[HerBDerb]

does urethane lose its springiness and elasticity when it's heated to that extent?

I'm not sure excatly what will change and how it will be affected, but heating/metling 'thane does change it's propeties.

[bredler]

I don't think urethane melts down very well at all. Most people who make bushings core out old wheels. When bushings are made commercially, the urethane is mixed up with different chemicals and it's poured into a mold (mould?). So it's not like you melt all this stuff down and pour it in then it solidifies. You actually mix chemicals together, they react and expand in the mold (mould?) and solidify. So I doubt that melting down old urethane for bushings would work.

[satori]

does anyone know how to make urethane? what's the general 'recipe' with ingriedients/preperation?

[bucksaw87]

so basically speaking, this is a bad idea and should never be spoken of again.

i had some other ideas too:
take and chop a hockey puck up for a bushing
go to autozone and buy some urethane suspension bushings off of a car
rubber stoppers from the hardware store

[Dubester]

i know a luger that uses car bushings on his luge.. a lot of urethane.

[Sleeveless]

I like to tinker with things too. But, bushings are really pretty cheap, $3 - 6, and are available in some many shapes and durometers. Play with dialing in your own set up using existing products. That should keep anyone busy for a long time.

I think with skateboards the best place to start tinkering is with the deck. You could redesign an existing deck, i.e. schlong or mini, or build one from scratch. There's lots of room for new deck designs. And, board building is a lot of fun.

Next, if you have access to a machine shop you could work on designing custom trucks. Imagine the possibilities, especially with all your knowledge setting up skate bushings!

Finally, with your machine shop skills you could make molds and start making wheels and bushings. But, I think urethane is pretty toxic stuff. There must be a reason skate companies farm that work out to casting companies.

Take a trip over to the board building section of this site. You'll find lots of inspiration.

[Geezer-X]

The urethane used for wheels and bushings begings as a 2-part compound; a resin and a catalyst. These are generally weighed out using an analytical balance, heated, mixed, and poured. Once the catalyzed mixture is fully polymerized, there's no going back. The hardened urethane can be cut, tooled, machined...but it doesn't melt and harden in the same way as thermoplastics which are used for injection molding.

In addition, urethanes are nasty stuff. In the uncured form they're full of isocyanates, which are nasty neurotoxins, and the dust from machining, once in you lungs, is there until you're cremated or the bugs eat your body. In fact, if you breathe urethane dust, eventually die and get buried, and then bugs eat your lungs, the urethane dust will end up in bug poo.

[dden]

The urethane used for wheels and bushings begings as a 2-part compound; a resin and a catalyst. These are generally weighed out using an analytical balance, heated, mixed, and poured. Once the catalyzed mixture is fully polymerized, there's no going back. The hardened urethane can be cut, tooled, machined...but it doesn't melt and harden in the same way as thermoplastics which are used for injection molding.

In addition, urethanes are nasty stuff. In the uncured form they're full of isocyanates, which are nasty neurotoxins, and the dust from machining, once in you lungs, is there until you're cremated or the bugs eat your body. In fact, if you breathe urethane dust, eventually die and get buried, and then bugs eat your lungs, the urethane dust will end up in bug poo.

MMM bug poo...

[bucksaw87]

hmm...i actually know a few guys in the tool and die/machine shop business...i'll have to talk to them about trucks and different grades of urethanes and stuff...maybe they can hook me up with a couple nuggets of urethane that i can lathe into stims or bushings

[satori]

The urethane used for wheels and bushings begings as a 2-part compound; a resin and a catalyst. These are generally weighed out using an analytical balance, heated, mixed, and poured. Once the catalyzed mixture is fully polymerized, there's no going back. The hardened urethane can be cut, tooled, machined...but it doesn't melt and harden in the same way as thermoplastics which are used for injection molding.

In addition, urethanes are nasty stuff. In the uncured form they're full of isocyanates, which are nasty neurotoxins, and the dust from machining, once in you lungs, is there until you're cremated or the bugs eat your body. In fact, if you breathe urethane dust, eventually die and get buried, and then bugs eat your lungs, the urethane dust will end up in bug poo.

sooo say i was trimming a cured, store bought busing and breathed in some of the shavings... no biggie?

[shapeshifter]

biggie....

[bucksaw87]

so...when you're lathing bushings, do you just put a respirator on? or would a bandana or one of those light-duty dust masks (like $5) from the hardware store work?

[shapeshifter]

a respirator would be highly recommended because of the noxious gasses that are created along with the dust.

[satori]

hmm well i wasn't wearing anything when i trimmed bushings recently- i thought the particles were only dangerous in their uncured form. i dunno if i ate/breathed in anything, but i seem to be ok.

[Lee W]

hmm well i wasn't wearing anything when i trimmed bushings recently- i thought the particles were only dangerous in their uncured form. i dunno if i ate/breathed in anything, but i seem to be ok.

Neurotoxins and carcinogens kill you slowly, unless of course you grind up a few sets of wheels and snort them.

[satori]

well lesson learned then, i guess a medical mask is a good idea. but i don't need to see a doc or anything right?

[shapeshifter]

not unless you notice an immediate reduction in your functional capabilities. what's done is done. we all find ourselves breathing a little epoxy, fiberglass dust, etc. at some time or another. it sounds like you were not in such a heavy dust ladened enviroment for too long anyway. keep aware of it in the future so as not to exacerbate the situation.

[Lee W]

Nah probably not, I really have no idea how bad that stuff is for you. Just those types of chemicals the more you are exposed the worse off you are. In certain jobs it's just a fact of life that you are exposed to those chemicals daily. Just when you do things like that with urethane, try to protect yourself as much as possible.

I really don't know the long-term affects of these types of things too much. All I know is if it's dangerous, keep it in the fume hood and wear gloves. And waft instead of sniffing...otherwise you pass out ---- that's as much as I know for dealing with dangerous chemicals in general. In your case, just wear a mask and try to not do it where the stuff will stick around for a while (ie. a closed garage). Once again though, if you are concerned search it on the internet and you'll have a lot more specific knowledge. Just try to limit exposure, that's the main thing.

[satori]

ss+lee, thanks 4 the advice. it was in a very well ventilated area (outside garage) so i'm not worried about the gases, but more than likely i snorted a bit of shaving.

i am having a hard time memorizing stuff for my exam, so i must be a lost cause.

did u know that 'franz ferdinand' was an austro-hungarian leader whose assassination likely sparked WWI? and 'john stuart' mill was the original creator of liberalism? pop culture is lame compared to real history.