28 replies to this topic

[bbr]

"Molecular mobility is increased through the absorption of water. The increase in spacing between nylon molecules lowers the secondary forces allowing easier translational motion. This is the major reasons for the change in physical properties discussed above. There is less resistance to applied stress from the decrease in intermolecular friction. The change in molecular mobility is significant enough that molded nylon parts can relieve molded in stresses as they absorb moisture."

Found from a plastic company

[Gator Bob]

Does boiling Graphite guides make them go faster too ?

[TSR]

Nylon is a very brittle material. In the old days, SimCo made the "Jet Flag" guides using a mix of Nylon and Vinyl, making them soft enough to resist shaft or blade fracture.
When Associated took over, the mix was changed to straight Nylon, and there is a history of pro races with guide breakage through the 1970s.
By 1971, we at Tam Checkpoint, boiled all our guides while also dying them with green stuff. I cannot recall a breakage of any guides in the team the whole time I was there.
We only did it once, for about 20-30 minutes in hot water. Never had to do it again.
Once cooled (takes whst, 3 seconds! ) I cut vertical slots on the blade with a thin Dremel disc, and with needle-nose pliers, bent each subsequent tiny blade one to the right, one to the left, so that only the lower edge of the blade would contact the side of the slot. It helped keep the cars from de-slotting if it tried to "push", especially in the surviving AMCRC tracks built with a "T" slot. Worked great for me, at a time when we were truly discovering serious speeds.

[swodem]

At work we manufacture a hardhat that has a nylon harness

The people who mould it for us boil the nylon components after they are moulded, otherwise they are very brittle.

Following the boiling process the parts are very flexible and virtually unbreakable