Restoring dry Nylon

[Dadio]

A lot of you probably already know this but for those who don't Nylon has a water content that dries out over time , when it dries it becomes more brittle and hard that originally intended . Now many of the cars we collect and restore used a lot of Nylon parts , gears , suspension arms etc were all quite commonly made of nylon , this represents a problem for those of us that still wish to drive our cars as they have had 30+ years to dry out and become brittle .
I did a bit of surfing to see if nylon could be rehydrated , I'd previously heard that you could boil old nylon parts to restore them but never tried it and now I'm fairly pleased I didn't , what my reading up taught me was that yes nylon could be rehydrated to restore its original property's and that hot water would be absorbed quicker , however the water should be no more than 60°C or you could detemper or warp the part , also the time suggested was in the order of 24 hours , 48 hours in cold water .
I recently received a set of BNIB Yokomo ZY-834B gears and want to use at least one of them so I thought I'd have a go at rehydration , one web site suggested sharing the parts together and listening to the sound they made in order to assess dehydration so I gave it a go and it was a very hard sharp rattle , after 30+ years I'm not surprised .
I don't have a method for heating water to 60° for 24 hours so I used hot tap water that I changed as it cooled while I was about the house and just left them cold soaking when I was out , I gave them 48 hours ,dried them out and repeated the rattle test , I was quite surprised by the difference , much duller and even the feel of them , they had that slightly greasy feel of new nylon , I was genuinely supposed , hope this helps someone .

[GoMachV]

That’s great to know, thanks for sharing!

[XLR8]

Could you have used a crockpot on the lowest setting?

[Dadio]

If you have a method of keeping to 60° or under it should be fine , I considered aquarium heaters or baby bottle warmers but in the end it only speeds things up , cold water just takes longer . If you knew the exact formulae of nylon then you can find the absirbsion rate , it basically depends on thickness ,temperature and grade but leaving it longer is not detrimental so if it's a thick piece then just leave it in for a few days to be sure , it's only 1-3% by weight depending on the type of nylon .
I should mention this has no effect on colour at all so the parts are still tan in colour , I have no idea how peroxide soaking to whiten nylon affects the strength , my gut says no don't whiten if you want to use the car but that's just my gut feeling .

[XLR8]

Thanks. Those are good suggestions.
I could imagine us storing our spare vintage nylon parts in old pickle jars filled with water.

[TRX-1-3]

.........I could imagine us storing our spare vintage nylon parts in old pickle jars filled with water.......

: The "next level" of R/C OCD!! Someone is filling pickle jars right now.

[Dadio]

He he ! Seriously though once rehydrated they should be good for years unless you live by the sea where salt can leach the water out quicker .