Restore old hard rubber parts


Information and questions on GL1200 Goldwings (1984-1987)
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tbeiler
Posts: 203
Joined: Tue Oct 18, 2011 9:25 pm
Location: Waterloo, Ontario, Canada
Motorcycle: 1986 Goldwing Aspencade,
1985 Goldwing LTD
1983 CX650 Turbo
wanted badly CBX 79-82

Restore old hard rubber parts

Post by tbeiler »



Hey All, just thought I would pass on how I restored old, hard, inflexible rubber parts.
The parts I worked with were the intake boots (carb to head) and air intake boots (air cleaner to carb), on my daughters bike (84 CB650 Nighthawk).
Was considering buying new rubber parts but they are obsolete, so I thought I would give it a shot to try and restore them.
Got this info online.

Use a mixture of methyl salicylate, otherwise known as wintergreen oil and isopropyl alcohol.
Ratio is 1 part wintergreen oil to 3 parts alcohol.
I used a 300 ml container of wintergreen oil and 900 ml of alcohol.
The oil is a bit pricey, $35 Cdn for the 300 ml size, but is 100% pure oil.
The isopropyl alcohol any drugstore will carry, but mine came from Costco, four 500 ml bottles for about $11 Cdn., it was 99% alcohol.

I put the rubber parts into a resealable plastic bags, poured in the mixture, 600 ml per bag, put the bags into a larger Tupperware container and stuffed some rags inside the Tupperware to put pressure on the bags to bring up the level to cover the parts. I only had a finite volume of fluid, 1.2 liters.

Left my parts in for 3 days, although checked them after each day. You could tell they were getting softer and more flexible with time.
After 3 full days, they are much more flexible and shiny. They do like new.
Big note to mention is that this mixture does not swell the rubber parts.

Did see some other methods online like ATF or brake fluid, but these methods apparently swell the rubber.

Got a few more rubber parts in the mixture and will install them in a few days.

Cheers



Good Hondog
Posts: 196
Joined: Sun May 14, 2017 6:56 pm
Location: Calgary, Alberta, Canada
Motorcycle: 1980 GL1100 Interstate

Re: Restore old hard rubber parts

Post by Good Hondog »

That's a great tip. Thanks for sharing that trick with us. I've struggled with that same problem restoring old vehicles and trying to save obsolete rubber pieces. What do you think the shelf life would be on that mixture if you kept it in a tightly sealed container? Does the liquid turn black as the rubber parts soak in the mixture?

tbeiler
Posts: 203
Joined: Tue Oct 18, 2011 9:25 pm
Location: Waterloo, Ontario, Canada
Motorcycle: 1986 Goldwing Aspencade,
1985 Goldwing LTD
1983 CX650 Turbo
wanted badly CBX 79-82

Re: Restore old hard rubber parts

Post by tbeiler »

The liquid has not turned black, although there is a little bit of black residue in the bottom of the container.
I did pour the mixture into a tall plastic container with a lid that seals very well to store it.
I will be checking it frequently, since I don’t know if the fluid will eventually affect the plastic.
On second thought storing it in a glass container might make more sense.

Another tip that I recall is to wash the rubber parts with warm water and soap and rinse well, this way
introducing less impurities into the fluid.

Cheers

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dingdong
Posts: 3853
Joined: Thu Apr 08, 2010 8:35 am
Location: Oklahoma City
Motorcycle: 1976 gl1000
1993 gl1500A
2004 NRX1800 Rune SOLD

Re: Restore old hard rubber parts

Post by dingdong »

Please check back at a later date. I would like to know if the process is long lasting or short lived. Thanks.



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