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Softening old hardened rubber.


superhawk996

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It's been discussed here, but I don't think anyone has done it.  The magic ingredient is Methyl Salicylate, AKA wintergreen oil.  The common recipe I found is one part wintergreen to 3 parts 99% rubbing alcohol.  Some dilute it down to 5:1 and it seems to work as well, but maybe slower.  One guy mixed the oil with Xylene and it also worked, but the rubber swelled up a lot.  He said that it goes back to normal after the solvent dries out.  Most say that 3-5 days soaking will do the trick, some have tested leaving them longer and apparently it doesn't damage or over-soften stuff.

 

The carb to airbox boots on the R5 were super hard, the only slightly flexible part was the very end where it fits onto the airbox and it was nowhere near soft enough to put on.  I mixed it stronger than most do, about 2:1, maybe 2.5:1.  After about 12 hours soaking the less hardened area had some noticeable flex in it.  They've now been in about 2.5 days and they seem soft enough to install, but maybe still a little stiffer than perfect.  I'll probably pull them this evening, maybe tomorrow.

 

This was the 12 hour check.  Hard to tell in the photo, but the lip I'm holding is flexed and it would barely bend with pretty strong pressure before.

image.thumb.jpeg.1adb1122b7eea78249c73aa451c32cbf.jpeg

 

New aftermarket boots are about $60, the ingredients were almost $50.  It made me consider new boots, but I've been wanting to perform the experiment.  Plus, all the rubber parts on the bike need love and I should have enough magic potion to do them all.

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Buddy had this issue on an older FZR track bike, bunch of cracks in the boots but still together. He used liquid electrical tape on them, couple coats and reinstalled. Did same for a buddy with an 1985 Honda dirtbike, he was looking to have some guy custom 3D print them until the price was going to be $350. Liquid electrical tape to the rescue. 

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I coated some cracked ones with silicone way back.  If I had to do it today I'd probably use Right Stuff, maybe liquid tape.  I watched a video where a guy used heat shrink tubing, it looked pretty good.

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Yeah - they are becoming more plentiful and less expensive. The one set does not look correct. The other set is 40 years old?

 

I thought the outer cylinders had a bit of a bend to them.

 

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This slips into place easily now.  Amazing that it went from hard plastic back to squishy rubber.  The other boot was half off and one side was compressed between the airbox and carb for god knows how long, that one's still a little tough in that area.  Since the ends were being pressed toward each other that area probably got thicker.  I could probably force it on, but I'll leave it in for another day to see what it does.

image.thumb.jpeg.9266fe311433c8b5017dad57fe235376.jpeg

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1 hour ago, superhawk996 said:

This slips into place easily now.  Amazing that it went from hard plastic back to squishy rubber.  The other boot was half off and one side was compressed between the airbox and carb for god knows how long, that one's still a little tough in that area.  Since the ends were being pressed toward each other that area probably got thicker.  I could probably force it on, but I'll leave it in for another day to see what it does.

image.thumb.jpeg.9266fe311433c8b5017dad57fe235376.jpeg

If you keep it, I'd be interested to see if it stays soft or rehardens.

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I'm curious too and it should be around longer than most vehicles I get.  As many as we see come and go, there are some that don't get posted about.  For once, I didn't go into it with the idea of flipping it, and I just realized that it's the first vehicle in forever that I've put no thought into the cost/resale value of.  It was an emotional acquirement, I just plain wanted to experience it.  When it became a trade with Carlos for something he wanted to experience that just made it that much sweeter.

 

The wintergreen smell is quite strong, in my mind that means that it's evaporating and leaving fast meaning that it would go right back to hard, but dunno.  Hopefully it's just coming off the surface.  People say that "it's a long term treatment", but with no stated timeframe.  The only comparison I've heard is that it lasts longer than softening with a heat gun which is seconds.

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3 hours ago, SwampNut said:

Holy shit.

 

And it bounces right back, it's crazy.  It's not mushy or gummy, just looks and acts like fairly new rubber.

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When I first started handling it I thought it had swollen...well, it did I guess.  It appears to have swollen back to about its original size as both ends fit as I would expect them to.

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13 hours ago, superhawk996 said:

This slips into place easily now.  Amazing that it went from hard plastic back to squishy rubber.  The other boot was half off and one side was compressed between the airbox and carb for god knows how long, that one's still a little tough in that area.  Since the ends were being pressed toward each other that area probably got thicker.  I could probably force it on, but I'll leave it in for another day to see what it does.

image.thumb.jpeg.9266fe311433c8b5017dad57fe235376.jpeg

Well, fuck. I would never thought it would be possible. 👍

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1 hour ago, tomek said:

Well, fuck. I would never thought it would be possible. 👍

I had a reasonable amount of faith based on what I'd seen/read, but I was shocked that it worked so well.

 

It's about 34 degrees out and it's still soft and pliable.  And it still smells strongly, but at least it's a pleasant stink...if you like wintergreen.  Maybe I should pour some into the gas tank for those behind it to enjoy.  Shit, maybe it'll condition the crank seals 😁

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Wow, I opened this thread thinking someone was too cheap to buy a pack of Trojans.

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Is anybody had a black bird that they've had to soften up? Any rubber boots or such?

 

I know there's a part in the carb models. I think that it's like a rubber diaphragm, but that rips?

 

One of the guys on the 1100F site tried to answer my question about longevity of the softness. The guys on the X site just beat me down and told me to go by new. It's only 140 bucks. I didn't explain a lot of what was going on though.

 

How long does the magic last? Does everything turn to a pumpkin at midnight?

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11 hours ago, XXitanium said:

How long does the magic last? Does everything turn to a pumpkin at midnight?

 

Looking at the SDS for Methyl 2-hydroxybenzoate says it's pretty damn volatile with a vapor pressure of 13, boiling temp of 222.  But it will be trapped inside the rubber which changes things.  This is a great question and hopefully Oscar will love the R5 enough to report in a couple years.  I suspect that trapped in the rubber, it will behave like most oils and be pretty stable.

 

Also...tip...the SDS for any product can tell you so much about it.  When I wonder what something is actually composed of, or how it may work, I read the SDS.  It also points out just how dangerous some things are that are sold to consumers willy-nilly.  For industrial use they'd require PPE, but for you to use...meh.

 

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13 hours ago, XXitanium said:

I know there's a part in the carb models. I think that it's like a rubber diaphragm, but that rips?

The vacuum diaphragms that lift the slides.  It's possible that one could condition them before they crack to add longevity, and it's something I gave thought to.  I have some junk carbs I could use for testing, I'll try to remember to do that soon.

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2 hours ago, SwampNut said:

 

For industrial use they'd require PPE, but for you to use...meh.

 

Well, the exposure time and/or concentration can have a lot to do with the reasons for missing, or lackluster warnings.  Extremely few people even pay attention to warnings anyway.  We have to tell people to keep their hands out from under mowers, and not to drink the fluid in their batteries.  Just the circle of life.

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3 minutes ago, jon haney said:

Well, the exposure time and/or concentration can have a lot to do with the reasons for missing, or lackluster warnings.

 

Oh, absolutely, but we really should be aware of these things.  And I have a pretty quick reaction to a lot of respiratory irritants, so I pay attention.

 

4 minutes ago, jon haney said:

Extremely few people even pay attention to warnings anyway. 

 

Well, right on this forum we have people who say you don't need PPE to use acetone in an enclosed space.  The fact that he shows signs of brain damage is total coincidence.

 

But this is why I commented that people would read and SDS or two; you learn so much, and it could change your life.

 

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