Removing rubber stains...any ideas?

[Danneaux]

Hi All!

I've recently found a problem with EDPM rubber causing stains on my bicycles' paint and powdercoat. Although it is happening to the black Nomad, it shows up better (worse) on one of my lighter colored bicycles as shown below.

I use EDPM rubber to isolate clamps from the bikes' finish...these marks were caused by the rubber strip supplied with a Cat Eye computer to go under a cadence sensor. I've recently found the same results after using strip of inner tube for the same purpose.

I know what the problem is...rubber bleeding rather than rubber bloom (generally seen as powdery white spots on cured rubber). Bleeding is caused by a leach-out of the component products of the cured rubber caused by time and pressure aggravated by environmental factors like heat, ozone, oxygen, and UV. The result is a little oily to the touch and this is what causes the stain when it is trapped next to the finish.

Has anyone else found the same?

I'd like to safely remove the stains, as I find the results unsightly. So far, I've tried the following on painted finishes, with no attempts made on powdercoat...
• Sun exposure
• Detergent/surfactants
• Clear coat rubbing compound
• Bleach
• Automotive wax
...with no visible improvement.

I'm a little leery about trying more abrasive methods and wonder if any of you might know of some nondestructive means to remove the stains...I'm stymied at present. Keep in mind, the stains are on both paint and powderoat and my options are more limited on powdercoat.

All the best,

Dan.

[geocycle]

Sounds like you need a solvent of some description.  Just be careful of the paint!

[Danneaux]

I agree on both counts, Geo'!

All the best,

Dan.

[geocycle]

Acetone? Methylated spirit?

[Danneaux]

Acetone? Methylated spirit?

Fortunately(?) the stain wraps all the way 'round the affected tubes, so I was able to try some things in a discreet area on the tire side in case of a bad result.

I tried mineral spirits and also white gas (naptha) with no result except for removing the wax I usually have applied over the paint. Each also proved safe for the test sample of unwaxed powdercoat I have.

In the end, I just may need to chalk this up to "beausage" (beauty resulting from actual usage) and leave well enough alone, keeping this experience in mind for the future and placing something to serve as an isolate beneath EDPM rubber pads.

I'm pretty sure I could make it worse.

Fair warning to others, though...left in place long enough and in severe conditions, the black rubber pads supplied with bicycle accessories (computer mounts, light mounts, lock mounts, etc) can stain paint and powdercoat even through a waxed surface. 

Thanks for the suggestions, Geo'.

All the best,

Dan.

[Danneaux]

Hmm...further thought has me turning to automotive detailing forums.

Apparently, various tire dressings (ArmorAll and other similar polymers) can "sling" with use and cause rubber staining on body panels that looks similar to what I am dealing with here on the blue paint and on the Nomad's black powdercoat.

I'll investigate further and return to post any solutions that work.

Best,

Dan.