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Carb Cleaner ~ = Brake Clean. Beware ...

Posted: 21 Apr 2021 19:21
by safiri
Last week I was doing some work on a MTB fork and got a whiff of the carb cleaner I was using. (I wanted to clean off the legs but leave a lubricating residue.) Smelled like brake clean. Sometime in the past few years Carburetor & Choke Cleaner has changed formulations and is now very close to Brake Clean. I wouldn't use either on rubber parts (or in a carb with the possibility of rubber parts).

New 3 on left, NOS on right.
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OReilly Carb Clean vs OReilly Brake Clean:
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Gumout: New vs. Old. The old had petroleum distillates that left behind a thin lubricating layer. That is no more.
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Re: Carb Cleaner ~ = Brake Clean. Beware ...

Posted: 04 Jul 2021 17:11
by Stu
Thanks for the notice about the changes. I felt something like that had occurred and usually wipe / spray my parts down with lubricant after using these cleaners. I have been unable to purchase Stoddard solvent for 25 years and finally tossed my parts cleaner. Spray cleaners and lubricants are a very poor environmental substitute.

Stu

Re: Carb Cleaner ~ = Brake Clean. Beware ...

Posted: 16 Jul 2021 08:29
by xr-nut
And if welding, be sure to clean all the parts to be welded with the brake clean before welding........................... :twisted:



















No, really dont do that. Dont spray brake clean on steel then weld it. it can kill you. google phosgene gas.

Re: Carb Cleaner ~ = Brake Clean. Beware ...

Posted: 16 Jul 2021 09:23
by DirtFarmer
I worked for a high pressure hydraulic clamp manufacture (5000 psi).

We use wipers, seals and o rings made from about any type of compounds available with a wide range of durometers.

We have used electrical contact cleaner for over 15 years for cleaning and displacing oil (checking for leaks) with no ill-effect.

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Re: Carb Cleaner ~ = Brake Clean. Beware ...

Posted: 16 Jul 2021 11:11
by safiri
Good to know.

From some quick web searching it appears :
- Toluene dissolves rubber so to be avoided. Note that toluene is in Brake Clean and in the new Carb Clean.
- acetone (in all 4 shown) will disolve rubber as well, but at a far slower rate (and the acetone will evaporate before much damage has taken place).

From https://en.wikipedia.org/wiki/Rubber_cement:
"Rubber cement (cow gum in British English) is an adhesive made from elastic polymers (typically latex) mixed in a solvent such as acetone, hexane, heptane or toluene to keep it fluid enough to be used. This makes it part of the class of drying adhesives: as the solvents quickly evaporate, the rubber solidifies, forming a strong yet flexible bond. Rubber cement is simply a mixture of solid rubber in a volatile solvent that will dissolve it. When the cement is applied, the solvent evaporates, leaving the rubber as the adhesive. Almost any rubber (pre-vulcanized or not) can be used.[1] The rubbers used might be natural rubber, gum mastic or gum arabic. Early solvents used included chloroform and benzene.[2] A small percentage of alcohol is often added to the mix. In the United States of America, current formulations include n-heptane."

I have used rubber cement to patch a lot of inner tubes (moto and bicycle), so n-heptane's effect (if any) would appear to be minimal as the tubes don't seem to be degraded.

CRC QD MSDS: http://docs.crcindustries.com/msds/1003719E.pdf
naphtha (petroleum), hydrotreated light 40-50%
1,1-difluoroethane HFC-152a 20-30%
2-methylpentane 20-30%
n-hexane 3-5%