[Radarr]

So I was stripping the flaking paint off of my Shiver the other day and somehow managed to loosen the bolt on the bottom left side of my fork leg. Needless to say, I managed to get oil on everything, including my brakes. As everyone knows, oil + pads = zero stopping power.

I tried the baking, I tried the burn with rubbing alcohol and isopropyl alcohol, along with everything else that people had suggested, and nothing seemed to work. Then I got a bright idea. Oil is just a hydrocarbon, insoluble in water, but very soluble in an organic solvent. And being as that I'm getting a chemistry degree, the two little gears started tinking, and an organic solvent I could readily get my hands on came to mind. It's the ever-so-useful (and cheap) acetone.

The procedure:
I took my rotor and pads off my bike and soaked them in a covered acetone bath for about two hours (acetone boils at about 130 degrees, low enough to evaporate a bath in a couple hours at room temperature), twice removing the and wiping them down with a paper towel and swirling the acetone around. The bath at this point had taken on a very dirty apprearance. I pulled everything out, wiped the rotor with a clean paper towel and set it aside. Then I rinsed the pads with fresh acetone, and placed over a heat source (a hair dryer - but be sure to not combine those two steps, unless you really want to start a fire) to dry them and remove any acetone still on the pads. I reinstalled everything on my bike and after about 2 minutes of use, they worked better than before.

The moral of the story is that it's good to know that my $30K invested in college has paid off - I saved $20 on new brake pads. Maybe now my investment will help someone else out.

 

[dexterq20]

SThen I got a bright idea. Oil is just a hydrocarbon, insoluble in water, but very soluble in an organic solvent.

That's exactly what I was thinking! Oh wait, no it's not...

Interesting technique, but I think I'm lazy enough that I'd just buy new pads instead of going out and buying acetone.

 

[Percy]

Acetone has sooooo many more uses than just cleaning brake pads, and setting stuff on fire or dissolving it!

Such as paint removal.
Or cleaning nail polish off ........things.

 

[thaflyinfatman]

ahaha sick, I've gotta try this. Any ill effects I should watch out for, like maybe dissolving the resin that holds the pads together?

 

[Radarr]

Any ill effects I should watch out for, like maybe dissolving the resin that holds the pads together?

I'm pretty sure the resin is an epoxy-like adhesive - insoluble in just about everything except really strong acids and bases. It's probably much more wear on it burning your pads than it is soaking them in acetone. But, I'll do a follow-up on this and post today after the ride.

 

[dhmtbj]

hmmm...pretty cool...maybe I'll give this a try...

 

[dhtahoe]

Wait... Acetone is known to melt the glue that holds the compound to the backing plate.

 

[Brian HCM#1]

Wait... Acetone is known to melt the glue that holds the compound to the backing plate.

That's what I was thinking. The old propane/mapp gas torch then sanding off the residue with mesh sanding cloth is the best method for salvaging pads.

 

[dhtahoe]

Soak them overnight in 100% Iso Alcolhol. Did the acetone once and PING. Nothing bad happened, but I was going slow that time.

 

[Jm_]

We use acetone at the shop to "clean" brake pads ocassionally, usually though I use honda disc brake cleaner when I have it available.

 

[dhtahoe]

I use honda disc brake cleaner when I have it available.

Brake Clean what a novel idea . Use it in the shop but not on the road. Makes the car smell.

 

[Jm_]

Use it in the shop but not on the road. Makes the car smell.

I also wouldn't suggest smoking while using it.

 

[zedro]

Sunlight dish detergent, boiling, heating on an element, torching, iso-alcohol...

i'm kinda weary about a full chemical assault tho, who knows what it can do to the pads.

 

[Radarr]

So after a full day of riding, the pads are holding up fine.

And a little chemistry lesson for you skeptics out there: The only difference between isopropyl alcohol and acetone is one bond to the oxygen. The IUPAC names are 2-propanol and 2-propanone, respectively. In terms of cleaning, this means that the acetone is better at removing less polar molecules from something (like oil) and the alcohol is better at removing more polar molecules.

Expensive brake-pad cleaners use a mixture of acetone, propane, butane, and some petroleum distillates - the last three would be better adhesive solvents that the acetone; like dissolves like is a general rule of thumb in chemistry. Based on the information provided at the brake cleaner manufacturer's websites, it will do a better job at destroying the pads than the plain acetone will, but nothing will happen that will adversely affect the pads as long as you don't leave the pads soaking for days on end.

What I'm slowly getting at is that cleaning your brake pads by soaking them in an acetone bath for 2 hours is like gently rubbing your arm with sand paper. If you do it too long, your arm will be raw and bloody, but as long as you stop before you get to that point, you'll be fine.

 

[Jm_]

Expensive brake-pad cleaners.

They are expensive? That's news to me.

 

[zedro]

What I'm slowly getting at is that cleaning your brake pads by soaking them in an acetone bath for 2 hours is like gently rubbing your arm with sand paper. If you do it too long, your arm will be raw and bloody, but as long as you stop before you get to that point, you'll be fine.

ok for some reason i got an impression of a much longer soak. Kinda like taking a one day long bath....uhhg

 

[Radarr]

They are expensive? That's news to me.

More so than a can of acetone from the hardware store. At least, that's what Google tells me. And I have to listen to Google. It knows everything.

 

[Radarr]

ok for some reason i got an impression of a much longer soak. Kinda like taking a one day long bath....uhhg

Mmmmm... pruny skin...

 

[dropmachine]

Just buy new pads you cheap bastards. They arne't that much.

 

[punkassean]

Acetone is much cheaper than new pads. Especially if you contaminate new pads. I can see tossing some old pads if you get oil on them but not new ones.

FWIW the torch method has worked well for me. You can see the oil sweat up and out of the pads and rotor and then evaporate. I have cooked a few pads though overdoing it.

 

[dropmachine]

If they are new pads I'd agree, try and salvage them. But really, these are your brakes man, onlything keeping your head attached to your torso and limbs intact. I'd rather get new pads and know i'm good to go, then try and save $20 only to find out that the acetone at the pads.

Perhaps its just me.

 

[dhtahoe]

So after a full day of riding, the pads are holding up fine.

And a little chemistry lesson for you skeptics out there: The only difference between isopropyl alcohol and acetone is one bond to the oxygen. The IUPAC names are 2-propanol and 2-propanone, respectively. In terms of cleaning, this means that the acetone is better at removing less polar molecules from something (like oil) and the alcohol is better at removing more polar molecules.

Expensive brake-pad cleaners use a mixture of acetone, propane, butane, and some petroleum distillates - the last three would be better adhesive solvents that the acetone; like dissolves like is a general rule of thumb in chemistry. Based on the information provided at the brake cleaner manufacturer's websites, it will do a better job at destroying the pads than the plain acetone will, but nothing will happen that will adversely affect the pads as long as you don't leave the pads soaking for days on end.

What I'm slowly getting at is that cleaning your brake pads by soaking them in an acetone bath for 2 hours is like gently rubbing your arm with sand paper. If you do it too long, your arm will be raw and bloody, but as long as you stop before you get to that point, you'll be fine.

Well Mr.Wizard nothing beats good old first hand eating dirt because your pad just crammed itself into the rotor. And working on aircraft I tend not to experiment. People get hurt that way.

 

[odiwik]

Are you a mechanic or an aerospace designer? We wouldn't be where we are today if it weren't for experimentation... Ask your parents about that.

The acetone trick seems to work just fine and isn't any harder on your brakes than isopropyl alky.. What's with the negativity and immediate defensive stance towards this topic? The brakes are biting as hard as they ever have now with no failures after a quick and observed soak.

 

[Ciaran]

... But really, these are your brakes man, onlything keeping your head attached to your torso and limbs intact. I'd rather get new pads and know i'm good to go, then try and save $20 only to find out that the acetone at the pads.

Perhaps its just me.

Yeah ya cheap bastids... buy some new pads.

 

[punkassean]

It's not cheap, it's wise. Hell it's not really even thrifty. It would on the other hand be wasteful to replace something that wasn't damaged beyond reasonable repairing.

:eviltongu

 

[Changleen]

The acetone method is more environmetally friendly than buying new pads.

 

[thaflyinfatman]

Just buy new pads you cheap bastards. They arne't that much.

They're like fifty freakin dollars an end over here, as if you wouldn't give it a shot when the alternative is that. Radarr is the guy with the chemistry degree (or studying for one, whatever), personally I'd take his word on what is likely to be harmful over the typical armchair experts'. I notice nobody has replied specifically to where he said:
"And a little chemistry lesson for you skeptics out there: The only difference between isopropyl alcohol and acetone is one bond to the oxygen. The IUPAC names are 2-propanol and 2-propanone, respectively. In terms of cleaning, this means that the acetone is better at removing less polar molecules from something (like oil) and the alcohol is better at removing more polar molecules."

 

[Radarr]

Just buy new pads you cheap bastards. They arne't that much.

But for the poor, starving, college student, a $4 fix is much better than a $20 fix, especially when the results are the same. If you have the money, by all means, buy new pads. Hell, just buy new brakes every time they need to be bled.

There is a point at which the pads aren't worth even trying to fix, I totally agree, but that isn't the point of this thread. If it were, the thread would be titled "The best way to save your old, worn-out brake pads for another two rides" or something dumb like that. Then I would have been told to go to Pinkbike, and life on RM would have continued as usual. This thread's purpose is to inform people that they have another option when it comes to making their bike work after doing something stupid like getting oil on their brakes while trying to strip the paint off of their fork and spilling oil everywhere.

And just for a little clarification, although the two molcules (acetone and rubbing alcohol) are very similar, they both react differently in a lab. I was talking about their use as solvents and cleaning agents when applied for a short period of time. And I did make a small mistake, the only difference between the two molecules is one bond to the oxygen and the alcohol has a hydrogen atom connected to the oxygen - hense the difference in polartiy, smell, solubility in water, etc... in many cases, one atom can make a huge difference (like PVC), but in the context that we're discussing here, it wont.

 

[Radarr]

Isopropyl Alcohol is on the left, Acetone is on the right.

 

[dante]

The moral of the story is that it's good to know that my $30K invested in college has paid off - I saved $20 on new brake pads. Maybe now my investment will help someone else out.

Cool, so now you just have to salvage 1,499 more brake pads to make it totally worthwhile!!!

 

[Radarr]

Cool, so now you just have to salvage 1,499 more brake pads to make it totally worthwhile!!!

hahaha, wait...

I guess then, this is me -> :nuts:

 

[zane]

It's great to see people apply their education to the bike world, my in-progress engineering degree has been useful a few times.

 

[thaflyinfatman]

Ok as an update, I have since tried this on my previously-barely-working Hayes pads + rotor. I now appear to have full power back! Will have to spend a day dhing on it before any real conclusion can be made, but this is VERY promising - they had no power and no bite before, now they have both back to normal. I don't recall any specific circumstance where the pads/rotor got contaminated, but recently they've just gotten worse and worse.

Thanks Radarr, you may have saved me several hundred dollars worth of brake pads over the course of my riding life

 

[Ciaran]

But for the poor, starving, college student, a $4 fix is much better than a $20 fix, especially when the results are the same. If you have the money, by all means, buy new pads. Hell, just buy new brakes every time they need to be bled.

If you are that poor and starving, sell your 3,000.00 dollar bike.

Seriously though, I remember my starving days very well. Sometimes you have to do what you can on the cheap in order to get yourself going again. And eventually you too will get to a point where you have more money than time (It's not fun.) and may be more inclined to buy new pads rather than salvage. I do tip my hat to you for thinking of this, though. Very clever.

 

[thaflyinfatman]

Just had a thought - acetone is an ORGANIC solvent, correct? So... what would it do to semi-organic pads (EBC reds/greens)? I only use sintered pads so I don't think it's an issue, but could it literally destroy the semi-organic pads?

 

[Radarr]

If you are that poor and starving, sell your 3,000.00 dollar bike.

It's all about priorities, man. Priorities. Food or a bike: you make that decision. And it was only $2300, thank you very much.

Just had a thought - acetone is an ORGANIC solvent, correct? So... what would it do to semi-organic pads (EBC reds/greens)? I only use sintered pads so I don't think it's an issue, but could it literally destroy the semi-organic pads?

This goes back to the original post: Soak them for 2 hours at most. Acetone is a good solvent for a lot of stuff - oil, grease, and paint. Mix the organic compounds with metals (hence organometallic prake pads) and bang, it's a whole different class of compounds that acetone doens't do much to (as far as I know and have experienced).

I've now used my pads for nearly 25 DH miles, and they are still running strong.

 

[-Steve-]

Thanx, so much for this awesome tip!

 

[nh dude]

so i did it. contaminated my pads. its been like 2 years pretty good run

gonna go the isop route torch/ bake them and if that doesn't work the to the acetone...

will check back after

 

[Kanye West]

Typical AutoZone brake cleaner is a higher percentage of acetone than most chem-lab acetone (cheaper too). You just absolutely cannot spray it directly on the pads. Best way is to spray it on sandpaper and scuff up the pads in a small pool of the stuff, then spend some time bedding them back in. More powerful than day one.

I usually add a little chamfer to the leading edge while I'm at it too. Seems to cut down on the noise a bit.

 

[Radarr]

Typical AutoZone brake cleaner is a higher percentage of acetone than most chem-lab acetone (cheaper too). You just absolutely cannot spray it directly on the pads. Best way is to spray it on sandpaper and scuff up the pads in a small pool of the stuff, then spend some time bedding them back in. More powerful than day one.

Tell me, how does AutoZone get more than 100% acetone into a spray bottle?