how to clean rusty brake drums?

[darrylspanhead]

hi i have a front brake drum that needs reconditioning! im going to get the inside and outside bead blasted but ive heard that i should NOT blast where the brake shoes ride (against the inside drum) and thats mainly where the rust is at! anyway any ideas on how to properly clean that part out so its clean and smooth again????

i also heard that you cant turn a brake drum...is that correct? why?

[steinauge]

You can indeed turn the drum but be careful how much you take out of it, if you get it too thin it is likely to flex and break under load-not good!.If it is badly rusted go ahead and bead blast it.I have beaded lots of drums without ill effect.If you find the drum badly pitted under the rust you likely should look for another one.

[darrylspanhead]

well before trying to get it turned or taking it in to be blasted...is there a good way to try and get the rust off to see if there is pitting occurring???

[Cotten]

darrylspanhead!

A wire brush on a drill will quickly give you a clue as to the condition of the rub surface.

The real problem with turning a drum is then fitting oversized linings.

Blasting is certainly a source of graphic horror stories!
But it is also quite necessary in most cases;
Like any strong medicine, it comes in many forms,
and when applied correctly works wonders,
but in the hands of the ignorant it becomes poison.

....Cotten

[darrylspanhead]

are you guys saying that its cool or not cool to blast the rub surface??? whats so horribly graphic about it??? i dont want to have to buy a new front drum so if its not safe let me know PLEEEEEEEEASE!!!!!!! i was just going to wire brush it or steel wool it (any one better then the other???) then have the blaster guys tape off the rub surface and blast the rest! does this sound like a good idea??

[Cotten]

darrylspanhead!

Your drum castings can take more pressure and aggressive media than most hardware, but please avoid good ol' boys that also blast bridge abuttments.

Most small cabinet blasters will not be able to do harm to a brake drum, without insane effort anyway.
If you are concerned with embedded abrasives after scrubbing it, get it warm with a heatlamp and hit it with the wire wheel again. Coarse Scotchbrite on a wheel is great. There is probably something specific for the job, but its up to others to google that,..
The dumpsters have already provided for me!

Blasting techniques become more and more critical with more and more delicate hardware, but the stigma for blasting practice has trickled down from the extreme among the ignorant.

A carb just crossed my benches that was horribly rough-blasted, apparently while assembled, and the venturi void completely filled with abrasive.
But to my surprise, when the venturi crap was washed out and evaporated on a glass dish, there was no coarse sand or silica, 'black beauty', or any other sharp media, but very fine round glass beads!
My guess is that the sand went out the exhaustpipe quickly, and the beads came out of the gas tank.

Nonetheless, a fresh topic on blasting practices applicable to the do-it-yourself enthusiast would keep me typing and editing jpegs for months.

And it may even save a few folks from horror stories in the future.

....Cotten

[Hog54]

Glass beading wont hurt a brake drum nomatter how much you blast.I have done hundreds of them and never had a problem.

[darrylspanhead]

hog 54 where are you located? ill send em to you! ok thanks you guys! so much help! ill brush as much as i can and ten find a glass beader that blast em if they need it! YOU GUYS ROCK!!!!!!

[Robert Luland]

Your front brake drum if a glide is casted. How much pitting could you possibly have? I don't see the need to blast anything. Just get in there with some elbow grease kid. As Tom said earlier. Just go to Home-Puke and get a course Stay-Brite pad. Bob L

[darrylspanhead]

yes sir i will do that! sometimes us kids just need a good push out the door and nudge out the gate, maybe even alittle kick in the ass!

thanks Bob L

[darrylspanhead]

bob L

so just want to say thanks for the advice...and anyone whos wondering...

A GREEN Scotch-brite pad and a solvent tank did an amazing job! elbow grease works wonders!!!

THANK YOU!

[59Panman]

I have been trying to find someone to turn my rear brake drum with no luck. Anyone have any suggestions? The drum is for my 59 that I purchased from Paughco.

[Omarine]

The other thing you could try is using the ol car charger method in a dunk tank and sodium bi carbonbate baking soda in it with the drum charged with the neg wire and some sacrificial steel charged with the postive

the rust should melt away from the drum as the steel attracts it....

once you get it out quickly spray it clean again and blow dry it....to avoid the flash rust...prime the areas that arent for braking. paint the outisde of it...

put it in use right away -- this should remove the rust with out all the abrasiveness of trying to scrape it off...it can only improve from the condition its currently in....

[59Panman]

I found a machinist locally who would turn it by machining up a mandrel to fit the drum. However, I don't know if we will be able to get the tight spot out without removing too much material?

[kitabel]

Repeat after me, 10 times: machinists are not engineers.
What he needs instead: give him a really nice star hub and lugs. He makes a mandrel (simple cylinder from bar stock) that's a slip fit into the hub bearing races. Turn it with a lathe dog.
Now, it rotates on the hub as it does in service.
If you don't get the high spot out the brakes will always chatter. If that takes off too much you need a new drum.
Drum damage vs. effects:
1. oval or irregular ID > chatter (pedal pulses)
2. rough finish > shoes work fairly well but wear out quickly
3. bell-mouth (taper) > shoes only make edge contact, poor performance
4. chrome, powder coat, 10 layers of paint > brakes work well the first time, then heat fade