Removing coating on aluminum motorcycle frame

A. If you succeed in removing the anodize so that you can polish the frame, you will want to anodize the part again. You won't be able to do this with Drano, and you won't be happy with a soft aluminum frame, since it will ding easily.

A. I've polished a couple of GSXR frames for myself and customers. By polishing it you're removing the protective coating of the frame. Aluminum actually oxidizes easier and faster than steel, the only difference is that the oxidation actually forms a protective layer thereby prohibiting any further oxidation. Unless you do something to prevent this your frame will turn dull very quickly and you will constantly be polishing it to make it shine. You can overcome this by utilizing some kind of protective coating. Some people use a clear coat to protect their polish. This is probably the easiest way to protect it.

As far as getting the old finish off, just sand it. Start off with 300 or 400 grit paper and work your way up to 1000. At this point you have to start buffing with polishing compound to bring out the shine. This sanding will most likely have to be done by hand so as to avoid swirl marks. Sand in a straight back and forth motion only. You can then use a high speed buffer for polishing. It's very tedious and time consuming but the results can be worth the effort. It takes me about 40 or so hours to do a frame and that doesn't include assembly or disassembly.

A. Don't listen to the old ones. If you have a drill and a sanding wheel that has scrubby pad in it, it looks like a small piece of sandpaper and then a piece of scrubby pad on a mandrel. At a low speed you can work with it (in one direction only, or you will mess it up). Then when you get the Alodine^^anodizing off, you begin to wet sand. Don't gouge your frame with the drill (very important) or you might be sanding for a while. You can get an assortment of wet paper varying from 320-600 grit. Keep the paper wet, always, with a spray bottle of water. Sand it until it starts to get shiny with water and then polish with Mothers Mag & Aluminum Polish ⇦this on eBay or Amazon [affil links] . If you don't use a good polish it will look bad. Count on polishing it about once every two weeks at the least. I have done two frames, a 94 CBR 900rr and a 98 GSXR 750.

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Ed. note: Thanks Doug. But don't listen to the new ones when they talk about getting "the Alodine off". Alodine (chromate conversion coating) is a totally different process than the anodizing we are speaking of and has nothing to do with this thread :-)

A. To remove the factory finish go to your local auto parts store and buy two cans of "Aircraft Striper".
It is very strong so use rubber gloves ⇦this on eBay or Amazon [affil links] . After that use 320 grit sandpaper and continue to 1500, wet sanding at 1000-1500. You can use a Black and Decker palm sander but sand in the same direction. Be careful not to sand to long in one area as not to burn the metal. Then use a high rpm buffer along with jeweler's rouge.

A. 1500 grit sandpaper, not RPM.

A. Use paint remover it's quick and easy. Buy the aerosol type for "aluminum" I've done 6 bikes this way and it always works. Then just sand with 400 grit for the final finish.

A. I have polished several frames and this is what I have found.

Skip the Easy Off oven cleaner ⇦this on eBay or Amazon [affil links] or the Aircraft Paint Remover (I have done it this way and it sucks and makes huge mess, WAY too much work too)..there is no better way to remove the clear coat than a standard drill and a polishing wheel adapter at your local Sears..you will need to buy 5" adhesive backed sandpaper pads for the adapter. Make sure to buy a couple packs of both 100 grit and 220 grit adhesive pads. Your next stop will be at local auto parts superstore and go to the automobile paint isle, buy wet/dry sandpaper in the following grits 400, 600, 800, 1000. Also stop by your local hardware store and pick up a bag of both #00 00 steel wool ⇦this on eBay or Amazon [affil links] and 000 steel wool ⇦this on eBay or Amazon [affil links] . You will strip 99% of the clearcoat with the 100 grit pads, try to use the drill in a consistent motion that follows the "grain" of the frame when possible. Progress from 220 grit pads to wet/dry and soapy warm water hand sanding from 400, 600, 800, 1000. During the wet dry phase you should make sure to sand in consistent movement that should follow grain of aluminum, DO NOT BUFF IN CIRCLES.

After the wet dry phase I then move to the #00 00 steel wool ⇦this on eBay or Amazon [affil links] and buff in the same motion with quite a bit of elbow grease, I then progress to the #000 00 steel wool ⇦this on eBay or Amazon [affil links] and do the same thing...if you have done everything properly your frame should look fairly polished at this stage but the final steps will bring out the "ultimate polish" and give you hopefully a mirror like shine that equals chrome plating. I use a converted angle grinder ⇦this on eBay or Amazon [affil links] with the guard removed for this buffing, you can also use a high speed buffer as long as it turns HIGH rpm. Your local Home Depot carries in the tool section a brand of products called DICO, they are in orange/brown packages and they are made for metal finishing. You will need to buy two buffing wheels, make sure to buy the ones that are very tightly stitched together as you will want to apply pressure to the frame with the wheel, the loose buffing wheels will not work the way you need them to. You will also need to buy a stick of EMERY ROUGE ⇦this on eBay or Amazon [affil links] , TRIPOLI ROUGE, and for optional last step you may want to buy jewelers rouge ⇦this on eBay or Amazon [affil links] (and a 3rd buffing wheel if you buy third stick of rouge). Fire up your buffing wheel and apply EMERY rouge to wheel, polish the frame in consistent movement, reapply rouge as necessary, progress to TRIPOLI rouge and fresh buffing wheel and then finally JEWELER'S ROUGE with a fresh wheel. DO NOT MIX rouges of different types on the same wheel, you will get inconsistent results. I use Mother's Alum. Polish for maintenance but occasionally will pull out buffer and give frame/swingarm a quick hit with EMERY rouge.

If you follow these steps you will be thrilled with result. It sounds like a lot of steps but if done properly it won't take as long as you think. I polished the frame of my R1 in day and a half, if removed from the bike the whole swingarm could be done in a weekend or less. I have also found different frames respond differently to different buffing rouges...for example the 93 GSX-R and 95 900rr frames that I polished responded very well to the TRIPOLI rouge, however on my R1 the Tripoli rouge made the frame look like sh*t. The basic steps I have outlined are necessary on any make frame, the very final finishing stages may vary a bit from bike to bike as I have found. This is THE WAY to do this correctly in my opinion, do not believe there is any big secret shortcut - polishing frame is big commitment. The biggest thing I have learned is using the drill and polishing adapter to strip the clearcoat - switching to this method saved me a HUGE amount of time.

Thanks

Awesome advice JRO. I followed your advice and got some great results. Thanks. All I can add for people doing this in the future is to sand as unidirectionally as possible. The more consistent direction the better it looks. And clean aluminum thoroughly with detergent before buffing or it will blacken the buffing wheel. I learned that buffing wheels can be run through the washing machine.

A. Before you attempt to sand and polish an aluminum frame. YOU MUST REMOVE THE FOLLOWING PARTS: GAS TANK, FAIRINGS AND ANY OTHER PARTS THAT YOU DON'T WANT DAMAGED!

STEP 1: YOU WILL NEED TO PURCHASE Aircraft Stripper. THIS TYPE IS NEEDED DUE TO THE TOUGHNESS OF THE ANODIZED COATING ON THE FRAME.

STEP 2: COVER ENGINE AND EXHAUST WITH PLASTIC BAGS OR TARPS AND TAPE OFF TO SEAL THESE COMPONENTS AND ANY OTHER COMPONENTS THAT MAY COME IN CONTACT WITH PAINT REMOVER. THIS STUFF IS VERY STRONG!

STEP 3: BEFORE APPLYING PAINT REMOVER MAKE SURE YOU ARE WORKING IN AN OPEN AND VENTILATED SPACE. HAVE A GARDEN HOSE HANDY FOR TWO REASONS: 1) RINSING PAINT REMOVER FROM YOURSELF (THIS SH*T WILL BURN YOUR SKIN!) 2) TO RINSE REMOVER OF PAINT REMOVER FROM THE FRAME.

STEP 4: READ DIRECTIONS FOR PAINT REMOVER! APPLY PAINT REMOVER TO PARTS OF FRAME THAT WILL BE EXPOSED (OUTSIDE OF FRAME ONLY). ONCE REMOVER IS APPLIED KEEP A WATCHFUL EYE ON THE REMOVER. THE PAINT REMOVER SHOULD START STRIPPING THE COATING VERY QUICKLY. USE A CLOTH TO WIPE A SMALL SECTION TO CHECK THE PROGRESS OF THE PAINT REMOVER. SOME AREAS MAY REQUIRE MORE TIME THAN OTHER, FOR INSTANCE THE PART OF THE FRAME THAT IS CLOSEST TO THE TANK WILL STRIP FASTER THAN THE AREA WHERE THE WELDS ARE.

STEP 5: ONCE THE ANODIZED COATING HAS BEEN STRIPPED BEGIN TO RINSE THE PAINT REMOVER OFF OF THE FRAME. MAKE SURE YOU RINSE PROPERLY CAUSE THE PAINT REMOVER WILL CONTINUE TO WORK LONGER.

STEP 6: WASH YOUR STRIPPED AREAS WITH WARM SOAPY WATER AND THEN RINSE AGAIN.

Gasoline-powered Air Compressors

on eBay or

Amazon

(affil links)

NOW YOU ARE READY TO BEGIN SANDING YOUR FRAME. THERE ARE SEVERAL WAYS TO DO THIS. THE EASIEST WAY IS BY USING A "DYE ANGLE GRINDER" (AVAILABLE AT LOWES, HOME DEPOT OR SEARS) AND YOU'LL ALSO NEED AN AIR COMPRESSOR [adv: air compressors on eBay or Amazon [affil links] , FITTINGS AND AN AIR HOSE. A 50 GALLON COMPRESSOR OR BIGGER WILL BE NEEDED. YOU WILL NEED TO BUY 3M SANDING DISCS FOR THE DYE ANGLE GRINDER FROM YOUR AUTO PAINT STORE START WITH A 220 GRIT FOR YOUR FIRST STAGE AND WORK YOUR WAY UP IN GRITS. FOR EXAMPLE: 220 GRIT, 320 GRIT, SKIP TO 600 GRIT, 800 GRIT, 1000 GRIT, 1500 GRIT, AND THEN 2000 GRIT. THESE SHOULD BE AVAILABLE TO THE AUTO PAINT STORE (YOU WILL NOT FIND THEM ANY WHERE ELSE UNLESS YOU GO ON-LINE) NOTE: THESE ARE NOT NOR NEED TO BE WET TYPE SANDING DISCS. AFTER YOU HAVE GONE THROUGH ALL THESES STAGES THEN YOU WILL BUFF THE FRAME WITH "MOTHER WHEEL OR ALUMINUM POLISH' SOLD AT ANY PEP BOYS, DISCOUNT AUTO PARTS, etc. TEST A SMALL AREA GOING THRU ALL THE SANDING STEPS THEN WITH POLISH TO SEE WHAT YOUR END RESULT WILL BE. THE TEST AREA SHOULD HAVE THE APPEARANCE OF A CHROME FINISH. YOU SHOULD NOT HAVE ANY HAIRLINE SCRATCHES IN YOUR FINISHED LOOK. IF YOU DO THEN YOU NEED TO CONTINUE SANDING STARTING WITH THE LOWER GRIT WORKING YOUR WAY UP TO THE HIGHEST GRIT.

IF YOU DON'T WANT TO SPEND THE MONEY $$$$, THEN YOU'LL HAVE TO DO IT BY HAND. DO NOT BE IN A RUSH TO START THIS PROJECT BECAUSE IT WILL TAKE SOME TIME TO GET THE CORRECT RESULTS. BEAUTY HAS IT'S PRICE AND YOU ARE GOING TO PAY ONE WAY OR ANOTHER.

TO DO IT BY HAND YOU WILL NEED THE FOLLOWING:
1) A SANDING BLOCK (IT'S MADE OF RUBBER AND SHOULD HAVE SLITS ON BOTH ENDS TO ATTACH THE sandpaper TO.
2) WET TYPE sandpaper STARTING WITH A 300 OR 400 GRIT, A 600 GRIT, 800 GRIT, 1000 GRIT, 1500 GRIT, 1800 GRIT, THEN 200 GRIT.

----- NOTE THAT THE 3M SANDING DISCS WILL HAVE DIFFERENT NUMBERED GRITS COMPARED TO HAND WET SANDING GRITS. THE TEXTURE IS ALSO DIFFERENT DO NOT COMPARE THE TWO.

STEP 7: BEGIN TO SAND YOUR FRAME STARTING WITH THE LOWEST NUMBER GRIT. FOLLOW THE FLOW OF THE FRAME AND KEEP AN EVEN PRESSURE WHILE SANDING. YOU ARE WORKING WITH A WET TYPE sandpaper SO IT MUST BE KEPT WET AT ALL TIMES. KEEP A BUCKET OF WATER AND A SPRAY BOTTLE BY YOUR SIDE WHILE SANDING. DUNK YOUR SANDING BLOCK IN BUCKET TO REMOVE SANDING RESIDUE. ONCE YOU HAVE SANDED THE FRAME WITH THAT PARTICULAR GRIT YOU WILL NOTICE THAT THAT PARTICULAR GRIT IS NO LONGER EFFECTIVE AND NOW YOU MUST MOVE ONTO THE NEXT GRADE OF GRIT. CONTINUE SANDING THRU ALL THE DIFFERENT GRADES OF GRIT UNTIL YOU HAVE ACHIEVED A SMOOTH FINISH. TO CHECK YOUR PROGRESS RUB A SMALL AMOUNT OF "MOTHER'S ALUMINUM WHEEL POLISH" WITH A CLEAN MICRO FIBER TOWEL TO SEE WHERE YOU ARE AND HOW FAR YOU NEED TO GO TO ACHIEVE THAT CHROME LOOK FINISH!

MY FAIR WARNING TO YOU: REMOVE OR COVER ALL PAINTED PARTS THAT YOU DO NOT WANT DAMAGED BY THE PAINT REMOVER OR FROM sandpaper! DO NOT START THIS PROJECT IF YOU PLAN TO RIDE ANY TIME SOON CAUSE YOU WILL BE WITHOUT YOUR BIKE UNTIL YOU FINISH.

GOOD LUCK

A. After polishing aluminum to bright shiny finish then use some type of automotive wax finish protection. It can be carnauba wax or synthetic wax. The polished bare aluminum finish was used by American Airlines for years and was even considered lower maintenance than painting but it must be waxed regularly to prevent the dull oxidation build up. In more corrosion prone environments from salt exposure then fresh water rinse often and wax even more often.

Please do not confuse chemical conversion coating ("Alodine" trade name) with "anodize" aluminum finish. Anodize is forced oxidation by electrical current in an acid bath solution (sulfuric, boric/sulfuric blend, chromic or phosphoric acids are commonly used) where the aluminum is the anode as in a form of reverse plating in that the base metal aluminum is changed to aluminum oxide. The thickness and hardness of the aluminum oxide determines the added corrosion resistance and can be color modified by adding stains or pigment from paint like materials.

It is not uncommon to clear top coating like poly urethane over anodize. As seen earlier in this discussion the high quality paint strippers can be used to remove this clear top coating but abrasive wet sanding is by far the best for removing anodize. Pure chemical removal can be done with caustic solutions. Sodium hydroxide or potassium hydroxide commonly found as part of products like Drano or Liquid Plummer. After the heavy aluminum oxide anodize removal then use nitric acid rinse or dip to desmut is best or with light smut use phosphoric acid (Naval jelly) to lighten the aluminum surface for a clean dull bare aluminum finish. This would be recommend for a rough texture surface like as cast finish that would be very difficult to add a uniform mechanical sand or abrasive polish finish.

A. Hi again. That's quite a mismatch and I think you'll have trouble sanding it straight without some experience and specialty jigging. I'd suggest disassembling it and trying to assemble the three pieces in the best order and with the best side up for a better fit … then tightening the bolts while using a clamp to hold the parts in proper alignment.

Henry Ford had some ideas on the problem you're experiencing of needing to pick & choose which ends of which parts to bolt together for a proper fit :-)

Regards,