WGB 

I have an Alan Super Record - which had, repeat had, a seized aluminum seat post. I have the post out and need to clean out the inside of the tube (oxidization and some long hardened grease).

With a steel frame I would use the "steel wool wrapped in coat hanger, hooked up to a drill" trick and in 30 seconds it would be shiny and clean. I don't know if that method is acceptable for an aluminum seat tube.

Any suggestions??

Ps I know I have to remove the bottom bracket first to prevent debris from getting in there....

sch

Use a scotch brite abrasive pad instead of steel wool and it should work nicely. A 6x9 pad cut into strips should do with a 1/2 or 5/8" dowel slotted on the
end as a driver.

Crankycrank

This^^^. Stay away from the power tools as some aluminums are fairly soft and will wear away shockingly easy.

fietsbob

take the BB Out and you can tie a string on both ends if the scotch brite ,,

there are some made with embedded carborundum, abrasive.

I have a pad of that stuff in my Kitchen , great with scorched pans..




....

Troul 

swivel around emery cloth down the post and blow out the debris when done.

Andrew R Stewart 

The old grease, unless REALLY hardened, will gum up any abrasive. Depending on how much there is I would consider doing a grease cutting solvent step before any mechanical methods. Andy

maddog34

PB bnlaster will soften the old grease...

and +1 to the scotchbrite... best i've found are the pre-painting red pads.... auto supply stores have them,,,, meant for metal/paint scuffing use... the green household type break into tiny particles too easily.

Coasterbrakefan

Steel wool + coat hangar will work quick and effectively.

Also, steel wool doesn't actually sand like sand paper, so there's no risk of removing excess material off of your frame.

Also make sure to clean inside the seat tube, and put a thin layer of grease an your seat post.

More importantly (depending on what type of bottom bracket you have installed), check your bottom bracket! Steel wool works great, but is messy. A good idea would be to stuff a rag down your seat tube before starting, and then remove the rag with all the junk its collected after you've finished.

Using anything else (aka. Sand paper) would be excessive IMHO. Hope this helps.

cyccommute 

Since the seatpost was seized, I doubt that there was much grease in the seat tube to begin with. If there were, the post would have seized.

There are other solvents that would be better and cheaper than PB Blaster. Finishline Speed Degreaser would be cheaper. WD40 would work too. A mineral spirits soaked rag would do just as well.

hankaye

WGB, Howdy;

When "Coasterbrakefan" wrote,


he wasn't being your friend.

NEVER use Steel wool with aluminum! You'll be setting yourself up for dissimilar metal corrosion. Regardless
of how careful you are you will be leaving tiny bits of the steel wool in-bedded in the aluminum. Best to stick
with the Scotch-Brite.

We used it on the aircraft for corrosion control FYI it's nomenclature was Aluminum oxide impregnated woven plastic pad. The Green pads were the equivalent of 220 grit and the coarsest we were allowed to use. Today's Kitchen pads don't work as well so get some from the Auto store. Always use the mildest means that you can when removing Corrosion. 13 years of Corrosion Control experience speaking.

hank

turkey9186

Shotgun cleaning rod with cotton swabs soaked in PB Blaster.

Coasterbrakefan

*Eye role*

I use steel wool on aluminium all the time with no problem.

Top tip! Use steel wool on aluminium seat posts, crank arms, handlebar stems, and any other "raw" unpainted aluminium components. Shines them up beautifully!

Another option people talk about for cleaning metal is using aluminium foil, but I find it's not as efficient as steel wool.

But any way, steel wool + coat hanger will work fine.

hankaye

Coasterbrakefan, Howdy;

all you want ... the items you mentioned are all easy to see and inspect,
the seat post pulls out, the rest are in the open, so when they look dull you
shine them up again. Well the dullness is corrosion and you're keeping up
with it. Good for you! Now how often do you pull the seat post and really look
into the tube? How often do you clean the inside of the seat tube? Weekly,
Monthly, sometime down the road when you think about it or ...
When it's difficult to pull out guess what (?), that's your corrosion holding it
in there fighting you for the post.

I truly hope you are not a shop mechanic and doing the steelwool cleaning to
customers seat tubes as they most likely won't be pulling the seat tube out ever
or until they pass it on to someone else.

hank

Iride01 

If you or a shop has a seat post reamer, I'd use that. Make sure it is the correct size.

If you have a friend that owns or works at a small machine shop, they probably will have a reamer the correct size. Likely they won't know what your bike's seatpost is supposed to be reamed to, so make sure you know.

hankaye

WGB, Howdy;

Reamers are good but might I suggest a Hone, something like this;
https://www.aliexpress.com/item/Winm...307870274.html
The stones will polish the inside of the tube and take of the minimum
amount of materiac at the same time. A reamer will remove material
and can clean the interior it just eats more material faster.
Go down to your local Autozone and ask to see their Brake cyl. hone
the spring loaded legs will allow you to insert it into the tube and as
it cleans up the corrosion you'll see the interior start to shine.

hank

Iride01 

I almost went that route once. But I have a friend that owns a small machine shop and I actually worked there for quite a few years. He has a good selection of reamers in that size range. So for me, free won out over the wheel cylinder hone that I would have had to purchase.

Sounds like you've used a wheel hone before.... was it able to do it's job without getting gunked up with old grease and such? If so, I may eventually get one.

Irregardless of what the OP uses, they should consider that some trash might make it down to the bottom bracket. May not be a concern, but I wouldn't want it down there. The reamer will definitely make the largest pieces of chips that might go places you don't want them.

hankaye

Iride01, Howdy;

Back in the day the use of hones for cleaning out break cylinders was an everyday sort of thing.
They have replacement stones for hones so the gunking up isn't that big a deal. Or you can always
boil them like a sharpening stone when it get full, same material ... A hone for the size of a seat
tube shouldn't cost more then 10 or 15 bucks extra stones a few more bucks. OR, ... like I mentioned
above, rent a brake hone from Autozone let them deal with the gunked up stones. Tool rental is cheap.
Yea, I'd remove the BB before I went to clean the crud outta there.

hank

J.Higgins 

Kudos to you, Hank. Obviously you've had some military aircraft corrosion training, as have I. My #1 hobby these days is rebuilding bikes. Lots of Kroil and lots of slide-hammer work to get out the last stuck seat post, lol. I also use a stainless pot scrubber and some mineral spirits to clean and prep the seat tube, because the next step is the brake hone. I'll only do this to a bare frame, but I actually dunk the BB into a wide plastic container filled with mineral spirits, and use my cordless makita to churn the hone up and down the seat tube like a butter churn. Comes out perfectly, and with a faint cross-hatch pattern. The mineral spirits act as a wash an lubricant, and actually keeps the stones running cool. I obviously dont do this long - just enough to clean it up.

hankaye

NoControl, Howdy;

Only enough to write the Aircraft Emergency Reclamation Instruction for the USS Nimitz (CVA-69),
back in 1983 which grew a lot and eventually became;

NAVAIR 01-1A-509-5, TECHNICAL MANUAL: CLEANING AND CORROSION CONTROL (VOLUME V) CONSUMABLE MATERIALS AND EQUIPMENT FOR AVIONICS (01-JUL-2009) [TM 1-1500-344-23-5 (ARMY) AND TO 1-1-689-5 (USAF)]

( and kick at a stone with toe )



hank