How do I clean out a rusty seat tube?

[FrankNBrew]

I pulled the seat post out of my 1956 Schwinn and the post was about 4" long. So I picked up another post of full length, but it does not want to go in any further than a couple inches. I need to clean lots of rust from inside the seat tube. Is there a special tool made just for this? Or is there something you can suggest to somewhat easily remove a lot of rust?

 

[Kevin B]

I slot a dowel rod length ways about 1" from the end. Then insert a strip of sand paper rolled in the direction of my drills rotation (actually emery cloth might be better). Next I chuck that up and put it in the tube running it up and down. I have been thinking about getting an automotive brake cylinder hone for using on bottom brackets, head tubes and seat posts.

 

[Willis617]

I slot a dowel rod length ways about 1" from the end. Then insert a strip of sand paper rolled in the direction of my drills rotation (actually emery cloth might be better). Next I chuck that up and put it in the tube running it up and down. I have been thinking about getting an automotive brake cylinder hone for using on bottom brackets, head tubes and seat posts.

I've done similar to what you describe, I have also used a wire coat hanger folded around some sort of abrasive material and twisted run in a drill motor, lastly a plumbers wire pipe brush with the handle cut off held by the set screws in a 1/4 inch hex drill extension, all with oil, the coat hanger then works well with a solvent soaked rag patch to clean, alot like cleaning a gun barrel

 

[Captain Awesome]

I slot a dowel rod length ways about 1" from the end. Then insert a strip of sand paper rolled in the direction of my drills rotation (actually emery cloth might be better). Next I chuck that up and put it in the tube running it up and down. I have been thinking about getting an automotive brake cylinder hone for using on bottom brackets, head tubes and seat posts.

Exact same method here. I used to have a small set of hones, but those are long gone

 

[Kevin B]

I found something on Instructables. Difference is this guy uses aluminum rod. Now I know they are called flap sanders. https://www.instructables.com/id/Simple-DIY-Flap-Sander/

 

[whitecoyote]

Try a 12 Gauge (shotgun) brass brush.

 

[amecks]

I never really knew they had a name - flap sander. I just used one to clean rusty tubes. It is a 1/2" steel tube about 15" long, and slotted maybe 2" for sandpaper. But I used a chunk of old belt sander loop which is very tough and rather coarse. Chucked it into a cordless 1/2" drill. It did a great job and the tubes came out very clean/smooth. Can post a photo if needed.

 

[Kevin B]

Steel tube is a great idea.

 

[FrankNBrew]

All great ideas! Thanks! I ordered a 1" pipe cleaning brush from Amazon. Interestingly when I removed the seat post I found a piece of metal pipe inside the seat tube. I'm guessing it's around 5/8" diameter. My only guess is somebody put that in there to prevent the seat post from going in too far?? I can't imagine any other reason for it. Maybe I'll try turning that into a flap sander.

 

[amecks]

I took a photo while I was in the garage yesterday. This sanding belt is tough and did a really good job of cleaning the rust out.