Reel Repair by Alan Tani

General Maintenance Tips => General Questions and Trouble Shooting => Topic started by: wfjord on April 13, 2017, 01:39:15 AM

Title: Corrosion on Shimano drive gear
Post by: wfjord on April 13, 2017, 01:39:15 AM
This is the underside of the drive gear of a Bantam MagPro BMH250sg XHS. There's some corrosion on the gear where it contacts the base drag washer. What is the best way to remove this corrosion?  Almost looks like rust. Isn't this a brass or bronze gear?

(https://cache.nebula.phx3.secureserver.net/obj/Mjc3MTlCQkIzNTExNjhFOTMyOUE6Mzg3NzAxZWNhNmY5Mjg4OTE0OGVlMDIxZGQ3NWQzYmI=?uid=73d3b842-2b9e-42db-8cda-0e835298b6e4)
Title: Re: Corrosion on Shimano drive gear
Post by: Rancanfish on April 13, 2017, 01:51:11 AM
I use the Sal method.

Lay a sheet of wet or dry sandpaper flat, (I wet it with a couple drops of oil).   I use 1000 grit because I don't have polishing tools if the sandpaper scratches.

Lay the gear flat and push it around in circles.  It will come out smooth. 
Title: Re: Corrosion on Shimano drive gear
Post by: ReelClean on April 13, 2017, 02:49:01 AM
Quote from: Rancanfish on April 13, 2017, 01:51:11 AM
I use the Sal method.

Lay a sheet of wet or dry sandpaper flat, (I wet it with a couple drops of oil).   I use 1000 grit because I don't have polishing tools if the sandpaper scratches.

Lay the gear flat and push it around in circles.  It will come out smooth. 

As Rancan said, I would only add find a small sheet of thickish glass to use as a flat surface.
cheers
Steve
Title: Re: Corrosion on Shimano drive gear
Post by: Cor on April 13, 2017, 03:02:16 AM
Ditto the two above, have done so often. ::)
Title: Re: Corrosion on Shimano drive gear
Post by: wfjord on April 13, 2017, 03:13:34 AM
Thanks, Rancanfish.  Will do.

ReelClean, coincidently I do happen to have a thickish sheet of glass under the neoprene mat on my work bench.

Thanks...
Title: Re: Corrosion on Shimano drive gear
Post by: ReelClean on April 13, 2017, 03:52:48 AM
Quote from: Cor on April 13, 2017, 03:02:16 AM
Ditto the two above, have done so often. ::)
Yeah, Dartanium washers leave a hell of a mess on main gears.
Title: Re: Corrosion on Shimano drive gear
Post by: MarkT on April 13, 2017, 03:57:37 AM
It looks like a washer under the gear disintegrated and stuck to the gear rather than being corrosion.
Title: Re: Corrosion on Shimano drive gear
Post by: ReelClean on April 13, 2017, 04:08:06 AM
Graphite can accelerate galvanic corrosion if exposed to an electrolyte such as salt water.  I suspect that dartanium might have a high graphite content from what I see on the washers in Shimano drags.  There may or may not be corrosion residue, but there is usually a lot of pitting and discoloration once the washer is scraped off.
Title: Re: Corrosion on Shimano drive gear
Post by: wfjord on April 13, 2017, 05:21:55 AM
Bought that reel off fleabay and just got it. Mechanically good & casted okay so I jumped right on overhauling it. The washers were greased, looked awful, stuck to the gear and covered with an ugly black grease of varying consistency. Had to remove them with an exacto knife and was really surprised to see what looked like rust on the underside of the gear. I just did some reading about Dartanium washers. Apparently they can get pretty nasty.

The black stuff on those pieces of paper towels in the photo is gunk that came from the drag washers.

(https://cache.nebula.phx3.secureserver.net/obj/Mjc3MTlCQkIzNTExNjhFOTMyOUE6ZTRjMTQ2YzgyYzEyNDBmZTkxMTdlODA1YWFkNTEyYzI=?uid=06114ace-adc8-4e20-bf40-35f4bed371dc)
Title: Re: Corrosion on Shimano drive gear
Post by: Lunker Larry on April 13, 2017, 02:53:14 PM
Don't need to scrape that gunk off. WD40 takes it off easily. You will still have the staining but the surface will be clean.
Title: Re: Corrosion on Shimano drive gear
Post by: humboldtdan on April 13, 2017, 05:42:35 PM
Are they still using dartanium washers?  Worst drag washers ever!