Fixing up a corroded K1100RS

[JonnyB]

Before I start, I don't fully understand the process of uploading photos, added them to Flickr, copied the URL into the "insert image" button and a little emoticon of a broken document came up. any help? I'll put links for the time being till I figure it out. Thanks

Hi everyone, this is my first post.

I just received delivery of my new (to me) K1100RS. I took a punt on eBay. Didn't ask many questions about the bike, although it looked in good shape in the photos. Everything works and it rides nice and smooth. 66,000 miles. Service book is filled out only to 12,000 miles.

https://www.flickr.com/photos/8294189@N07/35307533922/in/dateposted-public/

Looks good right, but the closer I looked, the more evidence of neglect was visible.

https://www.flickr.com/photos/8294189@N07/35307534012/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/34664634423/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/34664634003/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/35088010530/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/34664636623/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/35088012630/in/dateposted-public/

https://www.flickr.com/photos/8294189@N07/34664634523/in/dateposted-public/

and the worst, under the radiator:
https://www.flickr.com/photos/8294189@N07/35088010290/in/dateposted-public/
https://www.flickr.com/photos/8294189@N07/35307533982/in/dateposted-public/

The worst of it is actually powdery white oxidation on the engine under the upper fairing that I couldn't work out how to remove yet.

It seems in good internal mechanical condition except for the sad reality that it must have been left outside uncovered for 10 years or so.
Particularly there is aluminium oxidation bubbling through the paint in most places to a greater or lesser extent. I want to clean it up nicely but without going in for a full overhaul. That basically means avoiding removing the engine, and the more fiddly bits of electical equipment.

Interestingly though, it looks like it's had a pretty good service once upon a time, and they replaced most of the bolts around the engine and lower frame with nicely machined Stainless ones. Also the oil sump plate  looks recently replaced/reconditioned. There are also some nice braided brake hoses in there.

I think the first job will be to sort out that mess around the water pump. I'm not sure how, but I will need to clean out and re-protect the the cooling fins. The cylinder head and crank covers will come off and be repainted. I'd also like to renew the side-stand, center-stand and and exhaust (failing that, I'll chop at the headers and fit a 4 to 1 and custom exhaust). I also would love to freshen up the brake discs, ABS rotors and brake calipers, which are looking rusty, dulled or corroded. Question is, how can I protect these and prevent flash rust.

Does anyone have any tips/tricks to clean up slightly corroded painted aluminium, or will I need to bring it back to bare metal and start again? Are there any products to prevent aluminium corroding (like Hammerite for Alu).

If I can scrape some pennies together, I may also put a RAM shock on there as the old one is rusty (and a bit springy)

Much further down the line, this might end up in a cafe project, depending on funds and how I get on with it as a tourer.

Any info on rejuvenating your K bikes (K1100 preferably) please let me know.

Regards, Jonny.

[JonnyB]

Also, can someone tell me if this axle is fixed up correctly. It looks like there should be a pin in there or it should be further in?

Thanks

[Martin]

You could try a mag wheel cleaner but make sure it's not too corrosive and rinse thoroughly. A light coating of WD40 or similar will help keep corrosion at bay or you could try clear coating with matte clear. As far as the front wheel goes, where do you think you are missing a pin. I can't see anything wrong. Why do you think something is wrong?
Regards Martin.

[Laitch]

Also, can someone tell me if this axle is fixed up correctly. It looks like there should be a pin in there or it should be further in?

The large hole is there for insertion of a bar, screwdriver shank, or plug wrench rod to help pull the axle out when you need upper body exercise.

k1100 wheel assembly from MAXBMW parts fiche.png (40.87 kB . 484x285 - viewed 337 times)

[The Mighty Gryphon]

I can't really speak to the aluminum corrosion, but as to the frame rust(just wait to see what is hiding under the rear cowl) I have had pretty good luck with a wire brush on a drill followed by paper towels saturated with white vinegar wrapped around the rusty bits covered by plastic bags to prevent the vinegar from evaporating. 

Leave the towels in place for a day or so.  Keep an eye on them and add more vinegar when they dry out.  After you take them off, rinse with clean water, wipe dry, and follow with a "rust converting primer" that contains phosphoric acid.  Recoat time for the primer is about 24 hours, follow this with a red primer followed by a satin black enamel.  This should give you a fairly durable finish that will match the original paint.

On the aluminum, I would try a product sold here called "Aluminum Jelly".  Apply with a paint brush, let it sit for 5-10 minutes and rinse off with clean water.  Follow with a good aluminum primer and satin black high temp engine enamel.  I suppose the good news here is that the RS fairing will hide most of the aluminum funk.

[JonnyB]

Thanks all for the advice.

The large hole is there for insertion of a bar, screwdriver shank, or plug wrench rod to help pull the axle out when you need upper body exercise.

Thanks for clearing that up. I thought maybe some BMW scale split pin ought to go there but the hole is too big for that to make sense.


With the corrosion, as you suggest, I will try to brush it off and use derusting primer and paint or maybe just hammerite in some of the smaller hidden imperfections. The aluminium on the main engine casing is thick coated in white powder oxide, I will most likely need to get the brass wheel bit on a drill bit to take that off, then primer and high temp enamel as you suggest.


I want to get stuck into it but my conscience is telling me I should finish writing my uni thesis first, so it will have to be in Aug/September when I'm done.


I've also sized up and bought stainless screws/bolts/washers and plugs for most things I can easily get access to. They're all rusted up so it should make a big difference to the look. I might add a drop of rust neutraliser (Hammerite Kurust) into the steel threads to stop them rusting further before fixing the stainless fasteners in. Does that sound like a good idea, or should I just blast with WD40?

[Laitch]

A brush and Scotchbrite pad would be useful. I'd probably use a wire wheel and copper anti-seize for the original bolts if replacement is far off.

Are you studying agronomy or are you just a pepper aficionado?

[JonnyB]

Thanks for the tips,


I'm just a big fan of hot peppers, although I'm fascinated with botany and agronomy in general, I'm a chemical engineer by academics. Started with a desire to grow insanely hot things to try out on my siblings and now I'm engaged to an Ecuadorian girl so I like growing South American peppers to make authentic dishes as we cant get right the chillies here in London.

[The Mighty Gryphon]

As a ChemE I would think you would have some idea as to the corrosion processes and the best ways to correct them.  Painting without completely neutralizing the corrosion process is a waste of time and materials.  Take the time to prepare the surfaces properly.  You will be glad you did if you intend to keep the bike for more than a year or two.

As to fasteners, a 50:50 mix of automatic transmission fluid and acetone has been shown to be the best solution for breaking loose rusted fasteners.  Apply it to fasteners for a few days to allow it to work before attempting to remove them.  Be aware that there are some fasteners like those for the brake discs that are secured with LocTite and require heat to be broken loose. 

Invest in a good torque wrench and some copper anti-seize before you start replacing fasteners.  Unless you are using hardened stainless fasteners, I would suggest reducing the torque settings by 10-15% both to reduce stretch on the fastener and to allow for the lubricating properties of the anti-seize.

You should be able to do a fairly good restoration on your bike.  Except for the aluminum corrosion on the engine it is no worse than the K100RS I restored a couple years ago.

[JonnyB]

Thanks for the advice, yeah we learn redox reactions and the like but you can't beat the advise of a seasoned expert. Theory and practice often turn out very different. I know that aluminium oxides and hydroxides which is the white/grey corrosion on there react with both acids and bases, but then so does the aluminium, and from lab experience, bases like Sodium Hydroxide tend to stain the metal, so I might try a some oxalic acid solution (weak acid but a lot stronger than vinegar), then go over with some fine sand paper or pure brass wire wheel (steel brushes have ruined my alu parts before!)

Good suggestion with the ATF/acetone mixture, there are anti-oxidants in there that might even help protect the steel. Funnily enough, I tried to remove a rusty brake disc bolt unsuccessfully to size it up for Stainless replacements. I didn't realise they were lock-tited. I'll get my crème brulée torch on them! And I should apply anti-seize (copper slip) to the bolts when replacing them? I haven't been doing that till now. I guess torquing them right is crucial then in case they either fall out or stretch/strip threads. I'll get on ordering one.

[JonnyB]

Wondering if anyone can advise me: My ABS stepped sensor rings are rusted. I want to soda/sand blast the rust off and then protect with a paint or clear coat or something to preventing it flash-rusting back the moment I put it back on. Is this a wise thing to do (I'm planning to use an aerosol spray for a thin coat) or could it affect the ABS sensor?

Thanks, Jonny.

[Filmcamera]

There is a recommended gap of 0.50mm to 0.55 mm between the ring and the sensor on the front and 0.60mm to 0.65mm on the rear so as long as you have the correct shims to keep that distance I think a layer of paint or something should be ok.