The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: drewsonofdean on October 22, 2017, 11:36:56 PM

Title: Engine Corrosion
Post by: drewsonofdean on October 22, 2017, 11:36:56 PM
Hi All,

My bike has some corrosion all over the engine. It isn't deeply pitted or anything, but needs work.

Not sure what the proper technique would be. I am trying to avoid have it bead blasted or anything major like that...

Any pointers would be much appreciated!
Title: Re: Engine Corrosion
Post by: Adrian on October 23, 2017, 12:44:21 AM
Hi there - I had my motor rebuilt recently and they forgot to get the casing/block soda blasted so I had a completely restored motor that wasn't clean.
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I used a small green washing up scourer (about 6x4 inches in size) - and used it dry - I was surprised at how clean the casings became. Not blasting clean but pretty good.
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I could see the surface layer of corrosion drifting away as a fine powder so I could see the results quickly.
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So maybe this would give you a good enough finish :-)
Title: Re: Engine Corrosion
Post by: Barry on October 23, 2017, 03:13:50 AM
I've used the industrial version of a kitchen scourer - Scotch Brite sheets and mops. They are available in several grades but you need to be careful with the coarser grades as unlike kitchen scourers they are impregnated with abrasive particles.


  
Title: Re: Engine Corrosion
Post by: Tony Smith on October 23, 2017, 03:21:44 AM
Second what Adrian said.

I loathe physical effort and have tried every lotion and potion known to man in an attempt to improve the look of my engine case, gearbox and final drive.

I report 100% failure.

Obviously the "gold standard" is soda or vapour blasting, but that isn't possible on an assembled component. The only two things I have found to work are :

1/. Scotchbrite (green) and WD-40
2/. Paint (either Wurth silver wheel paint or Krylon "dull
     aluminium")

There is one other I'll mention in passing which I know works absolutely brilliantly but which is simply not available to we mere mortals. A German company called Henkel makes a number of Aluminium "washes" in a variety of colours - you will most likely find it in use at your local brake rebuilder, he will use it to restore the blue/gold/silver/red colour of brake calipers.

It works brilliantly and is very simple, clean and degrease the part, wash in solution "A", then wash in solution "B" - job done.

Now, here is the rub. The chemicals used are classified as "dangerous goods" and a 5lt kit costs in excess of $AU300.

Talk to your local brake rebuilder you never know... I asked mine and he wasn't interested.
Title: Re: Engine Corrosion
Post by: Justin B. on October 23, 2017, 11:52:19 AM
The method I've had good luck with has been a good thorough cleaning/scrubbing with full-strength "Greased Lightning" followed by Eagle 1 Mag Wheel Cleaner for bare wheels.  The Greased Lightning is a highly alkaline super strong cleaner and the Eagle 1 contains acid (phosphoric, I think) to get down into the pores.  I spray on, wait for a couple of minutes, then scrub like hell and rinse. 
Title: Re: Engine Corrosion
Post by: drewsonofdean on October 23, 2017, 01:04:33 PM
Guys thank you all for the feedback!!

I am pissed at myself for getting a bike with engine corrosion. But I guess its hard to get a 79' r65 without it?

Bought it in Washington, shoulda stuck to California bikes only!!
Title: Re: Engine Corrosion
Post by: Justin B. on October 23, 2017, 08:27:34 PM
The castings are raw aluminum so over time they will oxidize.  The '82 LS I rescued from New Orleans, after Katrina, was really nasty but the greased lightning and Eagle 1 made it fairly presentable.
Title: Re: Engine Corrosion
Post by: drewsonofdean on October 25, 2017, 10:16:37 PM
Thanks all, I will give these methods a shot and see what works best.