White powder where screws meet aluminum

[Fritz The Cat]

Just did my brakes and every screw I removed exhibited a white powder which I assume is from corrosion. The bike has never been stored outside as far as I know. It doesn't have any pitting in the chrome or any signs of weathering. When I removed the caps that cover the screws that hold the brake pads in, the space inside was full of white powder. Ditto on the screws that hold the brake reservoir cover on.

  I'm thinking this is due to dissimilar metals used. Is there any way to avoid it?

  Also, I have a screw on the clutch reservoir cover that won't break free. It's made of soft metal and the screw driver promptly mangled it when I applied torque. Why they used such soft freaking screws is beyond me. Any suggestions on how to proceed much appreciated.       

[olddog1946]

BEst thing to do is use anti-sieze on the bolts/screws..it is caused from dissimilar metals..
If you don't have one of those motorcycle impact drivers (uses a hammer to jar things loose) you can get similar results with the screw driver and a ball peen hammer, but the driver is the way to go.

[Ricky-D]

The has just been a recent thread regarding the hydraulic reservoir screws.

Understanding that there are different styles of (phillips head looking) screws with each needing a different screwdriver goes a long way to preventing stripping out the screw head.

Knowledge is power!

***

[JC]

Using a drill bit slightly larger than the screw shaft, I would slowly drill the top of the screw off and remove the remaining shaft with vice grips.

+1 on the dissimilar metal. A touch of anti-seize should help some.

[old2soon]

When i was in the Navy we called that stuff corrision. Spent my first couple months taking care of corrision. At sea with aluminum aircraft it was a never ending battle. RIDE SAFE.

[RP#62]

When i was in the Navy we called that stuff corrision. Spent my first couple months taking care of corrision. At sea with aluminum aircraft it was a never ending battle. RIDE SAFE.

But now its called corrosion.
(Sorry, couldn't resist - I'm an old navy brat)
-RP

[John U.]

Just did my brakes and every screw I removed exhibited a white powder which I assume is from corrosion. The bike has never been stored outside as far as I know. It doesn't have any pitting in the chrome or any signs of weathering. When I removed the caps that cover the screws that hold the brake pads in, the space inside was full of white powder. Ditto on the screws that hold the brake reservoir cover on.

  I'm thinking this is due to dissimilar metals used. Is there any way to avoid it?

  Also, I have a screw on the clutch reservoir cover that won't break free. It's made of soft metal and the screw driver promptly mangled it when I applied torque. Why they used such soft freaking screws is beyond me. Any suggestions on how to proceed much appreciated.       

It's probably too late now but for future reference, those screws that look like phillps are JIS (Japanese Industrial Standard)
http://www.rjrcooltools.com/vessel.cfm
More power to you. 

[YoungPUP]

Just to add some salt to the wound, the screwdriver in the tool kit fits the screws nicely...

[FryeVRCCDS0067]

I cut a slot in a stubborn reservoir screw with the appropriate cutting tool in my dremel and removed it without further problem. I didn't do it until the new screws arrived though.

I generally use locktite to avoid corrosion, the "low strength" type in the chapstick type tube. After using the chapstick applicators I'll never go back to the old bottles.

I don't keep the "high strength" type in my home shop just to avoid mistakes. I do keep it at work since I have one machine which requires it on a high-speed/high-torque drive assembly.

I wouldn't use locktite on reservoir screws though!

[JaysGone]

The phillips head screws on the Valk are J standard and yes the white powder is aluminum rust for lack of a better word.
I had to replace almost every screw on my project Valk as they all got buggered over the years from neglact.
Ant that nice white powder was almost everywhere.
Leave a Valk out doors in the fine Florida weather for 2 years............makes for a nice cheap restoration project. The bike that is not the restoration........

[Chrisj CMA]

    Also, I have a screw on the clutch reservoir cover that won't break free. It's made of soft metal and the screw driver promptly mangled it when I applied torque. Why they used such soft freaking screws is beyond me. Any suggestions on how to proceed much appreciated.       

That line cracked me up.  The screwdriver did it huh.......just like spoons made Rosie Odonald fat.......sorry but that there was just very funny to me (I hope you intended it to be)

For those that havent learned this and dont want to learn the hard way like me and Fritz.......I watched my screwdriver mangle a few screws way back when on my older bikes until I learned to:

A.  Not neglect them for years and then expect them to pop right off.  Especially the reservior screws that are right out in the elements.....I remove them as soon as I can before that white stuff appears.  Clean them and add some antisieze. 

B.  Anytime you get ready to remove a small screw like that in aluminum...Put the driver in and tap on the handle with a small hammer.......this helps "break free" the corrosion hold if there is any inside

C.  And probably most importantly.....make sure you are using the correct tool.  If it is standard phillips, size matters.  Many people select a too small of phillips head and they too get to watch their evil screwdriver mangle the head.  Or some people only have one driver (#3 usually) and use it on every phillips head the teeth will physically get into.......not ideal

[pocobubba]

I have replaced some of my screws with stainless . Does anyone know how stainless and aluminium react ?

[JaysGone]

The phillips head screws on this bike are not standard American head screws.
Most Sae phillips are numbers 00,1,2 or 3.
These on the Valk aint.
While close they are not the same.
Its very easy to booger them up using the wrong driver bit.
They are made to a Japanesse standard and are different altogether.
I went out and got the propper screw head bits for my driver set and have not had a single issue since with any metric bikes Ive owned.