White death - what to do?

[atpchas]

I'm assuming the corrosion I found inside this Stihl 026 is what goes by the name White Death. Whatever it is, what (if anything) can be done to stop it? The picture shows the only occurrence - under the FW side bearing. It looks to me like critical surfaces are still OK, but can the WD be stopped or should I just look for a replacement case?

 

[trappermike]

How old is the saw,and did you find a white powdery substance where the corrosion was? I'm not positive but I think that corrosion is from the alcohol in some of the new fuels.
Back in the 80's in older Stihls with metal tanks I used to see white goo(When wet) or white powder in the metal fuel tank of some saws,when I cleaned the tanks out there would be heavy corrosion and pitting in the magnesium tanks. We thought it might be from guys adding alcohol in freezing weather,so we took a little chunk of magnesium and dropped it into a cup of alcohol,in a few days it was almost totally dissolved.
I wonder if alcohol blended gas didn't cause that corrosion?

 

[Jacob J.]

From what I can see, your case is still usable. Wire brush off any of the loose material. There's not much to do with
it except give it a liberal coat of PB Blaster or something similar to slow the corrosion. There may be a way to paint
that but it would have to be heat and fuel resistant paint, which of course you can't leave on the bearing or seal seat.

 

[lmbrman]

I will be curious to see what you decide on this WD and how it works out. I have an old c5 I wanted to work on, but found similar but worse WD everywhere on and in the case.

Keep us posted, good luck!

 

[trappermike]

It seems the exposed unpainted metal was corroded. Maybe some kind of epoxy paint would work?
Maybe an automotive paint supplier could suggest something.

 

[cujet]

It is just about impossible to stop corrosion on magnesium once it gets started. Paint won't work. The corrosion is intergrannular and a surface coating will simply allow the corrosion to continue underneath.

The best bet is a thick oil that can penetrate and remain there. Products like LPS-3, Cosmoline, Par-Al-Ketone, Boeshield, Corrosion X heavy duty, and so on are often very thick oils, thinned with a carrier (like lacquer thinner, MEK, acetone or similar) .

The oils penetrate and then become waxy. They do a great job of corrosion prevention. However, they must be applied regularly for effective protection.

My guess is that you are not seeing corrosion anywhere the chain oil is. Just where it's dry.

 

[lwn9186]

I have also seen the corrosion like you have on saws that the bearing isn't exposed on that side. I think if you would clean it real well, coat with oil, install an open bearing, it will receive mix and be alright.

 

[CM76]

I have successfully battled mag corrosion using a chromic acid solution. Chromic acid is fairly easy to acquire, and is a long term solution to the 'white death'. Procedures can be found on the web.

Chris.

 

[Eccentric]

I have successfully battled mag corrosion using a chromic acid solution. Chromic acid is fairly easy to acquire, and is a long term solution to the 'white death'. Procedures can be found on the web.

Chris.

That's good information Chris. I have a couple of saws with WD starting, and I'd really like to save 'em.

 

[ncfarmboy]

Would the zinc chromate primer for alum. work? You can get it in a spray can.
Shep

 

[xtremez]

The race for the bearing looks untouched. I'd either bead/sand blast the corroded part, being careful not to over do it. Or like mentioned above use a wire brush on a dremel or something and then coat that surface with something. Id look into the POR 15 product line up. The have a coating that neutralizes rust. WD is caused by alcohol in the gas. It shows up everywhere now because our wonderful government is cramming alcohol blended fuels down our throat. Once you fix it up I'd start mixing some Marine Stabil in with your gas.

 

[CM76]

Be careful using a wire brush on corroded mag as it will contaminate the surface and assist the corrosion process. Glass bead cleaning is the way to go in order to prep the surfaces affected by this type of corrosion.
The application of chromic acid is the best way to neutralize the corrosion and prevent further breakout.

Chris.

 

[RiverRat2]

Another good post!!!

Be careful using a wire brush on corroded mag as it will contaminate the surface and assist the corrosion process. Glass bead cleaning is the way to go in order to prep the surfaces affected by this type of corrosion.
The application of chromic acid is the best way to neutralize the corrosion and prevent further breakout.

Chris.

It wont let me rep ya twice,,, somebody give this guy some green rep!!! Ehhh???

 

[lwn9186]

It wont let me rep ya twice,,, somebody give this guy some green rep!!! Ehhh???

Got'em

 

[trappermike]

So guys I'm still wondering if the White Death is the result of Ethanol mixed fuel in the U.S.,we don't really have it here in Canada and I've not seen this problem except in work saws in cold temps. where guys put alcohol in their fuel causing corroded tanks in saws like 056's.
Anyone else have a theory of what causes it?