Front cover corrosion

[Bendy toy]

Many of us are familiar with the dreaded front cover lifting paint syndrome.

Before showing blue black where ACF-50 has soaked in. Equal mess inside and outside the cover suggests stone chips are not the cause.

http://tapatalk.imageshack.com/v2/14/09/07/449012fd99bd7996fc4f09438b6ee3a0.jpg

Sadly I don't have an image after paint stripping.

This is recoated.

This is around the belt cover bottom retaining screw - similar lumpiness both sides of the joint ridge. Fortunately it's only obvious because I faffed with the lighting.

Further down, the surface around the bottom two bolt holes is very slightly uneven but the area between is smooth. Sadly I don't have a just stripped image. The centreline where stones should hit is original surface doesn't support the stone chip theory.

 

[TLSgazza]

I've got to do mine this winter, paint is peeling off all over it now, I also have a slight oil leak coming from under the black plastic cover,
Did you get both sides covered, and have you also coated the gasket surface where it attaches to the engine, I assume it's powdercoat you have put on it, have you had any trouble with it cracking when bolting back up to the engine around the bolt holes,

 

[Blackal]

Something which was related to me by a BMW mechanic:

There is a danger of the powdercoat on the bolt-landing faces - cracking in service. The bolt can then loosen and the cover work loose also.

Thin paint is recommended for those landing faces.

Al

 

[TLSgazza]

Something which was related to me by a BMW mechanic:

There is a danger of the powdercoat on the bolt-landing faces - cracking in service. The bolt can then loosen and the cover work loose also.

Thin paint is recommended for those landing faces.

Al

Which was pretty much why I was asking,

Ps: have you bought new bolts, if so what did you use, I was thinking about stainless but have heard stories about using stainless into aluminium ,

 

[Blackal]

Sorry Gazza - I skimmed past your post.

There is no problem using stainless bolts. I would coat the bolts in a low-yield nutlock - it acts as a lubricant, then cures to prevent the bolts workign loose.

Al

 

[Pukmeister]

I posted about this YEARS ago: My first 1200 had several covers under warranty.

The way I eventually solved the galvanic corrosion problem once out of warranty was to use a dielectric paint on the cover bolt threads to prevent the reaction between dissimilar metals.

I bought it from a yacht chandlers, it was by a munafucturer called 'Starbrite' (liquid electrical tape) but others had success with a similar product called 'Duralac'. Both are available on eBay.

 

[Bendy toy]

I suspect paint or powder coat will crack. The original was a very tough paint but seems to have failed at bolt holes rather than stone chips.

Next time I'd probably paint but I've powdered covers on other bikes with no problems.

If painting, chamfer the sharp outer edge of the joint, dip strip and paint with an etch primer inside and out. Leave bare metal for the seal and hall effect sensor. That way corrosion can't creep under the joint edge

Use a good gap filling sealant and washers under screw heads an a good quality copper base anti seize. Copper interrupts the galvanic effect between steel and aluminium.

Fit washers round edge towards the cover less cutting effect than the other side.

 

[Yellow Peril]

You had your cover dippied local to you? Just I have a couple of bits that need doing, did the dippers put on the galvanise after the dip?

 

[Bendy toy]

I had mine done by Terry and Will Wing near Totnes Devon. Wings Powder Coating.

They use Biostrip it's safe with aluminium and magnesium. If you don't want powder coat they can also grit blast it to key the surface.

I've had my FD case, swing arm and steering headstock done in "Titanium" silver powder coat that they use on alloy wheels.

The latter are to be honest a bit of bling but I didn't want a patchwork of colours on the bike.

In the Midlands, EnviroStrip Tamworth (who can do whole car bodies) will do a great job on bike parts.

 

[Bendy toy]

did the dippers put on the galvanise after the dip?

The coaters used a zinc primer on the steel parts then powder coat over. I had to clean some off where I forgot to tell them to mask it and it's certainly tough.

Galvanised is used on land rover chassis but too rough for a bike frame. Electro plate better but costly and may need special primer. Any undercoat/primer used with powder coat has to be electrically conductive. So it's pretty much as good as electroplating.

The primer won't work on aluminium and in my case did not stick quite as well to the stainless steel VIN tag.

The coaters had masked off the number but I didn't like the look so carefully stripped the stainless tag back to bare metal.

 

[Bendy toy]

Ive used a high solids content copper anti seize paste on the bolt threads. It's grease based but texture is more like stiff toothpaste. Think of set honey against Copaslip''s runny honey style. It's non greasy but is a lubricant so I've not used it under the washers for fear of them spinning on the paint. Pressure is one thing but torque and pressure has to be damaging.

Its probably worth painting the paste inside the bolt holes (in addition to coating the screw threads) but clean off under the washer landing faces.

Fussy? You bet! British road salt is harmful not only after winter but also for most of the spring and even longer if we don't get a lot of rain to wash it off.