Help choosing a primer for engine casing.

the beer hunter · Dec 5, 2009

Winter's here so it's time to do something about my flakey engine casing on my 1200GS.

I just need some advice on which primer to use.
Apart from price, what's the differance between these 2 Wurth primers?

£8.99 acid etch primer - 450ml

£18.99 wheel paint primer - 400ml

John Armstrong · Dec 5, 2009

I'd go for the acid etch primer as that's what was used when I did small repairs on aircraft that needed protecting afterwards.

the beer hunter · Dec 6, 2009

Cheers John, I bought a tin of U-Pol #8 acid etch primer from Halfords & I've spent a few hours in the garage this afternoon stripping bits off & prepping the casing.

:thumb2

Mr K · Dec 6, 2009

the beer hunter said:
Cheers John, I bought a tin of U-Pol #8 acid etch primer from Halfords & I've spent a few hours in the garage this afternoon stripping bits off & prepping the casing.

I'm watching!

:postpics

the beer hunter · Dec 6, 2009

Mr K said:
I'm watching!

I'm in no rush so I'm taking my time.
I've ordered Wurth paint & lacquer so I can't really get stuck in before that arrives. There's a set of A4 marine grade stainless bolts on the way too.

Day 1:

Assessed the situation.

Removed the crashbars & sump plate.

Made a start removing loose paint.

Tomorrow I'll take the paint back some more & clean.

Mr K · Dec 6, 2009

Doesn't look too bad.

:thumb2

the beer hunter · Dec 6, 2009

I took the sponge out when I bought the bike back in January 2007, (it's a 2005 bike btw) the casing was OK back then. I fitted a fender extenda at this time too.
It looks to me as if water has been exiting from the bottom of the belt cover & has just got underneath the paint & lifted it away.

At this stage of the job I've just got to remember - PPPPP :thumb2

What's the general rule regarding prepping the suface, should I remove all the paint or just the loose stuff?
The spec on the etch primer states it will stick to old paint as well as the bare metal but will the transition from bare metal to paint show up on the finished job?
As you can see from the 3rd photo, any defects in the surface will hardly shout out at you will it?

John Armstrong · Dec 6, 2009

The final finish all depends on the preparation.

I'd remove as much loose / corroded material as possible, but not by using wire wool to do it

Deleted account 211028001 · Dec 6, 2009

the beer hunter said:
I'm in no rush so I'm taking my time.
I've ordered Wurth paint & lacquer so I can't really get stuck in before that arrives. There's a set of A4 marine grade stainless bolts on the way too.

Day 1:

Assessed the situation.

Removed the crashbars & sump plate.

Made a start removing loose paint.

Tomorrow I'll take the paint back some more & clean.

Hi
what size are the bolts and where have you ordered them from?

the beer hunter · Dec 6, 2009

The 12 bolts around the casing are M6 x 30. (make sure you ask for allen headed set-screws i.e threaded right up to the head)

eBay has it all! :thumb2

There's a seller called boltmeup, if you send him a message with your requirements he'll put a set together & list it.

the beer hunter · Dec 7, 2009

..or you can go to shawstainless & get the full set (inc the bolts for the plastic cover) with washers for £15.95.

Wurth paint & lacquer from Performance Motorcare for £23.98

Both the above accept PayPal.

Right, I'm off to B&Q to get some more supplies, back later with an update. :type

the beer hunter · Dec 7, 2009

Day 2:

I didn't have to take the front wheel out but I wanted to replace the tyre so now seemed like a good time.

Made a start stripping back the paintwork. (Nitromors, £3.98 - B&Q

)

I'll do this in stages because it's very boring & I want to do a decent job.
I'm just applying nitromors in small areas with a small brush & slowly working around the casing paying attention to removing all the paint around the mounting holes. The bolts are removed of course.

I realised today that all the weight is over the front so it won't balance on the mainstand without some support under the front. (note jack under engine, axle stand under front axle & DRZ wheels on the pillion area.)

Still waiting for the paint & lacquer to arrive so I'll finish off the stripping another day.

Thanks to Easyrider5258 for the inspiration, info via PM & giving me a standard of preparation to aim for. :thumb2

Easyrider5258's 1200RT

the beer hunter · Dec 12, 2009

Day 3:

Stripped all the paint from the final visible area.
Roughed up with some wet & dry and cleaned.
Ran the bike for a while to warm things up.
Masked everything up.

Primed, painted & lacquered. :thumb2

the beer hunter · Dec 12, 2009

As soon as I peeled off the newspaper & tape I was impressed with the results.

What do you think? :thumb2

Greased up some new stainless bolts & threw it all back together.

I'm very impressed indeed.

from this..

to this..

Bolts by Chris Shaw.

John Armstrong · Dec 12, 2009

Looks good :thumb2

HondaMan · Dec 12, 2009

Looks like a really good job, well done :thumb2

Wonder how long it will last.......hopefully longer than the original but I'm not sure, especially if you use it in winter. Fingers crossed though, and like I said, looks real smart.

Pukmeister · Dec 18, 2009

Nice paint finish in your pics.

Instead of using grease on the bolts, you'd be better off using a dielectric paint to reduce the effect of a dissimilar (galvanic) reaction between the stainless and alloy eg starbrite or duralac.

http://www.bssa.org.uk/topics.php?article=89

Flipper_Man · Dec 20, 2009

Why on earth dont BMW use these bolts in the first place ?! Surely at the quantity they are buying the cost difference is neglible ?

Last year was supposed to be a big push for BMW Mottorrad to get the quality sorted. They accepted that with the big volume increases, quality had slipped (although I've had poor quality, through winter riding, with ALL the BMW bikes I've had in the last 10yrs ...). So why dont they take the time to have a flick through a couple of forums and see where the most 'popular' complaints are ?

I still think that BMW only get to hear from a very few disgruntled customers that ride their bikes throughout the year - and thats when the problems arise.

Looks like a great job btw. BUT a customer shouldnt have to take all the time this has taken to rectify an issue that should never arise !

komatias · Dec 21, 2009

Just as a side note, the reason you are getting oxidation on the aluminium parts is because the alu has not be sufficiently passivated to start with. This forms an hard oxide layer on the surface which stops the alu becoming "fluffy" and white. I have seen so many f650 engines with this, its astonishing.

The solution is to either passivate the parts yourself or use an etching primer.

The corrosion from dissimilar materials is also a cause but I think this is less of an issue.

the beer hunter · Dec 21, 2009

I was surprised how easy the old paint & primer came off & exposed the ally underneath, even the good areas with no corrosion.

A few years ago I stripped the paint off a set of Peugeot 205Gti wheels to polish them up & although the top layer came off easy enough, the primer was a bitch to remove.

I concluded there's a problem with BMW's priming process - it's not sticking to the bare ally!

Loads of paint just flaked off when I started to get stuck in.

Help choosing a primer for engine casing.

Registered user

Well-known member

Registered user

Registered user

Registered user

Registered user

Registered user

Well-known member

Registered user

Registered user

Registered user

Registered user

Registered user

Registered user

Well-known member

Registered user

Well-known member

Well-known member

Registered user

Registered user

Similar threads