James T Kirks' Magnesium respray

I would be careful with chemical stripping of the Kirk. The aluminium inserts (for bottle cages, drop outs etc) were glued in and prone to coming out.
 
Thanks for all your ideas and input re. my Kirk problems

My plan now is to continue to chemically strip the frame using a brush ( ie not dipping it )
carefully working around the bonded in panels behind the seat 'post' and under the 'down' tube also
the cable guides etc.

The RockShox that were painted at Argos are in fact magnesium, and the paint is still adhering well
except for small areas of wear. I can only presume that they were unaware of the material that they were
painting, and used an Alocrom/Alodine type of etching primer as a base to their paint system, thinking
they were treating aluminium. Whatever, it has certainly lasted well

On reflection, it may well be that Argos were aware that the adhesive used to bond the various bits of
Kirk frame together weakens at above 180 C , and did not want to reduce their oven temperature for
just one frame. I am going to see them in the near future, and will ask them

At the current slow rate of progress the frame should be ready for paint in about a week

Thanks again for your interest
 
Re: http://www.retrobike.co.uk/forum/viewtopic.php?f=1&t=341617

It has taken considerably longer than hoped for the frame to be ready for painting.
About eight weeks ! This has been due to a number of distractions, also the reduced 'power'
of the latest version of 'Nitroless' stripper. I ran out of my old stock about 3/4 thru' the job
and the latest stuff is pretty ineffective by comparison. My most recent activity has been
removal of the FAG b/b which came out easily, and luckily the threaded aluminium insert
was in good condition and not loose (which is a common problem)

The photo shows the frame as it is at this time, with the XC700 forks and wheels that will be used in the build. The original fork steerer was too short, so this new steerer was purchased from Dr. Marzocchi in Germany

Money wise, the basic frame was an ebay purchase for £19.99 , fortunately there have been no
problems with it ie loose/missing cable guides, dropouts etc. and about £12.00 has been spent on paint stripper. The XC700 forks cost £2.50 at a car boot sale ( I have recently located and purchased a fork overhaul kit from Switzerland ) I will price the finished build with photos as it nears completion
 

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Re:

It looks rather nice in it's raw finish.
I'd probably just go with etch primer and spray paint, thousands of frames and forks are made of magnesium alloy, I applied touch up paint to a couple of areas on my Kirk and never saw any adverse reactions.
I wouldn't get it powder coated though :shock:

Did you get the front mech mount with the frame?
 
Re: http://www.retrobike.co.uk/forum/viewtopic.php?f=1&t=341617

Thanks LGF for your encouraging remarks, I must admit that I had problems getting the bike to stay leaned against the door for the photo !
Seriously, I have heard all sorts of stories about Kirk frame 'problems' and having found this frame in good condition at a reasonable price
decided to proceed with the build. In the worst case scenario the parts I have collected for the restoration can easily be fitted to a different
project, though I hope not.

I have a suspicion that there may have been problems with the 'bonded in' sections of the frame leading to unwanted flexibility

For those unfamiliar with the design, the underside of the down tube and the rear of the seat tube have separate sections that were glued
in position after the main manufacturing process. In the event that these sections are not correctly fitted, then the torsional rigidity would
suffer considerably. Think of the difference of trying to twist a 'box' section tube compared with a 'channel' or 'U' section. I think
that issues of quality control may have been involved ( just a theory )

I should have mentioned that the extra long steerer was £25 and the XC700 service kit was £30 ( both included p&p )
The Shimano/ Mavic X 221 wheels were £30 , and the Thorn stem was £2.50

The frame was missing the front mech 'plate' and the rear mech hanger when purchased, however I managed to get both items and an extra
spare rear hanger from ebay for about £25

The frame will be etch primed ( Alochrome or equiv ) and stove enamelled dark metallic blue in the near future
 
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