Saturday 19 November 2011

POST 18 NOV 2011 - HINGES, PRAYERS & LULLABIES

Encouraged by almost three thousand views to date, from December this year I am going to try to post around the beginning and middle of the month, so by say the fifth of each month there should be a couple of posts to view.

Due to pressure from my real job, I've had very little time in the past three weeks to do much XK stuff.  If I was starting over in business, I would definitely consider the relatively hassle free and predictable world of classic car restoration as an alternative occupation.
So - following are a small selection of "hinge" related items, completed in past months, but not previously mentioned.
 

If you've ever wondered what exactly goes wrong with XK hinges making
doors drop / sag then this picture will help explain.  The hinge pin rusts and seizes
in the hinge arm causing the pin to rotate between the upper and lower
plates making them oval.  This picture shows the arm hole enlarged with a brass
 bush fitted. The worn oval plate holes have been taken out to 1/2" I/D


Top Hat shape washers have been made to interference fit into the
1/2" I/D holes, effectively creating new hinge pin locations in the plates.
The new pin has a nipple to allow grease into pin / bush bearing and is
an interference fit into the top hat washers.


Hinge assembled.  The important bit is to ensure that the arm rotates
on the pin and that the pin does not rotate in the top hat section washers.
 This is all well and good, as long as you can actually access and remove the hinges, which is only really possible in most cases by cutting away some part of the wing.  I am told that there is however an alternative solution (bodge)  to stop doors dropping / sagging due to oval hinge plate holes.  Before trying this, make sure you read and fully understand the last highlighted sentence of this section!  Also be aware that unless your very lucky or very clever, it will probably alter the original shut lines / panel gaps.
First try to get some easing fluid into the hinge pin.  Then with the door not quite fully open, jack up the back edge to the correct height / position.  With extreme care and much difficulty, weld the top and bottom of the hinge pins to the hinge plates to prevent them moving in the worn oval holes. 
The next part of the operation depends on your religious leanings but should certainly involve prayers of some sort before proceeding. 
The door is of course, now stuck open.  The hinge can't move because the top and bottom of the pin is welded to the plates and the centre part is seized in the hinge arm.  Gently rock the door too and fro (a lullaby might help in easing the stress at this point) and hopefully the pin will gradually free in the arm and rotate as it was designed to.  If it doesn't, then your well and truly buggered.


120 / 140 modified bonnet hinge
When I restored my 140, I had endless problems getting the bonnet to fit, until I realised that one worn and one almost seized hinge made the bonnet twist and and finish up in a different place every time I closed it.  The solution, whilst a little time consuming was actually very straightforward.  Flushed with my 140 success, I decided not to prat around with the 120 hinges and give them the same treatment. 
I drilled out the ends of the stepped pins which hold the two halves together and binned them.  Next I took out the worn 1/4" holes in the assorted remaining bits to just under 8mm to make them a nice fit for the shank of a stainless 8mm allen head bolt.  I had eight new stainless spacers and 32 x 1.8 mm thick stainless washers made up, then using lots of grease re-assembled each hinge.  I used nylocks (sacrilege !!!) to get an exact and equal amount of friction into each hinge.  The result is a really nice smooth movement with zero lateral play making bonnet alignment much less of a hit / miss affair.  Lots of minus points I should think, if I ever consider joining you concours nutters!  I will eventually paint the stainless spacers and fasteners black.

Another interesting little job.  Around 48 parts make up the door catch
assembly.  I always restore pairs of parts one at a time to save remembering
how it all goes back together.  After fully dismantling, cleaning, painting,
lubricating and re-assembling, the whole mechanism worked beautifully.
Finally
Jag Lovers Forum recently had a post from a bloke from Monaco asking about accommodation for the Goodwood revival next year.  All the usual and expected answers re. Posh Hotels at £300 /Night, Sailing Clubs, B&B's etc. so I couldn't help posting my genuine "recommendation"  Interestingly, UK readers will probably "twig" where it is before the link, whilst none UK readers will see it as the bargain it actually was.
Anyway, my reply to the question was :

This may be an interesting alternative to the usual suggestions and will also allow you to experience a far broader and possibly more typical insight into the average Englishman (and Englishwoman) than you will find at the Revival meeting. 
A few years back we stayed at a complex close to the seaside (like Monaco) within a small town with many Royal connections (also like Monaco.) It was around thirteen miles from Goodwood, had a choice of eateries, adequate parking, spa, swimming pool and a very large nightclub. I seem to recall that a four bed apartment within the complex, booked at quite short notice, for 3 nights cost around £250 – Just over £20.00 / person /night.  Beer was very reasonable, but choice of wine somewhat limited.  It was an interesting weekend and you should try everything at least once in your life.
www.butlins.com/resorts/bognor-regis

Saturday 5 November 2011

POST 17 - OCT 2011 - SPRING TIME IN SOUTH BANK

A few "sub projects" are required to keep me busy whilst the engine bits are away at the machine shop and the rear springs seemed a likely first candidate.
The easy route would have been to simply purchase a new pair for around £150 but that seemed like a bit of cop out.  The car as purchased sat very nice and square, if a little low on its old springs.  Closer inspection on dismantling showed them to be almost certainly original, with stamped Jaguar part numbers, beautifully made with tapers in both planes at the ends of each leaf.  One side still had its leather gaiter in place.

Research into bringing them back to their original condition throws up some interesting information.  Over time, the steel starts to lose its temper (spring) causing a change in "set" - they sag.  The spring rate is mainly determined by the number and dimensions of the leaves, but also to a lesser extent the quality of steel and the tempering procedure.  They need to be set back to their original shape and re-tempered to put the spring back in.  Further digging turns up Brost Forge, a long established business in North London with an outstanding reputation.  They specialise in spring re-tempering and have the original manufacturers specs on a wide range of leaf springs.  The cost including new bushes is around twice that of a new pair from goodness knows where, but I guess that's the premium for originality.

They come back looking a little more curved and covered in a nasty sticky tar like substance. I put them on the lonely shelf for finished bits and give them a disdainful glance every time I pass. After a few days, my resolve to consider them finished weakens and I dismantle them and send them to my friend Max to blast off the gunge.

Further trawling of the Internet and the recollection of a conversation with an XK owning acquaintance about the cure for squeaky springs results in the following, totally ridiculous, massively time consuming, very satisfying process.
Each leaf is linished on both sides, then sanded smooth (allow on average half an hour per leaf).  Clean thoroughly and apply two thin coats of Acrylic paint.  Next you need a large sheet of High Density Polyethylene (HDPE) cut into strips to fit between each leaf.  Rub copperslip into all surfaces and re-assemble.  You have now virtually eliminated friction between the leaves making for a super smooth and silent action.  As the spring pack height has increased by up to 6mm a new centre fixing bolt and new guide brackets are made to measure.

Final job is to carefully record all dimensions and send of to Wefco in Yatton to have a new set of leather gaiters made.


Dismantled after tempering.   Assembled spring had been
 "painted" or possibly dipped in some nasty tar like substance

After initial shot blasting - Original Jaguar part numbers
clearly visible but different although actual leaves are identical


After linishing, final smooth finish created with sander.
Very time consuming job but quite satisfying

Leaves painted with thin coat of acylic matt black.
High Density Polyethylene 1mm strips between leaves.
Very thin coating of copperslip rubbed into all surfaces before
final assembly.  New guide brackets made to accommodate
 additional thickness of HDPE inserts

Finally assembled and looking more like it should.
Just needs gaiters fitting - awaiting delivery from Wefco.
Shame to cover it up!

Detail showing nicely tapered ends of leaves.  HDPE can just be seen
between each leaf
So - one spring done and one to go!