July - December 2010

With winter quickly approaching it is the time to ensure the coach is prepared for a winter of wet and cold.

All the work to the lower paneling, as discussed, has been completed to a very high standard.

It is impossible to see where the corroded plate was cut out and new plate welded in place. All seams were filled with weld and ground to a fine finish with only the smallest amount of filler used to fair the plate prior to painting.

All plate was first treated with rust inhibitor, then painted in green primer.

If the coach was housed inside a building then it could have remained in primer, however the primer is porous so we had to press ahead and paint below the waist band in undercoat simply to protect our work over winter.

By the time we applied the undercoat both the air temperature and the steel plate were cold so the paint finish is not particularly great and will need a good sanding down and re undercoating before a top coat is applied, probably around July time next year.

All the corridor windows have been removed during the course of the year. The sills on which the fixed windows sit (every 2nd window) are, in every instance, completely corroded and have been cut out. We have had new sills pressed to the original design along with their restraining strips.

Many 'happy' hours were spent welding in the sills, which is a difficult task, as too much heat can cause the steel sills to distort, too little heat and the resulting weld is poor and has to be ground out and done again.

The restraining strips were held to the sills with brass M6 dome head machine screws. With the former steel sills and restraining strips having been badly corroded, the hydraulic action caused by the rust snapped the relatively soft brass machine screws leaving the whole assembly held together by rust.

Now the problem! Where in 2010 can you buy brass dome head M6 machine screws? The nearest I can find is Pan heads which do the job perfectly well, but are not the original design.

You may think this does not matter. The problem is that slots cut in the steel fascia strips align with the screws, which can be retracted with the fascia in place. If ever the window brakes this removes the need to dismantle the paneling. However, the heads of the pan head screws are too large to pass through the fascia slots.

The windows themselves have been completely cleaned, the glass being cleaned with fine wire wool and tee cut bringing it back to almost perfect condition and a very nice shine.

Cleaned and polished window being fitted back into place

In most cases the anodised frame is in excellent order with only small areas where corrosion has eaten away the anodising and the soft aluminium under it has powdered. The windows have lasted well for the past 60 years and will give many years of service yet.

Half the windows on the vestibule side can be lowered, these drop down into a brass and aluminium hopper with a drain at the bottom of the hopper that extends through an oval slot in the chassis frame. On extraction of the first hopper we have found the aluminium has completely powdered through.

3916hopper 3916hoppercorrosion

One of the better removed Window Hoppers. Notice the holes where the aluminium has powdered

This is probably caused by the close proximity of different metals and the presence of water. Aluminium is the less noble of this combination of metals and electrolysis has eaten away the aluminium.

Once the integrity of the hopper failed then water was discharged into the chassis itself leading to corrosion of the plate and the angle framework supporting it.

Fortunately the failure of the hoppers is relatively recent and the ingress of water has not caused serious damage. Left unchecked it would eventually lead to the corrosion of the structural members and ultimately the failure of the coach.

I believe this could be a ticking bomb in other un-restored coaches.

Once the hopper has been extracted from the coach, the rivets holding the aluminium to the brass frame are drilled out releasing the aluminium plate which will be replaced with new.

Every opening window has a spring compensating system to assist in the opening and closing of the windows.

With considerable corrosion of the steel plate and the window hoppers I was expecting this relatively delicate mechanism with its many springs and moving parts to at least be seized up. Thankfully this was not the case and each one looks and functions as if it was new.

3916cornerframe

Corner section of a restored window frame.

3916sills 3916sills2

The Pan head screws mentioned earlier, holding the restored window in place.

Work to the vestibule ends has been minimal. The corners of the chassis are very badly corroded.

Once the buffers had been removed and the rest of the small parts from the end of the chassis had also been taken off, further damaged plate was cut away to establish the extent of the work needed to return it to the original condition and strength.

The buffers have since been restored to their original condition along with a number of other parts.

Many hours have been invested by the various team members, We have been joined by another young member, Lewis, who is proving to be a very good addition to the team.

John continues his work with the compartment windows, having dismantled the interior paneling of the corridor prior to welding work and the removal of the asbestos panels behind the heating pipes, that contractors will remove during November. The funds for this were raised in the summer raffle.

The release of the heating pipes from the pipe clamps was particularly challenging due to corrosion of the bolts and the awkward location. Work will continue on the vestibule ends as the weather allows during the winter months.

The South side of the coach will be tackled during 2012. With more people working on the coach it means that fund raising has to increase to keep pace with the expenditure.

3916nov2010

Photo showing progress to date.