Beogram 4000: Hood Restoration - Exchange of Trim, Fixing Cracked Hinges, Spray Painting Corroded Metal Parts and Polishing

The Beogram 4000 that I am restoring right now came with a less than perfect hood. This hood 'had it all': Badly scratched plexiglass surface, corroded metal hinge parts, cracked plexiglass around the hinge area, and a wobbly plastic imitation aluminium trim strip (as it was standard on the early 4000). 

I set out by removing the plastic trim strip. Since it is attached with contact cement, I needed to bake the hood for a while in the oven at the 'warm' (~80C) setting. For this it is best to wrap it in aluminum foil to avoid hot spots:

After about 45 min in the oven

it was time to remove the trim. It can simply be pulled off from the warm hood. This leaves a bunch of contact cement residue behind:

This residue can be easily removed after soaking it in isopropyl alcohol for an hour or so. To do this I put isopropyl soaked paper towel on the glue

and covered it with aluminum foil to prevent evaporation:

After I wiped off the softened contact cement, it was time to fix the cracked hinges. Both sides had almost identical stress fractures around the bottom screw holes, a common issue with these hoods:

Since the cracks were still minor, this was a perfect application for my hinge patch kits, which consist of two patches and custom designed clamps that fit precisely on the patches:

This shows one of the kits installed, ready for plexiglass solvent to be applied:

The final result looks like this:

The patches are pretty thin, but they make the plexiglass a bit thicker, the price for having a stable attachment point for the hinge again. The application of the clamps causes some of the dissolved plexiglass to 'squirt' into the bolt holes, i.e. one needs to rout them out with a drill bit or similar after this repair process.

Now it was time to polish the hood, which looked like a used up ice rink after a skating competition:

I started out with 400 grit to remove the scratches:

This makes it homogeneously dull. After that the two hour process of polishing it back began. A nice workout in the garage!

I also repainted the corroded metal hinge parts:

This can be done fairly well by sanding the paint down and repainting the surface with black satin spray paint. This yields 'close-to-new' results:

After bolting the hinge back into the polished plexiglass hood, it was time to install an original Beogram 4000 aluminum trim, that I removed from a cracked 4000 hood (the result of a sad ebay experience with a seller who did not follow my packing instructions)

The application of contact cement to the hinge benefits from covering the area next to the strip with blue tape:

I brushed the contact cement on with a small cut to size foam block. It is essential to generate a smooth thin film. Otherwise the trim will be too high and not flush anymore with the hood.

Application of the cement to the aluminum trim strip is straight forward. When applying the strip to the hood, it is important to protect the contact cement from touching until the strip is moved into its precise location. This is helped much by placing a strip of parchment paper in between the strip and the hood:

Once properly positioned the paper can be pulled out and the strip pressed into the recess on the hood.

Since the hinge repair patches made the plexiglass a bit wider, it was necessary to conform the aluminium strip to the new shape. I did this with special clamps that I designed for these hoods a few weeks back:

They allow generating fairly high pressure on the strip, which creates a fairly conforming fit:

But a slight bulging due to the patches is unavoidable. 

The final step was to install new rubber bumpers on the front corners of the hood, to ensure a satisfying 'thunk' when closing it. I usually drill out the old degraded rubber with a 2 mm bit by hand, and then super glue a snippet of a 2 mm O-ring into the hole.

Trimming it to 1 mm length completes the installation:

And this is the final result:

Beolovely!