Beogram 4000: Installation of a New Precision Machined Solid Teak Frame

I recently received a lovely new CNC machined solid Teak plinth from Christian Hakansson, to be installed on the Beogram 4000 that I recently functionally restored.

Unfortunately, this Beogram had an original plinth that was damaged at the corners (please, watch out for door jambs when you carry your Beograms around!!...;-):

I removed the plinth:

If you do this at home, please, note that there is a 5th bolt under the keypad, i.e. the keypad needs to be removed before the plinth can be extracted. 

The deformed particle board under the veneer suggested that this plinth not only had damaged corners, but also had been in contact with too much moisture at some point in time:

The installation of a new plinth requires that the metal fixtures be removed from the old plinth to be transferred to the new one. I usually wrap the plinth in aluminum foil and then I put it into the oven for an hour at 200-250F. Once it comes out the metal parts can be separated with a suitable spatula or similar:

Once the parts are off, the residual contact cement

needs to be removed. I usually soak paper towel with isopropanol or goo gone and wrap the metal parts in it:

I put aluminum foil around it to prevent evaporation:

After 24 hrs the glue can be rubbed off with the drenched paper towels:

This shows one of the cleaned metal fixtures:

I use ultra thin 3M 300LSE adhesive tape for the installation. This makes the process much cleaner than with contact cement. The tape can be cut out with a razor blade to match the frame shape:

It is important to not cover the little spring tabs that are in the back of the frame:

Otherwise they can get glued to the wood and are not able to perform their duty (holding the plinth in place once it is pushed back) anymore.

Now comes the moment where the metal parts are glued to the wood. This is probably the most difficult task since one only has one try and the parts need to be placed precisely at the right level on the frame. This is greatly simplified by using the aluminum panels of the Beogram. They have the right thickness and can be used to align the metal parts with the frame.

It can be challenging to get the metal parts all the way into the corners since there is adhesive on both sides. I usually deal this issue by using some parchment or wax paper to prevent one side from sticking, while I push in the part all the way into the corner:

This shows one side glued while the other still has the paper in:

Sometimes the metal parts are not entirely conform with the frame in the corners. Many Beograms actually came with this issue 'factory installed'...;-). I sometimes use tongue-and-groove pliers to help seating the metal parts in the corners. Be careful not to damage the frame if you do this at home: 

This shows the new frame with installed metal parts:

And here a couple happy shots of the Beogram 4000 with the new frame installed. Beolovely!!:

Beogram 4000: Exchanging the Plinth Panels

The Beogram 4000 that I am restoring right now came with a shaved off plinth corner (why can't people be more careful when they lug their Beograms around?? Just walk slowly and watch out for door jambs!...;-). This is how it came:

Since 4000 plinths are rare like the 4000 itself, most likely you will need to get the plinth wood panels from a 4002 or 4004. This means the metal fixtures on the plinth need to be exchanged, since they are slightly different due to the different keypad shapes (see here for more detail on the differences).

The first step is to remove the plinth, which is held by 5 screws to the metal enclosure. One of the screws is under the keypad, i.e. it needs to be taken out if you do this as a separate procedure.

Once the plinth is out the metal fixtures need to be removed. This is best done by 'baking' the plinth for ~30-45 min in an oven set to the 'warm' position, which usually yields about 80C. I usually wrap the plinth in aluminum foil to ensure a more homogeneous temperature distribution.

After the plinth was heated up, I took it out and removed the metal parts by jamming a spatula in-between. The heated old contact cement gives way fairy easily:

Take care to not damage the veneer while doing this.

The next step is the removal of the old glue from the fixtures

which is easily done by wrapping them into isopropyl alcohol drenched paper towel

followed by aluminum foil to prevent evaporation:

After letting the parts 'stew' for an hour, the glue can be wiped off with the drenched paper towel:

The glue on the wood panels needs to be left in place to not damage the veneer, but that is not a problem since it usually seems to be very thin and well distributed. I think the wood absorbed the glue when they applied it.

The next step is to assemble the panels of the replacement plinth from the 4002 or 4004, which of course also had to be liberated from its metal fixtures with the above approach.

I use Gorilla wood glue and some specially designed clamps that can hold the panels precisely in place:

After the glue fully cures (~24 hrs), the next step is to glue the metal fixtures back into the wood frame.

The first step is applying fresh contact cement to the metal parts

 and the wood panels:

I use small foam blocks for distributing the glue

Key is to make a thin homogeneous layer, and one does not have much time with modern contact cements. It is best to do it in separate steps for each side of the plinth.

After the cement is fully cured (~5 min) precise alignment is key during assembly. Otherwise the plinth will not be aligned properly with the aluminum panels of the Beogram.

Luckily one can use the Beogram aluminum panels themselves for the alignment process.

Place them on a flat surface and tape them down in an aligned way. On the outside I use a straight ruler. The aluminum panels have just the right thickness to 'lift' the metal parts to the correct position inside the wood frame:

When assembling the cement coated parts, it is crucial that they are aligned before they are pressed into place. This is difficult with a L-shape, since it needs to be pressed/moved in x- and y- direction at the same time. The trick is to insert a parchment or wax paper strip on one side of the L and then press the other into place:

Once one side is in place, slide the paper out and press the other side into the frame.

And that is the result:

One word of caution, when transferring plinths: They appear to come in two slightly different widths:

This caused an issue with this Beogram 4000, since the first time I did this process I used plinth panels that were the wider type, while the shaved off plinth was the narrower type. This caused the transferred plinth to not align properly with the enclosure, and one of the corners came unglued again due to the stress on the frame. So, the above pictures actually show the second time I did this for this Beogram. A hint if you have to remove metal fixtures that were just glued with modern contact cement: The modern stuff still gets soft when heated in the oven, but does not come off by soaking in isopropyl alcohol anymore. I think it is a different formulation for quicker drying with some probably 'happy making' organic solvents involved...;-). The trick is to replace the isopropyl with 'Goo Gone'...same drenching process with paper towel/aluminum foil.

Anyway, this Beogram 4000 plinth is fixed!

Beogram 4000: Exchange of Black Painted Plinth with a Teak Plinth from a Beogram 4002

The Beogram 4000 that I am restoring right now came with a black painted plinth. Not sure why some people have the need to mess with a piece of iconic industrial design, but I guess "before you criticize a man, walk a mile in his shoes" (Steve Martin - the quote actually goes on: "That way, when you do criticize him, you'll be a mile away and have his shoes.'...an important point if you live in a country that has more guns than people...;-).

Anyway, here is a picture of the sad state of affairs:

As usual this plinth also had cracked guidance washers:

I removed the plinth. For this one has to remove the keypad since one of the bolts that hold it down is underneath.

Unfortunately, it is not possible to just take a plinth from a 4002 and bolt it into the 4000. Due to the slightly different sizes of 4000 keypad and the small aluminum panel that sits behind it, the metal fixtures that are glued to the plinth on the right side are different. You can see this here:

The top fixture is from the 4000, the bottom from the 4002. At the front of the plinth another small difference can be noted:

The tabs that hold the keypad down are a bit wider spaced in the 4000.

This means that the fixtures need to be exchanged. Removal is pretty easy since the glue gives when heated to moderate temperatures. I resorted to wrapping the plinths in aluminum foil and 'baking' them on the lowest setting in our oven (~85C) for half an hour. After taking them out, it was straight forward to remove the metal fixtures on both with a paint scraper that is pressed in-between the wood and the metal and then moved along until the parts are separated. The glue can be removed with Goo-B-Gone (thanks for this tip, Sonavor!).

One the parts are separated the most difficult part of the procedure begins: Butting them back together in a precise and straight way. This is critical, otherwise the plinth will not sit straight and of course that would be un-Beolovely!

In the past I used industrial strength adhesive tape for reattaching partially delaminated fixtures from plinths, and so this was my goto here, too. I put strips on the wood and trimmed them with a razor blade to match the footprint of the wood parts:

The key to attaching the fixture to the wood is to align it perfectly with the milled out groove that is in the lower part of the plinth. It turns out that the aluminum panels of the Beograms have exactly the same height as this groove, and so can be used as a 'natural' guide for reassembling the plinth!

I used the small aluminum panel of the Beogram and borrowed one from one of my 4002s to cover the entire right side of the plinth. Then I removed the tape backing on the front (and left the backing on on the side that no gluing wold occur while I aligned the fixture at the front) and pressed it in:

The Aluminum panels kept the fixture at exactly the same height front and back, ensuring a horizontal alignment.

Then I removed the tape backing from the strips on the side and pressed the fixture in:

Then I clamped everything together and let it sit for a while to ensure that the bond was solid:

Then it was time to bolt the plinth into the 4000. For this I used new 3D printed guidance washers:

They are available via the Beolover Shapeways store if you need some.

It is a good idea to get one manufactured in black to be mounted in the front center spot. This washer can be seen through the crack between the plinth and the aluminum panel if it is white.

This shows two of them installed:

Below the keypad -

and center front:

When I took out the original plinth, the mirror came off from the keypad cluster:

I am glad this happened so I had a chance to glue it back on in a lasting way with a couple dabs of epoxy:

Without this mirror in place it is impossible to see the strobe markings underneath the platter that are illuminated by the wonderful fluorescent orange bulb that is run at the AC grid frequency.

Allright, here is an impression of the Beogram with the new plinth on!

Beolovely! This looks so much better than the 'black ops' version! All that is left are a few final adjustments, and then it will be time for a first spin! I am looking forward to that! Playing a 4000 for the first time is always a special moment!