BeoGram

Re: Dustcover Restoration

Piaf — Thu, 18 Sep 2008 21:24:59 GMT

Hi Nigel,

With the right equipment I imagine someone could set up such a restoration business.

I remember watching in amazement woodworkers at the Rolls-Royce factory at Crewe polishing veneers with a polishing wheel that must have be a meter in diameter. Obviously a polishing wheel that size would be too large for a Beogram dustcover, but something to scale would be a definite advantage over the home grown “hobby” variety.

If indeed there is no practical alternative to step by step wet-sanding, then the cost of restoration is; of necessity going to exceed what a reasonable person would be willing to pay for such a service.

Still with a custom padded buck (to prevent flexing) and a large SLOW moving polishing wheel it seems to me that it could be done.

Jeff

Re: Dustcover Restoration

h1npw — Thu, 18 Sep 2008 04:28:20 GMT

If only there was a company / individual who could do this! But I guess the cost would be prohibitive. I simply don't have the time (or the patience) to be able to do it!

Cheers

Nigel

Re: Dustcover Restoration

Piaf — Wed, 17 Sep 2008 21:11:46 GMT

Hi Mika,

What I meant by support was the Plexiglas top is very well supported by the two side vertical Plexiglas pieces and the front vertical Plexiglas piece. There is no problem putting pressure on the forward part of the dustcover.

However, the back where is says “Bang & Olufsen made in Denmark” there is NO support in the middle and this is where caution needs to be used in sanding or polishing the dustcover.

My dustcover required a lot of work, due to my choice of sandpaper. Had I used the 600 grit in the first place, I could have saved myself a whole day…. basically wasted. The 2400 grit was simply not sufficient to remove the deep scratches that I had.

My initial error was compounded when I did not take enough time with the 1500 grit sandpaper to remove the scratches made by the 600 grit.

It was a comedy of errors….. not in the least funny!

With frustration mounting I must have pushed too hard in the middle at the back as I now have stress marks in the Plexiglas. My pride would like to think they were there before, but I doubt it…. I think the marks were caused by my pressing too hard…. and I pass this information along so people could avoid the mistake I have just made.

As mentioned before, had I placed a block of Styrofoam or some other suitable material at the back of the dust cover providing support, the stress marks would not have occurred.

But the real point is DON’T PRESS TOO HARD when working on the back portion of the dustcover.

Having said all the above, my less than perfect Beogram 4004 dustcover (microscopic scratches and stress marks notwithstanding) looks 90% better than it did. I would like to have rendered it flawless, but that was not the case…. and I have learned from my mistake. I shared my embarrassment for that reason so others would not fall into the pitfall I did.

Truthfully, my Beogram 4004 is not my most “perfect” Beogram, that honor goes to my Beogram 4002…. finicky moody beast that it is. The 4004 is also not my “best” Beogram as that would be the Beogram 4000.

However this Beogram 4004 with its teak (possibly Oak) shell is my most dependable turntable, never giving the slightest problem or issue. Unloved and ending up in an Arizona rummage sale, it is loved now…. with my apologies for the dustcover.

Jeff

Re: Dustcover Restoration

tournedos — Wed, 17 Sep 2008 15:05:56 GMT

Good to hear about your success, Jeff - I still have my 6000 and the 6500 waiting for attention. Both are presentable as they are now, but far from perfect (actually, I think the 6500 would become quite nice with just the old toothpaste polish trick! Just a couple of deeper marks...).

Regarding the support, why not just put the required height of support everywhere under the dustcover? I can't see why you should put any weight on the sides at all. A couple of (equal) stacks of books should do it, with a soft cloth in between to avoid scratching the underside of the plexiglass...

Dustcover Restoration

Piaf — Wed, 17 Sep 2008 14:12:27 GMT

The single most important factor is dustcover restoration is patience….. a whole lot of patience.

I have been using the Micro-Surface kit with excellent results on my Beogram 4000, 4002, and 8000.

Then I ran into trouble while working on my Beogram 4004. I had wet-sanded for an entire day with the coarsest of the sandpaper provided by the kit, 2400 grit. Somehow, I just couldn’t quite get the deeper scratches out.

So I decided to go to 600 grit, (Not included in the kit) which pretty much did the trick, however by that time I was growing weary of the project and would have been well advised to put it aside for a bit. I didn’t.

The secret to a flawless restoration, especially with the coarser grits is to change the sanding direction. When you change from vertical to horizontal and all the vertical scratches disappear, leaving only horizontal scratches then it is time to move to a finer grade of sandpaper.

Once the grit is relatively fine, say 4000 you can really begin to see what scratches you have left….. and I had plenty.

The other “secret” to an outstanding result is finishing with an orbital polisher. I use the Griot’s polisher, which I swear by with its variable speeds and Velcro attaching pads. This polisher is completely safe to use on Plexiglas as it does not rotate at a super-fast speed which creates too much heat and could burn the Plexiglas.

I first polish the dustcover until it is smooth as glass and then apply a coat of automotive wax for the finishing touch.

Since my impatience left an unacceptable amount of 600 grit scratches, I used the Griot’s polisher to correct this problem. It would have been much better to have done the job right in the first place, but the polisher did an amazing job.

However, there is one more caution which I unfortunately did not apply: avoid using too much pressure on the back of the dustcover as it is completely unsupported and will flex. The front is supported by the three side pieces and thus is of minor concern.

But the back of the dustcover in the middle requires a gentle touch. Over the course of three days of polishing I evidently applied too much pressure and caused stress marks to appear at the back of the dustcover. These are not cracks, but lines within the Plexiglas.

So the choice is either place something under the back of the dustcover for support, or simply do not press too hard. In any case, just take your time and you will be rewarded with an outstanding result.

Jeff