grundig: 1045W Clean speaker cloth

Fellow Radiophiles,

I am making good progress in the restoration of the Grundig 1045 that belonged to Andre de Melo in my youth. His son Fernando owns it now, and my restoration preserves the radio and fond memories with these friends. I remember hearing this radio during the late 1960's, while it played the soccer broadcast in the tavern that Andre owned next to his general store.

After replacing the rotted out power transformer with a replacement that was given to by RMORG member Ross Hochstrasser, and replacing three resistors and the original electrolytics, the radio is working again. I have another couple of weeks while I am in vacation at Furnas in the Azores to check out it's performance. The only weak tubes were the IF and tuning eye, but I replaced all just the same, while keeping the non-original old ones with the radio.

Ross also supplied me with a set of original knobs, which look great on the radio. I cleaned the three front brass pieces with the american Twinkle copper cleaning creme.

I have two questions:

1-What protective finish should I apply to the brass pieces in this very humid climate?

2-How should have remove the speaker cloth for cleaning?

Is the glue a contact type that softens with alcohol or acetone, or is it a wood glue that would soften with white vinegar and water?

Perhaps the cloth can be cleaned in place, but how?

Is there a danger of shrinkage? As seen in this photo, some shrinkage can be tolerated.

Regards,

-Joe

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Joe,

This is easy!

Mix household bleach and water, half bleach and half water, and bathe the cloth literally for a few minutes.

As soon as you hit saturation point to the cloth cover, push it against a a very thick white towel and try to dry it off as much as possible.

For an extra added bonus, first soak the cloth with a carpet/upholstery  "spotter"-cleaner, then apply the bleach mix.

Please post the after pics

 

Omer

 

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Dear Joe,

most people use a nitrocellulose laquer for a protective finish on buffed up metal. A search for "Zaponlack" here in rm will yield a few results (altough in german). There are varieties that are waterproof and which might be better suited for very humid environments.

Hope that helps, regards,
Mark

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The cloth is held on with corn starch, no need to remove the cloth.

 

Just stick with the directions for good results.

 

Omer

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Hello Joe,

You can clean the grille cloth still glued to the baffle board. I should try cleaning it first with upholstery cleaner, spray some cleaner onto the cloth (don't soak it), rub it in very gently with your fingers, leave it for a couple of minutes and then dab it off gently with a wet cloth and then a dry cloth and then allow it to dry. That's how I dealt with this similar bakelite cased 965WE which I acquired in the same sort of condition as the set on the 1045W model page .....

forumdata/users/4885/file/1955_Grundig_965WE.jpg

If that doesn't work then try the other recommendations above. You can get replacement cloth of course but it won't be identical to the original.

As for brass trim, once polished clean it with some alcohol and paint on one coat of clear metal lacquer with a small brush. The lacquer I use in the UK is cellulose based and dries in two minutes and it adheres extremely well.

Good luck. 

Regards .......... Howard

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Hi Howard,

 

Been there, done that!

The problem is, the starch darkens with age too.

As long as the particle board backing is kept dry as possible, saturating the cloth with a paint brush of the bleach/water combo, won't do any harm.

The trick is, the thick white towel, and absorbing the liquid off quickly as possible on to it, after a few minutes .

 

Omer

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Gentlemen,

Thank you all very much for all the good suggestions. The restoration on Howard's Grundig 945WE looks particularly nice.

I ended up removing the cloth with water and vinegar. I got this suggestion from an old issue of the Mid Atlantic Antique Radio Club newsletter. The vinegar solution softened the water based glue that was apparently used. I tried this approach by mostening a small section of the cloth, and noticed that it was loosening easily.

Then I made a serious mistake, that I am now recovering from. I ended up submerging the entire board in the vinegar water which cause serious delamination of the plywood. I arrested the disaster with a hot iron and managed to end up with a board that was somewhat de-laminated, but still flat. The board is now curing in a press with fresh glue between the laminations.

I think I would have done well, if I never submerged the board, and limited the wetting to the cloth. The thick layer of white glue under the cloth would have stopped most of the moisture. A spray bottle would have been good to wet the cloth, while keeping the board dry.

The cloth was very dirty as shown above, and this was the motivation for the removal. The cloth has been soaking in laundry detergent for three days. I have changed the detergent water three times, and the dirty section is dramatically cleaner to the point that there is almost no difference with respect to the clean cloth at the edges.

After the cloth is ready to be reattached, I am thinking of mostening the remaining thick layer of glue on the board, and iron the cloth back on with a warm iron. I will have to test the effect of the iron at the edge of the cloth that will not be exposed.

I had considered using bleach, but thought that the enzime action of a modern laundry detergent would be effective and gentler on cloth.

I spoke to Mestre Álvaro, who is a very fine local furniture maker and restorer with a lifetime of experience, and he suggested that an appropriate glue to attach cloth to wood would be the same type of glue that is used for wall paper. This glue should be similar to the suggested starch-based glue. The idea is that this type of glue will not seep into the cloth. The cloth also has heavy ridges that were the attachment points for the original glue.

I hope to deliver the Radio by the weekend, and should have some photos to post back.

The remaining restoration of the bakelite case gold trim will be done by a local restorer who specilizes in paint work. I may leave the lacker finish of the brass pieces up to him too, given my current time constraints.

I have been enjoying nice short wave reception in the 1045W, but no AM band reception, because the last state-owned AM transmitter at Ponta Delgada, S. Miguel island, in the Azores archipelago was shut down a few years ago. One evening I managed to get an overseas AM station at the low end of the dial. The rest of the dial is plagued with 50Hz buzz, and I have not been able to find the environmental source.

I also made a simple dual-banana to phone plug cable that the radio's owner, Fernando, will be able to use to play an external FM radio, CD's or mp3 files via the phono input.

Best regards,

-Joe

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Hi Joe,

I did your method on my first Grundig, and luckily didn't damage the wood.

I ended up replacing the cloth, with new cloth.

Essentially Joe, the trick with the old fashioned bleach (NaClO) diluted with water, is using a paint brush, for a few minutes, and then tamping the cloth off with a white towel.

You could use an air compressor  to dry it off quicker.

Kind of like a, "hit and run" approach!

I've used this method on practically all my Opus and Gavotte radios with great success.

At the end of the day, it smells nicer than when using vinegar!

 

Omer

 

P.S. As for AM, what about stretching the longest wire possible with a good ground, and having the antenna pointed towards the Mediterranean Sea?

 

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