An experiment. Rubber Diaphragm gaskets

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wrichard
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An experiment. Rubber Diaphragm gaskets

Post by wrichard »

Grateful for any comments on this proposed experiment.

I have used armour all on parts of a destroyed diaphragm gasket. Armour all claims that it penetrates rubber and other materials and offers protection. So far the rubber gasket has softened.
The next thing I tried was the rubber gasket between the tone arm and soundbox. Again good results the cracking has diminished and the rubber is more pliable.

My proposal is to try the compound which contains silicone on a soundbox with aluminium diaphragm where the gaskets have hardened.

I would be grateful for any comments you have.

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Re: An experiment. Rubber Diaphragm gaskets

Post by OrthoFan »

I've also read that "Goo-Gone" also softens hard rubber. I think it would be a great experiment. How long the rubber would remain "more pliable" I don't know, but if nothing else, it may make the diaphragm gaskets easier to remove if-and-when you decide to replace them and do a complete overhaul of the sound box.

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Re: An experiment. Rubber Diaphragm gaskets

Post by Inigo »

Be careful as the treated rubber could get stuck to the diaphragm and make further disassembling more difficult. I'd suggest adding thin paper or felt gaskets between the rubber and the aluminium. I've suffered from this problem in the past with a viva tonal reproducer.
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wrichard
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Re: An experiment. Rubber Diaphragm gaskets

Post by wrichard »

Many thanks for both of your replies. I thought about the rubber becoming sticky but the rubber I have treated so far has not become sticky. I take the point about a paper gasket.

I really only intend to carry out the experiment on a scrap soundbox with little merit. Certainly not the Edison Bell Electrophone or the Gilbert tone reflector.

And it is an experiment to see how much effect such a minimal intervention will have.

I will be updating regularly

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Inigo
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Re: An experiment. Rubber Diaphragm gaskets

Post by Inigo »

Ok, we will be expecting your report on the results good luck
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Re: An experiment. Rubber Diaphragm gaskets

Post by Orchorsol »

Oil of Wintergreen (methyl salicylate) is the fluid with which I've had the most success, although limited, in attempting to restore irreplaceable vintage rubber components. It is fairly toxic however.

What is the intention of the experiment? Is there a particular reason not to replace the gaskets in this instance?
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wrichard
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Re: An experiment. Rubber Diaphragm gaskets

Post by wrichard »

Orchorsol wrote: Thu May 22, 2025 7:41 pm
What is the intention of the experiment? Is there a particular reason not to replace the gaskets in this instance?
The intention is to not intervene in the soundbox but to ascertain if treatment with armour all softens the rubber enough to make a difference.

wrichard
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Re: An experiment. Rubber Diaphragm gaskets

Post by wrichard »

It begins
20250523_073716.jpg
In the original state. Gaskets are fairly hard. Rubber seal on back is pliable but for sake of completeness I'm softening that too.
20250523_073824.jpg
Treatment begins. This will be left for 24 hrs. The armour all has also worked wonders on my columbia portable leatherette.

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Re: An experiment. Rubber Diaphragm gaskets

Post by JerryVan »

Is that a paper label insdie the reproducer? If so, I hope the Armor All doesn't seep through and ruin it. How are you getting the Armor All to the back side diaphragm gasket?

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Re: An experiment. Rubber Diaphragm gaskets

Post by Curt A »

Gummi Pflege (flee-ga) is a rubber restoration treatment for dried out rubber seals on BMWs. It restores hardened door and window gaskets. I have used it and it works well. I have heard that automotive brake fluid also works, but have not tried it.
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