Dissolving Asphaltum from Edison Top Frames

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keywindgem
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Dissolving Asphaltum from Edison Top Frames

Post by keywindgem »

Is there anything that will dissolve the Asphaltum finish on the Edison Top Frames and other parts.?
I have tried a wire wheel but it is hard work, I tried a flame and scraper, that is hard work also.
I am not allergic to work but is there an easier way? :?

gramophoneshane
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Re: Dissolving Asphaltum from Edison Top Frames

Post by gramophoneshane »

I use caustic soda. I find a plastic container big enough to fit what I'm stripping, fill it with enough hot water to cover the object, then sprinkle in a table spoon or two of the caustic soda crystals. Be careful because a reaction occures that will make the water bubble, and the steam can chemically burn your skin, so wear protective clothing & gloves with plenty of ventilation.
Once the reaction settles, carefully insert the bedplate & let it sit in the solution of half an hour or so.
I then pull the item from the stripper & wash the item down with steel wool under running water.
Also, make sure you use plastic gloves & NOT rubber, as rubber will disintergrate rather quickly in caustic soda.
When all the paint is gone, dry the item with an old towel & then a hair dryer to prevent the bare metal rusting.
If you happen to get any caustic solution on your skin, just pour a bit of milk or vinegar on it to neutralise the caustic, and wash under water. You can also mix it with cold water, and it wont have a violent reaction like it does in hot water, but using hot water will speed up the stripping process. Just be careful not to beathe in the steam while the reaction is occuring (about 20 seconds or so).
You can also use regular gel stripper, and most likely soaking in metho over night would probably work too, but at around $4 a container from Woolies or Coles, caustic is cheap & quick, and you'll have enough to do 20 bedplates.
I also use it to strip paint & varnish etc off hinges & other metalwork.
Dont use it on timber though, as it will darken the wood & cause the surface to become fury.

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keywindgem
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Re: Dissolving Asphaltum from Edison Top Frames

Post by keywindgem »

Thanks GramophoneShane
I have used caustic, I did not know it would remove the Asphaltum type paint. Caustic works great if the water is boiling, I used to clean engine parts in a drum of strong caustic over an open fire, works in no time.
I already have a pressure pack tin of paint stripper, will try that first tomorrow and then do the caustic at the weekend if it does not work.
Peter

Uncle Vanya
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Re: Dissolving Asphaltum from Edison Top Frames

Post by Uncle Vanya »

keywindgem wrote:Thanks GramophoneShane
I have used caustic, I did not know it would remove the Asphaltum type paint. Caustic works great if the water is boiling, I used to clean engine parts in a drum of strong caustic over an open fire, works in no time.
I already have a pressure pack tin of paint stripper, will try that first tomorrow and then do the caustic at the weekend if it does not work.
Peter
Caustic Soda works great, and that's no lye!

Flvice
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Re: Dissolving Asphaltum from Edison Top Frames

Post by Flvice »

I am currently restoring an Edison Amberola 30 which I purchased as "restored" very cheap with 48 Amberol cylinders (9) of them were 5000 series :) ( Who says there are no bargins on EBay) The bed plate however, was obviously painted with a rattle can black paint and it looked awful. So, I figured that it was a good candidate. I researched here and other sites on the web and found some good information.

I plan on re-japanning the bedplate as in a thread that I found here, http://victrolagramophones.proboards.co ... thread=141 but it mentioned very little on how to strip the paint off the bedplate. I purchased a can of gel paint stripper that said it was for metal and heavy duty. Well after the first application all of the black spray paint came immediately off but the black asphaltum wouldn't budge. I tried several more applications, left it on overnite, tried scraping it off, but in the end I just had a big mess.

I found this thread and tried it and within a couple of hours it was completely stripped down to the bare metal. Every nook and cranny was clean with the help of a little steel wool. The Caustic Acid in the very hot water ( I used a plastic bucket) didn't generate bubbles or have any reaction except for a whirlpool effect in the bucket. I wondered if it was going to work.. well it worked brilliantly. :D Saved me a lot of work. Thanks to all on the forum who post and share their advice.

I waiting for my shipment of Black Pontypool Asphaltum to arrive from here http://www.libertyonthehudson.com/pontypool.html so if anyone has any tips or tricks as to repainting the bedplate, I would love to hear from you.

Pictures below.
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DSC04306.JPG

JerryW
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Re: Dissolving Asphaltum from Edison Top Frames

Post by JerryW »

This may be too late to help at all but I used the Asphaltum from the company you ordered yours from and I didn't like the finish when brushed on. My bedplate was very pitted in spots and I kept sanding down and laying more one but could get the brush strokes to flow out. Finally I cut it 10% with a fast drying lacquer thinner and sprayed it. It came out great. I baked it at 150 degrees for 24 hrs to harden it. Since mine is an early model (S/N 33...) I'm going to put the signature logo on the center back as the early ones had it and spray on a couple of coats of clear lacquer. Jerry W.

gramophoneshane
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Re: Dissolving Asphaltum from Edison Top Frames

Post by gramophoneshane »

Never too late Jerry. Forums are like reference libraries, and this thread will be recalled many times in the future by numerous collectors, so every bit of information proves useful ;)

Does anyone know how Edison originally applied asphaltum?
To me, it often looks as if parts were dipped in a large vat of the stuff, hung up to dry & the process repeated until a thick smooth glossy finish was achieved.
Obviously it wouldn't be practical to redo them like this on a hobbyist level, "IF" this was indeed the way they were done originally, but I must say I've rarely seen a refinished bedplate that looks quite the same as a good original.
I think the main reason for this is because most of us (myself included) tend to be a little too fussy & try to make them look perfect.
Spraying your paint of choice delivers a thin even coating over the metals entire surface, and after further coats that fill blemishes in the base metal, you normally end up with a smooth flat layer of paint that follows every contour of the casting perfectly.
A nice original bedplate however will usually have one or two runs, the paint pools in corners which seems to round them out more, and although the surface appears fairly smooth and flat, the layer of paint is not of a consistant thickness, even on flat level surfaces of the casting.
I think the inconsistancies of mass production give original bedplates more character, where we as restorers faced with refinishing a bedplate make a conscious effect to get the flawless finish that originals never had.

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