Orthophonic Reproducer Cleaning Advice Needed

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vichighmathguy
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Orthophonic Reproducer Cleaning Advice Needed

Post by vichighmathguy »

Hello,
I have my (first) disassembled orthophonic reproducer in front of me and am ready to clean it before rebuilding. I had planned to use my ultrasonic cleaner but have hit "pause" while considering that the diaphragm (aluminum) and body (pot metal) may be vulnerable to the process or to cleaning solutions. As I don't wish to damage the diaphragm or the remaining plating on the pot metal housing, I wonder if someone would like to share their approach to cleaning these parts without damaging them. There is Mouse Milk and who knows what contaminants accumulated from 90 years of use to get rid of.
Your input will be greatly appreciated - thank you!
Don Mayer

JerryVan
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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by JerryVan »

Can you show us a photo of what you have so far please?

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by vichighmathguy »

JerryVan wrote: Sun May 09, 2021 4:40 pm Can you show us a photo of what you have so far please?
I'm not worried about brass or steel parts - they will be fine in the ultrasonic cleaner with clock cleaning solution. Really just wondering what people might use for cleaning aluminum and pot metal without harming either finish or shellac (as this seems to be in good shape on the diaphragm). While I am at it, though: what do you like to use for resealing spiders on the diaphragms without snipping and using cyanoacrylate? The original seems to have more shellac than needed and I had thought about dissolving it and reapplying it in smaller quantity.

Thanks for you input!
Don
IMG_7156.jpeg

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by JerryVan »

I would not attempt to clean the diaphragm. I have only rarely found cases where the spider no longer seals at its attachments to the diaphragm. I suppose I would try resealing with beeswax, but only if necessary. While the diaphragm looks like a good one, hold it up to a bright light and look for very tiny pinholes in it, especially where it may appear to have small blemishes in the surface. Surprising how many are perforated.

As to cleaing the housing, it appears to be more tarnished/corroded than dirty. As for dirt, I would use a toothbrush, along with either soap & water, or a solvent to clean it. Any attempts at polishing usually removes plating.

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by vichighmathguy »

JerryVan wrote: Mon May 10, 2021 3:59 pm I would not attempt to clean the diaphragm. I have only rarely found cases where the spider no longer seals at its attachments to the diaphragm. I suppose I would try resealing with beeswax, but only if necessary. While the diaphragm looks like a good one, hold it up to a bright light and look for very tiny pinholes in it, especially where it may appear to have small blemishes in the surface. Surprising how many are perforated.

As to cleaing the housing, it appears to be more tarnished/corroded than dirty. As for dirt, I would use a toothbrush, along with either soap & water, or a solvent to clean it. Any attempts at polishing usually removes plating.
Agreed. Thank you for your comments. As there are residual solvents on the parts (Mouse Milk) and dust from years of storage, I had wanted to get that off before reassembling. I'll probably go with a Dawn detergent solution and an artist's brush, given the fragility of the diaphragm. Not as worried about the body other than preserving the gold. I have others that are too far gone to worry about finish, but this one is good enough to preserve.

Interesting tip about the pinhole perforations. I had held the diaphragm up to light and detected 3 or 4 at the points of attachment of the spider feet, but wonder if that is only because the original shellac thinned in the small gaps upon application. My current plan unless I learn of something better is to apply a small drop of Indian Head Shellac Gasket Compound at these points or maybe mix up a little orange shellac and go with that. I want the repair to be reversible.

As well, I will be polishing the needle bar's tapered bearing arbors and the interior of the ball bearing races. Also, I will find some "rubber" tubing to take up the distance between the steel washer that holds the ball bearings in place and the end cap. Under the end cap I hope to use a relatively soft O-ring to allow for some gentle pressure adjustment downstream against the bearings. My thought is that the bearings prevent excess movement in two directions while the O-ring/tubing/washer assembly prevents movement in the third direction but should not press very much on the ball bearings, just enough to prevent them getting out of alignment. In other words, the needle bar needs to be able to rotate easily but without linear movement and without undue pressure from any source.

Sorry for the ramble.

Cheers,

Don

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by JerryVan »

You may find this handy. It is from the website of Wyatt Marcus, who has rebuilt far more these than I have even looked at, and is the recognized expert.

http://www.pixelshelf.com/~wyatt/rebuil ... honic.html

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by vichighmathguy »

JerryVan wrote: Mon May 10, 2021 8:21 pm You may find this handy. It is from the website of Wyatt Marcus, who has rebuilt far more these than I have even looked at, and is the recognized expert.

http://www.pixelshelf.com/~wyatt/rebuil ... honic.html
Thanks very much for providing this. Yes, I had seen it and have plotted a course which parallels it. The questions regarding cleaning and patching small diaphragm holes weren't thoroughly covered in the article so I thought it would be interesting to ask what others do.

Here is a question: imagine the threaded ring which clamps down on the back of the reproducer has a break in it, the result of it being too tight around the back of the reproducer. After using cyanoacrylate to mend the break, is your preference to increase clearance by sanding the inside of the ring or the outside of the reproducer back which it must slip over?

Cheers,

Don

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by Inigo »

Herein there are similar instructions to the former, but there is some info on how to clean the diaphragm.
https://www.gracyk.com/orthosound.shtml
There was an article by Bob Waltrip more detailed about ortho soundbox repair, which I've read somewhere that was copied from other source, but I cannot locate it. There's a pdf somewhere in my pc. If I locate it, I'll post it herein.
Have you done a search in the forum? Maybe the information is already herein! Look for orthophonic soundbox restoration or something alike...
Inigo

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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by JerryVan »

vichighmathguy wrote: Mon May 10, 2021 10:22 pm
JerryVan wrote: Mon May 10, 2021 8:21 pm You may find this handy. It is from the website of Wyatt Marcus, who has rebuilt far more these than I have even looked at, and is the recognized expert.

http://www.pixelshelf.com/~wyatt/rebuil ... honic.html
Thanks very much for providing this. Yes, I had seen it and have plotted a course which parallels it. The questions regarding cleaning and patching small diaphragm holes weren't thoroughly covered in the article so I thought it would be interesting to ask what others do.

Here is a question: imagine the threaded ring which clamps down on the back of the reproducer has a break in it, the result of it being too tight around the back of the reproducer. After using cyanoacrylate to mend the break, is your preference to increase clearance by sanding the inside of the ring or the outside of the reproducer back which it must slip over?

Cheers,

Don
I would reduce the diameter of the step on the reproducer back. Even the nicest looking pot metal can sometimes be swollen. When the back swells, it pops the threaded ring open. To open up the inside of the ring would invite disaster as the ring would most likely crumble in the process. Besides, it's the diameter of the back plate that's the culprit, so to address that, would be the best plan. I have reused rings with just a single split, but it's tricky as they are now very fragile and prone to further breakage. I have never bothered to glue them, fearing fouling the threads with the glue.

For those very tiny holes in a diaphragm, I have used a tiny dot of shellac, or a tiny dot of silicone sealant. Each applied with the tip of a toothpick. Applying either to the backside is more cosmetically appealing.

I've answered a few of your questions here, based mostly on my practices and experience. I really like the results I get, but do not claim to be an expert. (I still have a lot to learn... ;) )

vichighmathguy
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Re: Orthophonic Reproducer Cleaning Advice Needed

Post by vichighmathguy »

Inigo wrote: Tue May 11, 2021 1:54 am Herein there are similar instructions to the former, but there is some info on how to clean the diaphragm.
https://www.gracyk.com/orthosound.shtml
There was an article by Bob Waltrip more detailed about ortho soundbox repair, which I've read somewhere that was copied from other source, but I cannot locate it. There's a pdf somewhere in my pc. If I locate it, I'll post it herein.
Have you done a search in the forum? Maybe the information is already herein! Look for orthophonic soundbox restoration or something alike...
Thank you, Inigo - I had done that, but using "soundbox" rather than "reproducer" netted more results - thank you! I'm looking forward to tracking down Bob Waltrip's article as I know of his reputation and am keen to see what he said.
JerryVan wrote: Tue May 11, 2021 1:22 pm I would reduce the diameter of the step on the reproducer back. Even the nicest looking pot metal can sometimes be swollen. When the back swells, it pops the threaded ring open. To open up the inside of the ring would invite disaster as the ring would most likely crumble in the process. Besides, it's the diameter of the back plate that's the culprit, so to address that, would be the best plan. I have reused rings with just a single split, but it's tricky as they are now very fragile and prone to further breakage. I have never bothered to glue them, fearing fouling the threads with the glue.

For those very tiny holes in a diaphragm, I have used a tiny dot of shellac, or a tiny dot of silicone sealant. Each applied with the tip of a toothpick. Applying either to the backside is more cosmetically appealing.
Thank you, Jerry (I hope that is your name) - this is the kind of response I was hoping for. I was waffling between the two options and have come around to address the back for improving the fit - more "meat on the bone", so to speak. I had thought about chucking it up in the lathe, but there is so little that needs to be removed that I think a little judicious hand filing will accomplish the task. Again, thank you to everyone who contributed.

Oh, and I did find a bottle of 35-year old shellac gasket seal (can't see to get contemporary bottles in Canada without ordering out of country and that takes weeks). I put a little out a day ago and it has set up sufficiently for me to do as you suggest re: a dot of shellac on a toothpick, my imagined plan pending finding an appropriate sealant.

Don

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