Credenza Maintenance

[Ampico66]

I picked up a 1926 Credenza on Craigslist. I'm going over the machine, touching up scratches in the cabinet, cleaning, etc. I have the back panels off and I wanted to know if there is any kind of sealing I need to do on the horn or where the metal neck is screwed together, or maybe the ball-bearing track under the tone arm. What maintenance does a Credenza usually need?

Damon
St. Louis, MO

[gramophoneshane]

I've never worked on one obviously, but I've heard/read that you should reseal all the joins you can reach in the horn as the wood can warp a little, causing the seams to open up, along with resealing the both ends of the metal horn section. This I image is best done by removing the horn from the cabinet. I think? there's also a felt washer between the tonearm & motor board that needs to be coated with grease to prevent sound leakage, and the tonearm bearings themselves also need to be packed with fresh grease.
Whenever I seal the joins of a normal wooden horn, I like to give both sides of the timber a coat or 2 of shellac, to seal off the fibres a little better and hopefully prevent future warping.
Hopefully someone that's actually worked on one will tune in with any corrections &/or additions you'll need to know.

[Nat]

The above pretty much covers it. I took mine all apart, greased the felt and the cork seals (replaced one with silicone), and painted the wooden horn with tung oil. The tricky one is if you remove the tone arm from its mount and re-grease the bearings. It took me an hour or so to get all the bearings back in; if you do this, a good coat of grease holds them in place while you put it back together.

Worth it - great machine!

BTW - cleaned mine all over with with Cotton Cleanser (sp?)and it really brought the grain of the wood out! Then polished it wit a beeswax polish. It looks as good as it sounds.

Keep us posted on what you do!

[OrthoFan]

This I image is best done by removing the horn from the cabinet. I think?

With the exception of the Consolette, the Orthophonic horn is pretty much integral to the cabinet and cannot be removed easily.

Years ago, RJ Wakeman wrote an article about re-sealing the Orthophonic tone chamber --

http://www.gracyk.com/credenza.shtml

He followed the recommendations of Bob Waltrip, painting the entire surface of the horn with glycerol.

Having listened to RJ's Credenza, I can say that it did, indeed, sound fantastic, but there has been discussion over the years, especially on the old OTVMMB, that such treatment is not really necessary.

Personally, I've never tried the glycerol treatment, but I have used penetrating oil based stain on the horn of the Credenza I used to own, as well as on the horn of my 4-40. I also used a hot-glue gun to seal any small seam gaps. In both cases, I did hear some improvement in the sound quality--notably stronger mid-range and more pronounced bass.

[estott]

I used clear silicone caulk to seal up the horn seams I was able to reach= a friend (who knows more than I do) advised against the Glycol treatment) and the seam where the cast iron neck bolts to the horn. The important points are to see that the tone arm joints are sealed with grease- I've used Vaseline and it works for me.

The old manuals said to test the tone arm seals by unbolting the neck from the horn, blocking the joint with a sheet of paper, then blowing smoke into the tone arm.

[Edisone]

I forget what kind of caulk I used on the joints - many of which were very sloppy & showed a disappointing lack of care at the Victor factory. I also packed the felt joint with heavy axle grease, and used a 50/50 mix of linseed oil & turpentine on every part of the horn I could reach. Warning: you'd better REALLY like the smell of turpentine, because you'll be smelling it for the next year or so!

[need4art]

Hi All,
This is interesting, I had read the article about how to treat the credenza horn over 2 years ago, but just got mine in Aug. It is interesting to note that as an art restorer that I use this same process to restore old wooden frames as well as wood carved Native American artifacts. The process was taught to me by a restorer that works for the Chicago Art Institute and I have seen it actually close up gaps in the frames and artifacts. The methanol acts as a carrier for the glycerine and breaks it down so that it will get into the pores of the wood better. I had tested how well this works by taking a 1X4 piece of tulip wood, sanding it smooth on one side and marking off 6 inch sections. I coated each section with the following: shellac,varnish,tung oil,linseed oil,linseed oil and turps, boat varnish. I let it dry over night and then cut each section in half to view how far each coating soaked into the wood. The methanol/glycerine was into the wood almost twice as far as the others.

It is a messy process and I coated it and let it set for 2 days. I took course cloth and then wiped it down hard.
I have no reason to believe that this would do anything but good and I have looked at items I treated over 20 years ago and they look just as good as they did the day that I coated them.

By the way for anyone wanting to do this you can still get the glycerol-glycerine almost anywhere but you can longer get methyl alcohol-methanol over the counter. Blame 9-11 for that. I order mine from VWR scientific and it runs $31.88 for a 5 liter container. But watch out shipping and special packing adds ANOTHER $49.32. I used to pay 24.80 a gallon plus tax. OH well I guess that's just progress...

Abe

[Edisone]

For what it's worth: only the worst hack piano men use glycerine to tighten tuning pins.

[need4art]

Well I can't say that I know much about piano tuning but I have found that most process's that the Chicago Art Institue and the people that work there would not be by and far "hacks". Perhaps a bit of enlightenment on the ills of the process are in order so that I might understand what is wrong with this process.

I have also heard that caulk or silicon should not be used to seal a horn but that beeswax should. Don't get that either

Abe

[OrthoFan]

For what it's worth: only the worst hack piano men use glycerine to tighten tuning pins.

I remember reading similar comments on the the old OTVMMB as justification why the glycerol treatment should not be used on an Orthophonic tone chamber, but have to confess, I've never seen the connection.

In the case of a hack piano repair job, I understand, the glycerin was used to prevent the tuning pins from slipping in their worn out or damaged holes. Eventually, due to the stress imposed by the strings, the holes would expand or crack, and the pins would slip that much more, or even pop out.

Of course, in the case of an Orthophonic horn, this is not an issue--no pins/no strings--and the glycerol is simply used to harden or solidify the wood.

Based on what I've read and heard from other collectors over the years, in addition to sealing any minute gaps or cracks in the wood, it also reduces sympathetic vibrations which can impact the overall tone quality. I remember hearing one more or less as-is Credenza, in fact, that sounded more like a cheap 1940s table model radio with the treble turned all the way down--a booming bass and hardly anything above middle mid-range. One could literally feel the entire cabinet vibrating in sympathy with the record.