Replacing Pot-metal

[winsleydale]

I just popped the back off of my 8-12 to check for hidden gems (clean it), and I saw that there is a pot-metal tube that connects the tone arm to the horn. This is cracking all over. Does anybody make replacements for these parts?

[billybob62]

This is an off the wall answer but I wonder if anyone else has thought of it or done it. On an out of sight pot metal part how about coating the cracked part or the entire piece for that matter with an epoxy glue such as JB WELD which could stop and also seal the cracking? Of course all the while looking for an okay replacement part for purity's sake. Am I crazy?

[winsleydale]

I don't think you're crazy; I had not thought of that.

[Edisone]

Sounds like a job for a 3-D printer. I wonder if Jay Leno would respond if you sent him some pics & explained the purpose of the part, etc. He has a big, expensive 3-D printer he uses to fabricate parts for ancient automobiles - maybe he'd like a challenge. I think it wouldn't even be necessary to cast a metal part, as strong plastic should be sufficient for a horn connection.

[winsleydale]

That's definitely an interesting idea. So interesting it just might work...

[Edisone]

You might turn him into a Victrola collector

[Victrolacollector]

I coat pot metal back brackets in epoxy or JB Weld. Let dry and sand smooth and paint black. I think of it as an ounce of prevention.

[winsleydale]

That would work, especially considering that this is fully within the cabinet and invisible to the observer.

[Bruce]

If the tube still has its structure and shape but is cracked try covering with Crazy Glue. The glue will penetrate the cracks and give the entire tube strength without changing its appearance.

Bruce

[TinfoilPhono]

This topic has been discussed in the past and I seem to recall some posts by people who found it successful.

I haven't had occasion to try it myself, at least not on phonograph parts. However 10 years ago I used it for restoring a shift knob for a 1928 Ford. I was happy to get it because it is a rare part, with a distinctive 'mushroom' shape that is not reproduced today, and was only used for 1 year. (I didn't like using a reproduction 1929-1931 knob.) It's also special in that it's made of soybeans. Ford was infamous as a soybean promoter, who experimented with them in making auto parts. This is the fruit of such an experiment.

However when I got it I found it was riddled with small cracks and looked like it might self-destruct at any second. It actually reminded me of pot metal in that sense (but with no swelling).

I took JB Weld and carefully pushed it as deep into all of the cracks as I possibly could, and wiped away the excess surface residue. While still wet I took a dark brown felt pen and went over all of the JB Weld. The color was absorbed into the JB and was permanently bonded. (Obviously not an issue with most phonograph parts.) After curing and polishing the result was amazing. You'd have to look very, very closely to tell that it was formerly too fragile to use. The cracks are not visible and the knob is rock-solid.