Pot Metal Repair

[edisonc250]

Anbody have success using JB Weld on pot metal tone arm?

[MordEth]

I know that John had been using it to rebuild a part—I’ll have to ask him how that turned out (assuming he’s finished it), but from what I saw the results were quite good.

If I remember correctly, he was shaping the repair against Saran Wrap, because the JB Weld wouldn’t adhere to it.

— MordEth

[Aaron]

I dont know what you mean by "JP Welding" but i have had my dads friend (who is a jeweler) weld parts together with the latest Lazer Welder on the market so if "JP Welding" is the same then it will work.

Aaron

[gramophoneshane]

I think John was pretty successful judging by the thread and px on the Edison board.

http://edisonphonos.proboards.com/index ... thread=634

[richardh]

This is intersting as I have a pot metal part that needs repair / rebuilding. Its a control mechanism for turning an internal radio ariel. The part that is broken is a half moon gear that has broken into several pieces. I have got some putty which the tin says sets hard as metal and can be filed or sanded. I was going to try molding a new gear out of it. As the teeth in the half moon cog are quite large I was going to give it a go. So this has come as a timely thread

RJ

[MordEth]

I dont know what you mean by "JP Welding"...

Aaron,

J-B Weld is an epoxy that is primarily advertised for automotive repair, because it can withstand high-temperatures (they show an engine block being repaired with it). Like any epoxy, it can be used to adhere quite a number of materials together.

The jeweler’s process that you describe is something else entirely.

I think John was pretty successful judging by the thread and px on the Edison board.

Shane,

Thanks for pointing that out; I’d forgotten that he’d posted about it. The last I’d heard, he still wanted to do some additional work on those parts...

Folks,

An old friend recently found a late model Victor portable at a yard sale and bought it for me as a gift. Mechanically and cosmetically it appears to be in good condition for the most part. However the tone-arm and the it's base were broken and swollen. The base was broken in two with a chunk missing and the lip on the base of the arm itself was partially missing and the U-Tube was frozen.

I decided this was a perfect piece to experiment on. I have put the base back together and am building up the missing chuck with J-B Weld. For the base of the tone-arm itself I first wrapped it with Saran Wrap and snapped the retaining ring in place (to form the channel that the ring fits in) and have slowly molded a new lip with the J-B Weld. The J-B Weld doesn't stick to the Saran Wrap. For the U-Tube I slowly forced it out of the socket and I used a medium grit sandpaper to grind it down and smoothed it with 000 steel wool.

I have a bit of “fine tuning” to do yet on the parts, but it seems to be a success. I hope to finally tackle that pot metal reproducer I mentioned in the other thread soon.

Regards,
J.

Hopefully this helps anyone with parts in similar need for repairs.

— MordEth

[AZ*]

I've repaired the damaged necks of HMV #4 & 5A soundboxes with JB Weld. They seem to be holding up quite well. I also repaired Orthophonic back brackets in the days before reproductions were readily available. They also continue to hold up 15 or 20 years later.

The issue I have with JB Weld is the slow cure time. The stuff tends to flow and lose its shape unless you have a way to prevent it.

For my most recent repair, I used the Quick JB Weld which hardens in 5 minutes. That solved the flowout problem.

[Shane]

Yes, I've had very very good results with JB weld for pot metal repairs. To echo what AZ said, the 5 minute formula is the way to go. This is especially useful if you have an odd-shaped part, or an odd-shaped crack or break... something that is difficult to clamp. With the 5 minute stuff, you can apply it and hold pressure on the part in your hand while watching TV for 5 minutes, and it should be dry enough to hold itself in place. Then let it dry overnight for full strength.

[edisonc250]

Thanx for all the fast replies..I used it and it worked great..It was the lat couple of inches of the tone arm where it attaches to the reproducer at the collar..perfect fit and looks great..I am almost done with the LU37..Sounds great...I am working on a Aeolian Vocolian Model G at the moment as well.
Thanx Guys

[B.B.B]

I’m a big fan of J-B Weld. The stuff is downright amazing!

It works on pot-metal, alloys, cast iron et. al.
I still haven’t found a metal-type material that it won’t bind.

There is only two things to keep in mind when using the stuff:

1. Curing time. Even the fast curing J-B should be left alone for at least 24h before being handled. The regular should be allowed to sit for a full week, to get optimum strength.
J-B Weld also benefits from heat. Not strong heat, but temperatures around 35-40 degrees Celsius allowes the stuff to bind even harder. Let the item sit on top of your fridge or in the boiler room while curing!

2) All types of epoxy resins are highly toxic. And it enters your bloodstream right thru your skin. Always use gloves!
Something even more toxic then uncured epoxy is cured epoxy. When sanding before painting you’ll fill the air (and your lungs if not protected!) with toxic particles.

But, if you let it sit for a proper amount of time & take some necessary precautions,
J-B Weld is a substance as useful as beer!