Repairing broken cradle of SC 1212 "Fatboy"

[RCMcDonald]

I thought folks would be interested to see the technique I used to repair the broken cradle "ear" of a Stromberg-Carlson 1212 "Fatboy". 

I used hardware-store epoxy, thickened with colloidal silica and colored with oil-based black paint to effectively recreate the broken piece.

The first pic below shows the phone as I bought it for about $15 on ebay.

The second pic shows the phone masked and a small wood screw inserted to form a stud around which I could form the epoxy.  Note that I ground off the corners of the top of the screw to make the head small enough

I mixed up a batch of two-part epoxy, using 30-minute epoxy from the hardware store (pic 3).  I mixed it with colloidal silica I had left over from a boat-building project (pic 4) and black oil-based lettering paint - just a few drops to get the right color.  Colloidal silica is available from West Marine and other marine supply stores.  I'm sure other thickeners would work, too. 

I mixed this in a plastic cup to the consistency of dry peanut butter, (pic 5) then used a popsicle stick to form the rough shape of the new ear (sorry, no pics of that). 

After about 30 minutes, the epoxy had started to firm up, and it becomes easier to shape.  The trick is to use plenty of denatured alcohol coat your fingers (using latex gloves) to shape the new ear.  There is a short window of time during the curing process to do this - too soon, and the epoxy is too squishy, and too late, and it won't be malleable.  Smoothing the epoxy out with the denatured alcohol also creates a smooth surface, and, if you can get right, means that little sanding or finishing is required after it's cured. You can also create the final shape by filing down the surface with a metal file and polishing with increasingly finer grits of sandpaper, but it's much easier to shape the partially-cured epoxy.

The final pic shows the finished product.  I'm not completely happy with the result, but that is due solely to my failure to match the exact shape of the opposite "ear" when I was sculpting the epoxy. A little more patience and perseverance to get the right shape while the epoxy was curing would have helped.

I have also used this technique to replace large chunks broken from a Bakelite case of an old European phone I found at a flea market.  I hope this is helpful to someone.  Feel free to let me know if you have questions.

Best,

Bob

[HarrySmith]

Nice Job!
Thanks for sharing the technique with us. How about a few "after" pics?

[RCMcDonald]

Thanks, Harry. Good point.  See below.

[LarryInMichigan]

The results look pretty good from here.

I believe that the cradle is completely symmetrical, so if it were mine, I would turn it 180 degrees so that the broken ear is on the back side of the phone.  it is held to the phone shell with a couple of screws.

Larry