[OldRestorer]

Today I finally got the urge to get into dial covers!

My PT-69 has horrible dial plastic so I did a bunch of research and here is what I learned and the stages of the process.

I started this journey by purchasing .020 plastic from USPlastics.com. It comes in a 24"x48" piece for only $12 and $10 shipping. Thats a lot of dial covers!

   

The tools you will need:

1. Heat gun
2. Round and flat file
3. Jigsaw (if available)
4. Hard board or solid wood (no plywood)
5. Plastic
6. Scissor
7 Saw
8. medium & Fine sandpaper
9. Drill
10. Clamps
11. 1/2 Wood
12. 1/4 wood
   

Step 1:
 Cut 2 pieces of wood (at least 1/2" thick wood) about the same size. They should be about 2" bigger on each side than the dial cover you are trying to make.


2. Place one of the pieces of wood inside the radio cabinet and trace the hole.
       

3. Use the drill to bore a hole for the jigsaw and cut out the piece. ( you cannot use the inner piece for the insert unless you want to wood fill and perfectly level the drilled hole)     


Cont. on next page

[OldRestorer]

4. Use the flat file to even out the sides and the round file for the curves if they are not square.  I found out through error that the bottom edges should be a bit tapered so the plastic does not crack or rip.
   

5.  Take the cut out you just made and the ¼” piece of wood and trace the inside onto the ¼” piece. Then cut out the insert. Sand the edges of the insert and fine sand the top and sides. They must be fine sanded or the plastic will pick up the detail.
   
6. On a clean surface place the UNCUT piece of ½” wood OR masonite down. Then attach the cutout to the center. Glue it, or screw it. You are attaching them so the center piece will not move off the base piece.
    [attachment=12077]

7. Take the bottom of the template and place it on a clean surface. Then cut out a piece of plastic the size of the base of the template. Make sure to peel off the protective film….. Place the piece of plastic over the base template. Then take the top of the template and fit it so it is evenly spaced around the bottom half with the plastic in between.  Use as many clamps as needed to apply even pressure. The bottom lighter colored piece if wood is just for a flat surface...
   

[OldRestorer]

8. Take the heat gun and from about 2” away, move slowly along the edge and as the plastic melts and the top sinks down, keep moving. When the top and bottom are sealed you can unclamp and remove the finished piece.
   
Congratulations! You made a new dial cover
   

Some little things: some dial covers may need to be deeper so keep that in mind. It will take practice unless you are that good.
   

[OldRestorer]

Here it is

[hsusmann]

Very interesting!

I just bought a dial cover for an RCA 10T from
Retro Radio Repair in GA for $18.

Next time I will try this method.

[morzh]

This is cool! Many radios use this type dial lenses, like my Zenith Bomber for instance.

[skyscraper]

Here's the link for Mark Palmquist, that hsusmann mentioned. His are great, if you don't want to do it yourself.

http://jmpalmquist.home.comcast.net/~jmp...index.html

[OldRestorer]

yeah, I'm cheap and for the price of one dial cover I can now make 100.
I have about 5 more radios that need this done so no thanks on the $18 each plus shipping.

[Warren]

That is close to the way we used to form Skylights. Only you would have the mold, similar to what you did. Then you heat the plastic in an oven. when it is pliable, after a few minutes, you take it out ( with gloves of course) and put it on the mold and clamp it down to cool. With skylights you would put it on a table with the form on it and use air to stretch the plastic to the height you want it and let it cool. You might find it forms better and more evenly if you try putting it in an oven for a few minutes instead of using the heat gun, which is hard to get an even heat all around it at the same time.

[tab10672]

One problem I have had with this method is air getting trapped under the plastic around the edges of the templet which would make the corners and edge lines look wavy. After many failed attempts I figured out that a piece of linen on the base under the templet would let the air escape as it flattened out over the mold.

[Warren]

When making a skylight they have a template that holds down the plastic around the edge and actually presses downand seals it against the table. Then in the middle of the table is a hole the air comes up through. You have to adjust the air so it only uses enough pressure to stretch the plastic as far as you want and let up when it gets to the height you want. For the dial I wouldn't use air because it makes the plastic higher in the center than around the edge. For a dial I would use the way oldrestorer did it except heat the plastic in an oven instead of using the heat gun.

[OldRestorer]

I am not fond of the oven idea. If I were doing 10 at one time maybe but I like hands on.

Gonna start making the new dial covers for my 41-22cl this week

[Warren]

It's to bad you don't like useing the oven, it's the best way as it heats the plastic pretty evenly and you can tell when it is ready to form and it forms very well that way...with a bit of practice. Thats why skylights,etc are done that way by business's. Actually it wouldn't work for trying to do 10 at a time, they cool off pretty quickly you couldn't get them all setup in their molds fast enough. But, you should do it the way you are comfortable I spose... That being said, your dial cover does look good.

[abes.cherif]

It is simply genial ! Thanks for sharing this. I'll do at least 10 dials I were expecting to buy !!

[Kestas]

I made my first one yesterday. I used the oven method. It took four iterations before I got something I was happy with.

You can read all you want about the procedure. It's a good start. But only practice will show you the fine points.