What to do about a stress crack?

[Greg G.]

I finally got around to getting some Novus to polish my NEC.  During the process, to my dismay I discovered about an inch-long stress crack on the left side.  I confirmed it wasn't just a surface scratch by taking the body off and checking underneath.  Sure enough, there it was.

What is the best way to try to arrest this thing and keep it from getting worse?

[Bill]

In many kinds of plastic - glass, too, I think - the solution is to drill a small hole right at the end of the crack. That will keep it from spreading, although it does not close the crack. I've done this in clear acrylic, which is pretty brittle, and it works well.

I suppose that on a phone, you would fill the crack and the hole with something that is a bit flexible and appropruiately colored. I'm thinking some kind of putty - but I have not done this step.

Bill

[Dan/Panther]

Brinybay;
I'm sure others will have other methods, but I've found over the years that the following method works on both plastic and bakelite, and arrests the spread as well as cover it very nicely.
You can VERY CAREFULLY make a small 'V' along the crack using a small sharp pointed object. Then I fill the groove with superglue. Place the phone so the crack is level, so the superglue will not run. After that I carefully sand off the raised portion of superglue, being careful not to sand into the surrounding area. Wet sanding the last bit to insure a very smooth surface. I then use a good polishing compound like Novus, or Brasso. The crack should be practically undetectable. Make sure the crack is clear of any white or discolored residue as this will show through the clear dried superglue. The superglue takes on the surrounding color.
D/P

[Greg G.]

Brinybay;
I'm sure others will have other methods, but I've found over the years that the following method works on both plastic and bakelite, and arrests the spread as well as cover it very nively.
You can VERY CAREFULLY make a small 'V' along the crack using a small sharp pointed object. Then I fill the groove with superglue. Place the phone so the crack is level, so the superglue will not run. After that I carefully sand off the raised portion of superglue, being careful not to sand into the surrounding area. Wet sanding the last bit to insure a very smooth surface. I then use a good polishing compound like Novus, or Brasso. The crack should be practically undetectable. Make sure the crack is clear of any white or discolored residue as this will show through the clear dried superglue. The superglue takes on the surrounding color.
D/P

What kind of sandpaper do you recommend?  I didn't know you could use Brasso to polish these. 

[Ellen]

D/P - what about making that V-shaped groove on the inside??

[Dennis Markham]

I'm a little slow...is that Bakelite or plastic?

[BDM]

Dennis, the one I saw at the show today was bakelite. Though they may have made those in thermoplastic also? Anyhow, that's not much of a crack. Not sure I'd worry about that right now.

[Dan/Panther]

Ellen;
If the crack is bad enough, I will use the same method on the inside, but add some mesh to add strength.

Brinybay;
As far as sand paper once you get it down smooth, progress to 1200 or even 1500 for an almost pefect patch. Yes Brasso works on many surfaces.
D/P

[Greg G.]

I was assuming it was Bakelite, but I'm not sure.  After I thought about it, I don't think I'll mess with it.  I'm not real skilled and have zero experience at this type of detailed work, top it off with no shop or tools to work with either.  I have a screwdriver set to take them apart and put them back together, but that's about it.  This one is a keeper and would be worth having it done by somebody who knows what they're doing.  It's not real noticeable, but it was like finding a scratch or ding on your new car.

[Dan/Panther]

Here is a before and after photo, of a very bad crack in a bakelite radio cabinet. This is one of the first attempts on my part, and since this cabinet, I've been able to improve significantly over what is in the photos.
D/P
I find that superglue works even better on plastic, because it will soften the plastic, and when it dries, it bonds better than it does on bakelite.
Also, I will take a razor blade, and scrap some material from the inside of the PLASTIC cabinets or phone, and mix it with the superglue, directlty into the brack or flaw. The razor blade shavings will melt, and very evenly color match the crack or flaw. This works great on larger flaws like a cigarette burn or deep gouge.
It is very important that the flaw be as clean, and dry, as possible. Superglue will dry clear if left to itself, but if any amount of moisture is present, it turns milky.
This is very similar to the artificial nails that Dennis has referred to. The superglue is the catalyst for the powder they use. At least some Acrylic nail systems use it. I'm not sure if Dennis' method uses that or not.

[BDM]

WOW Nice Dan. Maybe I could talk you into repairing a bakelite AE for me?

[Greg G.]

As far as sand paper once you get it down smooth, progress to 1200 or even 1500 for an almost pefect patch. Yes Brasso works on many surfaces.
D/P

I'm feeling a litter braver with these phones now.  When you say "progress to 1200", what level do you start the progression from - 400, then 800 and on up?  I was in Home Depot today looking to get a collection of sandpaper, but all they had were the lower numbers, highest they had was 400.  Also, what kind of tool do you recommend to make the V groove?  I posted some better pics also.

[Greg G.]

Also, I will take a razor blade, and scrap some material from the inside of the PLASTIC cabinets or phone, and mix it with the superglue, directlty into the brack or flaw. The razor blade shavings will melt, and very evenly color match the crack or flaw. This works great on larger flaws like a cigarette burn or deep gouge.

You just answered my next question, what to do about a deep gouge in a beige 500 I have.  This has been my "learning" phone, in that I'm free to experiment on it because if I screw it up badly, it's not a big loss.  I also looked around in Home Depot for some kind of plastic filler or putty, but didn't really see anything that would work.  There was some silicone stuff that may have worked and came in various colors, but I don't need a big tube of it for such a small project.

[Dan/Panther]

You can get finer sand paper from paint supply house or some auto parts stores.
One method I use for gouges is a Q-Tip dipped into lacquer thinner. Make a small puddle at the gouge, and carefully using circular motion blend in the gouge to the durrounding area, the lacquer thinner will melt the plastic and flow it into a more gradual pool. Then the smoothing by sanding process, like Dennis says the farther from the damage you feather, the less noticeable the flaw.
To make the crack larger I first clean thew cracxk veryu well, the from the backside glue it shut with superglue. Then I use a sharp pointed exacto knife to open the groove a little more in a "V" shape. then the superglue fill. Keep it dry, and let it set up for a few hours. It actually seem harder than the original material.
D/P

[JorgeAmely]

D/P:

The superglue you talk about, is it the same as Crazy Glue?