best repair practices for broken/cracked casing?

[corrupt_penguin]

So I have a keyboard casing that has suffered a broken standoff and in addition cracked standoff's. I need to repair them and I am looking for advice on how a more practiced individual would go about this procedure. I know there are commercially available solutions such as 'crazy glue' and I am also familiar with mixing epoxy such as JB Weld. I know that JB Weld can either hold anything or nothing depending on the material. I personally do not know how jb weld would react to the plastic but if it holds it would most likely be stronger then the original plastic, or it could possible melt the plastic and make a mess of things.

In regards to the cracked screw barrels I am thinking maybe some kind of brass tubing could be pressed over like a sleeve to restore integrity?

Thanks for any input you might be able to provide.

[rant] (sorry, I will get over this after I whine about it at least a few more times)
This damage was done by unsaid company whom swears this damage is impossible, but yet they are the only ones who have had tools on this keyboard. The damage pictured was how I found it when I finally opened it up just a few days ago. The unsaid company canceled my warranty for abuse and claimed no liability. Although at my suggested request they did in fact agree to send me a replacement standard keyboard casing as a sign of 'goodwill'. So thus its on me to repair this keyboard casing that some oversize orangatang with a power screw driver has managed to bust up with no consequence. [/rant]

[fohat.digs]

mixing epoxy such as JB Weld

the cracked screw barrels

In my opinion, JB Weld is absolutely the best repair for 90% of anything and everything that is broken. Remember that the slow set gray is twice as strong as the fast set, that clear epoxy is usually the weakest, and that "Super Glue" will die after weeks or months. Also follow the instructions to the letter and clean and prep thoroughly.

Unless you are really determined to squeeze those barrels inward, epoxy layered with strong fabric embedded as reinforcement is the easiest. If the interior threads are not tight enough for you, plumber's tape or strips cut from a baggie is a simple way to tighten it up.

[Tactile]

Assuming this case is made of ABS plastic:

If you can find a scrap piece of ABS plastic, use a file, knife, whatever to make a pile of fine shavings.

These ABS shavings will dissolve in acetone (nail polish remover). By varying the amount of acetone/shavings you can make a thin paste or a thick putty. The thin paste can be used to weld ABS parts while the thick putty can be used to form, or re-form, broken or missing parts.

You're working on the inside of the case so, obviously, matching color is not a concern.

[c.a.t.]

Personnally I use contact glue, it does great!

[Maledicted]

I haven't used them with a keyboard yet, but I really like these brass threaded inserts for repairing structural casing damage to Chromebooks. They have a flange, so they should help with providing more structural integrity than the original design. You would need to find long enough M3 machine screws for them though.

I drill out the cavity for the old insert all of the way through the case (or straight through the integrated standoff in this case) with a 5/32 drill bit and set the insert into the resulting hole with a soldering iron. The hole is just a bit too small without heating with the iron so that the insert has more surface to grab when it is installed.

The result looks something like this:



You may end up with a gap between the insert and where the original standoff would originally have met up with another on the bottom half of the casing if going that route.

mixing epoxy such as JB Weld

the cracked screw barrels

In my opinion, JB Weld is absolutely the best repair for 90% of anything and everything that is broken. Remember that the slow set gray is twice as strong as the fast set, that clear epoxy is usually the weakest, and that "Super Glue" will die after weeks or months. Also follow the instructions to the letter and clean and prep thoroughly.

Unless you are really determined to squeeze those barrels inward, epoxy layered with strong fabric embedded as reinforcement is the easiest. If the interior threads are not tight enough for you, plumber's tape or strips cut from a baggie is a simple way to tighten it up.

Don't they make J.B. Weld specific to plastics? It is called PlasticWeld.

I have used the standard gray stuff with plastics myself (since that's what I keep around) and it works well, but I have read that the PlasticWeld is better in some plastic applications.

Assuming this case is made of ABS plastic:

If you can find a scrap piece of ABS plastic, use a file, knife, whatever to make a pile of fine shavings.

These ABS shavings will dissolve in acetone (nail polish remover). By varying the amount of acetone/shavings you can make a thin paste or a thick putty. The thin paste can be used to weld ABS parts while the thick putty can be used to form, or re-form, broken or missing parts.

You're working on the inside of the case so, obviously, matching color is not a concern.

It does look like Unicomp cases are made out of ABS. Sharktastika's article on the New Model M states that they're a polycarbonate/ABS blend. I imagine he got that information straight from Unicomp.