What is the best way to repair a cracked 128 512k Plus case?

[68kbits]

I recently received a 512k that suffered a cracks case from a combination if poor packing and USPS abuse.

Is there a proper method to fix a crack in the front case?

There are no pieces broken off or missing, but there are three stress cracks that I Would like to make sure dont get worse and make them as invisible as possible.

My first thought was to use superglue...

 

[uniserver]

i always have goop around.

My plus suffered the same issues on the bottom near the feets.

Thin layer of Goop was smeared all around the cracked area on the inside, next is let the goop set up.

Goop has this great quality, as it dries it not only bonds, it also creates kind of a slight permanent stretching/tension.

I have some items that I used goop with 15 years ago and goop is still bonding nicely.

 

[68kbits]

Thanks, I have had excellent success with goop holding things together. I have never used it for a cosmetic repair though.

Did it hide the crack for you, or just keep it from getting worse?

 

[uniserver]

I was just talking mechanically, i was not really talking about cosmetic.

You goop the inside not the outside as i am sure you know.

The only way to fix it cosmetically would be a plastic body filler, ( bondo )

but then you will have mismatched texturing after sanding.

I think the goop will hold it together nice and tight though. maybe the crack might not be so noticeable once goop is dry.

maybe something else would be to try is epoxy and maybe a clamp, pressing the crack together as tight as possible.

maybe wipe off the excess before it sets up.

 

[James1095]

I've had good luck with solvent welding. I think the stuff is mostly MEK, it's sold for welding acrylic but it works on most ABS plastics too. Just be careful not to drip it anywhere as it will melt and scar whatever it gets on. I use a small syringe with a needle to put just a few drips right where I want it. Wicks into the crack and melts the plastic back together.

 

[Charlieman]

I've had good luck with solvent welding. I think the stuff is mostly MEK, it's sold for welding acrylic but it works on most ABS plastics too. Just be careful not to drip it anywhere as it will melt and scar whatever it gets on. I use a small syringe with a needle to put just a few drips right where I want it. Wicks into the crack and melts the plastic back together.

I'll second the recommendation for MEK or similar solvent welds. If you don't have a syringe, it can be applied by dipping the eye of a sewing needle into the solvent. Other glues will not prevent the crack from lengthening -- slowly, but it will happen.

A crack may be stopped by drilling a small hole (1mm) at its extent. Obviously such a fix may require some cosmetic work if it is visible.

Whichever fix you choose, practice on spare ABS plastics before trying to fix your Mac.

 

[uniserver]

wow that is a pretty neat process.

plastic welding.

 

[James1095]

A syringe is still the easiest way I've found to get it right where you want it with less risk of dripping. You should be able to get them at just about any pharmacy or veterinary clinic, they're typically less than 50 cents. Tap Plastics has them too for a bit more. Just don't leave solvent in them if you want to use them again, it expands and softens the rubber plunger after a while.

 

[68kbits]

Thanks, I will definitely give this a shot. I have a badly cracked (destroyed) monitor I will test this on.

Just received another compact Mac damaged in shipping.