Case Mods

It all depends on the materials. Various plastics use chemically different glues. Some can be fused with heat, some only harden further and become more brittle with heat. You need to research what particualt plastics you are working with, and then find the appropriate glues to hold it together. Just trying random glue might do nothing, might melt the plastics, might actually work. It might even do nothiing to one piece of plastic, and irreperably melt/scar the other piece. Ick.

As a former model builder (still have a few space models about), I've had the opportunity to work with a lot of exotic materials. I've found that most computer cases are made from ABS (acetyl butyl styrene) plastic. This is not just a plastic that's found in your typical Monogram kit, it's an engineering plastic. Thus, you have a few options. First of all, regular model glue will not put a dent in the stuff. Tube model glue, also known as cement, works by a combination of "glue" and solvent action; the plastic in most model kits is polystyrene and is fairly easy to work. I know that a few companies out there have actually used polystyrene for cases, but this makes about as much sense as making a car out of plastic... oh, wait, they do that anyway.
Next are solvents. Again, steer clear of regular model solvents. Some sites on the 'Net will say they work, I've never had any success. Your best bet is a solvent known as Tenax 7-R, usually available at better stocked hobby shops.
Another chemical you could try to use is MEK (methyl ethyl ketone); however, while it definitely works with styrene and probably ABS, it is pretty gnarly stuff and a known carcinogen. It just happens to be fairly easy to obtain (Carcinogen? Easily obtained? It is not my place to question these things...)
Your next options are epoxies. Probably a good choice, use slow setting simply because it is tougher in the long run.

Hope that helps!

Rob

As a former model builder (still have a few space models about), I've had the opportunity to work with a lot of exotic materials. I've found that most computer cases are made from ABS (acetyl butyl styrene) plastic. This is not just a plastic that's found in your typical Monogram kit, it's an engineering plastic. Thus, you have a few options. First of all, regular model glue will not put a dent in the stuff. Tube model glue, also known as cement, works by a combination of "glue" and solvent action; the plastic in most model kits is polystyrene and is fairly easy to work. I know that a few companies out there have actually used polystyrene for cases, but this makes about as much sense as making a car out of plastic... oh, wait, they do that anyway.
Next are solvents. Again, steer clear of regular model solvents. Some sites on the 'Net will say they work, I've never had any success. Your best bet is a solvent known as Tenax 7-R, usually available at better stocked hobby shops.
Another chemical you could try to use is MEK (methyl ethyl ketone); however, while it definitely works with styrene and probably ABS, it is pretty gnarly stuff and a known carcinogen. It just happens to be fairly easy to obtain (Carcinogen? Easily obtained? It is not my place to question these things...)
Your next options are epoxies. Probably a good choice, use slow setting simply because it is tougher in the long run.

Hope that helps!

Rob

Pretty much any slow-setting epoxy should do. You want to rough-up the cases where they are to be glued together, since the epoxy basically just "glues" as opposed to "welds" the plastics together. Use a little bit of medium grit, and that should do it.
(...also, ran out of room in my signature for all of them, but it has a name... "Phoenix"...)

As a former model builder

I didn't think there was such a thing. "Currently out of kits", perhaps.

But I digress...for Mac case plastics, I found ABS/PVC plumbing glue works very well (good ventilation required as per Astro Rob's post). Epoxies are good, but don't flex and might crack along the seam of an otherwise somewhat flexible case (thinking of something like a IIcx case here).

There are also specific glues for acrylic and lexan clear sheeting, if that's your cheese.

I've had great results welding ABS with ProWeld solvent welder, works with all ABS parts perfectly. I've also used it on polycarb with mixed-but-overall-good results. Model/hobby stores carry it, I got it at towerhobbies.com.

Main thing with solvent welders is the need for super-tight tolerances, which's perfect for cracked parts, but not so great when trying to match and weld fabricated parts. For those instances where you can't get a perfect fit, I'd suggest using a two-part acrylic adhesive, commonly available in auto parts stores sold for plastic repair (note, if it says 'epoxy', that ain't it.) Acrylics have very nasty fumes, so be sure to work in a well-ventilated area.

dan k