A lot of the older Macintosh computer are suffering from brittle plastic. It's not too uncommon now to just open one and snap a few pieces off. The plastic with this problem is known as ABS. It also has a habbit of yellowing. Here's an example of a cd-rom tray that had the clips broken:
What is one supposed to do in such a case? Well I guess crying is an option
. Another option is glue/epoxy but that usually doesn't hold well.
The best solution for joing two pieces of ABS is solvent welding using acetone. This will actually dissolve the plastic and once the solvent has evaporated the plastic will be solid once more. So you can take a piece of broken ABS, put a TINY amount of acetone to wet the whole surface of the the crack parts and then put them together again.
I say TINY amount because it doesn't take a lot the dissolve the plastic. Put to much and you risk dissolving too much ruining the finish of the part. In or to put a small amount I put the acetone in a 10CC/ml syringe. That way you can apply smalls drops very accurately. The acetone doesn't seem to affect the plastic/rubber in a standard syringe but if you wanna be 100% safe you can also buy a glass syringe.
After applying the acetone and joining the parts together have a bit of time to fool around with placement. Like most repairs usually playing around with it too much can make things worse. If you spill any acetone on the surrounding plastic refrain from wiping. This will only cause the plastic to smudge and look worse. Same thing if some plastic squeezes out of the crack. Do not wipe. Wait until the plastic is solid again and then remove the extra plastic.
Let the welded parts sit a day or two to reach full strength again. Voila you now have a fixed part.
The strength of the part will never be the same due to age but in my opinion this is one the best ways to salvage the parts you have.
In north american acetone can be bought at a hardware store in the paint section. I bought my syringes from aliexpress but they can be bought from amazon. If your in Canada you can also buy other plastic adhesives and solvents from https://plasticworld.ca.
Other notes:
Some of you might have notices that sometime different parts of a Mac turn yellow and others don't. That's because the other parts are not made from ABS. A Macintosh Portable for example is mainly made from a type of polycarbonate. I've tried acetone on broken Macintosh Portable parts and it didn't work very well. Maybe something like Dichloromethane (solvent) or methyl methacrylate (glue) would work better.
What is one supposed to do in such a case? Well I guess crying is an option
. Another option is glue/epoxy but that usually doesn't hold well.The best solution for joing two pieces of ABS is solvent welding using acetone. This will actually dissolve the plastic and once the solvent has evaporated the plastic will be solid once more. So you can take a piece of broken ABS, put a TINY amount of acetone to wet the whole surface of the the crack parts and then put them together again.
I say TINY amount because it doesn't take a lot the dissolve the plastic. Put to much and you risk dissolving too much ruining the finish of the part. In or to put a small amount I put the acetone in a 10CC/ml syringe. That way you can apply smalls drops very accurately. The acetone doesn't seem to affect the plastic/rubber in a standard syringe but if you wanna be 100% safe you can also buy a glass syringe.
After applying the acetone and joining the parts together have a bit of time to fool around with placement. Like most repairs usually playing around with it too much can make things worse. If you spill any acetone on the surrounding plastic refrain from wiping. This will only cause the plastic to smudge and look worse. Same thing if some plastic squeezes out of the crack. Do not wipe. Wait until the plastic is solid again and then remove the extra plastic.
Let the welded parts sit a day or two to reach full strength again. Voila you now have a fixed part.
The strength of the part will never be the same due to age but in my opinion this is one the best ways to salvage the parts you have.
In north american acetone can be bought at a hardware store in the paint section. I bought my syringes from aliexpress but they can be bought from amazon. If your in Canada you can also buy other plastic adhesives and solvents from https://plasticworld.ca.
Other notes:
Some of you might have notices that sometime different parts of a Mac turn yellow and others don't. That's because the other parts are not made from ABS. A Macintosh Portable for example is mainly made from a type of polycarbonate. I've tried acetone on broken Macintosh Portable parts and it didn't work very well. Maybe something like Dichloromethane (solvent) or methyl methacrylate (glue) would work better.
