Fixing a Cracked CRT with Plastic Welding

Overview

When I shipped a vintage Apple 2C monitor across the United States, I learned an expensive lesson about packaging fragile 1980s plastic. The CRT arrived with multiple cracks and broken sections. In this detailed repair video, I show you how to fix cracked vintage computer plastic using a hot knife plastic welding technique. While the cosmetic results aren’t perfect, the structural repair brings this 1986 Apple monitor back from the brink. This is a cautionary tale about shipping vintage electronics and a practical guide to plastic repair.

Key Moments

• Discovering the extensive shipping damage on the Apple 2C monitor
• Disassembling the monitor to access all the cracked plastic sections
• Learning the hot knife plastic welding technique
• Straightening bent plastic sections before welding
• Welding the major cracks from the inside for structural integrity
• Testing the repaired monitor - it works!
• Lessons learned: pack vintage electronics extremely carefully

Full Transcript (Edited)

Hey everybody, I’m here in my garage and as you can see here I have a bunch of CRTs next to me. That’s because this video is about a CRT repair, but not a circuit repair. In this one I’m going to repair the plastic on a CRT, in particular an old Apple monitor. That plastic broke because I decided last year, or maybe two years ago at this point, to ship an Apple monitor across the United States all the way from New Jersey back to my place here in California. I didn’t know what I was doing. So when I got the CRT at my place and I opened the box, I was surprised with a lot of broken plastics.

So in this video I’m going to show you how I went about repairing it as best as I could.

Tonight I’m working on a project that I’ve been holding off on doing for some time. A little bit over a year ago I bought this Apple 2C while I was on a road trip in New York and I decided to ship it to myself from New York via FedEx Ground. Unfortunately I did a very, very poor job of packaging the CRT and as you can see here, some of the plastic broke off.

What I’m going to try to do is use a method that I saw somebody doing online and combine some fiberglass filler. I bought this from a local Marine store (description below). So if you’re looking to get something like this, it’s a fine powder that you can combine with, let’s say, some super glue. If you make a mixture with this fine powder, you can add… you can basically fix some of these larger broken plastics because the powder acts as a reinforcement inside.

So I’m going to try that out. The first thing I’m going to have to do is carefully remove this cover off so I can see the extent of the damage. I think it’s just this big piece of plastic right there. And this one may come out, may come out pretty good. This one I’m a little bit worried because you can see here the crack is fairly severe. So yeah, I hope hopefully I can at least make it functional. It doesn’t have to be perfect because at this point I just want it to be structurally sane, or at least look like it’s structurally sane. And I’ll have an Apple 2C that works.

But let me take this off and we can go from there.

[After opening]

I just turned this around and I noticed that I also have a huge hit right here. Yeah, when you’re shipping CRTs, be careful. If you can avoid shipping a CRT, it’s probably better just to drive across the country, because odds are you’re going to end up with some really bad broken plastic. This is very brittle and it’s kind of falling apart. But hey, I’m going to try my best, going to see how it goes.

Right now I’m going to take this cover off. I think I can just lift it off. Maybe I took one, two, three, four screws off and I don’t see any other screws holding this. Let’s see, I don’t see anything else holding it.

So as I was taking this apart, I felt some pressure down here and none of this stuff is moving. I would expect the case to kind of come out. This has to go in because it’s kind of loose in there. So as this case comes out, this cable starts going in. Then I think I can probably unplug it in there. Otherwise you would have had to have this case kind of dangling with the end of the cable stuck to it.

But anyway, going back to what I just found. See these little inserts in here? They’re little rubber inserts and I’m using a… I think you call this a dental pick. I bought this many years ago. It’s useful for stuff like this. Can just pull it out and then inside of those is a screw. So I have one, two, three, four, five more screws here which are… it’s probably holding the board to the chassis. So I’m going to take those five and then continue sliding this out.

Okay, so I wanted to point out something that as I’m taking this apart amazes me honestly. This is a monitor from the ’80s and even back then Apple took great care into making sure their design and their aesthetics was unparalleled. I mean, look at this: they painted the screws that go in the back here so that it matched the color of the plastic. And these little rubber pieces that were covering the bottom screws, they’re color matched to the color of the plastic.

I mean, these screws are rarely ever going to be seen because they lay flat, yet they took the effort, they made the effort of color coating, or color matching (sorry), the little rubber inserts that cover the screws at the bottom of the case. It’s amazing! I mean, back then in the ’80s, Apple was already taking their design and the aesthetics of their machines so seriously that they went to the effort of making those color matched little rubber inserts. Just amazing.

Also, one great tool that you should have is a magnet tool like this, because this will let you get the screws out like that without too much effort. I’ll put links in the description for the tools that I’m using: this magnet, the dental pick, this little screwdriver that I use. It has a magnet at the bottom as well and it’s reversible, so you have Phillips on this side and then flathead. It just reverses. Then you insert this into the base and now you have a flathead. Then you flip it, you have a Phillips. Very useful for computer work, especially since it has a magnet at the bottom. Yeah, like I said, if you want to see those tools, the links are going to be in the description.

Let me continue doing this. I just have one more screw and then I’ll finally hopefully take that off.

[Working on the repair]

Okay, so this is the one that was caved in. Now it’s structurally better. You can still see the crack unfortunately, and here too you can see some more damage. And here. But I guess I’m stuck with that. That’s what I get for shipping it wrong. As long as it works… I think it does. I have to plug it in and see if it works. So you can see here this is still broken but it’s not coming apart. And this is the top part right here which is not coming apart.

So yeah, let me set up the computer. Oh, I have to show you one more thing that I found which unfortunately I’m going to have to live with as well.

[Shows additional damage]

Okay, so here’s the monitor and yeah, there’s one more crack right here. And this one I’m not going to do anything about. This is really unfortunate. That’s what happens with this plastic. It’s from 1986 and the year right now is 2022 (actually filming in 2023). That is really old, brittle plastic. So if you ever ship this stuff, pad it really well and give it some wiggle room because you do not want to have to deal with all these broken plastics. It makes something that was perfect look like it was coming from a garbage dump.

So yeah, let me, like I said, set it up. Let me do some cleanup here and see if the computer works.

[Testing]

Okay, here we are, the moment of truth. First, power on the monitor. So we got power here. And now I’m going to plug in, power up the computer. Oh nice! Apple 2C. Check this drive.

Well, I’m going to end this video right here. If you’d like to get any of the tools that I used in this video, check the description. I’ll put links there and you can go check them out. Yeah, stay tuned for the next video in this series. I’m going to try to see what I can do with this Apple 2C. I have a feeling that this drive is bad. I’ve tried to put floppies in there before and it doesn’t work, so I’ll have to probably take that one apart and see what’s going on.

Well, till next time, thank you.