Announcement

After 5 years serving the vintage Apple enthusiast community, ThinkClassic has been marked for closure and is now in caretaker mode. Please see this thread for further information. Please direct any questions, comments and enquiries about the website, management and ownership to this thread.

You are not logged in.

#1 2014-11-30 20:00:32

MJ313
Member
Registered: 2014-09-23
Posts: 498

Case repairs - Plastics

When it comes to our Macs, I'd venture to guess that most of us have had to deal with cracked/chipped/broken plastics. I think some people would opt to buy new parts if they were available, but a lot of parts just aren't easy to find these days or are too expensive.

With all that said, I'd like this thread to document the successful repairs you have done to improve your cases and broken plastic parts. Seems like a lot of people on here like the challenge of bringing something back that was in rough shape so maybe there's some good info to share.

Please share real world examples and try to include:
- Model and part being repaired
- Pictures, preferably before-and-after shots, but if you just have after, that's fine smile
- Tools you used
- Techniques involved

Cosmetic and/or functional repairs are both game. Maybe some people want to make something look the way it originally did... maybe some want to make something better to fit a mod/hack. It's all good. Show up your work! Basic repairs to Advanced... it's all good.


I'll start here with a pretty basic repair.

Model and Part:Power Mac 6100 bezel

OK... so, when looking at the front of this Power Mac 6100, you can see a hole where the bezel has snapped.





The first step is to clean up the chipped edge. A trick here is to use dymo label tape as a guide, and a scribing tool to carefully excise the chipped edge. Run a small file over it a few times to create a very clean edge.



I made this repair from some spare styrene sheet, because it's easy to work with and no stress will be put on this part. I have a bag called odds-and-ends that you can get at pretty much any hobby shop. Lots of differing widths of strip and rod available, separately as well. One bag goes a loooong way.



Cut out a chunk, glue it in place and trim to shape using the same technique before:



Mix up some paint. Mixing paint is a necessity because the shades of grey/beige can very so much. I use a Model Master enamel... Light Grey base with a few drops of Wood to make my beige. The wood has a hint of gold/yellow which really helps. This won't be identical, but you can get it pretty darn close.





Then clean your brush and wait for your piece to dry!

Last edited by MJ313 (2020-05-30 20:43:21)

Offline

#2 2014-11-30 20:44:41

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Apple Multiple Scan 14 Display hinge

It seems like a lot of these MultiScan 14inchers have this hinge problem. Mine came broken. smile

I was looking through my spares box and came across a piece of plastic that I *think* came with some blinds. I am not sure about that, but you can essentially build the same piece you need out of styrene. I used this because, well, it was there smile
(Basically you need a disk (for support) and a stem... make sure the stem fits in the hinge.)



Thin the support disk and test fit. When it fits, but some CA (super) glue or gorilla glue on the back of the support disk, fit the piece in the hinge hole and push into place! After it dries, the hinge will work nicely.

Last edited by MJ313 (2020-05-30 20:42:27)

Offline

#3 2014-11-30 21:45:44

ClassicHasClass
Member
From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
Website

Re: Case repairs - Plastics

That's a very nice repair on the 6100. I snapped a piece on my WGS 9150 when I was cleaning it (damn brittle old plastics) and I might restore it in the places where it matters with this method. Unfortunately, some of those are load-bearing.


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

Offline

#4 2014-12-01 03:34:05

markyb
Member
From: Aurora, OH (330)
Registered: 2014-05-16
Posts: 185
Website

Re: Case repairs - Plastics

That's championship paint matching there.


http://markyb86.weebly.com for some packs of old macintosh wallpapers, desktop patterns, windows wallpapers, sound files, etc.

Offline

#5 2014-12-01 05:13:45

jt
Member
From: Bermuda Triangle, NC USA
Registered: 2014-05-21
Posts: 1,470

Re: Case repairs - Plastics

You got that right! I must have hit the wrong button, I thought I'd replied. Thanks for detailing that monitor chin fix. The other one I'm loving.

I've gotta get my plastic welder out of mothballs and have a go at some of the projects I've got lined up for it, including hot air rework!

Offline

#6 2014-12-02 13:03:42

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Thanks guys! Classic - yeah, load bearing parts are definitely more tricky... those stinking tabs, bendy parts and such. I think there are some tricks there, but require a bit more work, tools and supplies. I'll dig around and see what I come up with. I am hoping someone who has done some case repairs with ABS cement, melted ABS or whatever can provide some top tips and pics. jt, haven't you been working on a Powerbook? Would love some ideas around that and whatever else you have got! These issues have been around along time and a lot of this is pretty standard plastic repair so I bet there are a lot of known and different ways to fix these issues. Some probably will work better then others, but maybe we can get some basic/intermediate/advanced fixes with pics put up here... smile

Offline

#7 2014-12-06 21:41:22

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Power Mac 6100 top panel tabs

This is about murdering stupid tabs.

I broke the back tab on the 6100. grrr:



But these are stupid. And unnecessary in my opinion. So to save the aesthetic appeal of the back of my 6100 (really, know one gives a fuck about the back of a 6100... but we'll proceed) I am going to fix this.

Here's where this gets a bit controversial... fuck the tabs. Gravity does an awesome job of keeping the top case on the computer and there's probably going to be either a monitor on top or a stack of other 6100s you picked up on Craigslist for a dollar. So just sand them off. 



Sonny that file sucks. Man up and get a real file.



After the tabs are gone, get some Acetone... apply it to the broken piece and the broken tab with a Q Tip (Ignore the fact that the tab is, in fact still OMG there, after I just sanded it off. I took this picture FIRST. Yup, out of sequence. Enjoy the ride. tongue :



Put together and hold tightly with a small clamp for a couple hours:



Done. Looks fkna fantastic and its eBay value has increased by maybe $2.00. big_smile

Last edited by MJ313 (2020-05-30 20:41:33)

Offline

#8 2014-12-06 21:54:24

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Power Mac 6100 top panel tabs (horizontal section)

OK, another stupid easy one here! Fixing hairline cracks.

These tabs tend to snap right off. If they break and you have the pieces you can just weld them back on... But sometimes these things pop and splinter and you aren't left with a clean edge. To avoid that, look for the hairline cracks and fix them before they become a problem!



Acetone is used here... the real issue is application and how big a mess of the case you want to make. You can use a paintbrush, a needle, Touch-n-flow system, etc. I had some microbrushes so I used one here. I picked up a small drop of Acetone with the brush and touched it to the very corner edge of the crack... capillary action pulls the acetone along and into the crack so there's no need to smear Acetone everywhere. 



I released pressure and the parts came together with a small bead of melted ABS along the seam. I wiped it off, in the direction of the seam, with a paper towel, and it's all sealed up. Fixed! Until the next crack appears of course tongue

Last edited by MJ313 (2020-05-30 20:40:55)

Offline

#9 2014-12-06 23:25:54

bbraun
Member
Registered: 2014-05-29
Posts: 1,064
Website

Re: Case repairs - Plastics

Awesome!  Great presentation.

Offline

#10 2014-12-07 03:07:32

mcdermd
Member
From: Corvallis, OR
Registered: 2014-05-12
Posts: 1,022
Website

Re: Case repairs - Plastics

I've had better luck with methylene chloride instead of acetone. That reminds me, I need to pick up some more.


Daily Drivers: 27" iMac 2.8 GHz Quad-Core i7 (Late 2009), 21.5" iMac 2.7GHz Quad-Core i5 (Late 2013), 11" Macbook Air 1.6 GHz i5 (Mid-2011)
See the restored heroes here.

Offline

#11 2014-12-07 14:31:07

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

mcdermd wrote:

I've had better luck with methylene chloride instead of acetone. That reminds me, I need to pick up some more.

Hey Dylan, thanks for the great tip! I've heard you like your Macs in top form... so this is definitely an indicator to check this out, for sure.

Offline

#12 2014-12-07 14:35:07

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Power Mac 6100 bezel tab

Jury is still out on this one... I used Acetone, but maybe Dylan's DMC is a better solvent solution.

These tabs break all the time:



I painted the broken edge with Acetone, and then, not caring about aesthetics, used it pretty liberally along the seam.



This morning it holds up well, tugging with my thumb. This is a flex part, so I am going to test it a bit to see how good this fix really is.

Last edited by MJ313 (2020-05-30 20:40:18)

Offline

#13 2014-12-07 14:44:55

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Kind of a funny aside... if you want to shore up all of your ABS plastics... just put them near a nuclear reaction! The gamma rays cause crosslinking of the ABS which results in strengthening of the plastic! tongue

http://omicsonline.com/open-access/the- … 11-152.pdf

Last edited by MJ313 (2014-12-07 14:45:38)

Offline

#14 2014-12-07 15:40:16

jt
Member
From: Bermuda Triangle, NC USA
Registered: 2014-05-21
Posts: 1,470

Re: Case repairs - Plastics

Good one, now you've got me thinking about trying ultrasonic welding.  Anybody a Dentist or have a buddy who is?

MJ313 wrote:

jt, haven't you been working on a Powerbook? Would love some ideas around that and whatever else you have got!

I'm mostly cannibalizing an re-building 1400s as soon as I have some time. Having a batch of cracked (cracking) lids to test repairs on will we a really useful process if I can pull that off. Maybe after I get back from visiting the rug rat after Christmas.

I've been mostly about destroying/remodeling Mac cases rather than refurbishing/preserving them in their SpindlyPlastic(R) glory. Current projects involve adapting a 5300 lid to the 1400c LCD as a Mustang ProtoHoaxMac and building the radius mockup/design study case in the Macintosh Clone announcement pic.

EVERYTHING is on hold until I get half of my "stuff" into a 10x10 storage room.

Last edited by jt (2014-12-07 15:53:45)

Offline

#15 2014-12-07 16:42:40

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

My Father-in-law likes to say, "If it ain't broke... make it better!"

I could see you two getting along well smile tongue

Offline

#16 2014-12-07 22:02:11

jt
Member
From: Bermuda Triangle, NC USA
Registered: 2014-05-21
Posts: 1,470

Re: Case repairs - Plastics

Sounds like it  .  .  .  mostly, folks tell me "You just can't leave anything alone. rollhmm



.

Last edited by jt (2014-12-07 22:10:27)

Offline

#17 2014-12-21 22:37:17

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Apple Multiple Scan 14 Display bezel chip

OK, this one was a bit more involved due to the fact I didn't have the missing piece. Which probably happens a lot with second (or third, or fifteenth) hand macs. I made this fix using Styrene and some of the same techniques as before.  Why styrene? Cause I have a lot of it! ABS would work fine too, I s'pose.

And, as with anything, this kind of fix is only as good as the amount of time you have to invest in making it look nice. It helps to have an airbrush.

Here's the chip!



So, first I used a piece of dymo label tape to outline the chip, and scribed along the tape edge to create a square edged hole. I find it easier to do this way, because I can get nice clean/straight seams which means less issues tying the new piece in.



I cut out a chunk of styrene and glued it into place with CA glue... this was real easy because of the right angles involved.  Moving on... I love this stuff to fill seams. It's pretty much just melted plastic. Smells nice, too. big_smile



Dab it on the seams, wait for it to firm up (but not dry totally) and wipe off the excess with Iso, perpendicular to the seam. It cleans up real well and makes the seams pretty much disappear.


I taped near the seams to avoid sanding anything I didn't need to, then sanded just a bit to make everything nice for painting.



This paint matching job needed a few colors... I used MM enamels... started with a Light Grey base in the mixing cup, and added 5 drops of Wood. Then 2 drops of Insignia yellow, and added drop after drop of Dark Ghost Grey until the color matched reasonably well...



I masked the area and rolled the mask about 2-3 mm off the surface to get a softer blend of the paint I was applying and the paint already on the Mac. It ain't gonna be perfect, but at least we can make it not look horrible. smile Then I took out the airbrush and hit it back and forth. Didn't take very much paint to cover.



Texture matching is... hard. So, in an effort to keep this a reasonable project, I simply applied a matte surface by repeatedly tapping the surface of the paint with sand paper. Note-- Tap! not Sand! Matte surface desired... not sanded smooth surface smile



I weathered it a little bit with whatever was on my thumb, and it turned out pretty well. Not show-room material here, but better then a missing chunk smile

Last edited by MJ313 (2020-05-30 20:39:44)

Offline

#18 2014-12-22 00:06:54

ClassicHasClass
Member
From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
Website

Re: Case repairs - Plastics

You are the plastic god.


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

Offline

#19 2014-12-22 01:00:18

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

lol! well, I don't know about that... but I guess I care enough to try. I would guess a lot of people wouldn't bother or wouldn't care about fixing old plastic computers that are destined to continue to break. That being said, I can't fix logic boards or write software applications... but I've worked with plastics a bit so maybe that's where I can contribute some ideas or get some discussion going. I bet other people have different or better ways to deal with this stuff. Lots of ways to skin a cat!

FWIW, here's what I usually build. smile

Last edited by MJ313 (2020-05-30 20:38:56)

Offline

#20 2014-12-22 18:04:06

galgot
Member
Registered: 2014-07-31
Posts: 40

Re: Case repairs - Plastics

I knew plastic modeling could lead to something. Long time I havent build any. Well done.
About Powerbooks, I disassembled a 1400 screen panel to see if a could repair and strengthen the plastic on the panel from the inside, near these cracks always appear. Wanted to see if i could add/glue some pieces of plastic or metal strap to make it more solid. But the problem is that there is already a thin metal foil glued on the inside ( that adds nothing to the strength of the thing) very difficult to remove. Also , it's very tightly packed, i doubt there is space to add  strengtheners inside...
That panel is not well designed for strength, it's like the back ports doors of the 3400/5300s, will fail one time or another.
Good Apple went to metal for the laptops now, At least we know the cases will last longer.
All my 1400s have these cracks, more or less, the only way not to make it worse is to open/close the panel by holding from each sides near the hinges to avoid too much levering.

Last edited by galgot (2014-12-22 18:06:08)

Offline

#21 2014-12-23 18:39:51

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

galgot wrote:

About Powerbooks, I disassembled a 1400 screen panel to see if a could repair and strengthen the plastic on the panel from the inside, near these cracks always appear.

The modeling makes it all kind of fun, if you are into that sort of thing smile  I haven't seen a PB 1400 in about 10 years, but I've heard of hinge and plastic issues on a bunch of forums. I've got a 3400 that is missing the back panel though, so I know what you are talking about there!  Rebuilding that could be a project and a half smile

Offline

#22 2014-12-23 18:55:53

MJ313
Member
Registered: 2014-09-23
Posts: 498

Re: Case repairs - Plastics

Model and Part:Power Mac 7600 CD Drive rail

My 7600 came without a CD drive rail. Kind of a weird piece to be missing, imo, but a good project here! This one doesn't take too long-- just a couple hours--  as there's no painting necessary, and finish can be a bit sloppy and no one will care smile



So my intentions were to take the existing drive rail and create a mirror of it. This would bite me in the future... I should've studied a bit more. Here's the good rail.



Measuring the dimensions with a ruler, the plan was to use styrene from the bag of Odds n Ends, and build layers, matching the heights and widths of the existing piece. So after measuring, I started cutting the styrene. Best way to deal with this is just score it a couple times with an exacto blade and then snap it with your fingers along the break. It breaks clean.



Here are some of the pieces I measured and cut out.



Glue! I started by tacking the layers together with instant set CA glue. Don't have to go crazy here, just enough to keep her all together.



Here's the rail, starting to grow from the ground up.



Here's a hint of an issue to come smile  Where I ASS-u-ME-d. oops.



After most of the pieces were in place, I melted it all together with some layers of plastic cement.



D'oh! First test fail. See the issue? The rails aren't mirror images. Some of the tab openings actually aren't the same size, directly across from one another!



Field mod time!

I removed and re-alligned the tabs in the correct positions.



Better!


Success! Now the CD drive doesn't wobble around! smile

Last edited by MJ313 (2020-05-30 20:38:37)

Offline

#23 2014-12-24 00:50:15

ClassicHasClass
Member
From: Electron Alley
Registered: 2014-05-26
Posts: 1,118
Website

Re: Case repairs - Plastics

You are a plastic god's deity.


Machine room (updated for 2019!): http://www.floodgap.com/etc/machines.html

Offline

Board footer

About ThinkClassic

ThinkClassic specialises in the use, maintenance, repair, restoration and modification of vintage computers and peripherals.