Cracked Hinge on Mac Portable
- Thread starter JDW
- Start date
One other person in this thread has the same exact problem. And @techknight has a recent video (mentioned earlier in this thread) showing a Portable with the same cracked hinge holder too. That means there are likely others out there.
Sadly, many Portable owners seem to be hibernating, Stephen. For example, I have tried REALLY hard to get a peep out of the folks in the Mac Portable FaceBook group, but it's like pulling teeth.
Gone are the days of DanTheAppleMacMan on EBAY who often sold Portables. Those guys were really knowledgable and would provide quick answers and feedback, but I never owned a Portable back in those days.
Seems like most Portable Owners these days never use the machines and simply have them in a closet.
Well, I've been working on a video about my Mac Portable for more than a month now, and once that video goes out, I suspect there will be renewed interest. And when people see my crack (ha ha), some may chime in after checking out their own machines.
What I can tell you is that hinge takes a lot of pressure when you close the LCD. A lot! The crack closes when I fully open the LCD. But if I put my thumb and all my might on top of that cracked hinge, hoping to keep it pushed closed while I close the lid... well... that's utterly impossible. So yeah. The lid puts THAT much force on the hinge! It's pretty crazy Apple chose to make it out of something other than metal. Even Portables with that hinge holder intact are ticking time bombs, in my opinion.
Also, when I first got my portable, there were other tiny parts that had broken off that subframe. None were critical. They were just tiny tabs. I was able to get them back on with superglue and they continue to be attached today.
It's because there is so much stress on that HINGE HOLDER that I have taken huge pains and a lot of time trying to figure out how best to CHEMICALLY WELD it back together. But tiny air bubbles compromise the strength of the bond a bit. DCM is better than superglue, by far, but not as strong as the original unbroken part.
The broken hinge cannot be repaired with glue, it will continue to break. I suspect that the existing structure can be reinforced economically (such as metal 3D printing).
I’ve been very busy recently but the direction I would explore is a custom 3D printed reinforcement bracket which is screwed into the existing sub chassis. Mounting points should reflect the force direction so that the new holes reinforce the brittle plastic - not weaken it.
FDM may be impractical if there’s limited space available. The metal option is becoming very affordable and would be my first choice.
Maybe it’s time for an old dog to learn new tricks (3D Modeling)? @JDW
I’ve been very busy recently but the direction I would explore is a custom 3D printed reinforcement bracket which is screwed into the existing sub chassis. Mounting points should reflect the force direction so that the new holes reinforce the brittle plastic - not weaken it.
FDM may be impractical if there’s limited space available. The metal option is becoming very affordable and would be my first choice.
Maybe it’s time for an old dog to learn new tricks (3D Modeling)? @JDW
Agree: without proper reinforcement it will never work for regular use. 3D printing something out of metal seems to be an interesting proposition, but I am afraid it would just offset the bonding issue somewhere else. Maybe waiting for a chassis to pop up on eBay is the most reasonable proposition, unfortunately many Portables are failing due to the LCD…
I am envisioning a perfectly form fitting bracket which is both epoxied and bolted into place — ideally, this will spread the load over the entire upper chassis rather than just the upper segment of the hinge mounth.
Definitely! This could be a great place to add more support for a bolted on reinforcement bracket - or just plain old reinforcement!There appears to be some voids on the underside of the subframe assembly (shown in this image on the left side) that could be filled in with putty to add reinforcement?
mod anyone tries it, I recommend a two part epoxy. I’m suspicious that this alone won’t eliminate the risk of cracking (could maybe even make it worse?) but it will definitely be stronger.
What I’m trying to do is avoid a situation that leads to a permanent gluing (via 2-part epoxy like JB Weld 24-hour cure) of the right side cylindrical hinge into its hinge holder. And it is the hinge holder that cracks, not the cylindrical hinge.
TechKnight shows here that he used some kind of 2-party epoxy to fix only the crack initially, but then he found his fully cured epoxy cracked, and then he proceeded to epoxy everything, including the cylindrical hinge that fits inside that cracked hinge holder, making it permanent and impossible to remove the right side hinge ever again. But that wasn’t his machine and he shipped it off to the owner and there’s no way to know whether it has cracked again or not.
I always have to roll my eyes whenever I give disclaimers like I’m going to do right now, because it’s never my intent to say anything that would tear down anybody or hurt their feelings, but I’ll just give this disclaimer anyway: I’m not criticizing anybody for doing anything. I am merely somebody who observes facts and considers what I myself should do in any particular situation. Disclaimer done.
I don’t want to make any fix to disallow removing of the cylindrical hinge because those hinges are lubricated inside and at some distant point in the future may need it again. It also makes removal of the LCD more fiddly.
Look, I’m a very busy person, and I get stressed out when overworked, and to be honest, if somebody sold a subframe assembly that wasn’t cracked on the right side, I’d probably buy it just to eliminate this massive repair headache. I’ve invested so many hours in it already that I’m ready to scream. But my guess is that all hinge holders on the right side are susceptible to cracking in the same way, so swapping out the subframe assembly may not be the most permanent solution, especially if you want to open and close your LCD more than a few times. And anyone who is going to use the machine will open and close it many times. If you don’t, it means you just closeted the machine and that would a real waste!
So it would be wonderful to see an excellent solution that not only can repair existing cracks but also reinforce unit units that haven’t yet cracked.
I’ve also spent hours with ChatGPT and while I know it’s not always accurate, I’m not getting a whole lot of super detailed feedback on this crack issue from real people who have the problem, so I really had no other choice. ChatGPT is adamant that I shouldn’t attempt drilling and screwing anything into the area of the cracked plastics and attempt to fix it because, according to ChatGPT, that may end up fracturing these aging plastics. But the greater problem is, you don’t have a lot of plastic thickness on that hinge holder anyway. Drill or screw more than a couple millimeters towards that cylindrical hinge and you’ll end up drilling or screwing into the cylindrical hinge!
TechKnight shows here that he used some kind of 2-party epoxy to fix only the crack initially, but then he found his fully cured epoxy cracked, and then he proceeded to epoxy everything, including the cylindrical hinge that fits inside that cracked hinge holder, making it permanent and impossible to remove the right side hinge ever again. But that wasn’t his machine and he shipped it off to the owner and there’s no way to know whether it has cracked again or not.
I always have to roll my eyes whenever I give disclaimers like I’m going to do right now, because it’s never my intent to say anything that would tear down anybody or hurt their feelings, but I’ll just give this disclaimer anyway: I’m not criticizing anybody for doing anything. I am merely somebody who observes facts and considers what I myself should do in any particular situation. Disclaimer done.
I don’t want to make any fix to disallow removing of the cylindrical hinge because those hinges are lubricated inside and at some distant point in the future may need it again. It also makes removal of the LCD more fiddly.
Look, I’m a very busy person, and I get stressed out when overworked, and to be honest, if somebody sold a subframe assembly that wasn’t cracked on the right side, I’d probably buy it just to eliminate this massive repair headache. I’ve invested so many hours in it already that I’m ready to scream. But my guess is that all hinge holders on the right side are susceptible to cracking in the same way, so swapping out the subframe assembly may not be the most permanent solution, especially if you want to open and close your LCD more than a few times. And anyone who is going to use the machine will open and close it many times. If you don’t, it means you just closeted the machine and that would a real waste!
So it would be wonderful to see an excellent solution that not only can repair existing cracks but also reinforce unit units that haven’t yet cracked.
I’ve also spent hours with ChatGPT and while I know it’s not always accurate, I’m not getting a whole lot of super detailed feedback on this crack issue from real people who have the problem, so I really had no other choice. ChatGPT is adamant that I shouldn’t attempt drilling and screwing anything into the area of the cracked plastics and attempt to fix it because, according to ChatGPT, that may end up fracturing these aging plastics. But the greater problem is, you don’t have a lot of plastic thickness on that hinge holder anyway. Drill or screw more than a couple millimeters towards that cylindrical hinge and you’ll end up drilling or screwing into the cylindrical hinge!
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I finished stripping off the chrome paint by hand using mostly a box cutter. I did the sides of the ribs too.
My plan was to use DCM to solvent-weld the transparent polycarbonate piece to the back of the ribs and then after that stuff JB weld (original 24-hour cure) down in between the ribs. But I can’t fit a toothpick anymore than you see in the photo below, so I realistically wouldn’t be able to stuff JB weld deep down in there at all.
So I’m wondering if I should solvent-weld that transparent polycarbonate piece to the back of the 5 ribs and just put JB Weld at the top and sides, or forgo the solvent-weld and transparent piece altogether and just put JB weld all across the ribs.
Hmmm…
My plan was to use DCM to solvent-weld the transparent polycarbonate piece to the back of the ribs and then after that stuff JB weld (original 24-hour cure) down in between the ribs. But I can’t fit a toothpick anymore than you see in the photo below, so I realistically wouldn’t be able to stuff JB weld deep down in there at all.
So I’m wondering if I should solvent-weld that transparent polycarbonate piece to the back of the 5 ribs and just put JB Weld at the top and sides, or forgo the solvent-weld and transparent piece altogether and just put JB weld all across the ribs.
Hmmm…
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Tape some paper to the side of the metal drive bracket, install the metal drive bracket, and stuff JB Weld between the fins and the metal drive bracket.
The paper should stop the JB Weld from sticking to the metal drive bracket?
Instead of paper, use a thin metal plate? Something less thick than the polycarbonate so more JB Weld can be stuffed in there.
This assumes that installing the floppy drive and the hard drive doesn't require the void between the fins and the metal drive bracket.
#46
Check the distance between the top of the fins and the rear cover when installed to see if there's room for some JB Weld above the fins.
Some playdough or similar material (putty) might be useful for testing clearances. If it's not too sticky, can be squeezed into shape and can maintain its shape after being squeezed.
The paper should stop the JB Weld from sticking to the metal drive bracket?
Instead of paper, use a thin metal plate? Something less thick than the polycarbonate so more JB Weld can be stuffed in there.
This assumes that installing the floppy drive and the hard drive doesn't require the void between the fins and the metal drive bracket.
#46
Check the distance between the top of the fins and the rear cover when installed to see if there's room for some JB Weld above the fins.
Some playdough or similar material (putty) might be useful for testing clearances. If it's not too sticky, can be squeezed into shape and can maintain its shape after being squeezed.
@joevt
Thank you for your advice!
It seems you are suggesting that I do NOT DCM-weld the transparent plastic piece over the backs of the ribs and instead use only JB Weld Original all across the back. Correct?
After many hours of research with ChatGPT, it seems the better JB Bumper Weld epoxy would be best because it can elongate up to 35%, versus a 1-2% elongation of the original 24-hour Cure JB Weld (steel reinforced, hardens like a rock). But alas, it is no where to be found on Amazon Japan, and the closest equivalent is Marine Weld which elongates 55% but costs (to my wallet), the equivalent of sixty freaking dollars. No way. No how. And so, I am sticking (ha ha) to my existing brand new tubes of hard-as-a-rock-when-cured JB Weld original formula for this fix.
Thank you for your advice!
It seems you are suggesting that I do NOT DCM-weld the transparent plastic piece over the backs of the ribs and instead use only JB Weld Original all across the back. Correct?
After many hours of research with ChatGPT, it seems the better JB Bumper Weld epoxy would be best because it can elongate up to 35%, versus a 1-2% elongation of the original 24-hour Cure JB Weld (steel reinforced, hardens like a rock). But alas, it is no where to be found on Amazon Japan, and the closest equivalent is Marine Weld which elongates 55% but costs (to my wallet), the equivalent of sixty freaking dollars. No way. No how. And so, I am sticking (ha ha) to my existing brand new tubes of hard-as-a-rock-when-cured JB Weld original formula for this fix.
I think it would look cleaner without the transparent plastic piece.
The JB Weld might perform better if it's thicker but I have no data or experience (more JB Weld probably means more elongation?).
It's a tossup.
If JB Weld doesn't stick to the plastic well then it would be nearly useless. Therefore, the DCM-weld would be the way to go. I think you've already demonstrated how well that works. If it fails, it would probably be a clean break and therefore easier to fix.
Well, I'm actually glad to hear you feel "it's a toss-up" because I already DCM solvent-welded the transparent piece to the back of the ribs today on my lunch break. 
I will shoot some photos for you this evening after work.
The only thing I've not yet decided is if I want to drill in order to add self-tapping screws BEFORE I apply any JB Weld. THAT is the question in my mind right now.
By the way, I really appreciate your reply. Had you not replied, this thread would have been me talking to myself very the last few days! I suspect @Stephen , @phunguss , and a few others have their popcorn out, watching me work with interest. And to be honest, I would likely be doing the same if another guy was breaking new ground in a similar manner. I'm just meticulous, careful and contemplative, which is why this process has taken so long. I don't want to mess up this fix by way of a bad choice!
I will shoot some photos for you this evening after work.The only thing I've not yet decided is if I want to drill in order to add self-tapping screws BEFORE I apply any JB Weld. THAT is the question in my mind right now.
By the way, I really appreciate your reply. Had you not replied, this thread would have been me talking to myself very the last few days! I suspect @Stephen , @phunguss , and a few others have their popcorn out, watching me work with interest.
And to be honest, I would likely be doing the same if another guy was breaking new ground in a similar manner. I'm just meticulous, careful and contemplative, which is why this process has taken so long. I don't want to mess up this fix by way of a bad choice!
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You would need to drill through the transparent piece and the plastic of the subframe?
The alternative to drilling or cutting is melting. Heat a metal pin (with soldering iron?) sufficiently that it can be inserted into the plastic. Is that possible? Will the hole that is created snuggly hold the pin or will the hole grow in size or deform the plastic? Beware of fire, toxic fumes, burning, and damage. Maybe the pin will be too thick to be inserted (i.e. too much plastic will need to be displaced)?
Maybe test in a safe area of the subframe the drilling or melting methods.
I've seen videos of 3D plastic prints where a metal standoff or nut is heated with a soldering iron and inserted into holes in the 3D print that are slightly smaller than the standoff or nut but what if there's no hole to begin with?
I appreciate you sharing your work. 3000 people have viewed the thread so I don't think you're just talking to yourself. I also have my popcorn out
Holy cow, I just noticed that Jason has a cracked right hinge holder too! Have a close look at his ribs, which are mostly missing in the middle!
SOURCE VIDEO
What's even more fascinating is that his machine doesn't have any of that chrome paint at all! Wow.
Later in that same video, it seems clear the chrome paint was removed somehow, although not an entirely perfect removal job...
I noticed that Jason never removes the LCD from the subframe assembly, which implies he may have fixed his right-side hinge by PERMANENTLY epoxying the cylindrical hinge to the hinge holder, just as TechKnight did in his video.
SOURCE VIDEO
What's even more fascinating is that his machine doesn't have any of that chrome paint at all! Wow.
Later in that same video, it seems clear the chrome paint was removed somehow, although not an entirely perfect removal job...
I noticed that Jason never removes the LCD from the subframe assembly, which implies he may have fixed his right-side hinge by PERMANENTLY epoxying the cylindrical hinge to the hinge holder, just as TechKnight did in his video.
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Anyway...
As I mentioned in the video I posted about a half hour ago, the little piece of plastic that looks like a latch of some sort actually serves no purpose at all that I can see...
Nothing seems to fit inside it.
What that means is I could put a clump of JB Weld on the left side of that rectangular hole without worry it will block the hole, since nothing apparently goes through that hole!
As I mentioned in the video I posted about a half hour ago, the little piece of plastic that looks like a latch of some sort actually serves no purpose at all that I can see...
Nothing seems to fit inside it.
What that means is I could put a clump of JB Weld on the left side of that rectangular hole without worry it will block the hole, since nothing apparently goes through that hole!