Repair broken PowerBook hinges and posts with hot air station

[Ferrix97]

Hi! 

A couple of weeks ago I started restoring a PowerBook with the typical issues: Bad caps on the display and stuck hard drive.

As usual, when I removed the front bezel and display, all the four supports crumbled into tiny pieces.

After seeing that glue doesn't always work and usually cracks again, I tried using my hot air station (the one I use to change SMD components) and melt together all the bits that fell off. 

So far I've done a couple of experiments, still haven't figured out the best airflow/temperature setting, but the results are quite promising and the display opens and closes normally.

Sorry for the blurry photos, will try to make a video once I get another PowerBook with cracked plastics.







Oh, And while heating the plastic I did use a fume extractor.

 

[bibilit]

Hi,

Promising..yes i have repaired quite a few of those Powerbooks lately, i will say half of them were bad in this area, probably the same way the 5300 series are.

And yes, glue doesn't work great, most of the time will not last for long.

 

[Unknown_K]

Two part epoxy would probably be better then glue.

 

[Ferrix97]

I think it was the first thing I tried, didn't work all that well either

 

[ScutBoy]

If you've got them to "stick", now pack a bunch of JB Weld or other epoxy around them as a strengthener. I've done this a couple times on different laptops, and it's helped a lot

 

[FacnyFreddy]

My Powerbook 5300 DC plug is encased in JB Weld after repairing the solder points. I put 3 coats of the regular stuff and not the "Qwik". I wait 5 min in between coats.

I also used a small amount to fix the bottom case where a crack was developing.

 

[bibilit]

Tested this afternoon while repairing a Powerbook 140, once heated, the plastic gets pretty hard, coated afterwhile with some epoxy.

 

[Ferrix97]

How hot did you get it? I had my hot air station set to 380°C IIRC

If it's ABS it should melt at about 250

 

[Trash80toHP_Mini]

I hear mentions of "glue" and I'm not sure what you mean?

Dissolve some spare MacABS in MEK and use that to chemically weld the joints. That should work where glues and epoxies won't grab the small surface areas. Check the MSDS for ABS cement available online from any Himprov Store's web site for the rough proportions. For Acrylic (Plexi) fabrication we dissolved various amounts of clear acrylic scrap into stock Acrylic solvent/glue from the sign supply or acrylics/laminates vendors. (Weld-On? Dunno, it's been a very long time!) They're a similar solution of acrylic and MEK. I've heard tales of success with using Acetone in this manner, but it's a rung lower in the Keytone family. MEK is a "hotter" more aggressive solvent.

Straight MEK needs very clean surfaces for capillary action to wick the solvent into the joint to provide a good chemical weld. For rougher surfaces, a thick slurry will fill the gaps/scratches/voids on surfaces like rough bandsaw cut parts, sanding such surfaces helps immensely, but isn't applicable to the problems at hand..

 

[bibilit]

 How hot did you get it? I had my hot air station set to 380°C IIRC

Around 300 °C maybe less, have not tried Trash80 method, but heard about it, next time maybe...

 

[Rajel]

I hear mentions of "glue" and I'm not sure what you mean?

Dissolve some spare MacABS in MEK and use that to chemically weld the joints. That should work where glues and epoxies won't grab the small surface areas. Check the MSDS for ABS cement available online from any Himprov Store's web site for the rough proportions. For Acrylic (Plexi) fabrication we dissolved various amounts of clear acrylic scrap into stock Acrylic solvent/glue from the sign supply or acrylics/laminates vendors. (Weld-On? Dunno, it's been a very long time!) They're a similar solution of acrylic and MEK. I've heard tales of success with using Acetone in this manner, but it's a rung lower in the Keytone family. MEK is a "hotter" more aggressive solvent.

Straight MEK needs very clean surfaces for capillary action to wick the solvent into the joint to provide a good chemical weld. For rougher surfaces, a thick slurry will fill the gaps/scratches/voids on surfaces like rough bandsaw cut parts, sanding such surfaces helps immensely, but isn't applicable to the problems at hand..

This is kind of the idea I had, using ABS/acetone paste. 

 

[techknight]

I used JB weld for plastics on an Alienware I have, because its hinges blew apart awhile ago. 

Its still holding up working today. Of course its apples and oranges here because were talking about plastics made in completely different decades. 

 

[Ferrix97]

I've made a video showing my last attempt. Unfortunately it was even harder to do with the iPhone in the way...

This is just another attempt, not a repair guide. I still need to figure out the best airflow and temperature setting.

But so far I can confirm that both my powerbooks are holding nicely and seem more robust than plastic or 2-part glue.

https://youtu.be/X_tqtJlVk2g

 

[Trash80toHP_Mini]

Nice video, here's one of pro level equipment for plastic welding.

Hot air plastic welding:

I like your approach, only suggestion that comes to mind offhand would be to use washers as heat shield/heat sink protection for the RFI shield. Temperature controlled soldering iron on my hot air rework station will be fun to try, especially in combination with the hot air tool as you've done. Gotta get a dedicated tip for the iron, but cleaning one used for plastic welding shouldn't be all that difficult to do.

Having an old Mac case to rip strips into welding rod on the bandsaw is almost required. The "sawdust" by-produst will be dissolved in a MEK/Acetone solution per formula in the Oatey MSDS sheet. MacABS percentage will be varied to create a selection of slurry gloppiness in addition to the baseline MacABS "cement" formulation for gap filling. Solvent welding requires near perfectly mated surfaces.

I'll have a lot of plastic welding to do in the near future.