J-B Weld (or other epoxy) + aluminum Powerbook?

4 replies [Last post]
Eudimorphodon's picture
Offline
Joined: Dec 21 2003
Posts: 1204

I've got a short/dumb question for any "redneck" hardware hackers/Powerbook experts out there.

Over the weekend in a "one for two" exercise I put together a working Powerbook G4 (Aluminum 15") out of two mangled donor machines (drop victims). It's all good for the most part, other then one thing: Both machines landed face-down and cracked some internal connection between the screen panel and the horizontal bit housing the hinge proper. Thus my Frankenstein creation has a slightly wobbly screen. It's not *bad*, but it's just enough that it'll sometimes make somewhat disconcerting popping noises when moving the computer.

Anyway, I'm thinking of fixing the problem by running a bead of J-B Weld or similar epoxy along the joint between the two pieces. It's a decision I'm sure I'd regret if I ever have to replace the inverter board housed in the hinge, but I can live with that. (I'm basically betting that the electronics will outlive the machine's usefulness, a fair bet given how the G4 is pretty grossly obsolete already.) I guess my two-part question is:

A: I've been looking at the PowerBook Medic's disassembly guide which shows how the hinge bit attaches to the rest of the display and it looks to me like for it to wobble like this it's legitimately broken and there's no point in ripping apart the display housing to try to fix it some "right way". Is that probably a fair assessment?

B: Does this sound like a reasonable plan, in that is it likely that a quantity of epoxy that'd still let me close the lid would be strong enough to hold against the forces of opening and closing it? I don't have much experience with it.

Thanks.

--Peace

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
eeun's picture
Offline
Joined: Dec 19 2003
Posts: 1891
I can answer the JB Weld part

I can answer the JB Weld part: It'll do fine. I've used it to repair the sides of a Tibook frame.
It takes a lot longer to set than regular epoxy. In that time, it can run a bit, depending on where you're applying it and how much you use. I made a small dam out of tape, so it stayed fairly close to the shape I wanted it.
If it's a part that's going to be under stress - like if the hinge is relying on it for support - you can strengthen the JB Weld against shear fracturing by stirring it a very small amount of fiberglass.

__________________

"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

Eudimorphodon's picture
Offline
Joined: Dec 21 2003
Posts: 1204
Thanks

Knowing it runs is useful. I'm wondering if it might be worth trying the "J-B Stik" putty form instead of the liquid. (There's a small crack between the two bits that I'm planning to squeeze as-shut-as-possible when applying the epoxy, but I'm sure I won't be able to get 100% closure.)

--Peace

eeun's picture
Offline
Joined: Dec 19 2003
Posts: 1891
The stick might work fine, bu

The stick might work fine, but I've found putty's best as a patch over something, and isn't as well suited to be an adhesion layer between parts.

__________________

"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

Eudimorphodon's picture
Offline
Joined: Dec 21 2003
Posts: 1204
Success

I ended up going with the strongest slow-set "DevCon"-brand liquid epoxy at the hardware store. It was sort of a pain to apply (*really* glad I didn't go with the quick-set now), but it seems to have done the job taking the wobble out of the hinge just fine. Only minor regret is I probably should of gone with clear instead of black, even if the clear was weaker. Eh. I guess considering what the rest of the laptop looks like I'm not going to let a black smear in the hinge bother me.

(When prepping things for application I did actually figure out the worst popping sounds were happening because one of the screen bezel screws was loose, to the point of almost falling out. Apparently that was letting the layers shift just enough to make the scary noises. Tightening it up fixed that but didn't help the wobble any.)

Anyway, yay. Two busted 1.5Ghz "Sudden Motion Sensor" Powerbooks + one $39 1GB SO-DIMM + one $89 250 GB hard drive = an excuse to put off buying a new laptop for a few more months, years, whatever. I have low standards.

(And also lets me give away *two* of my older Powerbooks, the 1.33 Al I was using *and* the old 867Mhz Ti which got a new hard disk from one of the corpses, to notebook-less family members.)

Go Team Venture.

--Peace