Here's my "trip report" from working on noisy plastic cases.

So as many of us with plastic-case portable machines do, I have several which 
emit a rather unfortunate creak when handled even if the screws of the entire 
assembly are aligned and firmly tightened. After an afternoon of research, I 
determined that the best solution is to find the contact points of the case 
that rub together and apply a little dielectric silicone grease. I was a little 
dubious about this, so I've started with my WP-2.

It isn't my daily driver, even though it's been sitting out on the coffee table 
for a couple of months. Every so often I'll pick it up to write something 
ephemeral but it's not as versatile as my daily 102. It still had a noticeable 
creak when handled, particularly around the front left corner and the RS-232 
port in the rear. The whole thing was a touch noisy when any kind of pressure — 
such as picking it up or using it on my lap — was applied. It put me off using 
it much.

I had a bit of familiarity with the disassembly process since I'd cracked it 
open shortly after receiving it in order to install the ramdisk which, by the 
way, is cheap and easy to do. I highly recommend it. What I wasn't familiar 
with were the finer points of the case fitting, so I took some time to inspect 
that.

There are a few places where creak is likely:
* along the sides of the keyboard where they contact the lower case
* the underside of the keyboard where the housing meets the lower case
* where the upper and lower case meet at the screw points
* the catch where the upper snaps in to the lower
* anywhere along the rim where the upper and lower meet
* the primary battery hatch

The inspection revealed that I was primarily suffering from the keyboard 
housing and the screw attachment points. There were a few places along the rim 
that also had some creak. I also found that the LCD sub-assembly creaked just a 
tiny bit; this is something I'm extremely wary working around but the first 
thing I was able to do is give one of the LCD board's mounting screws an 1/8th 
of a turn to firm it up equivalently to the others. One of the ports also 
benefited from less than a quarter turn.

After that, it was just a matter of finding exactly where I needed to reduce 
the friction. I chose Super Lube 92003 for this job. It's fully dielectric 
neutral silicone paste in a mineral oil base that's safe for HDPE. It has PFTE 
(teflon) as well which means it should only ever require a single application. 
A cheap fine point paintbrush from Amazon was the weapon of choice.

What I wound up with was a thin layer around the entire contact edge of the 
lower case that accounted for a little more than "a drop" of the stuff. I added 
a little residual smear across the screw posts of all five screws. The left and 
right sides of the keyboard assembly rubbed along the spot where they sit 
fairly snugly to the lower case; the bottom of the keyboard has a rim running 
around three sides that sits along the bottom. Those got another drop or so. 
After reassembly and some light flexing I found a couple of other spots that 
had friction. Whatever was left on the brush took care of them after another 
quick disassembly.

Cleanup of any of the minor lubricant-tinged fingerprints involved a rub with 
70% EPA followed by damp cloth with just a drop of detergent. I'm happy to 
report that the WP-2 has a near-new level of fit. You really have to lean on it 
to hear anything coming out of it at all and most of that is the LCD cover 
which I won't touch.

Next stop, the spare 102. It's got quite a lot of creak where the upper and 
lower meet along the back edge—you can easily see the movement. If I have 
success there, the daily driver is getting the same treatment, followed by the 
M100 which needs to be recapped before any lower-priority work is done on it. 
That's pending my soldering station being clear, because there's a C64 there 
that's in the process of having all the hideously failing Micron memory 
removed. I have to solder in short increments because of a tremor, you see...

I'm looking forward to the quality-of-life improvement when using something I 
handle frequently. Once I get a chance to work on an actual 102 I'll report 
back.

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