Thanks for giving a detailed report with specifics on how it is done. Why is it important to use a dielectric grease? I've used it to help prevent arcing on old CRT tubes and to conduct heat from chips, but this is new to me. Could it somehow help silence the creaks?
--b9 On October 13, 2025 5:48:49 PM PDT, Joshua O'Keefe <[email protected]> wrote: >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.
