Coating on Voyager bezels?

[tppytel]

I picked up a very nice 11C recently... cosmetically perfect apart from something that looks like very light "water spotting" in one spot on the bezel. I doubt I could capture it in a photo if I tried - it's not noticeable in normal use - but it's definitely "in" the finish somehow and not on top of it. I read somewhere - possibly incorrectly - that the Voyager bezels were not simple brushed aluminum/steel but had some kind of coating on top? I'm wondering if I could apply a very thin coat of matte (or satin) acrylic varnish (like I use for gaming minis) to the spots and then buff it out with a soft cloth to minimize the spotting, which honestly isn't very apparent anyway. Any advice/experience here? I can absolutely live with it as is, but I figure that a little acrylic varnish *probably* won't do any permanent damage and could be removed cleanly if it doesn't work out. This 11C is so perfect otherwise... I'd love to make it even more perfect.

[John Garza (3665)]

It's normal to clear coat exposed aluminum surfaces to prevent oxidation and maintain a bright finish. I'm sure Amazon has a ready supply of Al clearcoats.

[tppytel]

(03-29-2023 12:43 PM)John Garza (3665) Wrote:  I'm sure Amazon has a ready supply of Al clearcoats.

Thanks John. It makes sense there would be purpose-made coatings for this. I took a look. Mostly they seem to come in sprays, with brush-on/swab-on versions only in huge cans for ~$40. I might test out the acrylic varnish first since I already have it and I'm pretty sure it would be easy to take off if I don't like the result.

[Mark H. Shin]

Hello Todd,

I felt I must chime in on this...

I highly recommend against taking any further steps towards your apparent path...

It is fraught with high entropy! One, barely noticeable flaw, can turn quite quickly into a very noticeable flaw/error/regret, in that order.

As an example, please see my post #2 here.

I ended up having to strip to the entire coating, and remain not completely happy with the outcome...

P.S: How's that 10C? The 15C is still pristine!

[tppytel]

Thanks for the advice and link, Mark. I will consider your experience, knowing that you also know how hard it is not to tinker. Certainly I'll steer clear of any abrasives or anything with strong adhesives or solvents. However, I really do feel like that acrylic varnish should be close to risk-free as far as removal - it's designed to go on top of acrylic paints, so there are no solvents or volatile chemicals in there.

Did you ever coat that bezel you stripped? Or did you leave it naked? And does the bezel not come off separately if you disassemble the unit? It looks like you did a super-careful masking job and left everything in place.

The 10C is doing just fine and sitting right next to me, though I don't use it as much as I'd like. Due to the value of the unit, I do keep it at home where I don't need an RPN calc too often. Too much stupid kid stuff can happen in a HS classroom. I have a DM11L there that I use for quick numerical calculations. But then I'm most often doing some kind of graphing/solving work for my classes, so I'm usually using my Prime instead of a Voyager. I recently did a lengthy side gig for an extracurricular math group I work with and decided to throw that money at a DM42, so I'll have one of those kicking around soon too.

Glad to hear the 15C is treating you well!

[Mark H. Shin]

It seemed to be a clear coat layer and a base primer. Unless I am mistaken, and all the goo was just the stripped clear coat...

I actually did paint it with a (cheap) air brush, but the results were less than desirable. Investing in a professional air brush gun would have been more than the calculator itself.

Bezel is glued... I ended up leaving it naked brushed aluminum...

[tppytel]

(03-29-2023 10:41 PM)Mark H. Shin Wrote:  It is fraught with high entropy!

Yeah... you were right about that, Mark. That light spotting was showing partly worn-away clear coat, and any friction on it just stripped off the rest. Of course, after 40+ years it's no surprise that the coating was weak. I can take it off just with a fingernail. I'll probably go ahead and strip off the rest - it comes off easily with airbrush cleaner I already have around. I may just strip it and leave it naked. But this sort of thing looks like it could be helpful too. And I do have a good quality airbrush available from my hobby game painting, I'm reasonably competent in using it, and I'm sure I can find some scrap metal around my basement to practice on.

In my defense, I'd note that I bought this 11C "as is/parts" from eBay and the seller indicated it didn't power on. He seems to have obtained it from the HP facility in Boise somehow (employee? HP garage sale? dunno...) and said it was a factory return that had sat in storage for decades. Cost me only $45. But I popped in some fresh batteries and it appears to work just fine. Passes the internal self-test and keyboard self-test. Works fine after sitting for a day or two. It needs a replacement battery door and its own set of batteries (I pulled both from my 10C to test), but it appears to be perfectly functional AFAICT. I inquired with the seller and he didn't seem to have tested too thoroughly. So apart from the bezel spotting (which I couldn't see in the eBay pics) I basically got a pristine 11C for relatively cheap. I was expecting to tear the unit apart and screw around with soldering or transferring a donor PCB into it. So I'm not feeling too invested or conservative about this unit. With a 10C, DM11L, Prime, 50g, and soon-to-arrive DM42, I hardly need another little RPN unit around anyway. I figure I'll clean it up as best I can and gift it to one of my twins, who do both appreciate geeky old things.

[John Garza (3665)]

Maybe if you're not familiar with painting/finishing, but you ALWAYS strip off the old coat before applying the new coat.

Or you could take the bare aluminum to a specialty shop and get it adonized to your favorite color!

-John

[35/45/55/80/70/65/67/97/97S/91/92/21/22/27/25C/29C/19C/10/
31E/32E/33C/34C/37E/38C/41CX/28S/19B/12C/15C/33S/35S/32S/
48GX/50G/Prime/DM42]

[tppytel]

(03-30-2023 01:56 AM)John Garza (3665) Wrote:  Maybe if you're not familiar with painting/finishing, but you ALWAYS strip off the old coat before applying the new coat.

Of course that's the right way to do it! But I've found a few good-enough hacks on various vintage items over the years where a total strip-and-redo wasn't required. Seemed worth a try here. But for this particular unit the bezel clear coat was clearly weak already. No surprise for a 40+ year old calculator. I wasn't expecting too much going in.

Quote:Or you could take the bare aluminum to a specialty shop and get it anodized to your favorite color!

Now that is tempting. But our primary school color is kelly green and I don't think that green would mesh well with HP's 80's-era keyboard tones. But I do have a white TI-84CE (white is our other color) and I've been meaning to 3D-print a green slide case for it for years. When I was our department chair and in regular contact with a TI rep, I politely complained that green was underrepresented in their TI-84CE flavor offerings. "Mint" just wasn't going to cut it for us. He seemed sympathetic but sadly the message never got through to the TI corporate overlords.

But a green-and-white Voyager would just be insanely, over-the-top geeky for sure even if I'd be the only person in the school to appreciate it!