Front Panel Cleaning - Page 1
Forum section: electronics / general

author: nadona
author_rank: Regular Contributor
timestamp: December 07, 2012, 03:09:45 am
content: Hi guys,I ordered a used Tektronix 465B and it finally came today.I am elated to say that it appears to work well. However, the front panel is dirty. How do you guys clean it?I tried a Q-Tip dipped in rubbing alcohol and it works okay. Are there any better methods?Thanks!

author: Psi
author_rank: Super Contributor
timestamp: December 07, 2012, 03:25:58 am
content: The best method depends on if you clean it as-is, or if you take the scope to bits and clean the front panel while its removed.

author: FenderBender
author_rank: Super Contributor
timestamp: December 07, 2012, 03:31:01 am
content: https://www.eevblog.com/forum/projects/tektronix-465-repair-and-restoration/

author: w2aew
author_rank: Super Contributor
timestamp: December 07, 2012, 05:00:07 am
content: Quote from: FenderBender on December 07, 2012, 03:31:01 amYeah - that thread.I use isopropyl alchohol too, as well as Simple Green, and a lot of diligence and patience. Don't get too aggressive.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 07, 2012, 05:52:30 am
content: The 465 is a lovely scope. I have one too. Which is fortunate since a friend of mine was just given one, in apparently mint condition as if it's never been used. All the manuals, probes, even the little ziplock bags with all the probe accessories. Given to him by someone who when originally offering it, didn't even know the name of the manufacturer. Had owned it for decades, never used, didn't even know 'Tektronix'. Sigh. The guy was supposedly an electronics engineer, to which I say my arse he was. My friend had originally promised me he'd pass the gift scope on to me. Till he found out how nice it was. So, lucky I have one or I'd be green with envy! And pissed.Otoh, I'm told that ' Mr don't know Tektronix' idiot had recently binned a bunch of HP-IB equipped test gear, so I still hate him. Given that I'm putting together some racks of HP-IB gear for a project. Yes, I've met him, and yes, he's a dick.Anyway... one of the great things about Tek scopes of that vintage, was the manufacturing technology they used to make the instrument fascia. It's anodized aluminium (hey! this is an Australian forum, how come it wants the US spelling - aluminum?), with the colour (ditto, US spelling) embedded in the anodized layer before the sealing stage. Which makes the lettering etc virtually indestructible to anything but mechanical damage to the surface. Which is very hard anyway.So when cleaning dirt off things like this scope, and 7000 series scopes, you can be *much* more aggressive than with panels like HP made, where it's all just layers of paint silk screened on. The only thing to be careful of is damaging the knobs and other plastic parts.Depending on the dirt type I use Spray-n-wipe (on a pad, not sprayed!), white spirits, mineral turps, alcohol, even acetone. None of them show any sign of harming the fascia lettering on these Tek scopes. Even scotchbrite pads don't do harm, unless you scrub hard enough to damage to surface finish of the anodizing. (Which they can.)Actually, since I have a project where I'd like to have control panels as nice looking as these Tek ones, I've been looking into the technology used. And it seems to be something of a lost art.There is something called photo-anodizing, in which the surface is treated with photographic type chemicals after the initial anodizing stage, then exposed, processed, then sealed. But this is very expensive and probably not feasible for home improvisation.I've never been able to find anyone who knows exactly how Tektronix did these panels. Looking at the lettering on panels I have, with magnification, I can't see any sign of a silkscreen mesh. Maybe they did use photo-anodizing? But then why so few colours? I suspect they had some other trick.I'm setting up a crude home anodizing line, to try some experiments. First idea is to attempt to get the dyes from an ink-jet printed paper sheet to diffuse into the porous anodized layer, then seal it. Have a few ideas on how to do this. But it will take a while, since other chores take priority.Does anyone here know anyone who worked in production at Tektronix, during that era?

author: notsob
author_rank: Frequent Contributor
timestamp: December 07, 2012, 06:55:50 am
content: Perhaps, if you contact these guys, they may have a few ideas on how Tek may have made the anodised panelshttp://www.focuser.com/anodize.html

author: TerraHertz
author_rank: Super Contributor
timestamp: December 07, 2012, 07:25:45 am
content: Quote from: notsob on December 07, 2012, 06:55:50 amHeh. Thanks, but I already discussed this onhttp://groups.yahoo.com/group/anodizing101,and have bought the anodizing book from focuser. I'm currently in the 'gathering gear for the anodizing setup' stage.So far no luck with any specific information about the Tektronix method.It's interesting to see that on the abebooks.com second hand books site, serious textbooks about industrial anodizing processes are surprisingly expensive.

author: robrenz
author_rank: Super Contributor
timestamp: December 07, 2012, 12:30:25 pm
content: Magic sponges are also very good. They really are magic in removing dirt and stains with whatever solvent/detergent you are using. I believe they are melamine and seem to have some kind of microscrubbing action and they do break down quickly.

author: ModemHead
author_rank: Frequent Contributor
timestamp: December 07, 2012, 01:02:42 pm
content: For the scope in the thread referenced above, I started out using IPA, but progressed to scrubbing with baking-soda toothpaste to get some of the tougher stains. It didn't bother the lettering and graphics at all. In a fit of inspiration, I finished up with a few coats of auto wax to restore the shine. Meguiar's Carnauba, as I recall.The key of course, is not necessarily what materials you use, but the patience to take it all apart and then re-assemble.

author: robrenz
author_rank: Super Contributor
timestamp: December 07, 2012, 01:11:28 pm
content: Quote from: TerraHertz on December 07, 2012, 05:52:30 amI looked at a panel from a 7000 series plug in under a microscope at 45X and the the printing is just some type of dye absorbed into the porous aluminum oxide layer of the anodize. It appears to be a print per color process because the light green background areas are actually a dot pattern of somewhat translucent dye but you can see where they printed over that in areas later with the black dye which is very opaque. I don't see any indication of a sealant over the anodize/dye. I did pick away at the anodize layer in some printing that is under a knob and it is definitely dye thru the full depth of the anodize layer. It may have been a rubber pad transfer type of printing. FWIW

author: WorldPowerLabs
author_rank: Regular Contributor
timestamp: December 07, 2012, 04:06:13 pm
content: If you are taking the scope apart, you might have success with a method I've used often: scrub with quality dishwashing detergent and a stiff brush and plenty of hot water. The detergent is very good at cutting grease and is harmless to most surfaces. Don't tell anyone... but I'll sometimes use this method on something less complex than a 'scope without even disassembling the item. Just keep the water out of pots, switches, and definitely out of meter movements. In this case, I'll rinse with distilled water when I'm done and clean and relube pots and switches and then allow everything to dry for several days or more.