Author Topic: Restoration glory of Keithley 2001 DMM  (Read 212869 times)

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Offline TiN

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Re: Restoration glory of Keithley 2001 DMM
« Reply #525 on: May 18, 2016, 11:18:49 am »
Process depends a lot on UV light intensity, so best would be to have it for few hours under direct sunshine, swapping sides/rotating the thing each hour or so to get even white surfaces.
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Offline nidlaX

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Re: Restoration glory of Keithley 2001 DMM
« Reply #526 on: May 18, 2016, 11:50:12 am »
Whoa, nice ding restoration trick! I've gotta try that sometime. :-+
 

Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #527 on: May 18, 2016, 12:58:34 pm »
Whoa, nice ding restoration trick! I've gotta try that sometime. :-+
It depends on the peculiar properties of ABS plastic. Most other types of plastic won't do this. Practice on LEGO bricks, they are ABS too. A couple of ordinary LEGO, a hammer, and your heat gun can provide an oddly satisfying half hour of fun. Destroy, fix, destroy, fix, ...  >:D  But actually the point of practicing is to fine tune the temperature and technique. If the temp is too low, then you need to heat for too long to make the plastic become "plastic", and you risk heating the part right through, and then it might deform, losing the original shape forever. You want to heat the surface high enough to soften, but keep the structure underneath solid. Alternately, if the temperature is too high, then the surface will melt (not just soften) and will become glossy or worse. The ABS will also tend to lose its "shape memory" when heated too high, then it won't return to its original shape.

I wish I had taken pictures of the really bad ones before fixing. The difference is astonishing.
 

Offline plesa

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Re: Restoration glory of Keithley 2001 DMM
« Reply #528 on: May 18, 2016, 04:09:34 pm »
Process depends a lot on UV light intensity, so best would be to have it for few hours under direct sunshine, swapping sides/rotating the thing each hour or so to get even white surfaces.

I forgot to mention that it was whole day on direct sunshine ( I leave on garden in big transparent container with 4l of hydrogen peroxide) The circulation has been made by lot of bubbles made by peroxide decomposition.
 

Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #529 on: May 18, 2016, 06:12:17 pm »
Process depends a lot on UV light intensity, so best would be to have it for few hours under direct sunshine, swapping sides/rotating the thing each hour or so to get even white surfaces.

I forgot to mention that it was whole day on direct sunshine ( I leave on garden in big transparent container with 4l of hydrogen peroxide) The circulation has been made by lot of bubbles made by peroxide decomposition.
That method obviously isn't ideal.
Last week I did 5 panels at the same time (2 x K2001, 3 x K7001). Start to finish < 1 hour in the sun. I used 40 vol (very strong, 12%) hydrogen peroxide gel. I placed the panels in a shallow plastic container, I brushed on a thin layer, covered the container with plastic food wrap ("Glad Cling Wrap") to prevent evaportaion, and put it in the sun. The sun was at an angle, so I rotated the container a few times over the hour. I re-applied fresh HP after 30 minutes to help combat evaporation. Last time (2 weeks ago) it took 2 hours but it was partly cloudy. This time, 1 hour and done. The UV light is essential and you must be careful about what you cover the item with, or it will block UV. Maybe your panel, submerged deep in liquid HP, didn't get enough UV light.

I was happy to be done in only 1 or 2 hours. Too much time in HP and the dye in the plastic can bleach, leaving it with light patches. We want only to convert the brown/yellow Bromine back into colorless Bromide or Bromate.
 

Offline plesa

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Re: Restoration glory of Keithley 2001 DMM
« Reply #530 on: May 18, 2016, 07:14:03 pm »
Process depends a lot on UV light intensity, so best would be to have it for few hours under direct sunshine, swapping sides/rotating the thing each hour or so to get even white surfaces.

I forgot to mention that it was whole day on direct sunshine ( I leave on garden in big transparent container with 4l of hydrogen peroxide) The circulation has been made by lot of bubbles made by peroxide decomposition.
That method obviously isn't ideal.
Last week I did 5 panels at the same time (2 x K2001, 3 x K7001). Start to finish < 1 hour in the sun. I used 40 vol (very strong, 12%) hydrogen peroxide gel. I placed the panels in a shallow plastic container, I brushed on a thin layer, covered the container with plastic food wrap ("Glad Cling Wrap") to prevent evaportaion, and put it in the sun. The sun was at an angle, so I rotated the container a few times over the hour. I re-applied fresh HP after 30 minutes to help combat evaporation. Last time (2 weeks ago) it took 2 hours but it was partly cloudy. This time, 1 hour and done. The UV light is essential and you must be careful about what you cover the item with, or it will block UV. Maybe your panel, submerged deep in liquid HP, didn't get enough UV light.

I was happy to be done in only 1 or 2 hours. Too much time in HP and the dye in the plastic can bleach, leaving it with light patches. We want only to convert the brown/yellow Bromine back into colorless Bromide or Bromate.
Maybe not, but it works. The container is made from PP so it is UV transparent. I do not think evaporation is issue, hydrogen peroxide will sooner degrade to water and oxygen.
I'm also going to test it o keyboard plastic from other equipment.
 

Offline plesa

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Re: Restoration glory of Keithley 2001 DMM
« Reply #531 on: May 22, 2016, 07:02:04 am »
Tried to leave the front panel plastic in hydrogen peroxide for 5 days. After this extra long time exposed to sunlight the plastic ( not Keithley, but HP/Agilent) became light blue.
 

Offline TiN

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Re: Restoration glory of Keithley 2001 DMM
« Reply #532 on: May 22, 2016, 05:10:36 pm »
Yep, light-blue :)

Here I've got K2304 and 2001 with whitened panels assembled. Had this time rear bezel from 2001 before too + TAED and it stay in solution for way too long, 4 days, 2 of which were raining. Its now sorta bluish white. :) I'll snap few photos later to show. 1L Bottle of peroxide already gone, so need buy few more to continue other units.
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Offline Macbeth

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Re: Restoration glory of Keithley 2001 DMM
« Reply #533 on: May 23, 2016, 12:23:51 am »
Are we advancing the previous research that led to retr0bright? It seemed clear that a deep soaking in lots of peroxide was not needed, just a soapy suds (mixed with washing powder) application. It seems even 6% peroxide is good enough, never mind the "salon professionals only" 12% (or 40 vol as I have now learned it is known). A few hours in the sun and Bob's your uncle!

The blue thing is worrying. Glad I leave it to you pioneers in Keithley plastics rather than me  :-DD

Also, macboy's great hot plastic revival trick - before or after?  ???
 

Offline McBryce

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Re: Restoration glory of Keithley 2001 DMM
« Reply #534 on: May 23, 2016, 07:45:18 am »
Process depends a lot on UV light intensity, so best would be to have it for few hours under direct sunshine, swapping sides/rotating the thing each hour or so to get even white surfaces.


I forgot to mention that it was whole day on direct sunshine ( I leave on garden in big transparent container with 4l of hydrogen peroxide) The circulation has been made by lot of bubbles made by peroxide decomposition.
That method obviously isn't ideal.
Last week I did 5 panels at the same time (2 x K2001, 3 x K7001). Start to finish < 1 hour in the sun. I used 40 vol (very strong, 12%) hydrogen peroxide gel. I placed the panels in a shallow plastic container, I brushed on a thin layer, covered the container with plastic food wrap ("Glad Cling Wrap") to prevent evaportaion, and put it in the sun. The sun was at an angle, so I rotated the container a few times over the hour. I re-applied fresh HP after 30 minutes to help combat evaporation. Last time (2 weeks ago) it took 2 hours but it was partly cloudy. This time, 1 hour and done. The UV light is essential and you must be careful about what you cover the item with, or it will block UV. Maybe your panel, submerged deep in liquid HP, didn't get enough UV light.

I was happy to be done in only 1 or 2 hours. Too much time in HP and the dye in the plastic can bleach, leaving it with light patches. We want only to convert the brown/yellow Bromine back into colorless Bromide or Bromate.


Cling-Film (or whatever that transparent food covering film is called in your neck of the woods) works very well for covering the parts while they enjoy the sun. Just make sure there are no creases in the film on the sunny side or it can cause un-even bleaching.

McBryce.
 

Offline Richard Head

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Re: Restoration glory of Keithley 2001 DMM
« Reply #535 on: May 23, 2016, 08:40:47 am »
I've learned something! I'm going to try the hydrogen peroxide trick on my Avdantest spectrum analyser screen bezel. They are renowned for turning yellow with time/sunlight.
I hope it doesn't make the plastic brittle.
 

Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #536 on: May 23, 2016, 12:58:41 pm »
Are we advancing the previous research that led to retr0bright? It seemed clear that a deep soaking in lots of peroxide was not needed, just a soapy suds (mixed with washing powder) application. It seems even 6% peroxide is good enough, never mind the "salon professionals only" 12% (or 40 vol as I have now learned it is known). A few hours in the sun and Bob's your uncle!

The blue thing is worrying. Glad I leave it to you pioneers in Keithley plastics rather than me  :-DD

Also, macboy's great hot plastic revival trick - before or after?  ???
Some magic sauce is missing from TiN's and plesa'a attempts to have force a multi-day attempt. I have in the past added "Oxy Clean" (the concentrated stain remover powder, not the one marketed specifically as laundry detergent/booster). I found that it caused the HP to foam, and I didn't care for that. So my latest attempts did not use any Oxy booster at all, and it still worked like magic. As I said earlier, I used just a thin layer of 40 Vol (12%) HP gel brushed on, put into direct sunlight under cling wrap, and one hour later, done.

The heat reshaping can be done before or after color restoration. I have tried both ways and observe no difference to the result. I usually choose to do it after.

Here is one more weapon in the ABS panel restoration arsenal: Tamiya Extra Thin Cement.

It is a model cement with extremely thin consistency. It is perfect for fixing cracks in ABS. If you have a crack, just apply a small amount of this to the crack, it will instantly disappear into the crack by capillary action. The solvents then melt the plastic, and as they evaporate away, the crack is literally welded shut. If the crack has a little bit of a gap between sides, repeated application may be necessary. Each time, the solvent will dissolve a little plastic, filling in a little bit of the gap. (as with the heat reforming, practice with LEGO can be useful!).
 

Offline TiN

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Re: Restoration glory of Keithley 2001 DMM
« Reply #537 on: May 23, 2016, 01:11:01 pm »
Lego master give us another gem. I can see you tried many things on many legos to find out these tricks.
Thanks for sharing, really. I have cracks in 2400's panel "ears" which made it barely holding as a whole.
And it's bit different than 200x one, so I can't replace it directly. So I'll try to buy that cement to give it a whirl.  :-/O
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Offline McBryce

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Re: Restoration glory of Keithley 2001 DMM
« Reply #538 on: May 23, 2016, 01:14:49 pm »
Yup, thumbs up for that solvent. I used it to repair the bezel on my HP3478A and the crack is almost invisible now. One further tip however: Clean the surface inside the crack with Isopropanol first, especially if the crack is old, otherwise you weld a (visible) line of dirt into the crack too.

Regarding the bleaching. There's a product in the UK known as BBlonde http://www.superdrug.com/B-Blonde/Jerome-Russell-B-Blonde-Cream-Peroxide-40-Vol-12%25-Lightner/p/42293 which already contains the exact mixture needed for "bezel blonding" without the need to mix your own solution with Oxy or whatever. Possibly there's some similar product over there you could try?

McBryce.
« Last Edit: May 23, 2016, 01:20:19 pm by McBryce »
 

Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #539 on: May 23, 2016, 10:54:21 pm »
Yup, thumbs up for that solvent. I used it to repair the bezel on my HP3478A and the crack is almost invisible now. One further tip however: Clean the surface inside the crack with Isopropanol first, especially if the crack is old, otherwise you weld a (visible) line of dirt into the crack too.

Regarding the bleaching. There's a product in the UK known as BBlonde http://www.superdrug.com/B-Blonde/Jerome-Russell-B-Blonde-Cream-Peroxide-40-Vol-12%25-Lightner/p/42293 which already contains the exact mixture needed for "bezel blonding" without the need to mix your own solution with Oxy or whatever. Possibly there's some similar product over there you could try?

McBryce.
Good tip about cleaning the plastic before welding.

Interesting about the "BBlonde". Maybe the cream peroxide I have here also has some of the other active ingredient in it already, which is why it works so well. In any case, since it is very effective compared to what some of you guys are trying, I'd be willing to ship a bottle to forum members at cost.
 

Offline Macbeth

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Re: Restoration glory of Keithley 2001 DMM
« Reply #540 on: May 23, 2016, 11:02:15 pm »
I've got a Superdrug round the corner. For less than £2 for a bottle of BBlonde it seems a no brainer to give this a try. Now finding Lego bricks is another matter...
 

Offline TheSteve

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Re: Restoration glory of Keithley 2001 DMM
« Reply #541 on: May 24, 2016, 12:37:05 am »
I've got a Superdrug round the corner. For less than £2 for a bottle of BBlonde it seems a no brainer to give this a try. Now finding Lego bricks is another matter...

Lego costs more then Keithley gear...
VE7FM
 

Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #542 on: May 24, 2016, 12:44:05 am »
I've got a Superdrug round the corner. For less than £2 for a bottle of BBlonde it seems a no brainer to give this a try. Now finding Lego bricks is another matter...
I have  5 and 7 year old boys. I'm lucky if can not find Lego everywhere I look.
 

Offline McBryce

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Re: Restoration glory of Keithley 2001 DMM
« Reply #543 on: May 24, 2016, 07:58:43 am »
I have a 5 year old son = If I need Lego I just choose one of the pieces embedded in my foot!

McBryce.
 

Online xrunner

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Re: Restoration glory of Keithley 2001 DMM
« Reply #544 on: May 29, 2016, 11:03:08 pm »
How about credit where credit is due? I mentioned this technique in TiN's K2000 thread here. I came up with this crazy idea one day, decided to try it on a Keithley 199, and it worked like a charm. I am certain that I am not the first to do this but I hadn't heard of anyone doing it.

Wow - I tried this for the first time today. I tried it on an old GE camera controller case. I used the cream peroxide that is sold in beauty supply stores. I just brushed it on and covered it with plastic wrap, and left it in the sun for about 4 hours. I only did the top to see the difference. It worked that fast. Great tip and method.  :-+
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Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #545 on: May 30, 2016, 01:35:50 pm »
How about credit where credit is due? I mentioned this technique in TiN's K2000 thread here. I came up with this crazy idea one day, decided to try it on a Keithley 199, and it worked like a charm. I am certain that I am not the first to do this but I hadn't heard of anyone doing it.

Wow - I tried this for the first time today. I tried it on an old GE camera controller case. I used the cream peroxide that is sold in beauty supply stores. I just brushed it on and covered it with plastic wrap, and left it in the sun for about 4 hours. I only did the top to see the difference. It worked that fast. Great tip and method.  :-+
It really is amazing to see isn't it?

Let's be clear, I don't claim any credit for the whitening process. This was pioneered by folks at Retr0Bright who wanted a way to de-yellow vintage computers and game consoles. There is some additional history on their site.

I was claiming some credit for the process of removing small dents and dings in the plastic by heating it to a specific temperature with a hot air gun. This seems to "relax" the plastic and allows the damaged surface to return to its original shape. As above, I'm sure I'm not the first to do it, but I haven't heard of anyone doing this.
 

Online xrunner

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Re: Restoration glory of Keithley 2001 DMM
« Reply #546 on: May 30, 2016, 10:44:27 pm »
I was claiming some credit for the process of removing small dents and dings in the plastic by heating it to a specific temperature with a hot air gun. This seems to "relax" the plastic and allows the damaged surface to return to its original shape. As above, I'm sure I'm not the first to do it, but I haven't heard of anyone doing this.

I'll review that process: Do you think the unit shown in the attachments is a good candidate for that?

Thanks.
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Offline macboy

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Re: Restoration glory of Keithley 2001 DMM
« Reply #547 on: May 30, 2016, 10:53:06 pm »
I was claiming some credit for the process of removing small dents and dings in the plastic by heating it to a specific temperature with a hot air gun. This seems to "relax" the plastic and allows the damaged surface to return to its original shape. As above, I'm sure I'm not the first to do it, but I haven't heard of anyone doing this.

I'll review that process: Do you think the unit shown in the attachments is a good candidate for that?

Thanks.
No, it looks like that isn't simply dented but has chunks of material missing. There is no simple fix for that.
 

Online xrunner

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Re: Restoration glory of Keithley 2001 DMM
« Reply #548 on: May 30, 2016, 10:58:55 pm »
No, it looks like that isn't simply dented but has chunks of material missing. There is no simple fix for that.

Well ... I got it. What about the next best thing - would the process make it look any better, given that material is gone? Would it smooth it out?
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Offline Le_Bassiste

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Re: Restoration glory of Keithley 2001 DMM
« Reply #549 on: June 06, 2016, 06:22:55 pm »
recently got the chance to acquire a KEI2001 in beautiful condition (alas, a very faint display), with no pcb damages whatsoever. after giving it the full capacitor exchange, i decided to give it a shot with a home-brew MEM2 option. SRAM is an HY628100B that i salvaged from an HP-40G calculator. works like a charm after initializing it via the secret menu.
piggy-backed battery is not the most elegant solution, but don't know a better one.  the whole shebang just so fits under the hood with some clearance.
« Last Edit: June 06, 2016, 06:24:39 pm by Le_Bassiste »
 


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