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OT: This week's project problem

Forty years or so ago I cast a variety of high school and college memorabilia into some kind of clear plastic resin.

Over the years, banging around in storage boxes, they've taken a beating and are now pretty badly scratched up.

I have no idea what the material is :-(

Anyone have ideas on how to "de-scratch", or perhaps dissolve the material away?

Thanks! ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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Reply to
Jim Thompson
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I'd ask guys like these:

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Not knowing the material it's tough. I know that toothpaste can get deep scratches out of a DVD because I have done that. Other people used some sort of kitchen polishing paste (Brasso?) even though it was meant for metal. But be careful with chemicals that might develop.

Oh-oh, be _very_ careful. I can already picture the KPHO evening news ... "Good evening everyone, late breaking news, a large hazmat team has just been dispatched to ..."

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Reply to
Joerg

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Maybe Polyurethane or most likely Polyester resin.

You could start with Rubbing compound, and a scratch hiding wax (turtle Wax makes some). You could test using a Buffing wheel and Rouge. But that may heat the surface and cloud it.

There are solvents like MEK that will break it down, but you and your trinkets might dissolve too.

Cheers

Reply to
Martin Riddle

The only clear casting resin readily available 40 years ago was polyester. Take out the scratches with the finest sandpaper you can find (600 should be good) and then polish with compound and a buffing wheel. Forget about dissolving it.

Reply to
Glen Walpert

This is a pure guess: buff with jewlers rouge.

Ed

Reply to
ehsjr

"Martin Riddle" wrote in news:ho19a9$s10$ snipped-for-privacy@news.eternal-september.org:

Decopour. I've used it.

you also can buy plastic polish in auto stores. I'd try that before I tried the coarser rubbing compound. see what it does before you tear it up with coarser abrasives.

I used it (with a foam pad and cordless drill)to renew my auto headlights after they got cloudy. (then I recoated the plastic with an anti-UV compound from a CrystalView headlight refinishing kit I bought at WalMart.)

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Jim Yanik
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Reply to
Jim Yanik

The antique radio guys like NOVUS plastic polish. It is available in multiple versions for rough and smooth finishing.

--
Lead free solder is Belgium's version of 'Hold my beer and watch this!'
Reply to
Michael A. Terrell

You can get up to 2000 grit sandpaper at auto paint supply stores.

--
Paul Hovnanian     mailto:Paul@Hovnanian.com
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Dyslexics have more fnu.
Reply to
Paul Hovnanian P.E.

Sounds very similar to the casting resins used for embedding metallurgical specimens before grinding and polishing.

You might be able to find a metallurgical lab with one of those disk polishing machines who could be persuaded to polish them up, if they have flat sides.

Alternatively, a met. lab might be able to tell you what polishing media to use.

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
                                             (Stephen Leacock)
Reply to
Fred Abse

I agree, I think the stuff is called Flitz

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I have used one of their polishing kits to do the same thing. Worked pretty damn good.

Reply to
WangoTango

How about going the opposite direction? See if you can find the same material and recast them in another layer. That should pretty much fill in the scratches. Buffing them out some and then another layer might work better.

Reply to
krw

Amber? ;-)

--
Paul Hovnanian  paul@hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.
Reply to
Paul Hovnanian P.E.

kluger Kerl :-) ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

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| 1962 | The only thing bipartisan in this country is hypocrisy

Reply to
Jim Thompson

Sure. For tiny scratches, smear toothpaste on a flat object like glass, metal sheet, etc. and then slide the plastic object around in a figure 8 motion. Periodically add toothpaste and thin with a wet finger tip.

For deeper scratches, get Brasso polish, or if you can find it, plastic polish, and do same game. It works pretty quickly on plastic.

Jon

Reply to
Jon Elson

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