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A little notice about RetroBright !

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    A little notice about RetroBright !

    Hi,

    I hate to be the guy that brings bad news, but I stumbled across something I thought I had to share with you guys.

    http://aktuelbevaring.natmus.dk/afre...trobright.html

    It is from the National Museum in Denmark, they have tested RetroBright and will not recommend it because of structural changes in the plastic. I wrote them an e-mail aksing for further information about the test they performed. Obviously, since RetroBright consist of peroxid it will make structural changes to any plastic. They will not use it to preservation since it has a non-reversible effect.


    Any thoughts ?

    Vifa

    #2
    Just that I'm not sure what is new about that.
    Peroxides in general work because they provide free radicals, and those break polymer bonds.

    Like everything, it's a trade-off. TANSTAAFL.
    “Thus, we see that one of the obvious origins of human disagreement lies in the use of noises for words.”

    Comment


      #3
      I was always concerned about the long term effects of using it, now I know not to use it, I haven't actually read the article, but get the message.

      Comment


        #4
        No surprise--I had my own reservations about the stuff.

        Comment


          #5
          And I've always been puzzled about wanting to remove the real age characteristics of something anyway. If it's yellowed, it did so on its own. Leave it. Take your meds instead.

          Comment


            #6
            As someone who has used retrobright quite a lot, I'm pretty relaxed about it too. After all, Ambient UV (and O2?) exposure over time causes structural damage anyway; plastics become not only yellowed but also brittle.

            My retrobrighted machines certainly look better. It is possible to overcook the process and cause visible damage but with most of the machines I've processed the plastic looks and feels fine.

            I think the the important point here is to let people know that a computer has had the retrobright treatment if you go to sell it. Then they can assess whether or not it's important to them and negotiate or bid accordlingly.

            Tez
            ------------------------------------------------
            My vintage collection: https://classic-computers.org.nz/collection/
            My vintage activities blog: https://www.classic-computers.org.nz/blog/
            Twitter: @classiccomputNZ ; YouTube Videos: (click here)

            Comment


              #7
              Well, I don't know how many of you read Danish or how well Google translate mangles the article, but this is what it says:

              On ABS plastic, the Retr0Bright process is not recommended because they so far don't know about the long term effects.

              On other types of plastic, like PVC, PMMA, polyetylene, polystyrene and cellulose acetate, they observed visual changes on the surface and thus can't recommend the process at all.

              Basically, they're saying that a process developed to treat symptom A is not a good idea to use to treat symptom B. Like taking cough medicine against gastric ulcer.
              Anders Carlsson

              Comment


                #8
                An important clarification. Thanks Anders.

                Tez
                ------------------------------------------------
                My vintage collection: https://classic-computers.org.nz/collection/
                My vintage activities blog: https://www.classic-computers.org.nz/blog/
                Twitter: @classiccomputNZ ; YouTube Videos: (click here)

                Comment


                  #9
                  I knew I would get unpopular by stating this. I started this thread to inform people about the work the National Museum of Denmark is going through to find a preservative for plastic, and found it interesting that they actually tested RetroBright, which I also have used.

                  As mentioned in my first post I did contact them to get further information, as ABS was not mentioned in the article as one of the test materials.

                  This is the answer i received from Yvonne Shashoua, who works at the project:

                  "Retr0bright contains peroxide and are therefore likely to react with all types of plastic also ABS. I do not recommend Retr0bright as a preservative because it alter surfaces and is therefore a non-reversible treatment."


                  There are two pictures in the article showing a before and after picture of the structural changes, I guess, even though old plastic gets brittle, this is not helping any further ?


                  Thought you guys would like to know about this before using it.

                  Comment


                    #10
                    I do not think you are unpopular for posting about this, we appreciate your reporting the results of someone who has done the testing, even if it was in a language that most of us cannot understand.
                    Thank you.

                    Comment


                      #11
                      The other big thing to remember is that, as a museum, they are concerned more about exact preservation, not purely physical appearance restoration. I would venture that most vintage computer collectors are concerned more about physical appearance restoration than absolute perfect preservation. (Yes, there are some, and here, probably quite a few...) Their main concern was that it "changed" the structure, not that it "harmed" the structure. (Although they also say they don't know for sure the long term "harm" potential.)

                      It's like the difference between "restoring" a painting and "preserving" it. A museum cares more about preserving exactly what it is, and will clean it in completely non-changing ways. An art appreciant may care more about restoring it, and so may be willing to remove trace amounts of the original paint in an effort to clean it, where the museum wouldn't.

                      Personally, I care more about restoration of appearance. I'm willing to trade off the non-originality and potential for longer-term damage - since these type of things are already prone to longer-term environmental damage.
                      Apple ][+ through Retina MacBook Pro, 5150 PC through Core i7 8870/GeForce GTX 1080Ti and quad Itanium 9150M, and many in between.
                      Newton, Palm 1000, Palm V, N-Gage, Tapwave Zodiac, iPhone, iPhone X.
                      Intellivision, Game Boy through 3DS, Wii, XBone

                      Comment


                        #12
                        I work in a Museum on a piece of equipment called the Hartree Differential Analyzer. If you have a browser other than IE you can see a video here:-

                        http://www.cs.man.ac.uk/~chl/hartree.html

                        What we are and are not allowed to do is vey odd. The machine was delivered to the Museum when it was about 60 years old. We have to preseve it in that state. This is a big problem it was delivered in a half restored. it was left untouched for another 15 years before anything was done. So we can't undo bodges done in the original restoration. We can replace or missing or broken bits but we have to paint these pale blue. (there was no blue on the original machine). Of course we log every change but the Museum doesn't really like restoring things. It destroys their originallity. So I can see why they don't like retrobite. It changes somthing in a non-reversible way. For many enthusiasts yellow plastic is hated, for others its part of the items history. Personally I can see both sides, but its better that painting over...
                        Dave
                        G4UGM

                        Looking for Analog Computers, Drum Plotters, and Graphics Terminals

                        Comment


                          #13
                          Originally posted by Vifa View Post
                          I knew I would get unpopular by stating this.
                          Not at all. Any reports on research are very welcome, especially when they relate to what a lot of people are doing. Only thing is if it's not in the "common tongue" (i.e. English) it's hard for most people to read the original source. Google translate is a kludge when it comes to these kind of things so a good translation is needed.

                          Tez
                          ------------------------------------------------
                          My vintage collection: https://classic-computers.org.nz/collection/
                          My vintage activities blog: https://www.classic-computers.org.nz/blog/
                          Twitter: @classiccomputNZ ; YouTube Videos: (click here)

                          Comment


                            #14
                            Originally posted by Vifa View Post
                            I knew I would get unpopular by stating this.
                            As mentioned in my first post I did contact them to get further information, as ABS was not mentioned in the article as one of the test materials.

                            This is the answer i received from Yvonne Shashoua, who works at the project:

                            " I do not recommend Retr0bright as a preservative because it alter surfaces and is therefore a non-reversible treatment."


                            There are two pictures in the article showing a before and after picture of the structural changes, I guess, even though old plastic gets brittle, this is not helping any further ?


                            Yeah, don't be getting all sensitive - you're no less popular now.
                            In fact, maybe you're even more popular.

                            "I do not recommend Retr0bright as a preservative"
                            Yvonne is obviously trying to do something that I believe most of us using Retr0Brite aren't trying to do.
                            When I'm using Retr0Brite, I'm trying to get the appearance back to its original state, not preserve what it looks like now.
                            I'll be dead and buried before some of my pieces have got back to the yellow they were.
                            But if someone wants to go into a museum in 100 years and see a real old yellow/brown computer then they should be able to - I just hope they have a non-yellowed brochure of what they originally looked like as well, so people don't think we were crazy making them that color.

                            And if the structural changes need a microscope see the differences, I'm not worried about it at all.

                            That was a good article to point out - it makes us realize that we're not all after the same result.

                            Comment


                              #15
                              I think to fully be able to tell about long term effects, one needs some sort of accelerator lab in which the treated and untouched plastic can age faster. I've never used Retr0Brite myself, but have friends who have. Indeed I have a few personal cautions, but wouldn't write it off as destructive quite yet.

                              What I really objected about the Danish museum is when they try to apply the same process to other kinds of related materials. It sounds just as random as when people were asking Merlin etc about which other catalysators and funny stuff you can add to the H2O2, TAED and xanthan gum to get additional results. This is a result of theoretical chemestry put into practise, not a guesswork of let's mix a couple of leftover chemicals and see what we get.

                              It also reminds me about a computer magazine in the early 1980's who published a small machine code routine for creating white noise on the ZX Spectrum beeper. One reader posted a question whether the routine could be used for anything else than producing white noise, like it wasn't enough...
                              Anders Carlsson

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