For the skeptics and hold-outs...
CAN RETROBRIGHT REALLY MAKE PLASTICS BRITTLE?
Let's think about it logically. How can cleaning the surface (0.1mm worth?) of a piece of plastic penetrate through it completely such that it becomes noticeably brittle? All the plastics I cleaned are quite thick (1mm or thicker). And I found that cleaning one side of the plastic does not cause the opposite side to become clean. In other words, if you dip the plastic in the liquid form of RetroBright and aim only one side of that plastic to UV light, only the UV light side gets cleaned/deyellowed. Alternatively, if you use the gel version of RetroBright only on one side of yellowed plastic and then expose all sides of that same plastic to UV light, only the RetroBright side gets deyellowed. In addition, I found that any black marks on the plastic or very dirty areas that I did not thoroughly wash off before RetroBright deyellowing remained on the plastic after deyellowing, proving that the deyellowing process is so weak that it cannot even penetrate most felt tip pen marks (at least, not with the 3% peroxide solutions that I used). And if you think that the sheer act of "submerging plastics" into a liquid solution could make plastics brittle, consider that I used the gel form of RetroBright on all large pieces of plastic (i.e., most plastics I deyellowed) which means I used it only on the surface of one side of the plastic -- how then could the plastic become brittle?! So my contention is that RetroBright (with low concentrations of peroxide) doesn't penetrate 100% through the plastic, hence it cannot make the plastic "brittle like glass" as you must be thinking.
Now let's think about it practically. Has anyone noticed that I have a RetroBrighted HD20 sitting under my very heavy SE/30? If the plastic had become dangerously brittle due to RetroBright deyellowing, you would expect that the sheer weight of my SE/30 sitting atop it (especially with my 6 and 3 year old children beat on the top of the SE/30) would cause at least one hairline crack somewhere on the HD20, right? Wrong. It's as strong as ever. Please also consider that I did some significant flexing of plastics when I put my SE/30 case back together, expecially the back side of the SE/30 case and that HD20. I've pulled off and put on the back side of my SE/30 housing a number of times since deyellowing with no ill effects. I own a lot of vintage stuff, and there is one thing that I have found that makes plastics brittle -- TIME. So if you are worried about brittle plastics, start work on that time machine. The clock is your enemy, not RetoBright.
Conclusion. Simply put, if you are putting off deyellowing for fear of making your plastics brittle, you are missing out on one of the best reasons to own a piece of vintage computing equipment -- to make it look new again! Don't be the slothful man who worries about lions roaming the streets. Make some time on a holiday and give RetroBright a try. If you follow in my footsteps, you won't be disappointed. For I myself followed in the footsteps of our very own LumpyDog, and I certainly am pleased I made the time to do it.
CAN RETROBRIGHT REALLY MAKE PLASTICS BRITTLE?
Let's think about it logically. How can cleaning the surface (0.1mm worth?) of a piece of plastic penetrate through it completely such that it becomes noticeably brittle? All the plastics I cleaned are quite thick (1mm or thicker). And I found that cleaning one side of the plastic does not cause the opposite side to become clean. In other words, if you dip the plastic in the liquid form of RetroBright and aim only one side of that plastic to UV light, only the UV light side gets cleaned/deyellowed. Alternatively, if you use the gel version of RetroBright only on one side of yellowed plastic and then expose all sides of that same plastic to UV light, only the RetroBright side gets deyellowed. In addition, I found that any black marks on the plastic or very dirty areas that I did not thoroughly wash off before RetroBright deyellowing remained on the plastic after deyellowing, proving that the deyellowing process is so weak that it cannot even penetrate most felt tip pen marks (at least, not with the 3% peroxide solutions that I used). And if you think that the sheer act of "submerging plastics" into a liquid solution could make plastics brittle, consider that I used the gel form of RetroBright on all large pieces of plastic (i.e., most plastics I deyellowed) which means I used it only on the surface of one side of the plastic -- how then could the plastic become brittle?! So my contention is that RetroBright (with low concentrations of peroxide) doesn't penetrate 100% through the plastic, hence it cannot make the plastic "brittle like glass" as you must be thinking.
Now let's think about it practically. Has anyone noticed that I have a RetroBrighted HD20 sitting under my very heavy SE/30? If the plastic had become dangerously brittle due to RetroBright deyellowing, you would expect that the sheer weight of my SE/30 sitting atop it (especially with my 6 and 3 year old children beat on the top of the SE/30) would cause at least one hairline crack somewhere on the HD20, right? Wrong. It's as strong as ever. Please also consider that I did some significant flexing of plastics when I put my SE/30 case back together, expecially the back side of the SE/30 case and that HD20. I've pulled off and put on the back side of my SE/30 housing a number of times since deyellowing with no ill effects. I own a lot of vintage stuff, and there is one thing that I have found that makes plastics brittle -- TIME. So if you are worried about brittle plastics, start work on that time machine. The clock is your enemy, not RetoBright.
Conclusion. Simply put, if you are putting off deyellowing for fear of making your plastics brittle, you are missing out on one of the best reasons to own a piece of vintage computing equipment -- to make it look new again! Don't be the slothful man who worries about lions roaming the streets. Make some time on a holiday and give RetroBright a try. If you follow in my footsteps, you won't be disappointed. For I myself followed in the footsteps of our very own LumpyDog, and I certainly am pleased I made the time to do it.