Author
|
Topic: STS-101 Olympic pin acrylic oddity
|
Robert Pearlman Editor Posts: 47883 From: Houston, TX Registered: Nov 1999
|
posted 01-26-2006 08:35 PM
Several years ago, I purchased an acrylic off of eBay that contained one of the 1,000 lapel pins carried on STS-101 to celebrate Houston's bid for the 2012 Olympics. I know that several other readers here did the same.When I originally received the acrylic, it was as clear as glass. Unfortunately, I didn't photograph it then so I cannot show you what it looked like for comparison. Suffice to say, if it hadn't been more or less perfect in appearance, I would have returned it for another at the time. Several months to a year later, I took a picture of it for display on collectSPACE: As you can see, by the time this photo was taken, blemishes had developed. I could not explain these as I hadn't cleaned it with anything more than a damp cloth (if that). It was a mild concern but as the pin was still clearly visible, I didn't take any action. Here is how the acrylic appears today: The pin is barely visible even when its not backlit. Whatever happened to this acrylic is still happening. The blemishes are in fact tiny divots or craters. They can be better seen from the reverse: They are also not on the outside. Running your finger along the front of the acrylic reveals a smooth surface. The divots begin just below the surface. Though I realize its highly unlikely that whatever is at work inside this lucite is contagious, I've separated it from my others just the same (its not very attractive to look at it anyway - at least not in the traditional sense). Has anyone seen anything like this happen before? Has this affected any of the other STS-101 pin acrylics? Can anything be done to save my pin? |
4allmankind Member Posts: 1078 From: Dallas Registered: Jan 2004
|
posted 01-26-2006 08:47 PM
I just checked and my pin does not not have those craters. It looks like your piece might have the chicken pox!I hope someone here might be able to help you arrest that cratering. |
Paullywoggles New Member Posts: From: Registered:
|
posted 01-26-2006 09:21 PM
I don't know what is happening but the damage look very similar to acidic corrosion damage to steel. I see what looks like the damage to the side many have been from finger prints. Perhaps the oil from the skin is reacting to the acrylic. Just a guess. |
zee_aladdin Member Posts: 786 From: California Registered: Oct 2004
|
posted 01-26-2006 10:51 PM
At what various temperatures have this acrylic been through? Has it gotten over 100 degrees where it was stored? Do you remember? |
Robert Pearlman Editor Posts: 47883 From: Houston, TX Registered: Nov 1999
|
posted 01-26-2006 11:07 PM
The acrylic saw no more extreme temperatures then perhaps 75 degrees F. Its been indoors, in my apartment(s), the entire time I have owned it.If this was caused by finger oils then I would be very surprised. I haven't handled this acrylic all that often (hence my surprise when I saw its recent condition and how bad it had become). Plus I can't imagine my fingers are any more oily than any of the other owners. |
Spacepsycho Member Posts: 872 From: Huntington Beach, Calif. Registered: Aug 2004
|
posted 01-26-2006 11:29 PM
Robert, I sent your photos to a gentleman I'm dealing with who's an expert in acrylics and resin embedding. I'm sure he'll be able to let you know what's happening. I think the only course of action will be to remove the pin and recast it in other lucite material.From what I can see, it looks like the problem is with the lucite material in the border area between the first poured material and the 2nd layer when the pin was added. There may have been an unstable reaction or a bad chemical mix that has been slow to develop. Do you know who made up these displays and was it made of acrylic, lucite or a cold resin? |
Paullywoggles New Member Posts: From: Registered:
|
posted 01-26-2006 11:50 PM
Robert, it was a guess. Oil from skin is acidic to a degree. The pitting does look like what happens to steel and aluminum in a corrosive environment. |
Spacepsycho Member Posts: 872 From: Huntington Beach, Calif. Registered: Aug 2004
|
posted 01-27-2006 11:01 AM
What's happening here has NOTHING to do with acidic fingerprints, humidity or any external issues. This is happening due to a reaction between the original chemical mix when this piece was made.Corrosion to steel or aluminum occurs from oxidation with the air, not acid found in fingerprints and the only exception is with blued firearms or coins. Lucite is immune to temp changes under 240 degrees, any air trapped inside the lucite is isolated and has no effect on any embedded piece. Also, the metal of the pin is not an issue. You can clearly see that the pin is not and has not been the cause of these bubbles, otherwise the bubbles would only be around the pin, not across the entire 2nd layer poured area. Robert, I should hear something today, but I think the only course of action will end up being to remove the pin, then put it in another display. |
Paullywoggles New Member Posts: From: Registered:
|
posted 01-27-2006 12:58 PM
Ray, I am not sure if you were reading my statement correctly but steel in a corrosive environment does pit. It was a comparison. Corrosive environment does not just mean in air. But thanks for agreeing that oil from the skin can cause damage, e.g. to coins, etc.Look forward to the solution to Robert's problem. |
Robert Pearlman Editor Posts: 47883 From: Houston, TX Registered: Nov 1999
|
posted 01-27-2006 02:11 PM
I appreciate everyone's help and ideas thus far. I have taken a quick photograph providing a side view to illustrate the distribution of the divots. As you can (hopefully) see the majority of blemishes occur just behind the front surface rather than along the seam line. There is another kind of damage occuring along the seam, but it has a different appearance than the divots that are most prominent. |
Hawkman Member Posts: 400 From: Union, New Jersey Registered: Jan 2001
|
posted 01-29-2006 11:49 AM
quote: Originally posted by Robert Pearlman: Plus I can't imagine my fingers are any more oily than any of the other owners.
Well you didn't look particularly greasy when I saw you here in New Jersey over the summer. In fact, if I may paraphrase Paul McCartney in 'A Hard Day's Night', you were 'very clean'. |
cfreeze79 Member Posts: 466 From: Herndon, VA, USA Registered: Nov 2000
|
posted 01-31-2006 01:37 PM
Since the divots are limited to the surface, you may be able to have the lucite resurfaced thru heavy polishing (akin to a belt sander). I don't know if you have a TAP Plastics out your direction, but I'd contact them for advice. |
jeffbassett Member Posts: 109 From: Toledo Registered: Feb 2005
|
posted 02-06-2006 03:01 PM
Looking at the above side view picture, I am not so certain its really on the subsurface. It looks much more likely that its on the middle film where the pin is mounted in. Usually, they will do a pour of a slow drying resin and place an object in as its starting to harden, then pour in another more fluid layer. The resins are supposed to be made of two mixes in equal portions. If the second pour is not matched up perfectly chemically to the first, you can have a small chemical reaction, especially if there is an object to catch the separate pours into two two mixed layers where the two mixtures meet. The film barrier the pins is mounted on acts as a barrier between the two mixes. If there is an imbalance between the two, you will get a slow reaction like this over time as it reacts slowly die to the lack of exposure to the air. If its on the exterior, the reaction would be quick and visible in the first 24 hours. You can see the bubbling on the film cut out in the middle. I am afraid there is no good fix for this type of reaction. |