One thing that I've noticed but never bothered to ask about is the relationship between the color of the early "plastic" pens and deterioration of the plastic material over time. I'm talking here about the solid colored plastics of the late vac-fill pens, the fat Touchdowns, and the TM Touchdowns. I've seen that the material seems to shrink and (at worst) crystallize and go brittle over time.
I've got several Touchdown pens where there is a bulge at the point that the barrel gasket sits, where the barrel has shrunk around the gasket, forming a "ring" shape on the outside of the pen. At this point, the barrels on some of the pens are weak and brittle. Most of the pens I've come across are still functional, but some are so brittle that they crack or break when you go to remove the old gasket. I had one dark green pen were the whole back part of the barrel came off with the gasket.
You see it on the plastic caps as well. You'll see areas on the green and the blue pens that are darkened and which seem to have shrunk. Again, the greens seem the worst, followed by the blue and then the red and finally the black. The black again seemed to shrink the least.
So the worst of them seem to have generally been the dark green ones, with a couple of the dark blue pens having issues. The black pens seem to have fared the best. The dark red is somewhere in the middle.
Of the different generations, the TM Touchdowns seem to have the fewest problems, with the fat Touchdowns having more shrink issues than the TM, again in my experience.
For people who have seen many of these pens, is it also your experience that the dark green plastic seems to age the worst, whereas black seems to hold up the best? Was there any difference in the material used to color the plastic when they made these?
Edited by Ray-Vigo, 21 August 2019 - 14:44.