From Fernando Zarone Sent Sat, Feb 3rd 2018, 21:06
From Fernando Zarone Sent Sat, Feb 3rd 2018, 21:06
Lorne,=20 thank you for your exhaustive and scientific explanation. Every = material ages. Not only plastic materials, ceramics too. In my field = (dental prosthodontics), my research group is involved in a lot of = studies about zirconia aging now, and it is one of the most reliable, = strongest dental materials ever! In certain environmental conditions, = and after time aging, it changes its crystallographic shape and can = undergo catastrophic failures=E2=80=A6 Nothing is forever.=20 Neither do I want to think about the aging of those custom, rare = components in our machines=E2=80=A6 Better not toworry too much and play our old babies=E2=80=A6 =20 f > Il giorno 03 feb 2018, alle ore 20:24, Lorne Hammond = <xxxxxxxx@xxxx.xx> ha scritto: >=20 > chemically all plastic are unstable. I am not an object conservator = but it was explained to me about our plastics that they are all stable = until the last 10-5% of their life and then break down quickly. Some = will off gas and the gas will cause a red rust on nearby metals. > PVC plastics like tb-303 cases, will show breakdown first by becoming = oily. Freezing plastics slows down but does not stop the plastic = deterioration. All plastics are a complex chemical stew and there are = no easy rules like 1910 "French ivory" goes first then 1950s then 1970s. = It is not about chronology but about chemical bonds at the molecular = level. Professional conservators know about this but it is not easily = understood especially because the makers of things use plastics provided = by other companies with proprietary (secret) formulas. At work we have = stable plastics from the 1910-1920s, but all our drafting triangles = crumbled around the same time. >=20 > 1) Don't store your tb-303 in the bag. Keep off gassing risks to a = minimum. Put the case in a zip lock bag with a little nylon sack of = fish tank charcoal to absorb off gas, place in cool storage. > 2) Rubber going from black to red or hard and curly is not = collectable, has no sonic qualities and is not reversible. Replace it. > 3) Black foam in road cases. Scrap it out, replace it. It will powder = down into your keyboard mechanism. If so vacuum it out. A foam shop can = do a better job cutting (their saw is a hot wire and they have masks and = air systems for this and for the glues. Road cases were $600 new, pay = some bucks to have it redone correctly. > 4) Moog cables. Yes, heat shrink (it shrinks right?) is not so = stable, cut it off from around the wire and redo it. > 5) audio cables will get brittle over time. The chance of a short = caused by a break is there. Replace. > 6) Button contact strips in late 1980s and 1990 synths will go. If you = can get new replacements or NOS (same problem) you may get extra shelf = life. > 7) Plastic panels sometimes show crackling. Its there in my tt-303. So = far its just an aesthetic issue. > 8) No sign of knobs going, say Minimoog 1975 seems stable as are the = blue early Buchla knobs. >=20 > Lorne >=20 >=20 >=20 >=20 > -----Original Message----- > From: Fernando Zarone [mailto:xxxxxxxxxxxxxx@xxx.xxx]=20 > Sent: February-03-18 9:24 AM > To: AH send <xxxxxxxx@xxxxxxxxx.xxx> > Subject: [AH] Damn sticky plastic... >=20 > Hi all > after moving to my new house (more than 1 year) finally I am cleaning = / recalibrating / overhauling my machines in order to tweak their knobs = again=E2=80=A6 > I have noticed that some stuff, after more than 40 years, is going to = age, as I am :-( > In particular, plastic and rubber seem to be very prone to some = problems:=20 > - the soft original case of my TB303 has an oily, somewhat sticky = surface, although maintaining its colors and shape.=20 > - some of my Moog modulars=E2=80=99 cables (the original s-trigger = ones) have a short collar of black rubber around the cable at the level = of the metal screwed =E2=80=9Ctie=E2=80=9D locking it to the Chinch = Jones Jack. Such collars are melting, leaving a black sticky stain that = is very hard to remove Any suggestion? >=20 > Ciao >=20 > Fernando=20 >=20