rule of thumb on purchasing older acetate blanks?

[cymbalism]

just out of curiosity, how "old" is "old" when purchasing unused sealed blank lacquers? i picked up a box of 25 unused 7"s which look to be from the late 70s (no date on them) and when i opened them, i had to literally pry them apart w/my finger nail to get them out of the packaging and when cutting on them, i noticed some squealing and surface hiss only on certain parts of the blank, like when it rotated to a certain side the lacquer was foggy looking after the cut but not throughout the entire side, just in parts. i was just curious if its an age thing as i've read online that blanks get harder with age and apollo said they have a shelf life of a little over 10 years. when i went back to cutting on some 12"s from only a couple years ago (2005 - they had a date) they were clear and clean of any noise at all.

any idears?

[mossboss]

Hey
If the box is sealed well they will last at least 10 years If it has been opened the volatiles escape the castor oils seeps out of them and they will get "hard" even though hardness is subjective when it comes to them They used to come in tin boxes from Pyral as well as others with a 1/4" screw on the lid and bolt welded in the bottom holding the box sealed
So the answer to your question is: there is no answer Helpfull hey
Here is a recent experience of mine We where given a set of 10" acetates cut back in 1982 so as to press some 7's for a band We said no guarranties guys! It need to be re-cut Well there was no masters no originals apart from a video in mono Well!! They said go for it Their plated well we got plates out Now when we pryed the plate of the lacquers the coating fell to bits in 2" and 3" lumps all over I said this is not looking good however the plates looked very good We went ahead and pressed out of them and the pressings where fine in actual fact they sounded excelent So here is an example of how old is "old" I would have thought that after a lacquer is cut it would have a "lesser" life but as the above shows it is no indication Who really knows
By the way the silvering on those old lacquers looked absolutely brilliant It seems that age allows them to be silvered better since most solvents have escaped out of them This is an educated guess of course But I do recall reading somewhere that RCA did "sweat" them out prior to silvering in an air forced oven (CD4cutter?) so as to improve the silvering process
Cheers

[Aussie0zborn]

Interesting. We cut 10" lacquers that were about ten years old and they were perfect.

I'm wondering if heating these old lacquers would help?

[mossboss]

Hey all
Well Heating them will be of assistance any way but if their are lacking moisture it would tend to make them harder But having a bit of a think!!! about it since this post the addition of a bit of moisture may be a good thing Now when I used to smoke a pipe I used to put a small slice of potato in the pouch that kept the tobaco moist I see no reason that half a potato placed in the box for a week or so would not place sufficient moisture back into them so as to "soften" them It cannot do them any harm any way as they have about 10-15% water in them
Cheers

[emorritt]

I agree with mossboss about there being no definite answer as to how age affects a lacquer. I've opened cardboard cartons of old Presto blanks - no "seal" or other attempt to make the package air tight - and they're just as good as the day they were made. I've also opened boxes of many brands including Presto that you end up picking up a piece of aluminum and the entire coating falls off, or they're stuck together, covered in palmitic residue, etc. There are so many factors such as coating formulation, substrate characteristics, storage conditions, etc. etc. that can affect a lacquer disk that there really is no telling what you'll find in a vintage carton of blanks. I have a few boxes of Allied disks I bought back in 1977 that cut today just as well as the day I got them. Allieds!! They've always been stored in a controlled environment - no attics, basements, etc. - and kept in the original box. Even though they've been open all these years they are still noiseless, even cutting without a heated stylus. (I use them for my collection of home recorders.) Even lacquers that have been cut are found in many different states of condition. Moral of the story is don't expect something that's usable when purchasing "NOS" recording disks...

[cd4cutter]

Moss, I don't recall RCA Indianapolis or the USA studios employing a "sweating" process for lacquers. During the glory days of 45 and LP record manufacturing, there was almost no need to deal with "old" lacquers - lacs were cut within days of their being shipped out from Apollo, Transco, Pyral or whoever made them. We did, however, go to fairly great lengths to clean the cut lacs after they were received at the pressing plant. The oils that had leached out after cutting had to be completely removed from the surface before they were silvered. This was particularly a problem with the air freight shipment of lacs in the heat of summer. The temperature extremes the lacs went thru from the cold of flying at 30,000 feet, and then the heat they experienced in the UPS truck served to drive out the oils and volatiles from the lacs by the time we got them at the plant. We did find the use of thick styrofoam packing material to be useful in helping to shield the lacs from the rapid temperature swings. We used a solution of the standard commercial "Wisk" liquid washing detergent to clean the lacs, hand applied with a soft brush. We stored the used lacs together with their metal parts, pending a reorder on the title. But we rarely were able to get really good second metal masters from the lacs - the lacs were kept mostly to cope with some emergency that rendered all the original metal unuseable and the client in a big fat hurry for a reorder and there being no time for a recut. Remember, these were the days when clients expected two or three day turnaround from cutting to shipment of many thousands of records. The Indy record plant ran 24/7 with three production shifts per day during those days. And we were just one of several large record plants in the USA.

[mossboss]

Hey CD4
Thanks for that once again an insight into things as they where so to say I should really look up that reference again But as cd4 says they where just one of several plants so what took place in one plant may not have been done in another as it is usually the case even today What we do is not done in another plant and we do not do what they do
Cheers