Are some records more brittle than others?

[tinovanderzwan]

My opinion is that some compounds somewhat "dry up" over decades to the extent that internal forces grow inside the record until it cracks by itself, even if left untouched. The crack rims look apart by 1-2 millimeters and impossible to realign, which clearly shows - in my opinion - that there is indeed a tension inside the material with which the record is made.

An acoustic Zonophone is a record with which I clearly remember that this happened.

i agree the older discs have a high internal tension i think materials like bitumen and pine resin are to blame
a post 1940s record doesn't seem to have this problem i have a 1950s hmv record with a crack from edge to label that is still in line even after 20 years i also have a 1904 red g&t with the same problem that i bought at the same time that is now completely unplayable

bitumen when left on its own seems to crack and fall apart on its own accord and the crackling reminds me very much of what i sometimes see on records damaged by moist or mold maybe thats the problem?

tino

[VintageTechnologies]

I have bought many hundreds of acoustic 78's and Pathés through the mail. From breakage I have seen, I have concluded that American Pathés are more brittle than 78's of the same period. The French Pathés seem to have a different composition, and I am uncertain about those.

As for wax cylinders, the compound used after 1908 for Edison 2 & 4 cylinders was noticeably more brittle, noisier, and more prone to oxidation. Their only redeeming features are hardness and far greater resistance to mold. I generally avoid those.