Heating or Warming Blanks Before Cutting?

This is where record cutters raise questions about cutting, and trade wisdom and experiment results. We love Scully, Neumann, Presto, & Rek-O-Kut lathes and Wilcox-Gay Recordios (among others). We are excited by the various modern pro and semi-pro systems, too, in production and development. We use strange, extinct disc-based dictation machines. And other stuff, too.

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timinbovey
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Heating or Warming Blanks Before Cutting?

Post: # 48002Unread post timinbovey
Tue Oct 03, 2017 5:03 pm

I'm guessing many of you have seen "The 78 Project" where they traveled around the country recording "in the field" with a portable Presto. If you haven't watched the movie it's available in it's entirety on Youtube.

Anyway, I noticed in many scenes just before recording they warmed the blank disc under a lightbulb in a reflector, similar to an old photographers silver reflector, or what you might have seen hanging over a coupe full of baby chickens on the farm to keep them warm.

In this short trailer for the film, right at the very beginning you can see her removing a disc from under the light:

https://www.youtube.com/watch?v=OgY4KLMg1VU

Now I'm of course familiar with heating a stylus, although I've never done it. And I've heard tales of warning up old blanks to make them useable again (with very variable success). But I know these folks are using brand new Apollo blanks. They must have found some advantage to pre-warming the blanks before recording. Anyone know how effective this is, and just how warm you want them to be?

If you haven't seen the movie I highly recommend it.

Tim in Bovey

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Angus McCarthy
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Location: Bloomsburg, PA, USA

Re: Heating or Warming Blanks Before Cutting?

Post: # 48066Unread post Angus McCarthy
Sun Oct 08, 2017 6:23 pm

I can tell you from my limited experience in cutting (new old stock) lacquers that warming them does indeed seem to reduce the over all surface noise. I let it get quite warm but not hot to the touch, though I'm not sure what temperature it actually gets to (still need to grab one of those infra red thermometers to be truly precise). I have a desk lamp with a large red floodlight that I use to constantly heat the disc as it rotates. The 78 project folks preheat the disc and then put it on the machine. I would think that doing so would lead to increased noise as the disc cools.

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