Embossing polycarbonate: squeaks and squawks

[pentlandsound]

I've been embossing on polycarbonate with my new lathe for about two years now, and to date have had great results using PIAPTK sapphire styli, with good fidelity and practically noiseless grooves. I order the poly in sheets and cut out the discs by hand using a circle cutter; this is much cheaper than getting them CNC'd. However I'm having problems with a new batch of polycarbonate, with much louder background noise and often an irritating squeak or whine, particularly evident on the run-ins. I'm making 7-inch 45s only.

Having run many tests over the last few days, I find that if I polish the discs with household furniture polish, then apply WD-40 (the best embossing lubricant I've tried), and use a heat lamp, the squeaks and other noises reduce to a more-or-less acceptable level, but don't disappear entirely. The recordings themselves are as good as ever.

The problem batch is stamped PALSUN CLEAR POLYCARBONATE U V P. I can't find a manufacturer's name on the better stuff, but one sheet was stamped with the size and the number 263498. Unfortunately, my plastic supplier (a builder's merchant) just sends what's in stock and probably won't be able to supply "low-noise polycarbonate"!

Have other Trolls who emboss poly experienced differences between brands? Can anyone recommend a good one that's available in UK, and advise where to get it?

Thanks,

David

[Fela Borbone]

Some UV (ultraviolet filter) polycarbonate gave me this results.... Some have filter in one side only, and the difference is distinguishable

[diy_cutter]

The problem batch is stamped PALSUN CLEAR POLYCARBONATE U V P.

Hi David. I have not yet received my shipment of clear polycarbonate from Palsun. As soon as I have it I will do a cutting and embossing test. I'll post the results here or in my thread.

Sincerely, Eugene.

P.S.: And thank you for all the information I read from you on this forum!

[jjwharris]

I've moved from lighter fluid to brake cleaning fluid to clean my blanks - I think there is a drop in surface noise.

It's a lot cheaper too - probably makes you twice as mad, but hey, we're trying to emboss records anyway...

Palsun is the same brand of PC Peter King used, I think it was all UV protected too...

[tragwag]

I would double check that the blanks are as near to flat as possible.
with embossing, a change in depth is usually the cause for that type of noise