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Straigtening warped 78s

Posted: Sat Mar 31, 2018 12:24 pm
by toysbyroy
I found some Victor records that had apparently gotten hot and warped. I would like to try and save some of them. How could I get them to lie flat again? Thanks, Roy

Re: Straigtening warped 78s

Posted: Sat Mar 31, 2018 12:40 pm
by Teak
Put the record on a piece of glass and put it in the oven (or outside in direct sunlight during summertime) on a low temperature (ca 200°F ) setting till flat (couple of minutes). Caution, don't "overcook" it.

Jokes aside, its easily done!

Re: Straigtening warped 78s

Posted: Sat Mar 31, 2018 1:44 pm
by phonogfp
Teak's right - it's easy. I use 2 pieces of 12" x 12" plate glass. A record is placed between the pieces, and put into an oven at 175 degrees F. 200 might work, but I'm a bit of a chicken. Sometimes it takes up to a half-hour at 175, but I've never damaged a record at that temperature.

George P.

Re: Straigtening warped 78s

Posted: Sun Apr 01, 2018 12:19 am
by donniej
I use a thick steel plate on top of a pot of boiling water. Not enough temp control on an oven for my liking.

Re: Straigtening warped 78s

Posted: Sun Apr 01, 2018 6:59 am
by WDC
I used the oven method several times for both 78s and even modern LPs. However, with LPs I have to ensure that it won't go over 60 °C, 55 °C to be on the safer side. And 75 °C has always been enough for 78s as well.

For proper control, I use a cheap digital thermometer with an external sensor that goes into the oven. Works great but must not be left unattended while the oven is on. I only use hot air mode which ensures the most even temperature distribution. It takes lots of time to let it cool down but the results have been really good so far.

Re: Straigtening warped 78s

Posted: Sun Apr 01, 2018 10:55 am
by TinfoilPhono
I meant to try this technique when it was discussed previously but then forgot about it. Yesterday I took a badly warped 7" Zonophone disc that I display on my Zonophone A and heated it at 175 for 20 minutes. Piece of cake -- it's now perfect, and I love how the turntable pin snaps satisfyingly into place when I turn the disc. ;)

Re: Straigtening warped 78s

Posted: Sun Apr 01, 2018 11:24 am
by epigramophone
I have used the plate glass method successfully, but both the record and the glass must be scrupulously clean. Any dust or debris such as pet hair will become embedded in the record surface when warm and will be impossible to remove when cool.

Re: Straigtening warped 78s

Posted: Sun Apr 01, 2018 9:59 pm
by phonogfp
TinfoilPhono wrote:I meant to try this technique when it was discussed previously but then forgot about it. Yesterday I took a badly warped 7" Zonophone disc that I display on my Zonophone A and heated it at 175 for 20 minutes. Piece of cake -- it's now perfect, and I love how the turntable pin snaps satisfyingly into place when I turn the disc. ;)
Glad it worked for you, Rene. I did exactly the same thing in January...a 7 inch Zonophone which was so warped the first half-inch or so couldn't be played. Perfect now!

George P.

Re: Straigtening warped 78s

Posted: Mon Apr 02, 2018 12:50 am
by gramophone-georg
phonogfp wrote:
TinfoilPhono wrote:I meant to try this technique when it was discussed previously but then forgot about it. Yesterday I took a badly warped 7" Zonophone disc that I display on my Zonophone A and heated it at 175 for 20 minutes. Piece of cake -- it's now perfect, and I love how the turntable pin snaps satisfyingly into place when I turn the disc. ;)
Glad it worked for you, Rene. I did exactly the same thing in January...a 7 inch Zonophone which was so warped the first half-inch or so couldn't be played. Perfect now!

George P.
I prefer my records warped. Matches my personality.

Re: Straigtening warped 78s

Posted: Sun Apr 15, 2018 3:06 pm
by beaumonde
Don't try the glass plate-in-oven sandwich on any laminated record -- likely lam cracks will result.