How best to eliminate LP warps


I own about 2500 LPs, and I like to think they're flat.  Furthermore, I espoused the view that warped LPs ought to be discarded.  But lately I have found 2 or 3 of my LPs that do have warps but sound too good and are too precious for the music recorded on them to throw away.  So I am in the market for ideas on how to remove warps.  I am aware that there was a device on the market that looked like a large waffle maker, to be used for warp removal.  I think Furutech made it, but I never see it advertised these days.  I am also aware of the DIY method of placing an LP between two glass plates and heating the ensemble.  The question there would be how hot and for how long?  Any suggestions are welcome, especially opinions on the efficacy of the Furutech.  Thanks.  Please no comments on vacuum hold down; I think it's a great idea but none of my five turntables has that feature.

lewm

PVF, Perfect Vinyl Forever can flatten records for $12 each. They mainly clean records, but also offer this service. Minimum order is 12 records. I them once with impressive results. I did not however send a warped record to be flattened.

 Using a machine that costs hundreds or thousands of dollars may be appropriate for say an audio club, but for the average collector, it is too high a price. PVF uses a professional machine manufactured for this specific purpose. No electric blankets involved.

@pindac,  Would you mind telling me what metal the plate of AT-666 was made of?

 

@poorguy I never learnt what the metal was that is used on the AT-666.

I know others use this mat on this forum, and it might be possible to learn which metal is used if a wider inquiry is made.

I also know through this forum, it has been used without a Vacuum and has been rated as an attractive method, I have not heard the mat used in such a way, but would try it out in the near future, as I will be visiting the owner of the one I have tried out.

Again there are AT 666 owners on here who can offer a description with almost immediacy if willing to help.

The AT 666 is not always going to be able to successfully hold a Vacuum for a full period of a side of a LP, their age is contributory to this, the length of time the Vacuum is in place is a unknown, some do not produce a Vacuum anymore.

With the above in mind, it does suggest careful selection is required, when purchasing,  if a Vacuum is the important function for the mat.

    

I'd say unless the record is unplayable live with minor warps.

I've tried traditional and modern methods of trying to flatten reocrds with varying degrees of success.

Last machine used was the AFI Flat.

Most of the time it works pretty well, but it has ruined several records including a numbered Blade Runner soundtrack on red vinyl and a sonically mint early pressing of Fleetwood Mac Rumours.

The Blade Runner was a strange one as I had successfully flattened many colored records but QRP must have used some non-standard vinyl formulation that made it susceptible to heat damage. After treatment a rough orange peel pattern appeared on the record and it was unplayable. Other owners of this record have also experienced ruin using a variety of de-warping methods.

Caveat emptor when using these devices.