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

@terry9 , now try turning the record over.

@pindac , I really wish I had some of whatever it is you are smoking. I wish I had that kind of ...energy.

Tea Total is the Key, no fantastical stuff, followed by just a pure curiosity to learn a little about the what would be the best for the Vinyl Source.

For me it lead to the best environment that a Stylus can be functioning in.

In a very layman description, Vinyl Condition and Cleanliness/Purification within the Groove, Operational Energies Transferred to the Styli, Energies Transferred from the Styli.

I am fortunate to be able to have a support form very adept individuals, who are known for being able to produce methods or carry out work that reduces the effects of the above.

To receive a demonstration of a Vintage TT, with a modified bearing housing, using Modern Materials machined to be a best fit and have a lubrication that is hydrodynamic, is something when encountered is quite indelible, it is as memorable as the song 'Summertime', and has a similar impact, as once heard, one is happy to hear more. 

I have a friend who took these ideas, to a further level and had a Spindle Produced that has a Steel section within the Bearing Housing and a option to use a Variety of Materials that are in contact with the Platter, there material of choice when I was demonstrated this design was Ebony. 

My interest in the subject is no different to a savvy Modern Turntable Producer, they are looking at the similar materials and choosing these to work with their own dimensional tolerances for the materials to interface, this will then allow for their selection of lubrication that best suits those chosen materials and selected dimension tolerances.   

On the subject of a Warp, I have tried out a AT-666 Vacuum Mat and was not satisfied with the sonic trait and how it was perceived as influencing the SQ during the replay.

I do intend on owning a AT-666 and trying it with different materials under it and upon it the LP, to see if the sonic trait can be altered to one that is being perceived as more to my preference. As usual these outcomes are all subjective, and the usual undertaking of later arranged group demonstration, along with the variety of  listening sensitivities that comes with a mixed group,  could easily produce a host of mixed assessments, that are the antithesis of ones own. 

Not being Selfish, the final choice, does belong to the end user, but sometimes the comments made from others, does help with pinpointing traits that one may have been overlooking during their own evaluations. 

 

    

@mijostyn

I have done as you so rudely demanded. With the weight in place, it is perfectly flat on the other side.

I don't like obliging people with facts, only to be treated rudely. Goodbye.

Pindac, Please forgive me if I offended you in questioning the idea that TT bearings and their shafts commonly wear in the horizontal or lateral direction. I only meant what I actually wrote, that I have never seen it or heard from others that it is a common problem. As you may or may not know, I have a fairly extensive experience with vintage turntables, especially DD types, so my query was based on personal experience and past history with Technics, Denon, Victor, and Kenwood DD TTs. I also have extensive personal experience with Lenco and briefly with Garrard idler drive types. (Although there was nothing amiss with the spindle and bearing on my Lenco, because the Lenco was NOS, I did replace the entire assembly with a massive aftermarket spindle and bearing custom made in the UK.) I once commented on your subject by wondering out loud whether the lateral wear problem would possibly occur with a belt drive TT, where there is in fact a lateral force constantly in one direction on the spindle. I certainly do agree with you that vertical wear on the bearing and/or thrust pad is always an issue that should be addressed when one is putting any vintage or "pre-owned" TT into service. We have no disagreement there.

It would seem to me that if the spindle is wobbly in the bearing shaft, there is no solution at all except to replace the entire assembly with new.