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

If a research is done into using a Peripheral Ring, it soon becomes apparent that additional to the intended benefits of the increased inertia, the impact of the weight on the LP, and the reduction of the warped form around the rim, has shown, if the reports are accurate that new levels of quietness are achievable during the playback when the Peripheral Ring is present. 

Not all TT's can utilise a common design of a Peripheral Ring, so it is always best to check if the TT is compatible with the design being selected. One such design change could be the need for a shallower depth weight or a chamfered edge to a weight.

 

@dekay , nice thinking. The trick is there can not be any temperature differential across the record or you will make warps. Will a heating blanket and glass panes work? Sounds like a nice experiment to me!  

I just had a look at the Furutech unit. It is the same unit as the Orb with a different dress on!  The Orb is not sold here any more by license agreement. Lets see...$1150...$3270... nice racket. I'll follow @lewm to eBay.

Hey all. I wrote quite a bit about this. As many long-timers here often say, do a search.

mijostyn:

Thinking about it more it might be better to centrally locate the glass plates in a box with cardboard spacers (cardboard box with a top) and then wrap the box with the heating blanket.

This way the heat would be more evenly distributed.

I assume that many here may have digital thermometers with long wire leads for oven/grill cooking which could be used to monitor temp.

As already mentioned, lower temperature and additional time would seem to be the way to go, especially with DIY methods.

When I tried the glass oven method the oven used would maintain heat @ around 135-140 degrees (not any lower).

Doing so made the edge warp worse on a Pearl issue the "The Last Castrato".

I purchased another copy on line and it has a similar edge warp.

I only wanted to listen to it out of curiosity, so left it @ that (could not listen to the first cut on either side, and on the baked LP the first 2 cuts).

 

DeKay