Technics SL-D3 oil under rubber mat

Jusrelax

New Member
I have 2 Technics SL-D3's that have been in storage in temperature controlled conditions for a few years since 2006 then with me in plastic storage boxes for 5 years. They haven't been used since 2006, I purchased them in 1979 and kept them in vg condition only using to mix music. I was prepping them for sale and happened to lift the rubber mats on top of the platters and there was a layer of oil underneath on both tables. The oil didn't seep into the holes of the platter to the drive mechanism. I cleaned up the oil on the platter and mats. Both tables are functional.

Is this normal aging of rubber given they're 35 years old? The mats appear to be drier and shinier than I remember. I included some photos to show what they look like.
 

Attachments

  • 20150716_080117.jpg
    20150716_080117.jpg
    67.7 KB · Views: 123
  • 20150716_075729.jpg
    20150716_075729.jpg
    69.8 KB · Views: 128
how bizarre, I acquired a D3 about 6 months ago, that fits your description as well.
the rubber mat had gone hard and shiny (pretty much cracked when I lifted it) and it had a lot of oil residue underneath.
I thought the original owner must have spilt something on it, but looks like its not an isolated case.
 
how bizarre, I acquired a D3 about 6 months ago, that fits your description as well.
the rubber mat had gone hard and shiny (pretty much cracked when I lifted it) and it had a lot of oil residue underneath.
I thought the original owner must have spilt something on it, but looks like its not an isolated case.

Interesting given mine and yours are the same ages, must be the temperature and humidity conditions they were kept in. My mats are still flexible, though seem stiffer. Kept in NYC near ocean waters had 4 seasons and varying humidity.
If anyone knows a proper method to treat these rubber mats to keep in current condition and prevent further deterioration, please let us know.
 
Thanks for the valuable info. I kept 12" felt pads on top of the mats as I was usually mixing and that allowed the turntable to spin while allowing the record to be held, turned and then start spinning immediately at speed. So I never noticed the rubber until now.

Wonder if the rubber mats will continue to disintegrate and leach oil and become more brittle and crack. There is a slight motor, WD type oil smell when lifting them up.

Maybe I should remove them and treat with the silicone spray and keep separate in a Ziploc bag.
 
I know this problem from the D2 / D3 series. With several of them, the rubber mat leaks a liquid (looks like something silicone based) on the platter, gets more shiny and in the end rock-hard.

My thought too is that it must caused by age and storage climate. Some D's have it, some still have mats that are perfectly fine.

With other Technics turntables like the SL-1xxx MK1 and MK2 series I have not encountered this problem, though SL-1600mk2 is a bit of a hothead and can have a hardened mat (albeit without the liquid underneath). On the other hand, my ultra compact Technics linear trackers can get pretty warm too and none of them have a hard mat.

I guess it must be a combination of the manufacturing, the composition of the rubber, and the climate.
 
I've seen this also, My technics mat is fine, but found the same table I have at a junk store and the mat was shiny with an oil slick underneath. Maybe a fix was implemented in production that didn't effect some mats. My gut feeling is to avoid skin contact with the stuff. After being reminded of this, I'm revisiting replacing my mat regardless of how it feels now.
 
I have two SL-D202s whose rubber mats I stored, one on top of the other, for several years. Last year I went to put them back on the TTs and one was dried and cracked, but the other was totally fine. So it can't have been environmental conditions during that time anyway. Maybe previous aging caused it. It was weird.
 
If the Japanese mfg industry was anything like ours in the USA I bet that the mats were out sourced. Technics expertise was in electronics, not rubber molding. Rubber molding facilities tend to be hot, dirty nasty places. Complete with a full blown machine shop to make the molds in some instances.
Another common trend was to have more than 1 manufacture making the same exact part. A major problem in plant A could be handled by ramping up production in plant B.
This was very common in American mfg. As a machine tool service tech it wasn't uncommon to see 2 unrelated companies making the same part. Of course the purchasing dept would than pit the 2 companies against each other to drive the price down.
The other thing is that the raw materials could have been slightly different in there composition.
I have a mat off a 40 year old Sony that is brittle as a potato chip. Another old Sony mat that is still fairly supple.

BillWojo
 
Since no "real" rubber I know of breaks down like this, my guess is that we're dealing with vinyl, but vinyl with lots of plasticizers to make it rubberlike. PVC is normally a hard material, but if you grind it fine and mix it with oily goo, it becomes something like modeling clay-- tiny hard particles made to appear soft with a binder like oil or even water. Our vinyl records are basically the same thing, just not so much plasticizer.

I've never seen this happen on one of the TOTL Technics tables, only on the more affordable models. Has anyone seen this on an SL-1200? I'm sure environmental factors help accelerate the deterioration, but I suspect the main cause is simply age. After all, this is merely a mechanical mixture. There's no chemical bonding involved between the particles and the plasticizer. It's also possible that exposure to lubricating or skin oils starts the process, based on what happens to vinyl-upholstered furniture over the years.

Anyway, I think attempting to reintroduce plasticizer into a mat that's potatochipped is not cost- or effort-effective. My opinion/guess/gutfeeling is the most practical solution is to clean up the mess (wear gloves, just in case) and get a new mat of the same thickness.
.
 
Last edited:
Wualta, that's a very good theory and one that I can agree on. Neither of my higher end Technics show that trait. My SL-M3 nor my in need of repair SL-1500 MKII have any mat issues. As a raw material I'm sure a good rubber compound is a lot more expensive than a vinyl compound.
Ok, who on this board can do a chemical analysis on some old mat's? It would really be interesting to get to the bottom of this. I could break off a piece of the old Sony mat I have and ship it to who ever.

BillWojo
 
At Target last night, I bought the cheaper $3 ArmorAll Original spray which says:
Helps prevent cracking, fading, discoloration and premature aging
Helps renew and revitalize vinyl, rubber and plastic

vs

the $13 ArmorAll Outlast™ Trim & Plastic Restorer
which says
Restores plastic & vinyl like new (mentions rubber on box)

Given the info about the blend of materials these mats must be made of, doesn't seem they can be "restored" once so much oil has leached out.

In my case, both mats haven't cracked and still are flexible so maybe I can prevent further deterioration.

Wonder how many Technics owners haven't yet lifted the mats and got a BIG surprise as I did! :tears:
 
My used SL-1600mk2 came with its mat this way. It apparently happens with some Technics mats. My TT needed holes in the mat for the sensors, so it took awhile but I eventually bought a replacement.

It's not worth trying to salvage your mat and I don't think there is a way to stop the deterioration process.

If I were you I would get a replacement mat of the same thickness (unless you can adjust the VTA - I just don't remember). That is really your best bet.

good luck!
 
Interesting theme. Hi Y`all, i got myself an sld3 and the mat isn`t the best, anymore. Lucky me, i found the mat of a 1210 in the original box in the attic, just the TT was missing...
However, the 1210`s mat is fresh and soft and cosy like production day while the original d3 mat goes sideways. Bummer. So, Technics scraped the pennies there, i guess.
Still, the sld3 is a convincing piece without the hype. Like it.
 
Interesting theme. Hi Y`all, i got myself an sld3 and the mat isn`t the best, anymore. Lucky me, i found the mat of a 1210 in the original box in the attic, just the TT was missing...
However, the 1210`s mat is fresh and soft and cosy like production day while the original d3 mat goes sideways. Bummer. So, Technics scraped the pennies there, i guess.
Still, the sld3 is a convincing piece without the hype. Like it.

Welcome to the AK turn table forum.

According the one site.

The Technics SL-D3 is from 1979 - 1980 costing $170.00 new.
http://www.vintagetechnics.audio/sh...kMyI7aToxO3M6MTU6ImRpcmVjdF9kcml2ZV90dCI7fQ==

The Technics SL-1200MKII is from 1979 - 2002 costing $750.00 new.
http://www.vintagetechnics.audio/sh...rMiI7aToxO3M6MTU6ImRpcmVjdF9kcml2ZV90dCI7fQ==
Yes, there was a substantial price difference. :music:
 
Last edited:

I'm so thrilled that I found this thread. I have a bad habit of picking up Technics DD TTs like stray puppies. I have a SL-D3 that is a daily driver in my bedroom. When I saw a D2 come up for short money on Craigslist I snagged it. Everything was going great until I got half way through setting it up and decided to oil the bearing. When I tried to lift the mat I immediately knew something was up. This mat is brittle and was literally stuck to the platter. At first I thought someone glued it down. Peeling it off I was left with a thin brittle hockey puck and a platter that looked like someone swirled oily glue all over to hold it down. Since I have the D3 and know this is the correct mat, I knew something was just wrong with this one. The other is totally fine! Like others noted, there must be a batch of these that break down under certain circumstances. Luckily I had an extra rubber technics mat from another purchase that works just for this. I used spray nine to degrease and clean the platter, good as new. This old mat is toast! Here's the bottom of it - AFTER I wiped off the excess oil!
 
I know my SL1600mk2 mat is getting slowly harder, it's nowhere near as pliable as it once was. The SL1200mk2 mats seem fine, but I reckon they will all eventually harden up too.
 
They must have changed materials at some point. The mats from my earlier models (SL-20, 23, 1400, 1500) are all very soft and even smell new. The later mats don't seem quite that nice.
 
Back
Top Bottom