IBM 5251 Beamspring Replaceing Insulation mat. TOXIC MAT!! CHECK MATS

clickboyclick · 21 Jun 2018, 02:53

I washed my mat with soap water. It was oily and sticky with a gross residue all over it. After washing it looked good and the residue was gone. However 24hr later the mat was oily again and smelt like chlorine... the residue on it stung my skin. I put it in a ziplock. And washed the area and my hands. Hope I don't get cancer from it.

Anyway I want to buy a replacement mat. After taking measurements I found that my mat was .035 inch thick or 0.889 mm. I think .889mm is a odd thicknesses my guess it that it was closer to 1/32in or 1mm before it degraded. So I am thinking I need like a 12 x 20 inch silicone mat at 1mm or 1/32in thickens. After looking on ebay and a few places online I found this https://www.ebay.com/itm/Silicone-Rubbe ... 2236341584 (looks to good to be true idk its from china and will take a month). Also this does not look bad and I could drive there https://www.grainger.com/product/E-JAME ... heet-1MXA6 (considering a Adhesive Backing) or https://www.grainger.com/product/E-JAME ... heet-1MWE7

What do you guys think? I could use some help or suggestions.

OMG

while looking up mats and writing this I went get water and looked at my mat in the ziplock. It puffed up it and smells like chlorine really bad!!! I moved it out side in shed till I figure out what to do with it

I really hope I don't get cancer from exposure form this stuff

. When I started this restoration I didn't think I would encounter so much toxic cancer plastic rot

Well lads its official I need a mat replacement

I would suggest anyone that has these mats still in their boards check them

Dingster · 21 Jun 2018, 17:43

What kind of soap did you wash it with? Might have something to do with it

PlacaFromHell · 21 Jun 2018, 19:24

I just realized that mine has the same weird mat. The grease never dissapered, even with a very aggresive bath. If you want I can test a piece of 3mm thick EVA sheet that left over from my model F.

clickboyclick · 22 Jun 2018, 02:35

Dingster wrote: What kind of soap did you wash it with? Might have something to do with it

Regular dawn soap (not the constraint dish one).

PlacaFromHell wrote: I just realized that mine has the same weird mat. The grease never dissapered, even with a very aggresive bath. If you want I can test a piece of 3mm thick EVA sheet that left over from my model F.

Hum. Glad I am not alone. I have wrote ibm a email about archive request for the materiel sheet for the IBM 5251 and explained my situation about the plastic will keep updated on that. Yeah test to see if the EVA sheet would work. Do you own multimeter? I don't. Just more sure you don't short you board. idk how resistive EVA is to current. My pcp board has these copper plates exposed on the bottom of it.Personally I was considering silicone mat 1mm thick from ebay. This one in particular https://www.ebay.com/itm/Silicone-Rubbe ... 2236341584 its just shipping will take a month and I am not 100% sure yet if this would work. People tell me that they just reuse the insulation mat and yolo it.

PlacaFromHell · 22 Jun 2018, 04:28

Wait a sec, have you experimented discharges from your keyboard using that mat? Even with a well placed ground cable is still bothering. I'll test it tomorrow if have time.

clickboyclick · 22 Jun 2018, 19:10

PlacaFromHell wrote: Wait a sec, have you experimented discharges from your keyboard using that mat? Even with a well placed ground cable is still bothering. I'll test it tomorrow if have time.

Ok so this is interesting.

I have yet to receive any response from IBM however I contested the Computer History Museum and learned that the insulation mats that ibm used at the time are neoprene-based aka polychloroprene and I think you can pick out the word chlorine in that. Which imo explains the chlorine smell and sting on contact with skin.

PlacaFromHell · 23 Jun 2018, 05:41

Okay, I overslept but here is:

Spoiler:

Sorry for my crap camera skills. It works perfect, even the feel reminds much more Fness right now. Still using the same Xwhatsit threshold. Definitely do it.

clickboyclick · 24 Jun 2018, 03:49

PlacaFromHell wrote: Okay, I overslept but here is:
Spoiler:

Sorry for my crap camera skills. It works perfect, even the feel reminds much more Fness right now. Still using the same Xwhatsit threshold. Definitely do it.

wOW It works? Thanks for testing it man.

PlacaFromHell · 24 Jun 2018, 05:57

No need to thank, just help someone if you can