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geekhack Projects => Making Stuff Together! => Topic started by: OldIsNew on Wed, 03 May 2017, 23:54:24

Title: Plastic sheeting for between Model F XT PCB and backplate
Post by: OldIsNew on Wed, 03 May 2017, 23:54:24
I've started restoring a IBM F XT board that didn't show any signs of previously being opened, but when I removed the PCB the clear plastic sheet between the PCB and backplate that I've come across before wasn't there. The keyboard has been working fine but both the backplate and PCB are showing signs of corrosion where they've been in contact and I want to make a replacement for the plastic sheet:




                      [attach=1]       [attach=2]    [attach=3]


I've had a little difficulty finding clear plastic sheets of adequate size  but did find these: http://www.staples.com/Grafix-Impress-Stencil-Film-Clear-16-x-20-6-Pack/product_1545612
Does anyone see any potential problems using this type material, or have any other suggestions?
Title: Re: Plastic sheeting for between Model F XT PCB and backplate
Post by: fohat.digs on Fri, 05 May 2017, 09:01:32
I always assumed that it was clear mylar (polyester) since that is a material that is almost entirely inert and impervious. Before CAD, large sheets of clear (frosted) mylar were common for drafting.

That said, I doubt that the material is particularly important since it is in a sheltered environment and probably won't see much abuse.
Title: Re: Plastic sheeting for between Model F XT PCB and backplate
Post by: OldIsNew on Fri, 05 May 2017, 14:17:23
I always assumed that it was clear mylar (polyester) ...
That said, I doubt that the material is particularly important since it is in a sheltered environment and probably won't see much abuse.


Thanks for the reply! The Grafix sheets are made of Dura-Lar - I figured they`d be ok and it looks like that should be the case. From a product description:

"Dura-Lar is a polyester film that’s a mix between Mylar and Acetate. This film comes in a variety of different types (wet media, matte, clear, etc.) which all have specific features but overall, Dura-Lar is heat-resistant, durable (will not tear, absorb color, or discolor), and is acid free and archival."

I`m going to pick some up as see how it works.
Title: Re: Plastic sheeting for between Model F XT PCB and backplate
Post by: JP on Fri, 12 May 2017, 13:57:03
I've been restoring some Model F's so this might come in handy.