Planing Plastic?


Did you know that you can plane plastic? Me neither. I used my old Stanley #4. Its sweetheart era blade was razor sharp, though I’m not sure it needed to be. The “shavings” are UHMW (Ultra High Molecular Weight) polyethylene. I also mic’ed these (never measured shaving with a micrometer before either). They were exactly .001″. The plane left a beautiful surface on the plastic. Smooth as glass.

Guess what else? You can cut this stuff with a chisel too. Live and learn.

I’m using UHMW for the drawer runners in the little toolchest I’m building.  I originally had some maple for this, but I wanted to try using some new materials just to see if I could do it.  After a great deal of searching I finally found exactly what I wanted – 5′ strips of this stuff already dimensioned to 1/2″ x 1/4″.  When it arrived, it was exactly 1/4″ thick material, but the 1/2″ dimension was rough sawn.  Of the two, I would have rather had the 1/4″ rough.  The drawer sides are grooved to accept 1/2″ runners. Honestly, I panicked a little at first.  How am I going to cut this stuff?  Can I sand it?  Scrape it?  Turns out it planed beautifully.

One trick:  Once I cut the strips to length, they were twisted or bent slightly.  You can hand form this stuff.  I got out the piece of Corian I used to use for scary sharpening and used it like a surface plate to make sure it was pretty straight.  This helped with the planing too.  This stuff has no real stiffness of its own.  You need a good flat surface to work on.  That’s not my bench!

8 thoughts on “Planing Plastic?

  1. mzierten

    UHMW polyethelyene is similar to nylon, both are kinda soft, and tend to deform easily. I once made a part in a machine shop with nylon and the deflection made it difficult to hold tolerances with. Delrin is a better choice if you need dimensional stability and a low coefficient of friction.

  2. Jonas Jensen

    Do you know if bone or ivory were ever used as drawer runners?
    I suspect that normal bone from an ox would do. Elephants who will give away their teeth tend to be a ittle harder to find.

    And a last thing; please Adam, can we have a drawing for your small toolchest?
    Brgds
    Jonas

  3. zdillingerzdillinger

    You can also plane aluminum, although it is tough on the plane iron, body too if you use a wood plane (don’t use a wood plane, save them for the real stuff).

  4. Bill Lattanzio

    I used UHMW for the runners on my panel sled. I was skeptical about the plastic machining like wood, as the manufacturer states. But I had no problems putting a minor back bevel on the plastic using a block plane. It is a bit too flexible for my taste but it worked well. My one minor issue with it was that when I installed it with screws it bulged a bit, even after a pilot hole and counter sink. Even still, it worked as advertised.

  5. Edward in Vancouver

    Yup, been doing that for about 10 years now, albeit with nylon cutting boards. I “used to” make some extra change resurfacing nylon cutting boards from my employers-by running them through my Dad’s thickness.

    FWIW, Matfer, a fancy French kitchen equipment Co, that supplies professionals has a “cutting board resurfacer” looking remarkably like a LV Bu smooother-but with disposable blades, and oriental sushi chefs tend to iron their nylon cutting boards smooth with a regular clothes iron.

    1. Adam CherubiniAdam Cherubini Post author

      Plowed! Kinda funny too. Using a 150 yr old tool to cut modern materials! That wasn’t as easy as surface planing it. I had to make a ….jig… to hold the plastic. In retrospect, I should have just cut the 1/8 or 3/16″ dado in the case side with a chisel. Hate to make jigs, let alone for 2 parts!

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