Need help identifying plastic

Jim Sullivan

Well Known Member
Supporting Member 10
Well, I was cutting a piece of the slab this morning for some seat risers for the B1 tractor I'm restoring. I cut the piece with a circular saw and it cut very nicely and didn't melt at all. The top and bottom are fairly rough textured surfaces but the cut is very smooth. 20180829_064353.jpg
 

Junky

Well Known Member
It looks like Corian to me, and the only way that I can suggest to verify, is that Corian only comes in 1/4" - 1/2" - 3/4", so if it is thicker than 3/4", it must be something else.
 

Jim Sullivan

Well Known Member
Supporting Member 10
I cleaned all of the parts out of the interior last week. I'm getting very close to starting on the floor. Hopefully my headers will be back from Jet Hot this week and I can get the four door off the stands and then it's on to the '62. But if the headers don't come back, then maybe I start the floors sooner rather than later. That is, unless some other project rears it's ugly head.
 

JED

Well Known Member
Supporting Member 5
Looks like UHMW-PE (ultra high molecular weight polyethylene). It is slippery stuff usually used for slideways, bearings, etc. Also cutting boards.

I'm giving my guess of Delrin but I could be wrong. It comes in black and natural white. It's very hard and has a good amount of weight. If it is, that slab is worth some money. I'd ebay it if you can verify that. Even if it's another kind of plastic, that's a big chunk and should be worth some money.

I don't think it has a specific use in the size it is in, but rather stock material to make something from. Probably came from a manufacturing plant that someone worked at. (nobody will miss this one little piece) :D

Hard to tell without seeing it, but my guess would be Delrin or UHMW. I'm told that UHMW floats in water and Delrin (acetal) and PTFE do not, but I have not personally confirmed this. One major consideration is how a material is fabricated or machined. Delrin/Acetal is a very hard plastic and machines very well and can be held to tight tolerances (+/- 0.005″) whereas realistically (+/- 0.05″) is the best you can get out of UHMW without extraordinary measures. UHMW is much softer and less dimensionally stable; however, it is slicker and (much) more economical.
 

Tooth

Well Known Member
Supporting Member 3
Looks like the same material I see every day in meat rooms, cutting board? Won't melt, and very durable.
 

Jim Sullivan

Well Known Member
Supporting Member 10
Hard to tell without seeing it, but my guess would be Delrin or UHMW. I'm told that UHMW floats in water and Delrin (acetal) and PTFE do not, but I have not personally confirmed this. One major consideration is how a material is fabricated or machined. Delrin/Acetal is a very hard plastic and machines very well and can be held to tight tolerances (+/- 0.005″) whereas realistically (+/- 0.05″) is the best you can get out of UHMW without extraordinary measures. UHMW is much softer and less dimensionally stable; however, it is slicker and (much) more economical.
This stuff cuts and machines very well. I'll have to try the float test and see what happens.
Looks like the same material I see every day in meat rooms, cutting board? Won't melt, and very durable.
It would make a nice cutting board but I don't think he wife would like to lift and move this slab, besides I don't think I could ever get it clean enough.
 

bobs409

 
Administrator
I recently used my band saw to cut thru some 3/8" cutting board and it cut differently than the black delrin I have. To describe, I'd say it left a plastic burr on the back of the cut. Looked light a burr on the back of steel would make. It just pulled right off easily. I almost want to say it very slightly melted?

The black delrin cuts and machines a LOT nicer! If you drill or machine it, it comes off in shavings and not gummy at all. And it feels denser. You would not want to get hit on the head with it!
 
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