Polycarbonate dishwasher safe ?

Don't know why not. Polycarbonate tumblers do fine in a dishwasher.

Best regards, Spehro Pefhany

(Marcel Gonzalez) wrote: (clip) I will be using cutting fluid, and would like to take off all the oil residue. (clip) ^^^^^^^^^^^ Don't treat this as gospel, but as a cautionary thought. I used to hear that polycarbonate motorcycle helmets could be seriously weakened by paint or solvents, etc. So I wonder about possible effects of the cutting fluid.

I've turned polycarbonate (think we call it acrylic in England?) using cutting fluids with good results. BUT I believe I once read somewhere that acrylic can absorb moisture. (If there is an real expert out there correct me if I'm wrong, I usually am!). I do remember a piece of clear plastic on top of a fish tank quickly started to sag in the middle and had to be turned over regularly.

Might be worth a practice piece first.

Alan

Polycarbonate (Lexan is one brand name) is a completely different plastic from Acrylic (Plexiglas is one brand name). Polycarbonate is soft, tough, slightly yellowish rather than clear. Acrylic is hard, brittle and crystal clear. You would use polycarbonate to stop bullets and acrylic to focus light.

Best regards, Spehro Pefhany

I machined thousands of parts for these folks :

(Including the clear polycarbonate tubes)

Never a problem with a dishwasher cleaning of any of the delrin, uhmw, stainless or poly carbonate parts.

Dig the pepperoni slicer....pretty cool, huh?

Umm, polycarbonate is the generic name for Lexan; it is NOT the same as acrylic. Acrylic is the genric name for Plexiglass, which I believe is called perspex on the other side of the pond.

Acrylic is brittle and hard, cuts cleanly with care, and will easily take a high polish. Don't dally in the cut, especially drilling. The tool heats up, and melts/deforms the work. If you look at the edge of a large sheet, it will typically have a neutral clear to yellowish clear tone cast.

Polycarbonate is somewhat gummy, but has exceptional impact resistance; hence its use in camera bodies, and helmets. One of the easiest ways to distinguish between acrylic and polycarb is to cut off a small scrap, place it on a hard surface, and whack it with a hammer. Acrylic will shatter, poycarbonate won't. Polycarbonate doesnt' finish and polish near as well as acrylic. If you look at the edge of a polycarb sheet, it will have a cold, bluish tonal cast.

Also, polycarb does absorb moisture. I learned this when I tried vacuum forming some sheet. Had no end of problems till I called a local shop that does this all of the time. He explained it was moisture in the sheet and said the easiest way to deal with it was by baking the sheet at 200 deg F for 24 hours followed immediately by the full heat and forming operation. Worked like a charm. Now that I think of it, I would be curious if the baking procedure would improve machinability and finishing?

David Glos

Polycarbonate is poor stuff to polish( and certainly not the same as acrylic), acrylic (perspex) polishes brilliantly, but you really need the specific polishing compounds to get perfect results. Cutting with clean water works OK, but beware the dreaded rust! Dishwasher is alright, but will kill a decent polish, I'd just wash by hand. Mark

I also have found that if you look at the edges of clear polycarbonate and acrylic (after removing the paper or plastic coatings) polycarbonate has a slight blue'ish cast, where acrylic is white. Also, if you place polycarbonate between two polarizing filters, hold it up to a light, and bend it, you will see interference patterns. Not in acrylic.