Plastic Plywood

[jTr]

I have been producing a product out of MDF plywood and staining to suit - now my client is requesting a solid plastic version. I've read many threads about plastic sheeting used for signs, but not sure which one is the right product.
Needs to be solid black plastic, easily machinable - cut out profile, drill mounting holes and radius edges with round over bit after CNC processes.
Is "Starboard" the right stuff?

jeff

[jzarski1]

Starboard is great maching. It's just really expensive. That would be my first choice looking at your requirements.

John

[knight_toolworks]

sintra/pvc foam may work well depending on the application.

[wayne_walker]

Jeff,

ABS is another option. Available in virgin material or general purpose which is a regrind core with a virgin cap. It has a hair cell texture on one side and smooth on the other. The thickest available is .375" at about $135.00 for a 4' x 8' sheet.

Depending on the application and size it is not very rigid unless it is formed or has a stiffener. It machines pretty good and can be bonded.

I buy my ABS from Laird Plastics.

Wayne

[tlempicke]

Plexiglas is not all that expensive, machines nicely and will make great lighted signs. The one big trick is to blow air on the cutting tool at all times.

I used a 1/4 inch steel brake line and fastened it to the Z car using some un-used holes in the mounting plate for my spindle. A couple of little bends and I have a blower that delivers sir to the tool tip and, just as important, to the material around the tool tip.

I use a veteran (well used) 2 flute 1/8 inch ball nose cutter, 14000 RPM and 100 inches per minute. 8% stepover. This produces a nicely surfaced impression that you don't really have to touch.

[coryatjohn]

Why does plexiglas need to have air blown on the tool when cutting? What PSI do you have coming out of the brake line? Is there any sort of fitting (like a Venturi) or just a tube with an end?

[jerry_stanek]

There are 2 kinds of plexi extruded and cast the cast machines a lot better than the extruded

[jTr]

Thanks for the suggestions - as I need to be close to .75" thickness, looks like Starboard is the stuff. Expensive, but saves a lot of sanding/finishing time.

Though not related, I'm intrigued by the plexiglass carving. Since I've got some sizable polycarbonate cut offs, I may try that procedure.

jeff

[Chuck Keysor]

Jeff, what about Corian? I have only cut small left overs, but it works great. I have no idea if it is like Starboard or not. Maybe someone can comment on their differences. Thanks, Chuck

[jerry_stanek]

Komatex Celtex or Sintra is a lot cheaper I pay about $130 for 18 mm Celtex

[twelchPTM]

Starboard is great stuff. I use alot of HDPE sheet goods and love working with it but Starboard by King Plastics is very expensive, get in touch with the folks at Total Plastics Inc. they cary the sheets from several manufactures including viacom and densetec, the only significant difference from one manufacture to the next is slight texture on the surface.