Surfacing Plastic

[cwshop]

I've been ask to resurface a piece of hdpe that is 1 inch by half meter by a meter. It is used in a press to cut cloth material shapes. The customer wants to take off about 1/8 inch to clean up knife marks. I've planed wood pieces that size with a bowl bit and works very well. Could I use the same bit and speed? Anyone that can help me on this would be nice.

[coryatjohn]

HDPE cuts really well with standard bits. They have to be very sharp though. If your bowl bit has any chips or is dull, the result won't (literally) won't be pretty. HDPE cuts with similar feeds and speeds (in my experience) to medium hardness woods. I suggest taking off 1/16" first to experiment, varying the F&S to get the best cut with your bit. No matter what you do, there are going to be machine marks. HDPE doesn't sand well either.

[dlcw]

I've been ask to resurface a piece of hdpe that is 1 inch by half meter by a meter. It is used in a press to cut cloth material shapes. The customer wants to take off about 1/8 inch to clean up knife marks. I've planed wood pieces that size with a bowl bit and works very well. Could I use the same bit and speed? Anyone that can help me on this would be nice.

Not sure what the customer expects as far as a final surface? Another option might be to see if there is a cabinet shop nearby with a wide belt sander. Make sure it is a double belt with a low grit first belt and a very fine second belt. This might produce a reasonable finish. I've run HDPE thru my wide drum sander with decent results. It is a double drum configured with rough and fine grit paper. Yes, it does leave sanding lines. If you want a polished surface result, then maybe a wide planer would work - as long as it has VERY sharp knives with NO nicks (as stated before about bits).

[gundog]

I use bits made by Onsrud to machine plastic they are made for soft plastic but you will still see tooling marks if that matters. The 2 flute 52-000 series work best for bottom finish you can also call them they will give you the info you are looking for with the proper speed & feed range. If you use a bit designed for wood it will work but your surface finish won't be as nice.

[cwshop]

Thanks for input. I think I can pull it off. The finish doesn't have to be perfect, just flat. Slight tool marks are OK the customer said.
Thanks

[garyb]

I would recommend the 66-300 series, its a 2 flute SC upcut Bottom Surfacing tool. these tools have a corner radius, size depending on tool dia.
Gary

[knight_toolworks]

its not hard to do and you could do it with a surfacing bit. but as others say you will have tool marks. running it through a wide planer or sander would be better though. but one caution it will most likely warp. so maybe doing both sides would be best not sure really.