Cutting Plastic

[Stevekane]

Hi, bit of an odd one and wondered if anyone else had any thoughts, this morning Ive been asked to trim about 10mm off the edge of a load of “recycled plastic” boards, I think they are solid plastic and are being used around the edge of a bowling green,,,so at a guess its a 100 plus mtrs in total. I know from experiance that some plastic is very brittle and shatters and Im hoping that this is the more malleable stuff but does that melt and stick? Any thoughts on blades,does it blunt blades very easily, and last but not least, will that amount kill my poor old cheap site saw,,any other ideas?
Steve.

 

[Bingy man]

I’ve cut many different plastics with a multi tool. I always try it first on an off cut if possible. Another option is with a hacksaw as the teeth are finer . When I’m cutting 4” plastic soil pipe I use a fine tooth handsaw . In other words you need to try cutting it and find the best method because as you say some plastic is brittle and others are soft . 10 mm is not a huge deal though can’t the plastic strips be pushed into the soil- maybe if you could explain the need to lose the 10 mm other members will advise you better .

 

[Johnwa]

I've cut 8mm perspex with a track saw with no problems although I must admit not in the quantities you need to cut. Just let the blade do the work, dont force things and you should be ok. Clean your blade regularly with a wire brush if neccessary. I didnt find a need for lubricant.

 

[Sideways]

My guess is recycled plastic means something like those decking boards made of recycled plastics.
Those will have some flex, perhaps similar to electricians plastic conduit.
I cut that with a tct wood blade on my mitre saw without any issues.

I'd use a general purpose or finer saw blade, not a rip blade.
As there is a lot to do, whoever is asking you to do them this favour should be buying you a blade, not expecting to wear yours out. We are talking recycled plastics after all.
Buy a metal / plastics specific blade for the job. It will be what, £30 to £50 ? Bosch do a blue one. They will have received a more than fair deal. You will have a part worn blade left over for your trouble.
Take your time so the blade doesn't become hot enough to melt the plastic. I wouldn't lubricate either.

 

[worn thumbs]

I've cut acrylics,polypropylene,polycarbonate and UHMW with success.I used a fine blade and if you have a triple chip it would be the best option.I wouldn't expect plastic to shatter if the table insert is reasonably close to the blade,but your extraction may become choked with the bird's nest of swarf that comes off.You won't be cutting rapidly as the stuff is almost always denser than wood and it will still cover the workshop floor with particles.Do wear goggles and try a small piece first before taking the whole job on.

 

[MF1000]

Depending on the age of the recycled boards the plastic could suffer from embrittlement due to UV exposure….I’d try different saws etc on a scrap length before I even agreed to do it

 

[eribaMotters]

Steve, you are probably looking at more like 160+ metres. Best of luck.

Colin

 

[Stevekane]

Many thanks everone, and I will,of course let you know how I get on, as Colin says, its maybe 160mtrs,,so quite a job and Im worried about not only the blade but the poor old saw. Its being done as a favour provideing a test piece goes well. The boards are lining a shallow ditch around the edge of the green and stand on their edges, I immediately suggested sinking them lower but they apparently sit on a course of laid bricks so the height is fixed. I must say its not a job Im looking forward to!
Steve.

 

[Orraloon]

A bandsaw may be better than the tablesaw and less likely to heat up and melt the plastic. I cut the odd small bit of plastic on the bandsaw now and then. I would try a test piece as others have mentioned to see if its practical.
Regards
John

 

[Mick Stafford]

For cutting most plastics I find a jigsaw with a metal cutting blade works best

 

[dephill]

Most recycled plastics I’ve ever come across (not necessarily sawn) have been on the softer side.
I don’t think you should have too much trouble but I def. agree with Sideways about getting a new, preferably triple chip, blade to do the job. And give it and the saw a break every 5 mins or so to avoid excessive heat build up.
I think your saw will get through it, just don’t push it too hard/rush it.
Good luck!

 

[MrKenny]

I've recently started researching outdoor furniture building for a friend, and we've looked at using the (usually) black planking and CLS profiles available in recycled plastic.
Fixings would be mostly bolts - the 'but' is that a lot of the stuff carries manufacturers warnings it 'may' contain metal filings ..

 

[Spectric]

When I’m cutting 4” plastic soil pipe I use a fine tooth handsaw

The mitre saw works wonders on plastic pipe, just take a gentle cut and you get clean square cuts. One of my pet hates is seeing waste pipes cut that are not cut square so when put into a fitting they leave a gap.