Alternatives to 3mm acrylic sheet

My son and I are making a kind of rear hugger (except it’s not hugging the wheel) for his custom CG125 scrambler, it’s purpose is to stop spray from the back wheel hitting the foam air filter and it will cable tie to the frame and need enough flex to carry on up under the seat towards the rear light.

We brought some acrylic sheet in 3mm & 5mm and only the 3mm piece has enough flex to work, shaping it with a jig saw was fine but drilling 5mm holes for the cable ties has caused it to shatter. We used a brand new drill bit and the guidance is to use a worn drill bit to avoid the bit grabbing the sheet and damaging it.

I’m thinking of something along the lines of what’s used in plastic large volume fluid drums / containers. Needs to be flat not curved and allow a bit of bend / flex.

It’s must be black, ideally matt or satin.

Size is 575mm x 115mm.

Can anyone recommend any alternatives?

It’s one of these, which I now want:
https://www.instagram.com/p/C1oke3ns9h7/?igsh=MWtrYnMzdTU0MXdwdg==

Yeah, acrylic is very brittle. You need to work up in drill sizes very slowly.

What about carbon fibre sheet?
ebay

@kayak23 the sheet you linked to isn’t big enough. Will carbon flex enough? The weave look isn’t what we’re after but I guess we could spray it but that adds another stage.

Acrylic is a really bad idea for that purpose – you want something that can bend and take an impact (said as an ex-trials bike owner!)

A type of polyethylene would be good – cut some from a liquid container/drum (such as an ibc)

Or https://www.ebay.co.uk/itm/174747203204?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=I4aYgJ4XT5K&sssrc=4429486&ssuid=SFMKawcoTnG&var=&widget_ver=artemis&media=COPY

Get any colour and wrap it if you need to.

You could try a similar thickness polycarbonate sheet. Much tougher than acrylic but more expensive. To avoid splitting drilling acrylic you can clamp two pieces of scrap wood either side of and drill through making sure that you use a new spot each time so that the acrylic is properly supported

Will carbon flex enough?

Thinner sheet will. It’s much stronger than acrylic so you might find going thinner will be strong but give you a bit of deflection.

3mm polycarbonate?

Online plastics

Give direct plastics in Sheffield a call. They stock a massive range and will be cheaper than eBay I suspect.

Let them know what it’s for and I’m sure they’ll have a range of options for you

I’d definitely go for polypropylene. It’s a softer and much more tenacious material. Harder plastics will crack at fixing points and snap rather than flex. Polyprop has a much more sinewy strength to it and sort of becomes more resilient at the points it’s under more stress.

You can use it quite thin as a result – I’ve got a set of Orikaso folding cups and plates for camping somewhere that are made of 1mm polypropylene and press studs – and the Ass-saver type rear mud guards that fold and brace themselves in your seat rails are the same stuff and the same principle

You can buy it in sheets but you might already have some in your recycling bin – anything with a recycling symbol with a 5 in the middle. 5 litre screen wash bottles, 10 litre paint pots and so on.

HDPE.

Tough, flexible, shapeable with heat, weldable.

Pretty sure it’s what mud huggers are made of. Aswell as the containers, pipes, icbs, milk bottles etc.

you can get black polypropylene buckets and bins for a few quid that would be big enough to cut out the section you need

Qwerty.

Where abouts in the country are you?

I have previously cut up empty 25 litre black creasote drums.

Have a search around for people using 20 or 25 litre containers. Car wash people etc.

What about an old plastic mudguard?

Use a hot air gun to bend and shape.

Thanks all, ordered some HDPE polypropylene 👍🏻

Going to suggest finding a print company or similar, who has 25ltr bottles holding Isopropanol. They’re ideal because they’re perfectly clean inside once they’re empty. They’re usually sent back for refill, but will often flog one for a few quid.

Thanks all, ordered some HDPE polypropylene 👍🏻

How? They are different polymers.

HDPE is High Density PolyEthylene