moulding temp of acrylic

[revken]

anyone know what temp acrylic sheet has to be to be make it plyable? i don't need to make it really soft, just enough to curve it slightly

[Large]

http://lmgtfy.com/?q=at+what+temp+does+acrylic+become+pliable

[scotty]

that is a pisser

[Large]

http://lmgtfy.com/?q=That+is+a+pisser

[davio]

if acrylic is what fairing screens are made from 5 minutes in my oven at 150 c and its like hot toffee

[revken]

lmfao!!!

[revken]

thanks guys, particularly davio, you were exactly right! trying to flatten out some screens to make different shapes. cheers.

[xa-mont]

acrylic is difficult shit to work with.

I say just make something out of fibreglass and deal with it not being see-through.

What kind of thing are you thinking of making rev?

[revken]

I have a couple of old screens that I wanted to reshape to make a new fly screen to go above the new headlight. It is difficult to work with in a way, the tricky bit is getting the right shape. I may have to make a mould for it. Fibreglass could work, just a bit messy is all, but then even better would be an old screen that is already a profile I could use, that I could just cut to fit. I did manage to get the perspex stuff to flatten out. I actually don't want it see through.

[oldskool]

Screens are not acrylic, screens shatter with sharp impact acrylic does not.
Acrylic has a water content so I was told recently and will get bubbles in it if heated too quickly has to be heated very very slowly.

[Redmohawk]

Acryilic will shatter just like glass with enough speed, but scratches less. Perspex (Lexan is a trade name) is prob what your thinking of Old's Thats the stuff bullet proof glass is made with. A 5 mm strip 50 mm wide will really take some abouse in a vice belted with a ballpeen hammer but it scratches easyer than Acrylic. Most modern bike screens would be made of a Hybrid of Perspex.

Perspex in small sizes for a screen in 3 mm would cost around $25 retail aprox. Is mouldable using a household oven set to about 150 dec C. If you make a mold and its glass smooth with say body filler and paint etc you could blow mould most any shape you want , just keep the pressure and temp low or the plastic will take imperfections from the mold and look hazy.

[Redmohawk]

The water content of both acrylic sheet and perspex is so low that any effect we could measure would be insignificant, Its an issue with powdered ingreadiants in the manufacturing process and effects shrinkage of the final product. Most manufactures take this into account in the manufacturing process.

Bubble's formed at heating would be from eather direct heating issue (IE heated with a gas flame) or from outgassing of product due to molecular breakdown from excess heat (just far to much heat in one area) . Generally both are heated in large ovens prior to blow forming, the ovens are just insulated boxes with oven elements the the top. Using a old bar heater mounted correctly with Alumimium heat deflectors to vary the aperature of heat exposure to a narrow beam is a very effective way to bend both to right angles etc.

[oldskool]

Im going buy what a perspex joint told me when I was looking for Lexan that perspex was the brittle one and that Lexan had a higher water content so much so you need a special former to heat and bend it.
But saying that I could have got it arse about.

[Redmohawk]

NA mate , they just want to do the bending for you with there "special bender" lexan is perspex just a trade name acrylic is the brittle one . Perspex can be bent in a pan brake if you like but will get strech marks a little Usally looks ok up to 90 deg though. If you need specifics or a better price on it let me know (used to be in the industry a while back) makes ok scatter shields for lathes etc, just wont stop much over 1000 fps is all, so not bomb proof but good stuff anyhow.

[revken]

I change the curves on an old fly screen I had, almost flattening it out by heating in the oven, which runs a bit cool so had it set at about 200C. I've made a pattern of the shape I want, and I'll cut it out on the weekend, then work out what shape it needs to be, if indeed it needs to change. I'll then be painting it. Unsure as to what colour, as the rest of front end, headlight housing and tacho is satin black.

[Redmohawk]

If you decide to paint it , use a prep agent for plastic to help the paint stick or it will peel off with vibration causing small cracks in the paint. Most paint places have a primer specifically for preping plastic now days that will work well.

[revken]

got some, that's how I prepped the headlight shell

[revken]

got my screen to about the right shape, had an old flyscreen I heated up and sort of flattened out a bit, and then cut out the shape. Got to get the mounts made, then it's time to paint it and put it on the bike. Cool!

[Redmohawk]

top stuff , home built is hot shit!

[revken]

most of the bike is lol. It may not be the prettiest, but its built not bought. some pics of the headlight conversion almost done. Its now up and running. Just the screen to go.
http://img.photobucket.com/albums/v298/revken/IMG_0051.jpg
http://img.photobucket.com/albums/v298/revken/IMG_0052.jpg

[sickboy]

its looking menacing Kenneth,and thanks again for the seat job.

[fimpBIKES]

i vote no screen!!!! :D

[revken]

The bloody paint work on the top area (that would be hidden by a screen) has bubbled in the sun, so I either fit the screen or sand it back and re-do it AGAIN!!!