Thread: Where do I find "plastics" for guards

Dredged from the back of the mind, I think that methyl ethyl ketone (MEK) (sp.?) is suitable for solvent welding, but don't quote me.

This is the same chemical as used in the primer, and the glue, for PVC plumbing pipes. Haven't tried it, but worth a go...

Not real good for you, though, so use in well ventilated area, blah blah

If memory serve me ( and that's far from guaranteed these days...) I believe that Chloroform "welds" perspex types of plastic. Just make sure you use it in a well ventilated area or you could risk kidnapping yourself...


Scott in Peakhurst.

Well don't I feel ripped off.
I went to a plastics supplier in West Gosford and they had a lot of scrap. But just tonight I was looking through what is left of my purchases and a strip of that white breadboard stuff about 350mm long 25mm wide and maybe 10mm thick cost me $1. That was the cheapest!a piece 250x150x10 was $5.
I was happy and was going to recommend that company, but not now.

Originally Posted by har616

Big shed,

Good suggestions. I sometimes forget about the yellowpages on the internet however the search capability seems to be much better now than when I last used it.

The vacuum pumps are more difficult. I had already googled this in a variety of ways however I was wanting a pump suitable for a woodworking application and it is not apparent from the results of the search as to whether they are suitable. Most of the results relate to high vacuum or industrial applications.

I had hoped that someone within the forum had more specific knowledge. Previous threads directed me to businesses that no longer appear to exist.

Even searching for suppliers of plastic materials is difficult - almost all of the organisations I scanned appear to be fabricators rather then retailers of small amounts of product. Cadging a few bits of acrylic or perspex or polycarbonate wasn't going to solve the adhesive problem and unfortunately "plastics" is such a generic term that I wasn't letting me identify good options.

Once again I had thought that others would have tried to use these materials for similar applications and there would possibly be a body of knowledge that would simplfy my search.

I have some good suggestions above and will follow through - it is just going to take a bit more time than I had hoped.

Terry

I have done some vacuforming at home ,mainly making parts for model aircraft .
My vacuum pump is an old fridge compressor ,I just use the suction side to pull a vacuum in a old modified dry chemical fire extinguisher ,then using a valve draw the
plastic into the mould or over the form after heating it.
Mine is on a small scale but it works ok for my purposes.
I managed to make some acrylic boxes by making a wooden mould , heating the acrylic sheet in an old oven until it sagged and then sucked it into the mould.

Some links I have bookmarked

http://www.tapplastics.com/shop/product.php?pid=169
http://www.crclarke.co.uk/Products/LineImg/1220.htm
http://designability.com.au/catalogue/
http://www.amiles.com.au/stripheater.htm
http://www.cityplastics.com.au/acrylic.html

Whilst most are not here in Oz there is some good information on the pages
Hope this helps
Kev

Originally Posted by Woodlee

My vacuum pump is an old fridge compressor ,I just use the suction side to pull a vacuum in a old modified dry chemical fire extinguisher ,then using a valve draw the
plastic into the mould or over the form after heating it.
Mine is on a small scale but it works ok for my purposes.
I managed to make some acrylic boxes by making a wooden mould , heating the acrylic sheet in an old oven until it sagged and then sucked it into the mould.

This sounds really interesting, Kev, would be great if you have time, to put up a thread with some more details & some pics, both on the vacuum setup and how you made the boxes.

I had thought about using a fridge vacuum pump for a vacuum chuck on the lathe, but seeing as you are using the old fire extinguisher as a "receiver", sort of the opposite of an air compressor by the sounds, I'm assuming the pump is capable of pulling a fair vacuum but is fairly slow?


Cheers................Sean

A glue in the UK is called "Plastick" and is a mixture of solvents the most useful being tetrahydrofuran. Tetrahydrofuran is used with others for swimming pool pipe welding.

PETG is a tough plastic, not as tough as polycarbonate, but miles better than acrylic.

Be careful when moulding plastics, it is VERY difficult to keep the toughness properties, and if it's a serious guard you're making, you might need it. Heat treatment to anneal it is difficult, and time consuming. Cut sheet and cold bends are the way to go if possible.