advice for shaping plastic?

SilentCyan · Post by **SilentCyan** » Sat Feb 23, 2008 2:35 am

i guess i'll start off by saying that i am not in the SCA but rather a fairly small local group where the rules are a lot less strict. in fact armor isn't even required though me being the little sissy i am decided it would be a good idea to make some. i've been working with plastic and was hoping you all would have a few suggestions for shaping it. sadly i'm not exactly sure what kind of plastic it is though. i do know that is was the wall for a fairly cheap above ground pool that we used to own. it's an 1/8 inch thick, dark grey, doesn't shatter when cold. my attempts to shape it with a small heat gun failed and i'd rather not try an oven.

Uryen · Post by **Uryen** » Sat Feb 23, 2008 2:44 am

Dark grey plastic is probably ABS (Acrylonitrile Butadiene Styrene) which is a thermoplastic. If it is not forming with heat, it may be a thermoset plastic which once made into it's original shape you cant do much to it but throw it away.

Andrew Young · Post by **Andrew Young** » Sat Feb 23, 2008 2:44 am

Son what you need is a set of metal clothes, a rattan sword, and a whole lot of testosterone!

seriously....I build movie reproductions/props a lot so Im pretty familiar with plastics, composites and fiberglass, resins etc. Take a picture of it and Ill tell you if its a fools errand or workable. Some plastics are easier to work with than others.

SilentCyan · Post by **SilentCyan** » Sat Feb 23, 2008 2:55 am

i actually use a pair of nightsticks

thanks for the offer though, i'll get a picture of it later today seeing as how its getting ridiculously late.

i have broken two pieces of it that were roughly the size of playing cards. one i bent back and fourth(ends were touching) a few times before it finally snapped. the other one i laid over an open vice(about two inches) and hit it fairly hard with a hammer. first time the hammer just bounced off but the second time the piece snapped right in half and i could almost have cut myself on the edges.

SilentCyan · Post by **SilentCyan** » Sat Feb 23, 2008 7:00 pm

here you go, sorry about the glare

http://img181.imageshack.us/img181/9114/1000235gl2.jpg

Ld Thomas Willoughby · Sat Feb 23, 2008 8:18 pm

I'm guessing that's a layer of fiberglass on the one side?

Andrew Young · Post by **Andrew Young** » Sat Feb 23, 2008 8:47 pm

It could be a composite material or simply plastic heated on a piece of material that had that pattern....then smoothed on the other side.

Hard to tell.

Uryen · Post by **Uryen** » Sat Feb 23, 2008 8:51 pm

I think it's polypropylene, Dynel or acrylic fibres in a thermoset plastic. Pretty much like fibreglass in many ways, and completely useless for reshaping into anything.

SilentCyan · Post by **SilentCyan** » Sat Feb 23, 2008 9:22 pm

the pattern on the one side i think is the result of a layer stuff, similar to ground cloth that you would use in gardening, having previously been semi melted onto it.

St. George · Post by **St. George** » Sat Feb 23, 2008 10:38 pm

vacuum forming is the top way to go. No doubt.

Here are some plans for an inexpensive way to do it.

http://www.halloweenfear.com/vacuumformintro.html

g-

Halberds · Post by **Halberds** » Sun Feb 24, 2008 12:56 am

I think folks do it in the kitchen oven.
My wife will not let me use her oven for anything like that.
However this works quite well:

Ever think of pounding some light weight steel?

Hal

AaronT · Post by **AaronT** » Sun Feb 24, 2008 2:39 am

DukeAlaric (George S.) wrote:vacuum forming is the top way to go. No doubt.

Here are some plans for an inexpensive way to do it.

http://www.halloweenfear.com/vacuumformintro.html

g-

I'be used an vaccum former similar to this to make instrument panels, theres a lot of possibilities with this thing.

raito · Post by **raito** » Sun Feb 24, 2008 4:37 pm

Best advice is to know what material you're using. If you don't know, don't use it. Plastics can be mean mothers, chemically.

SilentCyan · Post by **SilentCyan** » Sun Feb 24, 2008 10:28 pm

i know that and i figure that this stuff is safe one because nothing has happened to me yet and two it shouldn't be that dangerous if it was used in pool construction. then again you never know...

thanks for the link. i'm going to have to try something better than my heat gun first though to see if i even can reshape it. think a wood stove would be any good?