I bought some plastic boards from New market last weekend. I say plastic board cause thats the only name the shop keeper could tell me. I think its a closed cell polyethylene board. I am probably wrong. but the properties are similar. Its hard, its relatively light but approximately 10 times heavier than Styrofoam and does not bend. It breaks before deforming.
They are pretty strong but i was able to make a clean cut with a Utility knife just as the shop keeper told me. But it takes a lot of patience and skill to make a clean cut and large shapes are just that difficult to pull off.
As always the lazy mind has a tendency to look for easier ways. And I came across “heated knife” the tool used to cut this type of materials with ease. I tested the concept by heating some Utility Knife blades using fire and it worked.
Unfortunately i dont have a heated knife lying around. Googling around looking at how it works I thought it would be relatively easy to make one using a soldering iron.
I have this pretty “old” soldering iron with wooden handle and large tip. Since I have a spare i decided to make a knife out of it.
The method I used is simple. I heated the soldering iron tip high and then hammered it to make a flat shaped head.
Once I was satisfied with the hammering a little sanding gave the edges some sharpness.
CAUTION: Using hot knife to cut plastic will release hazardous fumes. Try not to breath on them.
I tested the knife on a piece of board.
Although it wasnt like cutting butter. But it was definitely close to cutting vegetables :) . I managed to cut a square board with smooth edges in less than a minute. It takes a while to get the tip heated. And perhaps due to its extended surface it looses heat faster and needs a break after cutting a while.
The edges are relatively smooth as well. You can make the edges better by slicing off the extra melted drops of plastic with a knife.
I am pretty impressed by the results, I will surely use this new plastic board for my future prototypes. I cant wait for the weekend to get around. ;-) .