Questions about alumilite

[kenlicciardello]

I have had a problem with 3 different blanks, all cast with alumilite. They turn very smoothly, lots of ribbons and smooth easy cuts. But when I get down to a thin part, the material seems to stretch. Almost like it got too hot and softened.

I was wondering if it was a casting issue or getting the material too hot during sanding or what?

2 of the blanks were purchased here from a nameless person that has sold lots of blanks and 1 was my first casting attempt. In fairness to the person I purchased these from, all the others I turned worked fine. So my guess is it is something I am doing.

Thanks for the help.

 

[sbell111]

2 of the blanks were purchased here from a nameless person

That alone is a good reason not to deal with a member of Medusa.

 

[workinforwood]

Could be a combination of many things. Doesn't sound at all like the casting persons fault though. When you polish them, can you get a pretty good shine, or not so much? If you can't get a real nice polish on them, they are likely the original alumilite water clear. That material is a little more stretchy like hard rubber. If you are taking the blank super thin you have a higher risk with that material of heating it up and stretching it. The CC Alumilite which I use, is a little harder, but even still it could reach that point if pushed to the limit of super thin. Heat from the tool will spread quicker when the material is thinner and it's simple physics from there, plastic will soften in heat. How it is glued and how well it is glued will have an effect, if the material is on a tube, the hole is reasonably tight and very well packed with glue will create best results. So, my conclusion is in one way or another you are likely the problem, and possibly not even your fault really..you could simply be asking too much for this material to handle, or if you feel you are leaving plenty meaty on the blank then examine and try new techniques to solve the problem. Alumilite is a very popular product in pen making.

 

[fernhills]

Also, you really do not have to sand at a high rpm. I have sanded them with water at a high speed and i have sanded them at a low speed with water. I do not see the difference in shine one way or the other, If heat is an issue, minimize it. Good luck, Carl.

 

[kenlicciardello]

Thanks for the info.

The first blanks never polished to the luster of pr blanks that I have done. I believe the casting I did was crystal clear alumilite. These issues happened on the very thin portions and they did pick up some heat during sanding. I didn't think about the plastic softening again like that so that may be it. The holes were reverse painted and the tubes were roughed up and glued with 5 minute epoxy. They fit tight. Glue dried overnight.

I agree it was probably me and I will start by working on sanding technique and watching out for heat build up. Thanks for the help.
Ken