Does anyone know why...

Signed-In Members Don't See This Ad
R

redmanpa28

Member
Joined
Jan 20, 2011
Messages
7
Location
Ohio
I recently received my order of alumilite clear and the blanks I have cast seem to be extremely brittle. Brittle to the point that I can't seem to turn them without blowing them out. I would like to cast some more, but I want to find out what I may be doing wrong.

Thanks in advance
 
Signed-In Members Don't See This Ad
This is not normal. I assume you have turned other plastic before? If not, then even Alumilite Clear can be blown up by not having sharp tools and taking it easy. If you are used to turning plastics and it is still very brittle, then something is wrong. One of the nice things about Alumilite compared to other plastics is it is much more forgiving and less likely to explode.

Tell me more about your measuring and mixing process. Did you measure equal parts of A and B by WEIGHT? Did you mix it thoroughly until it was completely clear with no streaks before adding any colorant? Are the blanks straight resin or is something embedded in it?

If you measured and mixed properly and nothing is embedded and have turned plastics before, then it sounds like you have a bad batch of Alumilite.

Let us know more so we can try to help!
 
Yes, I have turned Inlace and acrylic dozens of times. I have always kept my tools very sharp using my tormek. As far as mixing goes, I use graduated cups I purchased from Alumilite.

These blanks don't have any embedments. As for mixing, I was very sure that there were no streaks or swirls in the mix before I added my coastal scents pigments. I'm beginning to think, like you, that it is a bad batch.


Thanks

Redmanpa28
(Scott)
 
It sounds like you mixed by volume if you used graduated cups. Curtis' post says that you are to mix by weight so you need a good scale for that. Different liquids will have different densities and therefore different masses for the same volume.

Michael
 
I mixed by volume last night, and there is a difference in the amount of part B. I won't have time to turn tonight, but hopefully I will tomorrow night. Can't wait to see if it does make it less brittle.
 
The new blanks seem to turn a lot better. Need to experiment with adding just a little bit less part B. Still a little brittle. Thanks again to all for the solution to my dilemma!
 
Absolutely there is a huge difference between volume and weight. If you mixed by volume then you have too much B in the cup and the B is the "catalyst"..eventually you will notice the B resin gets crusty if you don't clean your pouring bottle and the A side never dries..so you have added extra crispy into your blanks. If you have more A then B then you will have the opposite effect, and if you don't mix the two together enough you will have soft spots in the blanks, and even more likely it can be sticky on top because the A side floats to the top. This alumilite you bought is supposed to be a bit more brittle than the old clear stuff too..the extra brittleness allows for a better polish and shine on the blanks, but it is not so extra brittle that it compromises the strength and elasticity of the blank which makes it so great for pen making. Just mix by weight with a digital scale and all will be good.
 
You must log in or register to reply here.
Back
Top Bottom