Ive got maybe a dumb question

[dale]

I know they say there is no dumb question but
On acrylics do they harden after time, what I mean from the time they are made to used, if you poured them in January then use them in December will or do they harden more then if you used them in May?

Hope that makes sense.
I dont make my own and purchase them at a wood store and some are like cutting glass while others will turn pretty good.
They are all out of the same material. So this last Tuesday night I had 16 pens to make for Wed.. (dont you love those last last min orders?) I planed to do 3 acrylics.
The first one was ok
The second one was hard and blew up. (I have read what you guys say and I wasnt horsing the cutting I was taking it easy)
So I just decided to forget them and just use wood Pink Ivory, Purple Heart, Yellow Heart, Paduak for the womens pens.

Now today I turned #3 and it came out really good.


dale

 

[dalemcginnis]

I haven't noticed any getting harder over time however it has been reported that the amount of catalyst used effects hardness. So, even though the blanks may be the same style they may not be from the same batch and they may have used too much catalyst in one batch.

 

[Chasper]

Not all resins are the same, various suppliers use different formulations. Also as mentioned, the amount of catalyst makes a big difference between brittle and highly prone to chipping out and pliable enough to turn out long smooth ribbons.

I've had a few hardness problems when I've needed to turn something on the same day I do the casting or even the next day, but after a week or two I believe they get to their final firmness. There is an exception to that when you are mixing other materials into the resin. I mixed up a batch of resin and stirred in some pipe tobacco, it took months for it to fully harden.

 

[TellicoTurning]

I've noticed that Acrylics tend to be harder than poly resins too... they often look similar and sometimes the stores make a mistake in calling them the same thing.. Acrylics tend to be more likely to chip and crack... IMHO.

 

[bitshird]

I agree with Chuck, Acrylics are more prone to chip that Polyester Resin which is more prone to chip then Polyethylene resins.

 

[dale]

Thanks
Now I will now do a lot of reading on the different types. I knew there was a difference in the acrylics vs. Poly just in the reading I've done but after your answers I need to do more reading
Again thanks

Some day I may learn & try it on my own

 

[DurocShark]

Opacity of the colors can affect the brittleness as well.

Try a PR blank from exoticblanks or one of the other guys who make outstanding PR stuff.

 

[Mac]

I have had some that act different ,so now I always use a skew ,start to finish and have not had any more blowouts.
hope this helps.

 

[glycerine]

What I have started doing with acrylics (or sometimes wood if segmented with metal) is sand them round on the belt sander before I even put it on the lathe. I'll put the bushings on and trace the diameter with a pen. then sand down to about that point on the belt sander. When I put it on the lathe, I can pretty much finish it off with a scraper and then sand paper.
I know, it almost defeats the purpose of using a lathe, but I haven't had any blowouts yet...