Acrylic blank quality

[bastallard]

I bought an acrylic blank today and when I started turning it I found a lot of air bubbles, and when I got down to the bushings there were still bubbles on the edge. Should I expect a refund or a new blank, and maybe even new tubes?

I appreciate your opinions.
Thanks Bob

 

[ed4copies]

Acrylic is a commercial product, made under great pressure (tons).

Unless you got an "end cut", you mean some other kind of plastic. Polyresin or alumilite would be my guess.

In any case, bubbles are not good. However, in some casting they are VERY VERY difficult to eliminate. So, the definitive answer to your question is, "It depends".

If they were "home cast", what did the caster say?

 

[bastallard]

It was store bought, and when I called the store the guy said that the person that I needed to talk to wouldn't be in until tomorrow and he would call me, so I'm gonna have to wait for any answers from them, I just don't want to be uninformed when they call me back.

 

[Chatham PenWorks]

Are you new to "acrylics"? The reason I ask is because, being too aggressive will cause what look like air pockets in a perfectly good blank. If you can see complete bubbles under the surface, it's the blank. If you are seeing "pockets" on the surface, you may need a lighter touch, or a sharper tool.

 

[ed4copies]

Many acrylics (I think all, but never use an absolute) are made in sheets.

The edges CAN indeed have holes--but the manufacturer (or whoever gets to cut them into blanks) SHOULD be smart enough NOT to sell these.

I have never seen them offered for sale when I bought acrylic blanks---but it probably COULD happen.
FWIW

 

[alphageek]

I bought an acrylic blank today and when I started turning it I found a lot of air bubbles, and when I got down to the bushings there were still bubbles on the edge. Should I expect a refund or a new blank, and maybe even new tubes?

I appreciate your opinions.
Thanks Bob

If its truly air bubbles, most vendors will offer a replacement or a refund. I doubt it on the tubes, but you can turn to the brass and re-use them if you want.

If you haven't turned all of the material, I'd suggest using the cut-off or any remaining material to show the problem. Since you said it was store bought, that MIGHT help you cause you can show them.

There is a very wide variety of materials that are "resin" blanks. And even when made with the same materials there is huge variations.

 

[bastallard]

I can't say for sure what kind of plastic it was, the tool I was using was just sharpened, and the inside of the bubbles were shiny.

 

[ed4copies]

I can't say for sure what kind of plastic it was, the tool I was using was just sharpened, and the inside of the bubbles were shiny.

Inside of a broken off chard is shiny too.

You can identify bubbles pretty easily--They are ROUND!! Air makes round bubbles. Chunks that are taken off by a tool are usually NOT round, they are oval or other irregular shapes.

 

[alphageek]

I can't say for sure what kind of plastic it was, the tool I was using was just sharpened, and the inside of the bubbles were shiny.

If it was Woodcraft, it was likely PR (polyester resin) of some sort or another but could have been something else. If it was Rockler it could have been PR, Acrylister, Acrylic Acetate, Rhinoplastic or other brands but many of those state it in their name. If it was them (or anyone else) it can't hurt to ask them. If they know, the type can help you with recommendations.

Each of those listed turn a bit different and sometimes even different colors turn different.

 

[redwd707]

Are you new to "acrylics"? The reason I ask is because, being too aggressive will cause what look like air pockets in a perfectly good blank. If you can see complete bubbles under the surface, it's the blank. If you are seeing "pockets" on the surface, you may need a lighter touch, or a sharper tool.

I just started turning plastics but I saw this same thing. I would have swore I got into some bubbles at one point, luckily the material was clear enough that I could see they were on the surface only, not inside the blank. They were very smooth, shiney little pits, but they were not bubbles. Just something to keep in mind.

 

[sumterdad]

When you were turning it. Did it sound like a smooth flowing or was it a rough hacking noise

 

[bastallard]

it was smooth but when I got into the bubble area I could feel the surface give, like it seemed softer, and I was going very easy, my hearing isn't the best so I didn't hear it so much as feel it.

 

[ironman123]

Last week I turned my first acrylic and I thought it had a zillion bubbles in it but after being told by members here to speed up my lathe, slow MY working speed and treat it like shaving...a very little at a time, I went back to the blank and it turned out beautiful.

Ray

 

[bastallard]

I've done a couple of acrylic pens and I did ruin a couple blanks, but this one was different.

 

[Displaced Canadian]

Do you have a picture if the blank?

 

[Monty]

it was smooth but when I got into the bubble area I could feel the surface give, like it seemed softer, and I was going very easy, my hearing isn't the best so I didn't hear it so much as feel it.

Are you using a gouge? Sounds like you are trying to remove too much material at one time.
You need a very sharp tool, very light cuts and high speed, especially when you are first learning to turn "acrylics".

 

[Rfturner]

I have turned alot of acrylics before and I will repeat what others have already said, Fast turning speed, take your time, Sharp tools and light cuts. You will find that some brands of acrylics chip out easier and some cut like butter. It sounds like it is most likely chipping out as I had this same problem when I got started.

 

[sumterdad]

yea it sounds more like you were taking to much off. I have to keep reminding my wife and little girl of not to do that when they turn a pen. Then when it happens they get nervous and dont want to finish so I usually have to finish it for them. Until they get their nerve back.

 

[bastallard]

I was going lightly with a just sharpened round nose scraper, and this blank looked sketchy from the get go, it was very rough looking blank and one of the corners was misshapen. It seems like acrylic blanks for the most part don't have bubbles/air pockets normally so I'm not going to worry about it too much.
thanks for the info
Bob