Acrylics ??

[avbill]

I believe another member asked the question and little was answered and I can't find the thought.

I'm a bab in turning experience maybe 30 to 40 pens. I also have about 20 blow outs also. I dont know if should brag about that fact with this group. [:I]

I'm still learning the CA/BLO finish also. I switched over to acrlic until I like the finish of the CA.

So heres the questions: There seems to be differences in quality of acrylics blanks. Some are very hard and are very brittle then placed on the lathe to turn. Others tend to be softer yet harden enough and easier to turn. What are your thoughts in the differences placed into the marketplace by our suppliers.

Yes, we start with sharp tools. And take small cuts ! Yes I sand to 12,000 grit mm and then buff with a micro polish.


1. Is Acrylic acetate (AA) easy to turn? What do you have watch for? 2. Is there differences between different suppliers? What are they?
3. How different is a polygem to an acrylic acetate or even the celluloid blanks ?
4. Am I assuming correctly that ones true-stone blank is equal to another acrylic-gem? Difficult to turn? What to watch for?
5. Is a celluloid more difficult to turn than a AA blank ?
6. If I forgot a question that needs to be address ad it in please.

Are there any additional tips in turning acrylic blanks that I might run into as a starter in the acrylic arena.

Many thanks your your thoughts
bill Daniels

 

[alphageek]

First off, I will not put myself as an expert, but someone who has been through a bit too.
I find that most acrylics aren't too bad - acrylister (spelling?) is the most brittle that I've found. AA, PR, celluliod all turn nicer for me.

I've turned my first tru-stone recently.. Not much worse than acrylic - but not all tru-stone are equal. There is a seller here with tru-stone and he lists very nicely which are harder to turn.

Also you said you have sharp tools/small cuts... What speed? I've recently moved up to the fastest spot on my belt. With that and practice, I'm getting better - the stuff coming off the lathe reminds me of "easter grass"..

 

[follow3]

Hey Bill,

I agree with alpkageek, the AA, PR and Celluloid seem to be about the same. The Acrylester is another animal all together. It is very brittle, take extremely light cuts as your gouge could zip right through and ruin the blank in the blink of an eye. If it weren't for the awesome colors, I wouldn't even turn the stuff. Another trick with the Acrylester is to leave the blank a bit larger than the bushings and finish it with sand paper so you can sneak up on the right size without going too small.

The biggest revelation I had when learning to turn plastics was speed! The faster the better. Also when sanding, wet sand not dry and clean the blank between grits. Also, when you are done, don't dry it off with a rag while the lathe is turning, I did this once with the lathe turning too fast and it heated up the blank and ruined the finish.

Also like alpha said, when you get it right, you should be making Easter basket grass.

Good Luck, have fun and keep on practicing.

Steve

 

[johnkofi]

I don't have any idea from one Acrylic to another, but I know that the ones that I have bought at Rockler are not even close in quality of the ones I have bought at Wood Craft. I won't buy any from Rockler again.

 

[les-smith]

Here is a post I made covering some of your questions. It might help a little

http://www.penturners.org/forum/topic.asp?TOPIC_ID=28980&SearchTerms=acrylic

 

[avbill]

Many thank for the replies-- but what is PR stand for: Poly ____?

Bill DAniels

 

[Proud_Poppa_of_2]

Originally posted by avbill

Many thank for the replies-- but what is PR stand for: Poly ____?

Bill DAniels

Polyresin

 

[babyblues]

Well, I haven't turned any celluloid yet, but I have turned some acrylic acetate, Ed's polyresin and acrylester. I haven't had any problems with any of them. However, I don't find that faster is better and it depends on what material you're turning as to what tool to use. Acrylic acetate is softer than the others but easier to melt. So, if you're trying to turn it at warp speed, you're going to melt it. I've been able to turn the entire thing with a sharp gouge. Acrylester is indeed brittle, but the colors are awesome. It is actually better to turn it at a faster speed (I use 2600rpm). If you're too heavy handed, they will explode. Literally, explode. You'll be finding pieces all over the shop for weeks after. I use a skew and spindlemaster like Ed Davidson does in his videos. I find that works best. He is the Ed that makes the Ed's polyresin and I have to say that is my favorite. EPR is not as brittle as acrylester, but it turns just like it. Wet sanding is best with all acrylics. I do the same as Ed in his videos. Wet sand to 600, sand the length of the blank with 600 by hand just before you take it to the buffing wheels. I can get some really nice CA finishes, but they're inconsistent and frustrating, so I fall back on acrylics to keep the pen turning juices flowing after my frustrations with CA. Good luck!

 

[rherrell]

You say you MM to 12,000 then buff. I think you're going backwards. Try wet sanding to just 600 and then do your buffing. I think you'll be surprised.

 

[jwoodwright]

I've tried a lot of different ones. It does take a special touch and I prefer my trusty 1" gouge. Just a HSS, old timer. I "break" the corners wirh either 60 or 80 grit paper. Then introduce the bevel about the middle of the blank, rotate cutting edge and super glide and get all covered in thin ribbons of material. Back to middle and go the other way... etc... Then I wet sand to 2000 grit, MAAS Metal Polish. Pens are nice and glossy. Customers complained pens were too slick if I went higher.

 

[hilltopper46]

Originally posted by avbill

Many thank for the replies-- but what is PR stand for: Poly ____?

Bill DAniels

Polyresin

Polyurethaneresin

or

Polyethyleneresin

Which are both used to cast with but are two fairly different animals.

 

[Cecilia]

I've used several different types of acrylic. My favorites are Acrylic Acetate from Berea (Hut) and Inlace Acrylester from Woodturningz. Woodcraft has recently started carrying a new line (their own?) of acrylics that I may try. The IA can be a bear to deal with if you're new to turning, so get some turning time in on the AA first. I'll be as thorough as I can be. Hope it's not toooo much detail.

First, when you're prepping the blank for the barrel, don't drill all the way through. Cut the blank a little longer than you need, set your drill press for about 1/8" from the end of the blank, drill only that deep, then trim off the end with the bandsaw. I use Gorilla Glue for gluing barrels into blanks. It fills gaps and holds better than CA, so I don't have to worry about catching the blank and having it separate from the barrel. The only downside to it is that the gold-ish color of the glue, together with the brass barrel, shines through some materials. (They now make a GG that dries white. I'm guessing it will hold as well, but I haven't tried it yet.)

When the glue has set, you can use a cornering jig to cut off the corners with a bandsaw, which shortens your turning time and reduces (but not completely) the likelihood of a catch. When working with any acrylic, make sure you have sharp tools (I generally use a fingernail gouge and a skew) and don't apply too much pressure. For finishing, I sand up to 400-600, including a couple of types of 3X pads. (The 3X pads seem smoother than their paper-backed counterparts with the same grit. As in, the 320 pad is smoother than 320 paper.) Then Micro Mesh from about the third MM grade (2400?) up to 12,000, then polish with Hut Ultra Gloss.

I recommend against using MicaPearl. It's at least as difficult to work with as IA, and not as pretty. To me, it just isn't worth the trouble. AcryliGem and PolyGem are easy to turn, but I find they often crack during assembly. During turning, they throw a fine powder, as opposed to the Easter grass ribbons you get from AA and IA. When I press the nib/finial/mechanism into the brass tube, the AG and PG blanks crack. I've tried chamfering the barrels and lightly sanding the pen components before pressing them, but the material still cracks more often than not. Corian and some of its cousins turn easily too, but also tend to crack upon assembly, though less than AG and PG.

If you decide to try Inlace Acrylester, do yourself a favor and ask one of the reps at Woodturningz to send you the flyer with hints and tips for turning it. I had serious issues with it before, but I haven't lost a blank since Jeff explained what I was doing wrong and got me that flyer.

That's everything I can think of right now. Hope it helps!

 

[Russianwolf]

I've turned exactly 3 plastic blanks (I say plastic since I'm not sure which category they fall into).

I'm 1 of 3. The two I turned last night did fine until I got to the final shaping of the nib end. That's when they just decided not to work. I was using GG and have a feeling that I didn't get good enough coverage on that end as there was no foam visible. So it was likely my own fault. The upper barrels look great though []

The blanks I've turned were a Crushed Pearl which did pretty well (with my out of round turning lathe) and the 2 last night were from WOODPENPRO. I did realize after turning the upper that I should paint the inside of the blue and white blanks he sent. You could see some yellow from the brass.