Please tell me about the "plastics"

Signed-In Members Don't See This Ad
sorcerertd

sorcerertd

Member
Joined
Sep 30, 2019
Messages
3,087
Location
North Carolina, USA
This isn't really a question about making blanks, but about using them. There are so many names out there. I assume quite a few of those are trade names, but the only ones I've worked with so far are Acrylester, Lava Bright, and Rhino plastic. I'm sure there are plenty of personal preferences out there, so please tell me about yours.

What is the difference between the commercially available blanks (including small batch stuff you folks make and sell on your own sites and/or through other retailers) in terms of working with the materials? Is it truly a "you get what you pay for" market with these blanks? Have you got a favorite (or a few) and why do you like working with that type? Which ones cut/drill better, polish better? What are your customers happiest with?
 
Signed-In Members Don't See This Ad
Cellulose Acetate is like crack to me. It has not been made since the 1930-40s. Usually, you have to find a hoarder willing to part with his stash. I like the depth, polishes up easily and looks great. Biggest detractor is it is usually sold as a tube, and you have to find kits that work with it. I have gotten to be an expert at hand reaming with a drill index.
 
carlmorrell said:
Cellulose Acetate is like crack to me. It has not been made since the 1930-40s. Usually, you have to find a hoarder willing to part with his stash. I like the depth, polishes up easily and looks great. Biggest detractor is it is usually sold as a tube, and you have to find kits that work with it. I have gotten to be an expert at hand reaming with a drill index.
Click to expand...
Agree with everything Carl said. I LOVE acetate—the tubes stuff from the 1940s and 1940s as well as Mazzuchelli's slightly more modern cebloplast from the 80s and 90s. The downside with the older stuff is that it's very thin in outer diameter—often 12mm or less which makes it tough to use. But that is part of the fun; finding a way to make it work!
 
an answer to this question could go on forever.....because there are so many types of "plastic" out there, and we all have our opinions and feelings on what we like and use. I don't have a problem with most commercially made blanks. Some are harder than others but most of them turn well. I avoid Inlace Acrylester. I personally don't like how chippy it is or how easy it is to melt. Most of what I turn now is custom poured blanks made of either Urethane resin (Alumilite Clear) or PR - Polyester resin (Silmar 41). I don't use much epoxy resin because it takes so long to cure and can be hard to demold.

Urethane resin turns very smoothly and is very durable. The drawback is it is harder to get a glass like finish but you can apply a CA finish. You will find most embedded object casts are made with this. Kitless pens work well with it also, because it is so durable and takes threads so well.

PR is also good to turn as long as it wasn't cured too hot or turned while cold. If so, then it can get chippy. I mix mine with only 2-3 drops of catalyst per ounce and I like to put it in my pants pocket for 30 minutes prior to turning since my shop can get a little cold. Nothing shines as easy, nice or clear as PR in my opinion. It requires no CA for a glass like finish.
I use it with feather, carbon fiber and snakeskin casts.
 
@sorcertd

Todd, I think it best for you to ask about specific materials; otherwise the responses could go on forever and still not meet your needs.
Some names we hear/use are strictly brand names, some refer to a broad class of plastics, and some are chemically fairly accurate & specific.
In my experience, even the sellers of blanks do not always know the category or classification of the products they sell under certain names.

One word used a lot to refer to some of the blanks we commonly use is "acrylic", but is that a generic or specific name ?

Some of the "plastic" blanks we commonly see and use are the so-called AA blanks. . I think that means "acrylic acetate". The black is AA-25.

I am no expert on plastics. . It is a very big subject. . My experience, even with those used for pen blanks, is by no means complete. . I stab at a few.

For home casting of pen blanks, the brand name Silmar 41 was quite common for a while, and it was/is referred to as PR because, generically, I believe it is a "polyester resin" whatever that means, but I think it has a quite specific meaning in a general sense !

A few types have been dealt with above by Carl, Eric, and John.

You mentioned 3 types in your Original Post above ....

Acrylester : - Frankly, I don't know, altho' I've probably used it for pens. It could be another name for "acrylic acetate"; I just don't know.
Or maybe it is related to the term, "polyester", which we commonly use to refer to a broad class of synthetic materials, some wearable !
PSI sells some pen blanks that they call "acrylester".

Lava Bright : - This may refer to a particular maker's product, and probably refers to a urethane, possibly with the brand name of Alumilite.
The maker I am thinking of has several product styles, several with names that include the word, "Lava" ... see www.muttblanks.com
Alumilite, a brand name, is sometimes used in a generic sense. . It is extremely nice/easy to turn and thread, polishes to med. shine.

Rhino plastic : - May be a brand name, or a more general term. Somewhat "chippy" to turn (like acrylester). Be very careful. Polishes to good shine.
I like it a lot for the brilliant shine it can have. . I recommend you try it ..... but turn it with care ! This term is used quite specifically
and could in fact be a brand name.

So that's my spiel, for what it's worth, incomplete tho' it is and must necessarily be. . I am open to correction wherever necessary, too.
 
Last edited:
magpens said:
Todd, I think it best for you to ask about specific materials; otherwise the responses could go on forever and still not meet your needs.
Click to expand...

Hey Mal, that was sort of my intention. I wasn't looking for "forever", but am fine with it going on for a while. I don't have any specific need for any specific application, but just wanted a general education based on the experience of those who have used them.

@JohnU ,thanks for that warm-up tip. My shop is a bit chilly in the winter (though it's comfortably cool in the summer).
 
jttheclockman said:
This has been talked about a few times. Here is an article in the library that you can download.
https://www.penturners.org/resources/acrylic-revolution.69/

I am trying to find the thread I think it was Eric who posted.
https://www.penturners.org/threads/not-all-plastics-are-acrylic.148328/#post-1924610
Click to expand...

Thanks for that John. I suppose I could have used the search. The thread you linked... wow, that's a lot of info. Very good suggestion about a table/spreadsheet to list the different types and such. Really most of us would only need to know generalized turning properties.
 
It's pretty simple to classify custom made blanks because they are either PR, Urethane or epoxy. Commercial blanks are a bit different. Just know if it's called Alumilite - that it's the brand of resin and not a specific resin. Alumilite makes urethane resins which are "white" ."clear" or "clear slow". Any resin they make that begins with "Amazing" is an epoxy resin. Silmar 41 is a brand name of Polyester resin. Rhino plastic is a brand name of blanks made with Polyester resin. Lava blanks are a line of color casting blanks with a certain style of mixing but are made with urethane resin. Most blank makers come up with a brand name but that doesn't tell you the resin type. They chose the best resin for the job at hand, since they all have their pros and cons when it comes to usage.
 
nobodyparticular said:
Apologies if this has been explained in older threads - but why is this material not produced anymore?
Click to expand...
I think there are a few reasons, one being they were hard to make and unsafe practices were used. The formulas never followed the companies when they went out of business and they never shared recipes. Takes to long to cure and make. Also expensive.

I bought some blanks the other day and got to turn one and absolutely love this material. It is called Omas Pearl blanks. OMAS USED TO MAKE PENS FROM HIGH END ACRYLATE AND CELLULOID. This material is harder than acrylics that we are use to. Turns harder too. The color is way more vibrant. The silver I used has so much sparkle and shine and depth to it, it will be hard to photograph to give its due. The Italians sure did know how to make pen blanks. To this day all the Italian blank material I have is way above anything made today. The only thing that comes close is some of the Trustone products out there.

I believe in todays world, pickguard material is made somewhat the same as the old pen making material
 
Last edited:
jttheclockman said:
I think there are a few reasons, one being they were hard to make and unsafe practices were used. The formulas never followed the companies when they went out of business and they never shared recipes. Takes to long to cure and make. Also expensive.

I bought some blanks the other day and got to turn one and absolutely love this material. It is called Omas Pearl blanks. OMAS USED TO MAKE PENS FROM HIGH END ACRYLATE AND CELLULOID. This material is harder than acrylics that we are use to. Turns harder too. The color is way more vibrant. The silver I used has so much sparkle and shine and depth to it, it will be hard to photograph to give its due. The Italians sure did know how to make pen blanks. To this day all the Italian blank material I have is way above anything made today. The only thing that comes close is some of the Trustone products out there.

I believe in todays world, pickguard material is made somewhat the same as the old pen making material
Click to expand...

Ah, I see - thanks for sharing your insight John. I found some information about the chemical side of the manufacturing process on the internet and can easily see big potential for uneducated attempts to go wrong in various horrible ways.
 
jttheclockman said:
I think there are a few reasons, one being they were hard to make and unsafe practices were used. The formulas never followed the companies when they went out of business and they never shared recipes. Takes to long to cure and make. Also expensive.

I bought some blanks the other day and got to turn one and absolutely love this material. It is called Omas Pearl blanks. OMAS USED TO MAKE PENS FROM HIGH END ACRYLATE AND CELLULOID. This material is harder than acrylics that we are use to. Turns harder too. The color is way more vibrant. The silver I used has so much sparkle and shine and depth to it, it will be hard to photograph to give its due. The Italians sure did know how to make pen blanks. To this day all the Italian blank material I have is way above anything made today. The only thing that comes close is some of the Trustone products out there.

I believe in todays world, pickguard material is made somewhat the same as the old pen making material
Click to expand...
I think the pick guard material might actually be true celluloid—cellulose nitrate. Those sheets are so thin. I've thought about trying to laminate a bunch with acetone to try and make something thick enough to turn a pen from but haven't tried it.
 
EricRN said:
I think the pick guard material might actually be true celluloid—cellulose nitrate. Those sheets are so thin. I've thought about trying to laminate a bunch with acetone to try and make something thick enough to turn a pen from but haven't tried it.
Click to expand...
You might be right Eric. I know they are a different material than our acrylic pen blanks we see today. I have a bunch of it that I want to incorporate somehow into a pen blank or two. Beautiful colors so need to work on that.
 
EricRN said:
I think the pick guard material might actually be true celluloid—cellulose nitrate. Those sheets are so thin. I've thought about trying to laminate a bunch with acetone to try and make something thick enough to turn a pen from but haven't tried it.
Click to expand...
They probably are true celluloid. I know that you can solvent weld sheets to form a block, but I don't think acetone is the best choice. I have always heard you should use MEK (methyl ethyl ketone) or THF (tetrahydrofuran). A few things to keep in mind, first, rermebre ventilation. You don't want to be breathing any of those. Second, be aware is going to that it is going to take a looooong time before the solvent has completely worked its way out and you have a block you could work with (think weeks to months). Third, don't think you can try to speed up the process by applying heat lest you find out firsthand why cellulose nitrate is also known as guncotton.
 
When i looked at the Stew Mac site they add a $37 hazardous fee to shipping these (crazy). Must be true celluloid.


Sent from my iPad using Tapatalk
 
You must log in or register to reply here.
Back
Top Bottom