Alumalite vs Castin Craft

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Eric1075

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I just tried my hand at casting a bottle stopper blank using Castin Craft (PE). Mixed it, added pearl ex, put it in a pressure pot at 45 psi for 5 hours. When I removed it it was a little tacky. I know the number of drops of catalyst will vary dependant upon temperature which can be a bit of a hassle. I am guessing Alumalite is better since its a 1:1 mix. The other thing I wondered was, does Alumalite stink as bad as PE? The odor from the Castin Craft was pretty bad.
 
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Alumalite does not have the odor but requires pressure casting you do not need pressure for casting craft. Casting craft may feel tacky for a while even after it is turntable.
 
Castin Craft (PE)? I assume you mean Castin Craft Polyester resin. Polyester resin is often abbreviated PR. Anyway, polyester resin is designed to be sticky on the surface exposed to air and the stickiness is not related to the amount of catalyst. I'll not go into why it is sticky. The sticky surface will eventually dry. I leave my casts in for 24 hours and most always the exposed surcease is cured dry and not sticky. If it is, I set it in the sun and all is good soon. I use 3 drops of MEKP per ounce no matter what the temperature and that works good for me. Alumili9te is a 1 to 1 mix, but by weight and not volume.
Do a good turn daily!
Don

Eric1075 said:
I just tried my hand at casting a bottle stopper blank using Castin Craft (PE). Mixed it, added pearl ex, put it in a pressure pot at 45 psi for 5 hours. When I removed it it was a little tacky. I know the number of drops of catalyst will vary dependant upon temperature which can be a bit of a hassle. I am guessing Alumalite is better since its a 1:1 mix. The other thing I wondered was, does Alumalite stink as bad as PE? The odor from the Castin Craft was pretty bad.
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Thanks for the replies. Yes. I meant PR, not PE. In any case, just to be clear, the PR will still be a little tacky even after it has cured? If I put it on the lathe and turn away the outer layer is it safe to say the rest of it will be solid?

Additional questions I have are, when trying to do a dual color swirl should I wait a little while allowing it to thicken slightly with the hope that each color will set rather than pouring and creating a mix where the two colors blend together?

Is Alumalite the standard for casting turning blanks?

Thanks!
 
Both PR and alumilite are good for making your own blanks. Alumilite is better for kitless pens since it can be tapped whereas PR cannot. Alumilite is also better for worthless wood or fusion casting. I prefer PR for label casting but others use alumilite. With PR you want do a 2 color swirl when the PR first starts to thicken. PR can be turned when it's tacky if it has cured for 24 hours or so.

Alumilite is mixed 1:1 by weight not volume. I tend to use PR more because I do not have a good pressure set up. The alumilite casters can give you greater insights on alumilite than I can. Hope this helps.
 
Be careful with letting it thicken, it can go from water thin to snots to hard jello in seconds. So don't turn your back on it.
 
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You can get rid of the tacky surface by warming the blanks once cured by putting them into a toaster oven on the lowest setting for an hour. Once cooled the surface won't be tacky. Don't use your kitchen ovens, get one from the second hand store.

You don't need a lot of heat and some people put their blanks in the hot sun. I am leery of doing that because of the UV light. It breaks down plastics, so why give it a head start. We actually don't use a toaster oven. I had an old waffle iron that opens flat and a self contained metal drawer unit that bolted under a bench. A few sticks on the waffle iron to hold the blanks off and set to it's lowest setting (light barely comes on) does the trick nicely. You could probably use a crock pot the same way.
 
Curly said:
You can get rid of the tacky surface by warming the blanks once cured by putting them into a toaster oven on the lowest setting for an hour. Once cooled the surface won't be tacky. Don't use your kitchen ovens, get one from the second hand store.

You don't need a lot of heat and some people put their blanks in the hot sun. I am leery of doing that because of the UV light. It breaks down plastics, so why give it a head start. We actually don't use a toaster oven. I had an old waffle iron that opens flat and a self contained metal drawer unit that bolted under a bench. A few sticks on the waffle iron to hold the blanks off and set to it's lowest setting (light barely comes on) does the trick nicely. You could probably use a crock pot the same way.
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I put mine on top of the frig. Its a model with the coils on the back so the heat comes up the back and over the top. I also dry my reverse painted blanks up there.
 
Eric1075 said:
Thanks for the replies. Yes. I meant PR, not PE. In any case, just to be clear, the PR will still be a little tacky even after it has cured? If I put it on the lathe and turn away the outer layer is it safe to say the rest of it will be solid?
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Yes is the best answer. I keep mine warm overnight, and they are usually solid in the morning. But I think PR blanks will continue to harden for a few days as long as they are at 70 degrees or above.

Eric1075 said:
Additional questions I have are, when trying to do a dual color swirl should I wait a little while allowing it to thicken slightly with the hope that each color will set rather than pouring and creating a mix where the two colors blend together?

Is Alumalite the standard for casting turning blanks?

Thanks!
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If your PR is around 70 degrees, you should wait somewhere around 15 to 20 minutes after the mekp is added before you pour. Although, the humidity, type of coloring you add, and even the color of mica makes a difference. Did that clear everything up?:rolleyes: There is a definite learning curve to multi colored pours, and a lot goes into getting the timing right. A general rule of thumb is that it takes about a gallon of resin pours before you get a good feel for when to pour. It's not that you will waste a gallon, but you will for sure have some bad casts along with the good.

And I'd say PR is the standard, but I really like alumilite better.
 
Wow. You nailed it with that response. I mixed 2 cups to do a 2 color swirl pen blank. After 10-15 mins it was still watery. I quick googled PR and it said roughly 20 mins before it thickens. I left the shop for 5 mins ( bad move ) and upon returning it had set up to the point where it couldnt be poured. I now have 2 single color bottle stopper blanks cured in 2 bathroom paper cups.
 
I haven't worked with Alumalite yet but simply based on the fact it isn't supposed to stink like PR, I think Alumalite will be my resin of choice particularly during the colder months. Unfortunately the laws of nature seem to pull any and every odor created in my shop and pull them thru the laundry room and up to the 1st floor. If you think the odor of the PR will give you a headache, thats nothing until my wife smells it. That headache is 10x worse.
 
I'm at around the half gallon mark and had mostly success. What I look for is I pull the stir stick straight out of the mixed PR. If it stays together in a thin stream it's still too thin. Once it starts to break into drops I pour. At that point you may have only a few seconds. I've done pours where it's thin at the start and almost rock hard at the end.
 
I missed the fact that you mentioned PR in your post when describing when you start your pour. Do you know if Alumalite sets as quick as PR? I was hoping to hear that Alumalite is thicker than PR, hence allowing you to do a 2 color pour without having to pull it off in 5 seconds. :)
 
Eric1075 said:
I missed the fact that you mentioned PR in your post when describing when you start your pour. Do you know if Alumalite sets as quick as PR? I was hoping to hear that Alumalite is thicker than PR, hence allowing you to do a 2 color pour without having to pull it off in 5 seconds. :)
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I don't pour Alumalite but the videos I have seen shows it being rushed into the pressure pot while for PR you have around 20 minutes before it starts to set.

I think you have a 4 minute working time with Alumalite.

Try this

https://www.youtube.com/watch?v=pQ63Fky5ca4
 
MEKP is NOTHING TO USE IN THE HOME! In my college chemistry class, the MEKP was kept under a fume hood, and we weren't allowed to bring it into the lab under any circumstances. At the amounts used for blank making, I don't think it is deadly, but IT CERTAINLY can make you very sick. A few years back, a couple reported on this site that they made Castin Craft blanks on the coffee table in their living room! Their last reported post was that one of them was in the hospital, and the other was extremely ill. I never saw another post from them. You must use MEKP in an area that is well ventilated, and never where the fumes can enter a house.

By the way, not all Alumilite needs to be pressurized. The Alumilite clear must be pressurized to remove all the bubbles, but if you want an opaque blank, the use of Alumilite White can be done without any pressure at all. Another great advantage of Alumilite White is that it sets up in about 10 minutes or so.

I hope this helps.
 
It does. Having never used Alumalite ( I'm grabbing some at Michael's today) when mixed, is it watery like PR or is it thicker? What frustrated me about PR was doing a 2 color swirl. It was watery at first so i was afraid the 2 colors would just blend together instead of swirling but still remaining as 2 distinct colors. As I mentioned I havent been about to nail down the exact moment where it thickens but still pourable. I missed that moment and wound up with 2 single color bottle stopper blanks.
 
Eric1075 said:
Having never used Alumalite ( I'm grabbing some at Michael's today)
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Unless your Michaels carries some thing else, I don't think thats the same Alumalite (clear or white) that everyone here is talking about.

I do think there is a product there that is made by the Alumalite company but its not the same Alumalite that everyone here is talking about. I did check it out once and I think its an epoxy resin.

I'll try to find the thread here where I asked about it.

Here it is http://www.penturners.org/forum/f43/so-confused-alumilite-question-134356/

This is not what people are talking about when they say Alumalite.

51fWYxIsECL._SY300_.jpg
 
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Eric1075 said:
I missed the fact that you mentioned PR in your post when describing when you start your pour. Do you know if Alumalite sets as quick as PR? I was hoping to hear that Alumalite is thicker than PR, hence allowing you to do a 2 color pour without having to pull it off in 5 seconds. :)
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Alumilite is probably slightly thinner than PR. But the properties are so different, the thickness doesn't really come into play. And I think Alumilite is slightly easier to learn. I use alumilite clear that has a working time of 7 minutes. I don't have a problem with 4 color pours, but after that, it gets kind of tricky. There is a new version with a longer cure time, but I've never tried it. And once you learn the timing of PR, you'll have more than 5 seconds to pour.

OOPS said:
By the way, not all Alumilite needs to be pressurized. The Alumilite clear must be pressurized to remove all the bubbles, but if you want an opaque blank, the use of Alumilite White can be done without any pressure at all. Another great advantage of Alumilite White is that it sets up in about 10 minutes or so.

I hope this helps.
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If you use white alumilite, you'll limit the amount of color options. You can use opaque dyes with the clear alumilite, and get more color variations. Also, the white will mask the pearl effects from using mica powders. In addition, you can add white dye mixed with colored dyes in alumilite clear to get the same colors from using white alumilite with colored dyes. I think white has it's place, but clear is more versatile IMHO. Confused yet.:wink:

And a consideration of using alumilite is the cost. The resin costs about double of PR. Plus you need 2 cups to make 1 color. A scale is almost a requirement to make sure you have equal amounts of A & B. I use a scale for both PR and alumilite.
 
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I have done a few PR castings and cure the castings by putting it in a upside down coffee tin in the sun. Solves the UV problem and my wife's oven.

Guess there are some advantages to living in sunny South Africa
 
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