PR vs. Alumilite

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Curtis STARS in a video comparing the two on the Alumilite website. :biggrin:

My luck with Alumilite hasn't been great, but most likely its my fault for not mixing it right.

Alumilite Pros: Lower Odor, easier to turn, faster demold time
Alumilite cons: finicky to mix, less open time


PR Pro: Longer open time, better for clear casting so I'm told, easier to mix
PR cons: FUMES!!!!, more chippy to turn
 
One thing that Curtis also shows is how much more durable alumilite is. The tossed two turned blanks in the air (one PR and one Alumilite) and the alumilite bounced while the PR broke.
 
SO what I am to gather is

Alumilite is less brittle than PR.

The brittleness of PR is directly proportional to the how hot it is mixed

PR shines up better than alumilite

PR stinks

Alumilite not so stinky

What about difference in pouring. I have read that Alumilite needs to be put under pressure no matter what then someone said it did not. WHich is it? PR can go both ways.
 
There are other important characteristics:

- Label casting = easier with PR (less bubbles) but needs isolated to prevent bleeding/leaching of the ink/colors/paint. More tolerant to water/moisture.

- color mixes/swirls = easier with Alumite but is VERY finicky about water. Any moisture in the powders, colorants, inclusions (e.g., shredded money) or strong humidity in the air will cause Alumite to foam 2-3 times its size

Alumite can cast/cure QUICKLY (e..g, heat resin = minutes, and easier to get fresh (order online from many places); and is more precise in controlling the mix (by weight/exact)

Castin Craft (PR) cures slowly with less controled/exact mix (drops of MEK per vague resin amounts) ... 2? 3? 15? who the frick knows? the supplier doesn't know.
 
I have not started with alumilite yet and only used PR when in Japan.

Question on Alumilite: Can you vary the open time? From what I have read, 4 to 5 minutes of open time. Can Alumilite be adjusted to an open time of 10 to 20 minutes or so?
 
That's the big thing that keeps me away from Alumilite the short 5-6 minutes work time. I tried Alumilite a few years ago and then it did not polish up as nice as PR but I think they got that fixed. Now if they could just get it stay open for a good 10 minutes. One of the cons of PR is the shrinkage. The shrinking will give you headaches if you don't plan for it. There are so many variables.

.
 
bruce119 said:
That's the big thing that keeps me away from Alumilite the short 5-6 minutes work time. I tried Alumilite a few years ago and then it did not polish up as nice as PR but I think they got that fixed. Now if they could just get it stay open for a good 10 minutes. One of the cons of PR is the shrinkage. The shrinking will give you headaches if you don't plan for it. There are so many variables.

.
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I can tell the client it just got out of the swimming pool.:eek:

How would it be a head ache?
 
I haven't been playing with Alumilite very long, and have only tried the Clear so far. Based on my limited experience, however, the open time is temperature dependent. You can slow the gel time by chilling the resin, and accelerate it by warming or by stirring. Once it kicks, however, you need to pour, swirl, and put under pressure right away. Otherwise it will set and you'll wind up with lots of bubbles in the casting.

I've been using heat and stirring to get different colors to gel at the same time so that they swirl instead of mix. That timing is easier to accomplish with Alumilite than PR.

Polyester Resin work time, gel time, and set rate are also temperature sensitive and dependent on the amount of hardener used (among several other factors). Both Alumilite and PR curing reactions are exothermic (generate heat). When PR gets hot, it cures faster and becomes brittle. A certain amount of hardener (e.g. MEKP) is required for strong cross-linking, but beyond that the blanks will be stronger, less brittle, and shrink less with a slow cure.

Alumilite set time is much shorter and you can demold the blanks a lot sooner than you can PR. Both continue to cure for at least a day after hardening. Alumilite (which is an urethane resin) is stronger and more flexible than polyester resin. It tends to chip less, and is less prone to breaking than PR.

PR polishes to a higher shine than Alumilite Clear.

I hope that helps,
Eric
 
leehljp said:
I have not started with alumilite yet and only used PR when in Japan.

Question on Alumilite: Can you vary the open time? From what I have read, 4 to 5 minutes of open time. Can Alumilite be adjusted to an open time of 10 to 20 minutes or so?
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The normal open time for Alumilite Clear is 7 minutes, not 4-5. It will increase with lower temps and decrease with hotter temps. You can get a longer open time by keeping it in the refrigerator. In the summertime here in Central Texas, I have to keep mine in the refrigerator in order to have enough time to pour my blanks. Then again, I still prefer the Alumilite Water Clear and its normal open time is only 5 minutes to begin with.

To answer your last question...no, you can not get 20 minutes even if you freeze it!
 
bruce119 said:
Now if they could just get it stay open for a good 10 minutes. .
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That is in the works! I have a test batch here in my shop, waiting for me to have some time to test it out that will have an even longer open time. Assuming the development is anything like the Alumilite Clear that I helped them develop, I may have to test a number of different formulations until it is ready for production. Of course, this is assuming it is even going to work!
 
As I have said numerous time, I have to disagree that PR polishes better or to a higher gloss than Alumilite Clear. It is easier to get a super gloss with PR but you can get the same with Alumilite if you know how. I have done a black blank where I used a piece of black PR and a piece of Alumilite Clear dyed black and epoxied them together. I then turned the blank, sanded and polished it as if it was one blank so I would eliminate any difference in the amount of time I spent on each. When I was done, I could not tell where one started and the other stopped based on gloss. I could tell a very slight color difference but that was it. My wife could not even tell the difference in the color no matter how hard she looked at it and swore it was all the same material.
 
Since joining IAP I have started casting. Ive tried PR several times and I am sliding along the learning curve. I have been considering trying Alumilite too. What is the best source?

Scott
 
watch_art said:
So if you add less hardener and let it cure longer the PR should be easier to work with?
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Absolutely the more MEKP you add the more heat the finished product will be more brittle. Don't rush it I do 3-4 drops per once then again depending on mass. I can demold after 12 hrs it's still a little tacky but a little time outside in warm air solves that.
 
I think they are two different materials for different things.
Almilite(or uretahne resins)-are good for worthless woods,and place that you want strength(PR is brittle).
PR-for total resin casting,and needs no finish,but is brittle oh I use a syringe to and the hardener @ .90 % by volume.
Hope that helps,Victor
 
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MesquiteMan said:
.... I have done a black blank where I used a piece of black PR and a piece of Alumilite Clear dyed black and .....
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As far as I'm concerned the black die Alumilite sells is pathetic! I have been a loyal Alumilite customer for several years now and have made hundreds of blanks using their white, water clear and finally their crystal clear but am looking for an alternative when it comes to making pure black blanks.

Their other dies work great but I'm fed up with wasting time and expensive material mixing the crystal clear with their black TAR, which they refer to as black die. I can mix a 400 gram batch, add the black die (which you have to thin with part "A" to even get it out of the bottle) then stir the heck out of it, only to be turning a nice blank a few days later and hit a pinhole size gooey "TAR pocket" then have to trash the entire blank.

I believe these gooey tar pockets are very tiny bits of die that regardless of how hard you mix the resin, stays suspended in the properly mixed resin and being black, you can't see it when mixing.

The only thing worse is to spend time cutting down a small fountain pen section, drill and tap it and the LAST step is to shape the grip THEN turn into one of the dreaded "TAR pockets". I've trashed more work because of this and Alumilite's answer to the problem....... Yeah, that's just how it is! :mad:

Since you have their ear, why not get them to give us a black die that will actually drip out of the bottle like all their other colors rather than having to dig it out with a Popsicle stick?

If anyone is considering making black blanks or using black die with other pigments, I would say THINK TWICE before considering Alumilite.
 
Hmmm, I have used a lot of Alumilite black dye and have not had the tremendous troubles you have, George. Then again, I am not thinning mine with part A. I use odorless mineral spirits and just do not have the level of difficulty that your post indicates. Just pour in a little odorless mineral spirits, put the cap back on, and shake the hell out of it. I remember recommending this to you in the past. Has this not worked for you either?

Also, if you are needing black, why not use either of their resins that are already black and not have to mess with the dye? When I need pure black, I use Alumilite RC-3 Black or Alumilite Regular Black, depending on what I have on hand at the time.
 
I have pretty simple criteria for deciding when to use PR and when to use Alumilite.

If it needs structural strength (most of my pens have plumbing tubes, so this is not necessary) or if it needs precision hand threading, or if the material embedded is VERY porous, it gets poured with Alumilite.

For everything else, I use PR.

My basic reasoning it because I can pour PR for about 1/3 or 1/4 the price of pouring Alumilite. A five gallon bucket of PR resin and catalyst cost me less than $150. I passed out before I got the final price of 5 gallons of Alumilite.

The point I'm trying to make is that one is no better than the other. Both products are necessary in the market place, simply because the strengths and weaknesses of each. Which product YOU choose should be strictly chosen because of YOUR needs, not because it's what everybody else does.
 
PenMan1 said:
My basic reasoning it because I can pour PR for about 1/3 or 1/4 the price of pouring Alumilite. A five gallon bucket of PR resin and catalyst cost me less than $150. I passed out before I got the final price of 5 gallons of Alumilite.
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Granted, I know nothing about this, but I'd like to try it one day, where is the best place to get both products from?
I looked a bit and found a gallon of PR and 1 ounce catalyst for $81.53 and Alumilite is $114.50 for 2 gallons. How many pens can be cast from that?
 
MesquiteMan said:
Hmmm, I have used a lot of Alumilite black dye and have not had the tremendous troubles you have, George. ......
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Hmmmmmmm back at ya! I figured I'd be called either a liar or an idiot that doesn't know how to stir a stick or spatula so I took a photo of a pen that I had a considerable amount of time invested in when I finally encountered the black goo pocket. It doesn't take much to ruin a pen, just half a pinhead size glob creates a nice little crater.

MesquiteMan said:
......Also, if you are needing black, why not use either of their resins that are already black and not have to mess with the dye? When I need pure black, I use Alumilite RC-3 Black or Alumilite Regular Black, depending on what I have on hand at the time.
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Why not....... because I also use black with clear and other color dies to create different looks when mixed with different PearlEx powders. Here is (WAS) a lower pen body where I bond a solid black finial then blend the parts together to create solid black merging into a shimmering dark silver look. I made and bonded the finial, drilled and tapped the body and was turning to the body to it's final size when I first noticed the tiny kidney shaped blob deep inside the blank. Scratch another hour and more money in the trash!

Alumilite recommends thinning the black die with part A so I just follow their recommendations.
 

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PenMan1 said:
My basic reasoning it because I can pour PR for about 1/3 or 1/4 the price of pouring Alumilite. A five gallon bucket of PR resin and catalyst cost me less than $150. I passed out before I got the final price of 5 gallons of Alumilite.
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Andy, I think you math may be off! I believe a 5 gallon kit of Alumilite costs around $550. I don't remember exactly since I never even look at the cost.

Using your numbers of $150 per FIVE (edited for my typo, per George's post below) gallons for PR and your claim that you can pour it for 1/3 to 1/4 the cost of Alumilite, that would put the 5 gallon Alumilite at $450 to $600. However, remember that the 5 gallon KIT of Alumilite is 5 gallons of A and 5 gallons of B, making a total of 10 gallons of mixed resin. That makes the cost for 5 gallons of mixed resin, using my $550 above, come out to $225 which is 33% higher than your PR price.

Yes, Alumilite IS more expensive, I am not denying that. But please give accurate cost information!
 
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JamesB said:
PenMan1 said:
My basic reasoning it because I can pour PR for about 1/3 or 1/4 the price of pouring Alumilite. A five gallon bucket of PR resin and catalyst cost me less than $150. I passed out before I got the final price of 5 gallons of Alumilite.
Click to expand...

Granted, I know nothing about this, but I'd like to try it one day, where is the best place to get both products from?
I looked a bit and found a gallon of PR and 1 ounce catalyst for $81.53 and Alumilite is $114.50 for 2 gallons. How many pens can be cast from that?
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Alumilite has different prices for different types on their website. Their clear is $160 for a two gallon kit from their website or simply by calling them, did you find it at a reseller for less?
 
MesquiteMan said:
PenMan1 said:
My basic reasoning it because I can pour PR for about 1/3 or 1/4 the price of pouring Alumilite. A five gallon bucket of PR resin and catalyst cost me less than $150. I passed out before I got the final price of 5 gallons of Alumilite.
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Andy, I think you math may be off! I believe a 5 gallon kit of Alumilite costs around $550. I don't remember exactly since I never even look at the cost.

Using your numbers of $150 per gallon for PR and your claim that you can pour it for 1/3 to 1/4 the cost of Alumilite, that would put the 5 gallon Alumilite at $450 to $600. However, remember that the 5 gallon KIT of Alumilite is 5 gallons of A and 5 gallons of B, making a total of 10 gallons of mixed resin. That makes the cost for 5 gallons of mixed resin, using my $550 above, come out to $225 which is 33% higher than your PR price.

Yes, Alumilite IS more expensive, I am not denying that. But please give accurate cost information!
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If I read correctly, Andy said he got PR for LESS than $150 for FIVE gallons not one gallon. Just giving accurate cost information!:biggrin:
 
Texatdurango said:
MesquiteMan said:
Hmmm, I have used a lot of Alumilite black dye and have not had the tremendous troubles you have, George. ......
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Hmmmmmmm back at ya! I figured I'd be called either a liar or an idiot that doesn't know how to stir a stick or spatula so I took a photo of a pen that I had a considerable amount of time invested in when I finally encountered the black goo pocket. It doesn't take much to ruin a pen, just half a pinhead size glob creates a nice little crater.

MesquiteMan said:
......Also, if you are needing black, why not use either of their resins that are already black and not have to mess with the dye? When I need pure black, I use Alumilite RC-3 Black or Alumilite Regular Black, depending on what I have on hand at the time.
Click to expand...

Why not....... because I also use black with clear and other color dies to create different looks when mixed with different PearlEx powders. Here is (WAS) a lower pen body where I bond a solid black finial then blend the parts together to create solid black merging into a shimmering dark silver look. I made and bonded the finial, drilled and tapped the body and was turning to the body to it's final size when I first noticed the tiny kidney shaped blob deep inside the blank. Scratch another hour and more money in the trash!

Alumilite recommends thinning the black die with part A so I just follow their recommendations.
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George, why so touchy???????

I never called you either a liar or an idiot that doesn't know how to stir a stick or spatula, George. All I said I that I have use a LOT of Alumilite black dye without the problems you are experiencing. Sorry you are taking this as some type of attack but it is just posted as a fact.


Alumilite recommends thinning the black die with part A so I just follow their recommendations.
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Ummm, actually, George, that was MY recommendation to you in a phone call a few years ago. If you call and talk with Mike or Carol, they will tell you to use either Part A or Odorless Mineral Spirits. Actually, Mike will most likely tell you the OMS as he is the one who told me about it. As a matter of fact, Mike even sent me some OMS about 5 years ago when I asked him about the thick black.
 
CURTIS ;
My post reads less than $150 for 5 gallons of PR. At my last pricing, Alumilite was $550 for 5 gallons. Using the last quotes that I have (last week) that puts my math EXACTLY in the middle of the 1/4 to 1/3 as much for PR.

Not trying to "start" anything. These are just the numbers I have. I use both PR and Alumilite. I like Alumilite. But it most of my instances. PR works just fine.

My whole post was about using what works for each individual's particular needs. I'm sorry if this was somehow lost in translation. BUT, my math is very accurate according to the quotes I got on March 30, 2012. If my pricing on Alumilite is less than I was quoted, please let me know.
 
MesquiteMan said:
..... If you call and talk with Mike or Carol, they will tell you to use either Part A or Odorless Mineral Spirits.....
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Perhaps disguise your voice or have a friend call call and ask Carol what to do about the black TAR problem and she'll likely mention thinning with part A but when I called several months ago, having forgotten our phone conversation of 3 or 4 years ago, she didn't say a thing about mineral spirits but when asked if they were working on a solution she said "No, that's just the way it is" but she did caution me not to thin the dye with clear part A then use the die to tint white alumilite since they were incompatible.
 
PenMan1 said:
CURTIS ;
My post reads less than $150 for 5 gallons of PR. At my last pricing, Alumilite was $550 for 5 gallons. Using the last quotes that I have (last week) that puts my math EXACTLY in the middle of the 1/4 to 1/3 as much for PR.
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Andy, buddy, you are missing my point!! Yes, your quote was correct at $550 for the Alumilite 5 Gallon KIT. That is 5 gallons of A and 5 gallons of B. That means you are getting 10 gallons of Alumilite Clear for $550. That puts it at $275 for the equivalent 5 gallons of PR or $55 per gallon.

Now, granted, I may have some typos or bad math as well but I have an excuse! I am currently on some really good Vicodin as I type!
 
Curtis:
I do get you point. I had a typo in the first post. I should have said (BEFORE SHIPPING, because it is more expensive to ship 2 five gallon buckets) that I can pour PR for 33 percent less.

WHAT I DID SAY IN ERROR, was that PR costs me 33 percent as much as Alumilite. IN REALITY, PR is 33 percent less expensive.TOTALLY DIFFERENT!!!
 
Thanks for the clarification, Andy! Yeah, that is a big different and what I was having issue with. I see it quite frequently here where folks will say Alumilite is double or more in cost than PR which is just not the case most of the time.

Also, not sure what you mean by 2 5 gallon buckets is more expensive to ship. Yeah it is more expensive to ship 2 45+/- pound packages than one. It will be cheaper to ship Alumilite than PR in 5 gallon containers, however, since PR will have to ship as dangerous goods I believe where Alumilite does not.
 
Texatdurango. Their clear is $160 for a two gallon kit from their website or simply by calling them said:
No I did not find it for less. I just randomly picked one. I think it was the white or clear cast.
What is the difference between the 3 clear alumilite?
The point of my post was that if 2 gal of alumilte is 114 or even $160 it is the same cost as PR from the site I was looking at. I must be looking at the wrong site. I may start with alumilte (Curtis was convincing) but then I need a pressure pot right?
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Hey, lets all go down to the Dirty Inkwell. Drinks are on me and we can all shake on it.

So, summers here are 100+ degrees and I am not going to be allowed to cast in the house. So, which will give me the longest working time?
 
Haynie said:
Hey, lets all go down to the Dirty Inkwell. Drinks are on me and we can all shake on it.

So, summers here are 100+ degrees and I am not going to be allowed to cast in the house. So, which will give me the longest working time?
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Mark,
No doubt about it, polyester resin will give you the longest working time in any setting, hot or cold! With PR, you are talking hours.... to many hours, with Alumilite you are talking minutes regardless of the temperature!

BUT........ working time isn't everything! It really depends on what you are going to make with the blanks. There are many opinions about this subject but as far as I am concerned, Alumilite cannot be beat for casting pen blanks where you mix in dyes (except black) and pigment powders. Threading properties are exceptional and I cut threads in pens four years ago, and have used the pens pretty regularly and the threads show no signs of wearing out.

If you have access to a pressure pot, a 32oz kit of clear Alumilite is $25, cheap enough to give it a try, and that will make quite a few blanks. The hobby shops have quart cans of casting resin for around $20 as well so for around $50 you can compare to your hearts content.
 
Haynie said:
SO you DO need a pressure pot for Alumilite.

PR it is.
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I used to make "worthless wood" blanks where you want the resin forced as far into the wood grain as possible so pressure is a must.

Also I use clear and white with colored dyes and PearlEx pigments, these blanks too need pressure to get rid of the bubbles.

When mixing small 30 gram batches to test new colors I do not put them in a pressure pot and it shows....every one of them have tiny air bubbles throughout the blanks so I would say that I wouldn't use alumilite for pen blank making without a pressure pot in the above situations.

The above situations are based on my personal experiences only and I am simply sharing my personal opinion, not necessarily facts.
 
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A pressure pot is a must...

Texatdurango said:
Haynie said:
SO you DO need a pressure pot for Alumilite.

PR it is.
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I used to make "worthless wood" blanks where you want the resin forced as far into the wood grain as possible so pressure is a must.

Also I use clear and white with colored dyes and PearlEx pigments, these blanks too need pressure to get rid of the bubbles.

When mixing small 30 gram batches to test new colors I do not put them in a pressure pot and it shows....every one of them have tiny air bubbles throughout the blanks so I would say that I wouldn't use alumilite for pen blank making without a pressure pot in the above situations.

The above situations are based on my personal experiences only and I am simply sharing my personal opinion, not necessarily facts.
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Hello,

I agree with the need to use a pressure pot with Alumilite... I also do not bother to pressure "colour samples," since they will never be sold and are only used as a visual reference for the "recipes" of each colour. Like Texatdurango, I also see tiny bubbles throughout the cured resin in these NON-Pressure treated colour samples. If you pressure treat them of course, they would have no visually discernible bubbles, but why bother for a small colour sample?

No matter how carefully I've stirred , I have always gotten those tiny bubbles in non-pressure treated colour samples. I have not tried using my ultrasonic cleaner to see if the colour samples would still have any tiny bubbles, but it sounds like a test is coming... :) I use two 15 gallon pressure pots for casting any Alumilite other than the above referenced colour samples.
 
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