Alumilite versus Silmar

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andyk

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Is there a difference in Alumilite and Silmar? Or are they essentially the same thing? Since the passing of Mr. Fiberglass (RIP) where does everybody go now?
 
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Yes, there is a major difference. Alumilite is polyurethane resin and Silmar is Polyester resin. They are totally different products and the only similarity is that they both start as liquid and end up solid if done right!
 
MesquiteMan said:
Moisture won't make it sticky and gooey. Not having it mixed completely does that. Moisture causes it to foam.
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Thanks Curtis, Ive been trying to cast dried flowers from my sons birth and the Mothers Day idea went out the window. Half set up great and the top half came out sticky. I'll keep trying until I run out of the flowers. Well at least I know they are dry enough. Thanks
 
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John, how dry is dry enough? The need to be oven dry to work best. For mixing, I suggest getting some clear plastic drinking cups to mix the resin in. Then pour in your 2 parts. When you first pour them together, they will be cloudy. Stir until there is not cloudiness or streaks AT ALL. Then add any dye and mix completley. Then pour.
 
Curtis, you brought it up... so now I'm asking. What are the advantages/disadvantages of one over the other. I've had good luck with the Castin' Craft resin from Michaels, it just doesn't seem very cost effective. From what I've read the dyes for each product are different correct? With the Castin' Craft I just use Testors acrylic paints and PearlEx powders.
 
I am a Silmar man myself, check my thread titled casting material reference. silmar is less brittle and less expensive than castin craft. and more shiny than alumilite. you also DO NOT have to fight with the shavings the fricken time that you are turning.
 
MesquiteMan said:
For mixing, I suggest getting some clear plastic drinking cups to mix the resin in.
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Curtis, I've noticed that you've mentioned Sam's Club a couple of times where you get these.

Since we don't have a Sam's around here do you happen to know if the Walmart plastic cups are the same? Does your box say Sam's and by chance what oz cups they are?
 
i don't know about alumilite, but if you use silmar or CC, I recomend "Paper" cups. Not wax coated either. plastic will melt. most of the paper cups can hold up all the way through the curing.
 
Plus Alumilite doesn't stunk up the place to a point where everyone wants to gag, in fact it has almost no smell at all.

Rah Rah Rah
 
mostangrypirate said:
i don't know about alumilite, but if you use silmar or CC, I recomend "Paper" cups. Not wax coated either. plastic will melt. most of the paper cups can hold up all the way through the curing.
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When using polyester (Silmar) if you use the cheap plastic cups they will melt. BUT go to wall mart and get the better "CRYSTAL CLEAR" "Hefty" cups they work fine and will NOT melt I have left resin in them for days and they have not melted. On the other hand if you use the cheaper frosted brand name cups you will not be able to mix it fast enough before it starts eating the bottom out.

As for pros & cons alumilite verses polyester just do a little searching. You should find enough to keep you going a long wile. Each one has pros & cons. It's all been said before like I said just use the search.

Bruce
 
Simply put, alumilite is better for casting objects/labels/worthless wood, and PR is better for casting just colors. Now the crystal clear alumilite is supposed to give PR a run for its money with casting just colors, but I've never used it so I'll let others speak on it. Alumilite is more expensive, but worth it in the end because it's a lot easier to mix than PR. I wasted most of my first gallon of PR just trying to figure out the ratio of PR to hardener.....alumilite is just 50/50 mixed.
 
GouletPens said:
Simply put, alumilite is better for casting objects/labels/worthless wood, and PR is better for casting just colors. Now the crystal clear alumilite is supposed to give PR a run for its money with casting just colors, but I've never used it so I'll let others speak on it. Alumilite is more expensive, but worth it in the end because it's a lot easier to mix than PR. I wasted most of my first gallon of PR just trying to figure out the ratio of PR to hardener.....alumilite is just 50/50 mixed.
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From what I have read it seems to me that you have it backwards. Everyone says that the Silmar is better for casting things because it's easy to polish up and you don't have to deal with the moisture issue like you do with alumalite. However for just colors, Alumalite seems better from everything I've read. Care to elaborate on why you feel it is reversed?
 
jleiwig said:
From what I have read it seems to me that you have it backwards. Everyone says that the Silmar is better for casting things because it's easy to polish up and you don't have to deal with the moisture issue like you do with alumalite. However for just colors, Alumalite seems better from everything I've read. Care to elaborate on why you feel it is reversed?
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Well, first off, whatever you cast should be dry dry dry. Moisture in PR or alumilite will cause problems. I've never used simlar 41, but I've used the artstuf.com PR which is similar from what I understand. PR is less expensive so it's better for casting just colors...it uses more material and is more cost effective. When cast, it'll turn and polish much like an acrylic acetate.

The reason alumilite works well for casting objects, particularly wood, is that it needs a CA finish to really polish up well. This is the water clear I'm talking about, I've never used the crystal clear. Since you're putting a CA finish over the wood anyway, it goes over the alumilite as well and seals it all up nicely. This goes for any other object you might be casting....you usually want a finish on it so the exposed part of whatever you're casting is sealed.

Of course, you can use either or both for whatever purpose you like. Personally, I like that alumilite doesn't smell like PR and is easy to mix, just 50/50. It cures in 1/10 the time of PR and is, in my opinion, much harder to screw up casting. I think most people tend to prefer one or the other and use that for both casting objects and casting just colors. Most people are dead set on one or the other though, and can't be convinced otherwise!
 
GouletPens said:
The reason alumilite works well for casting objects, particularly wood, is that it needs a CA finish to really polish up well. This is the water clear I'm talking about, I've never used the crystal clear. Since you're putting a CA finish over the wood anyway, it goes over the alumilite as well and seals it all up nicely. This goes for any other object you might be casting....you usually want a finish on it so the exposed part of whatever you're casting is sealed.
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I guess this is the part that I don't understand. Why would I want to have to add a second step of finishing by applying a CA finish to the Alumalite when I could just MM the PR? In my mind that is a drawback to Alumalite, not an advantage.
 
jleiwig said:
I guess this is the part that I don't understand. Why would I want to have to add a second step of finishing by applying a CA finish to the Alumalite when I could just MM the PR? In my mind that is a drawback to Alumalite, not an advantage.
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Keep in mind, this is working with Alumilite WATER CLEAR, which is just one product they have. That's the one I use because I bought 2 gallons of it about 2 weeks before I found out about CRYSTAL CLEAR, the newer, better alumilite product. Crystal Clear is supposed to finish nicer like PR. The fact that water clear didn't finish as nicely as PR was the exact reason why they formulated Crystal Clear, to address this specific problem. I haven't yet used Crystal Clear, but this is what I understand of it. Curtis can certainly speak to it better since he's tight with the alumilite crew.

You're exactly right though, having to CA finish over the water clear alumilite is a drawback, and an argument many PR advocates have against the product. But there are many advantages I feel that outweight the PR in many cases, especially if the new crystal clear product polishes like PR. The only drawback then would be the price.
 
jleiwig said:
I guess this is the part that I don't understand. Why would I want to have to add a second step of finishing by applying a CA finish to the Alumalite when I could just MM the PR? In my mind that is a drawback to Alumalite, not an advantage.
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I would have to agree with Brian. All though I now prefer Silmar over Alumilite (as I said before they both have pros and cons).

But which ever you use and cast materials such as worthless wood, coffee beans or my shredded money. You will have to put a CA finish on. When you have 2 different materials coming through the surface there is no avoiding it. They have different hardness you will fell the opposing material what ever it mite be. The only way to eliminate it is to apply a CA finish.

Bruce
 
bruce119 said:
I would have to agree with Brian. All though I now prefer Silmar over Alumilite (as I said before they both have pros and cons).

But which ever you use and cast materials such as worthless wood, coffee beans or my shredded money. You will have to put a CA finish on. When you have 2 different materials coming through the surface there is no avoiding it. They have different hardness you will fell the opposing material what ever it mite be. The only way to eliminate it is to apply a CA finish.

Bruce
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Well put Bruce. Note that when using alumilite water clear, if you're just casting colors and not casting around a material like wood or coffee beans or whatever, you'll still need a CA finish to get a high gloss. You won't with PR. That's the one instance where the CA finish will be necessary for alumilite but not PR.
 
bruce119 said:
I would have to agree with Brian. All though I now prefer Silmar over Alumilite (as I said before they both have pros and cons).

But which ever you use and cast materials such as worthless wood, coffee beans or my shredded money. You will have to put a CA finish on. When you have 2 different materials coming through the surface there is no avoiding it. They have different hardness you will fell the opposing material what ever it mite be. The only way to eliminate it is to apply a CA finish.

Bruce
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Yes I understand that. I read from his postings and others that all Alumalite finishes need CA to shine like PR after just MM and a polish, not just on dissimilar materials. Am I wrong in stating that?

I'm not trying to advocate PR over Alumalite, just trying to make sure I have my facts straight.
 
jleiwig said:
Yes I understand that. I read from his postings and others that all Alumalite finishes need CA to shine like PR after just MM and a polish, not just on dissimilar materials. Am I wrong in stating that?

I'm not trying to advocate PR over Alumalite, just trying to make sure I have my facts straight.[/quote]

Yes I that is my experience though it does shine up good but not as good as PR. BUT I am not familiar with this new crystal clear that I guess they just released. I was using the later water clear that was about a year ago when the crystal clear was not out. Maybe it is better I see it has a longer 7 min. pot life that is a big plus. The older water clear only had a 4-5 min. pot life and that was one of the cons.

Bruce
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Crystal Clear polishes up like PR. Like Bruce, I highly recommend that you apply a film finish of some sort over any blank that has something embed in it that comes to the surface.
 
I am I right in saying that Alumilite rquires pressure for casting? Which then requires: air compressor, HF paint pot and related fittings, CA expertise for finishing, scale for measuring Parts A & B, different colorants than PR. Anything I missed?
 
andyk said:
I am I right in saying that Alumilite rquires pressure for casting? Which then requires: air compressor, HF paint pot and related fittings, CA expertise for finishing, scale for measuring Parts A & B, different colorants than PR. Anything I missed?
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The air compressor, pot and fittings you need for both...or an ultrasonic cleaner to vibrate out bubbles. You can cast either without the pot or ultrasonic, but you risk bubbles. CA expertise, not if you use crystal clear. Both polish up the same that way. The scale, yeah, that's a whopping $10. And the colorants you can use for both, just not acrylic paints. transtint or mixol and pearlex work well in both. You make it sounds like alumilite is so much more fuss. Well, do both and tell me which is easier.
 
You only need CA expertise if you are doing castings with stuff embeded that comes to the surface. As one who has done more of this type of casting than most, I highly recommend it for ANY type of resin that you use. I recently switched to Crystal Clear for my cactus blanks thinking that it would be better for my customers to be able to polish the blanks without putting a CA finish on them. I did a couple of pens and the resin polished very nicely but it still did not look the way I wanted since every place the cactus is exposed on the surface looks different than the resin around it. Of course with "Worthless Wood", you need something to finish the wood portion anyway.

As for a pressure pot, yeah, you can do PR without and you really need it for Alumilite. That, of course, assumes you are talking about pure resin with nothing in it. If you do PR with wood, then you need pressure too so that the resing gets into the smaller crevices better.

It is one of those things...if you only want to do pure resin, then use PR, deal with the smell, and don't worry about pressure.
 
For alumilite, straight resin, no embeded objects, 30 psi. If you embed something such as "Worthless Wood", my opinion is the more the better. I use 80 for all of my "Texas Collection Worthless Wood"™ and "Original Cactus Blank"™ pen blanks.
 
Thanks for clearing that up everyone. I'll start with PR, since it's cheaper to mess up and move to Alumalite at a later date to see if I like it.
 
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