# Casting Resin Comparison sheet



## DTI356 (Jan 3, 2008)

Hey guys,

Thought I'd post this comparison I made from some data sheets I got online and thru request.

It's a comparison of Micro-Mark, Smooth-on and Alumilte resins for making castings.

I compiled this data for my own purposes but thought some of you may be interested. I had heard that Micro-mark uses Smooth-ons resins for thier own branded resins....and after comparing the data I'd have to agree.

So much for trying it as a PDF

Here's a jpg of the file.....I hope this helps those interested.

http://i1044.photobucket.com/albums...1292459972










Tell me what you think


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## Michael Glavin (Jan 2, 2009)

Brian, 

Interetsed but your link is not working.... 

Michael


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## DTI356 (Jan 3, 2008)

Well, I sure don't know what the heck is going on.....cut'n'paste the http in my first post, hopefully that will get you something....


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## rkapuaala (Jan 3, 2008)

Try this


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## rkapuaala (Jan 3, 2008)

Did you get the gel times on those? Pot life is very subjective. I pick resins that take a while to gel so I can take a little more time to pour.


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## silverstatespecialties (Jan 2, 2008)

Posted By rkapuaala on 15 Dec 2010 06:15 PM 
Did you get the gel times on those? Pot life is very subjective. I pick resins that take a while to gel so I can take a little more time to pour. 

I refrigerate mine in a small fridge; this gives me about twice the pot life to get everything mixed & poured.


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## DTI356 (Jan 3, 2008)

rkapuaala, 

Thanks for making it viewable. That is all the info I got from them. 

I agree with you....I prefer more time to work since the pot life actually starts as soon as you put the 2 parts into the same container.....then you have to mix them, then you can begin to pour. When I started I actually bought the Alumilite Regular and lost quite a bit since 90 seconds is nothing unless your mold is very simple and you work very fast. Not to mention the Alum. Reg is also a bit thicker in viscosity so it pours slower....it was a lose - lose for me. 

Now I prefer the Smoothcast 305. I'm not doing production line work so fastest de-mold time isn't important to me. The thinner material flows easier into crevases also.


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## Mike O (Jan 2, 2008)

Brian, 

Thanks for compiling the data. I've used Aluminite in the past with good results and have been able to get good parts without air bubbles. I had a product from another company (can't recall which) that indicated a vacuum was needed to ensure no bubbles. Does the Micro-Mark/Smooth on need a vacuum system ? 

Thanks, 

Mike


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## DTI356 (Jan 3, 2008)

Mike, 

The Smooth-on material I use is thinner (lower CPS number) so it is faster to allow air to surface, so my answer is you don't need a vacuum system. 

If you are making parts for outdoors then the Alumilite seems to have a big edge in the thermal deformation temperatures. I'd imagine the 140 F resin may begin to deform if painted black and left in the sun on a hot summer day.


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## rkapuaala (Jan 3, 2008)

I have not had good results vacuuming resin after it is mixed. I compress all my castings in a pressure bot after the resin is poured into the mold. I have the regulator set at 60-70 psi range. I also vacuum the resin prior to pouring, both a and b. The resin I purchase is custom made and has a gel time of 3 minutes. Just enough time to pour around 5 figures and (my record is 8) and get them in the pressure pot before the resin starts to gel.


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## Mike O (Jan 2, 2008)

Brian, Rkapuaala, 

Thanks for the insight. I've had issues with small bubbles forming on the surface of the mold in the past when casting fairly large items like a building foundation. I'm still fairly new to this and some of the reading I've done indicates using a vacuum system would mitigate the bubble problem. I'll try the thinner material. Rkapuaala, when you say you vacuum the resin prior to pouring, is that after you have mixed a & b. Seems intuitively obvious, but I wanted to ask. 

Thanks, 
Mike


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## David Leech (Dec 9, 2008)

Hi Mike, 
Yes, mix A + B and then vacuum. 
It has to be as near to a complete vacuum to work completely. 
I had a friend who lived close by who had a glass vacuum bell jar set up and only when I was working with Smooth-On Crystal Clear I would use it. 
You need to mix in a container with many times the volume as the stuff froths up as all the air is extracted. 
This probably took 30 secs, then release the vacuum and take out the resin and pour. 
I use Smooth-On 300 and 325 for all my castings and have never needed to vacuum them and have seen no evidence of bubbles. 
One thing that a friend did was to stir and shake the A and B just prior to mixing, which of course created bubbles. 
Let them sit for an hour or so after stirring and shaking before using so that the bubbles come out. 
I then pour each part into a separate clear container to make sure that they are bubble free. 
Also when mixing, do a good job, but don't mix in air, just stir around and around, if you see what I mean. 
I think that casting is one of those things where you find the products and methods that suit your needs. 
Also you have to expect some failures at first, but practice makes perfect. 
All the best, 
David Leech, Delta, Canada


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