aluminite question

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polarbear1

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I just worked on my first two aluminite casting and in each there is a pocket of soft aluminite. I believe the mold leaked a little and I mixed a second batch and poured it on top of the first to fill the mold. Was the addition of more aluminite the problem, or did I not mix one of the batches enough?
 
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Two things; did you mix by volume or weight? The parts have to be mixed by weight. How long did you let them set? If using clear alumilite you will need at least 1 hour...if you put anything in the mix then it will take longer. Well 3 things,...be sure to mix very very well...Ok 4 things...if you are casting in a really cold environment it will take longer to set.

Hope this helps, Eugene.
 
If you have unset Alumilite, then you did not get it mixed thoroughly. The best way to insure you get it all mixed is to use clear plastic cups from Sam's or similar. Pour the 2 together and it will be cloudy. Mix until it becomes absolutely clear with not streaks and you have it mixed properly. Adding more Alumilite is not the problem. If, however, it is just a soft spot right after you take it out but still warm, let it sit until it cools and the soft part will be hard.

Also, not to be a smart a$$ but notice my subtle hints above? :) It is Alumilite, not Aluminite. No big deal, just thought I would point that out.
 
Thanks, I figured I was spelling it wrong but did not think my spell checker heard of Alumilite.and did not want to take the time to look it up:). I did it by weight, it sat for 5-6 days before I put it on the lathe, I did not mix in anything but the alumilite, it sat outside unseasonably warm these days in Southern California probably in the 70's or 80's during the day, so it must be I did not mix it well enough.

Thanks
 
ElMostro said:
Two things; did you mix by volume or weight? The parts have to be mixed by weight. How long did you let them set? If using clear alumilite you will need at least 1 hour...if you put anything in the mix then it will take longer. Well 3 things,...be sure to mix very very well...Ok 4 things...if you are casting in a really cold environment it will take longer to set.

Hope this helps, Eugene.
Click to expand...

One thing that I have been curious about is when I go to the Alumilite website they talk about this 1:1 ratio for all varieties of Alumilite, but only for the Clear do they specifically say 1:1 by weight. Furthermore they sell these pumps to dispense 1 oz at a time. Does the White, Black and Tan do 1:1 by volume and only the Clear by weight?

Chart from their website
http://www.alumilite.com/Category.cfm?Category=Casting Resins


Pumps they sell
http://www.alumilite.com/ProdDetail.cfm?Category=Tools&Name=1 oz. Pump Dispenser
 
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MesquiteMan said:
If you have unset Alumilite, then you did not get it mixed thoroughly. The best way to insure you get it all mixed is to use clear plastic cups from Sam's or similar. Pour the 2 together and it will be cloudy. Mix until it becomes absolutely clear with not streaks and you have it mixed properly. Adding more Alumilite is not the problem. If, however, it is just a soft spot right after you take it out but still warm, let it sit until it cools and the soft part will be hard.

Also, not to be a smart a$$ but notice my subtle hints above? :) It is Alumilite, not Aluminite. No big deal, just thought I would point that out.
Click to expand...


Careful, Curtis. Correcting spelling is a slippery slope with a pond of piranha poised to partake of portions of your anatomy waiting at the bottom!

Good luck,

William Cavanaugh, Former Chief of Grammar Police :wink:
 
From what I understood (and this could be wrong) the issue of 'by weight'
is important mostly in very small quantities. Because you measure into two
containers and then pour from one container into the other and mix, when
mixing small quantities it is possible that enough is left behind in the first
container to throw off the ratio. I think they were talking about under 1 oz.

Example: you measure out 1/2 oz Part A into container 1. You measure out
1/2 oz. Part B into container 2.

When you pour container 1 into container 2, there is still resin left in the
first container. It is stuck to the sides, even if you scrape it out. (and with
the raised lettering stamped into the measuring cups, there's a lot of area
that will still hold resin)

If 1/20th of an ounce gets left behind on a 10 ounce mix, it changes the
1:1 ratio by 1/2 of a percent. (not terrible) But on a one ounce mix, that
1/20th oz. throws it off by a whopping 5%. That's not so good.

Again, this is just my understanding. It could be all wrong. And I made up
the numbers for illustration of the point, not because they're accurate.
I think the water clear resin is more susceptible to problems with mixing
ratio errors than other resins, but the larger the mix; the less important
the 'by weight' ratio becomes.
 
OK lets here how Curtis goes about mixing a batch and how critical are these measurements.

While we are at it Curtis when mixing colors do you mix in one solution first before you combine them or do you combine them and then add the color???? If you do one solution then which one??? Also do you have to adjust anything when adding colors???

Did not mean to Hijack the thread but thought it might all go together. I am just ordering some today to try.
 
NewLondon hit it on the head! The only problem is wasting 3 cups!

I use one cup only. I place the empty cup on my scale an tare it out. Let's say I am going to need 8 oz of mixed resin. I then add 4 oz of a and then finish off with B to the 8oz mark. I then mix until it becomes completely clear (clear cups help here) and pour. Pretty simple.

As for volume vs. weight...in larger quantities, volume is not a big deal but is still less precise than by weight. It is just easier to use weight to get the precise mix, especially in small quantities. The clear is definitely more sensitive to the proper ratio.

As for color...Alumilite suggests to add the color to the A side and then add your B. I transfer my dye to CA bottles so that I can use drops. I use about 1 drop per ounce of mixed resin. That is such a minuscule amount that it does not affect the ratio significantly. I prefer to mix both parts together and then add the dye. As I said above, I use clear plastic cups. When you first pour the A and B together, they are cloudy. When completely mixed, they become water clear. If I add the dye first, I can not see this so I add the dye after mixing and have not had any problems at all.
 
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MesquiteMan said:
As for color...Alumilite suggests to add the color to the A side and then add your B. I transfer my dye to CA bottles so that I can use drops. I use about 1 drop per ounce of mixed resin. That is such a minuscule amount that it does not affect the ratio significantly. I prefer to mix both parts together and then add the dye. As I said above, I use clear plastic cups. When you first pour the A and B together, they are cloudy. When completely mixed, they become water clear. If I add the dye first, I can not see this so I add the dye after mixing and have not had any problems at all.
Click to expand...

So what do you do when using dry pigments? I hesitate to add those post-mix because
they can take a while to get stirred in w/ no lumps.

I did my first alumilite cast last night. Tried worthless wood and a blue w/ hi-lite green
mix. Loved the color, but ended up with lots of voids. (should have stuck it in the PVP).
I also underestimated the amount of resin needed to fill the mold (or perhaps I overestimated the volume occupied by the wood).
 
Remember, Alumilite is fast but you have MUCH more time than you realize. I don't use dry pigment but I guarantee that I could mix it with no problem. Most folks get rushed because they think they are running out of time. When I first started, I rushed around like a chicken with my head cut off. I was afraid to pour more than 6 ounces at a time, thinking I would not have time to mix and pour. I now mix and pour 20 ounces when making cactus blanks. That includes mixing in the color as well as metal powder to get the swirls.

The next time you mix up a batch, mix a little more than you need and leave it in your cup and you will see how much time you have. You should have plenty of time to add the dry pigment and get it all mixed.

Without pressure, you might as well forget "Worthless Wood"! It is an absolute MUST!
 
Jason,

Don't even waste your time with vacuum and Alumilite. There is not enough time to do it properly and it does not make the cast any better. This is from LOTS of experience!
 
MesquiteMan said:
Jason,

Don't even waste your time with vacuum and Alumilite. There is not enough time to do it properly and it does not make the cast any better. This is from LOTS of experience!
Click to expand...

Did you ever try pulling the vacuum then pouring the Alumilite into the mold
(while the mold is in the vacuum)?
 
sbell111 said:
How is this possible, given that the entire shop is not under vacuum?
Click to expand...

Ball valve on the lid of the PVP with a cup of resin on it and the mold
below. Once the PVP is to vacuum, pour the resin into the cup, open the
valve and let it run into the mold. You have an instant ?15?psi forcing the
resin into the voids of whatever, and no air in the piece to create bubbles.

You may also have a ball valve that never moves again.... but as far as
I know that's still an unknown. (which is why I asked if Curtis had done it)
 
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