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RAdams

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I got my first ever gallon of Silmar 41 earlier today. I already had my pot, and heat box, and mica, and everything else ready to go.


I mixed up a batch of blue pearl. PERFECTION!

They sat in the pot for an hour at 40 PSI, then an hour in my homemade hot box (small box with a heat lamp) They are cooled off now, and hard, and straight, and beautiful!

After that, i decided to give it another whirl. This time, i put in some antique gold with a bit of red pearl. another amazing set of blanks!


MAN THIS STUFF IS FUN! now just to come up with names for my snazzy new colors!
 
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a agree with Rob........my first casts (several attempts) turned out looking like i had swallowed some Weird stuff a few hours before......
persistance!
oh what a challenge you have ahead of you.....if they are turning out great to start with........where else do you go?
congrats on the pours...........PICS!
 
My first blanks came out really well. Unfortunately, that success lulled me into a false sense of security. I ended up not following all of my steps on the second batch, leading to big puddles of sticky PR on my workbench and floor.
 
Well, unfortunately i spoke too soon. Sorta anyway. They turned out top notch don't get me wrong, but when i turned one of the "root beer" looking blanks, it was basicly transparent. I used some of the same color to color the inside of the blank, wich didnt seem to help because the tube was quite obvious.

I am going to try one of the blue ones tomorrow and see what happens. The bottle stopper blanks should be ok though. I also made a wild green and pink one that reminds me of watermelon, but it is almost transparent as a whole blank, so i know it won't work.

Any ideas as to how to remedy this would be much appreciated!


P.S. Pics to come soon of the blanks.
 
more pigment or powder in the resin. Use them in thicker pens so you dont have to turn away as much resin. You could alway break them up and pour them into another mixed color of resin.
 
yep, kinda what i thought the problem was. How much mica shuld be used for a 8 to 9 Oz. pour? I read somewhere that is was 5 to 7%? that would be considerably more than i used. for a 10 Oz. pour, 5% would be 1/2 Oz of color?


Oh yeah, almost forgot. I just posted pics. sorry for the quality, and for posting 4 in a row. hope that isn't against the rules.
 
I did not see them in the thread, i didnt know they were in the gallery. I like the silver and purple, have to see that one finished, should be cool.
 
yeah i don't know how to put them in the thread. sorry.


Silver and purple? you mean the pink and green? that one is CRAZY translucent. I am going to smash it, and throw it in a " potluck" type pour.
 
RAdams said:
yep, kinda what i thought the problem was. How much mica shuld be used for a 8 to 9 Oz. pour? I read somewhere that is was 5 to 7%? that would be considerably more than i used. for a 10 Oz. pour, 5% would be 1/2 Oz of color?


Oh yeah, almost forgot. I just posted pics. sorry for the quality, and for posting 4 in a row. hope that isn't against the rules.
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Polyester Casting Resins (Silmar 41) can take a filler load of 5% to 7%.

8oz approx = 240mL * 5% = 12mL Pearl-Ex type filler.
9oz approx = 270mL * 5% = 13.5mL Pearl-Ex type filler.
10oz approx = 300mL * 5% = 15mL Pearl-Ex type filler.

My general rule of thumb is 1ml of Pearl-Ex type filler per metric ounce (30mL). But make up your own rule as this one is mine!

Micropearl, and Macropearl are not pigments, and look best when added at 1%. Pearlants should be calculated to fit into the total filler load. Pearl-Ex Micro and Macro Pearls will cause a color shift to some base pigments (Red) and you may have to add a correction pigment.

Pearlwhite, while it is a pigment, is a pearlant and should be treated as such. You really need to use a white pigment base.

Pearls and Pearlants are considered part of the total filler load as should liquid/paste pigments.

If you are using true metals (brass powder, aluminum powder...) you need you measure by weight. True metals can inhibit cure by causing a thermal inhibition, they absorb the heat during the cure. Some powdered metals are chemically incompatible with PR and will cause inhibition.

These are my general rules of thumb, some are based on information from the plastics industry, some are from experience. Take them or leave them, make your own.
 
Wow. thanks for all the info. now i just gotta convert ML to an SAE dry measurement.

But, looking at a little syringe i have for emergency sutures, 15ML would be a MEGATON compared to the tiny little bit of mica i put in.I guess i need to find a powder measuring system that is accurate with small amounts. I think that is something my local head shop could help with i am sure.
 
well ok then, i tried to convert, but you gotta know the densities, and gravities of the substances converted. i will just keep adding more and more powder till i find a good amount for coloring i guess.
 
RAdams said:
Wow. thanks for all the info. now i just gotta convert ML to an SAE dry measurement.

But, looking at a little syringe i have for emergency sutures, 15ML would be a MEGATON compared to the tiny little bit of mica i put in.I guess i need to find a powder measuring system that is accurate with small amounts. I think that is something my local head shop could help with i am sure.
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Michaels carries Lil' Dippers, in the casting section, they are 1 mL scoops, and come in a pack of 5.

Coastal Scents carries o.15mL & o.3omL scoops that are a good item to add if you place an order with them.
 
Casting isn't as difficult as some make it seem. Although I do measure everything, it is not necessary to get technical on exact percentages. Just add as much colorant as needed to make the resin as opaque as you want it. It will still be fine even if you put a 1/4 oz. of pigment in 1 oz. of resin. It's just a waste of pigment. Just experiment and have fun.
 
RAdams said:
well ok then, i tried to convert, but you gotta know the densities, and gravities of the substances converted. i will just keep adding more and more powder till i find a good amount for coloring i guess.
Click to expand...

Some people like consistancy, and from a profit standpoint- materials control. The ability to write down and follow a formula/recipe and read a catalyst chart does not make casting difficult. To maintain consistancy, you have to have repeatability. My Urple-Purple is 99.9% the same from batch to batch. It is also distinctly different from my color Graple.

What is it you are trying to convert? Pearl-Ex, and many micas have very(extrememly) low weight. The Pearl-ex are coated plastic foils. Just measure by volume, either in mL(cc) or tsps. If you were to go by weight to reach 5% fill with Pearl-ex, your resin would be so loaded it may not cure, and if it did cure, it may be too brittle to handle.
 
I am using the coastal scents mica sampler. The only referance i have is watching someone make a set of cactus blanks, and they only used a touch of color, so i thought that was all you needed to cast any color. I figure i will make a couple more sample batches this evening and see what i get.
 
RAdams said:
well ok then, i tried to convert, but you gotta know the densities, and gravities of the substances converted. i will just keep adding more and more powder till i find a good amount for coloring i guess.
Click to expand...
That's my method. Is it completely repeatable? Nope. Do I need to absolutely make teh same color resin over and over again? Nope.
 
i gave it another go this evening. I have really been enjoying mixing two half batches of different colors, and mixing them in the mold.

Tonight i added about 6 or 8 times more color than before. I kept adding color until it coated the mixing stick good.

I mixed up half a batch of black pearl, and half a batch of white pearl.

I experimented with the pours as well. In one mold, i poured white in one end, and black in the other, then used the stir stick to give it a few whirls. The next one, i poured black covering the bottom of the mold, then i poured the white into the black. The last pen blank mold, i started with white, and then black. For my bottle stopper blank i just poured both at the same time and left it alone. My wife kicked in for the naming process as well.

There was nice seperation of colors in all of the blanks. the bottle stopper, and the blank that i poured from both ends came out with the most color seperation.

I have also decided to put a spin on any color control issues that i may have by telling my customers that every PR pour is as unique in color as a piece of wood. I never know what i am going to get until i turn it.


i will try to post pics as soon as i find my camera.

P.S. you guys were totally right. making your own blanks is crazy fun! and the fumes are cool too.
 
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