I need a little help with casting PR

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Chris88

Chris88

Member
Joined
May 27, 2009
Messages
112
Location
Louisiana
Hi everyone I hope yall are having a Happy Easter. I have been trying to cast some pen blanks with PR. I am having all kinds of problems. The main one is tiny air bubbles. I have put the mold with PR in a pressure pot, and did some and left them out of the pressure pot. With everyone I would tap the mold to get the air bubbles out so I thought. I am using pearl x powders. Have read every thing about casting. Not sure if I am missing something.

Thanks Chris
 
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I mix the color/powder in the PR first, then set the container in an ultrasonic cleaner, or even on the table for my bandsaw. This vibrates the bubbles out. Occasionally give it a slow stir to help the process along.

Then I add the MEKP catalyst stirring slowly. Back on the saw it goes for 5-10 minutes. Then it gets poured.

The time varies due to what I'm doing with the resin. If I need color definition between two different colors, I'll leave them on the saw longer. If it's a solid color, I'll pour then put the mold on the saw.

An interesting thing about using PearlX is if you put the mold on the saw or US cleaner, the flakes of ParlX will align. This has the effect of changing the material's reflective properties evenly so two sides of the pen might be bright, and two sides dull. This can be a neat effect if utilized properly. Kind of like crosscutting wood.
 
Thanks for your reply. I will have to try your way. The ultrasonic cleaner was going to be my next purchase. I have yet to have two colors come out. I am having problems with one color LOL.
 
If you take the measure of Pearl-Ex you are planning to use and put it in your toaster oven at 100F-125F for 30 minutes or so, that will drive off any moisture the powder has absorbed. Moisture can cause bubbles in PR.
 
Chris , I cast PR and don't use any pressure or ultrasonics . The way I do it is to mix the pigments (I use coastal scents mica powders , similar to pearl x) in the resin then let it sit for about an hour so any bubbles rise to the top and pop . Then I very gently but throughly mix in the MEKP , be very careful not to introduce any new bubbles .
I have started preheating the resin which thins the resin and allows the bubbles to rise faster but I used to get great results without the preheating , the preheating just speeds things up a bit . The main thing is to not mix any new air into the resin when adding the MEKP . Keep the mixing stick on the bottom of the cup and mix slowly .
When I pour the resin I pour it in a small stream at one end of the mold which helps keep new bubbles from being introduced .
I even cast clear this way and then use a method similar to Don Ward's to remove any bubbles that may have stuck to the tubes during the pour .
 
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I want to think yall for all of your help. Now I know what I was doing wrong. I was mixing the pr and the color pigments to fast and adding a lot of bubbles to it. Then when I added the hardener I would stir it fast. And that add a lot of bubbles to. Also I needed to put it on the bandsaw to vibrate the bubbles out. Butch I like the idea of setting it out for an hour to let the bubbles come to the top. Now I know to take my time and go slow. Next will be adding to colors that should be fun. Sorry about the pics and look no BUBBLES.

Thanks again Chris
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IMG_1141.jpg
 
ldb2000 said:
Chris , I cast PR and don't use any pressure or ultrasonics . The way I do it is to mix the pigments (I use coastal scents mica powders , similar to pearl x) in the resin then let it sit for about an hour so any bubbles rise to the top and pop . Then I very gently but throughly mix in the MEKP , be very careful not to introduce any new bubbles .
I have started preheating the resin which thins the resin and allows the bubbles to rise faster but I used to get great results without the preheating , the preheating just speeds things up a bit . The main thing is to not mix any new air into the resin when adding the MEKP . Keep the mixing stick on the bottom of the cup and mix slowly .
When I pour the resin I pour it in a small stream at one end of the mold which helps keep new bubbles from being introduced .
I even cast clear this way and then use a method similar to Don Ward's to remove any bubbles that may have stuck to the tubes during the pour .
Click to expand...
Just a thought since I have not done any casting but have reading as much as I can but would it help to introduce the MEKP into the resen via a syringe? Thus no bubbles from the pour or would that just be overkill?
 
Great job Chris . Glad to see you got it worked out and you are now bubble free . I tried several different ways to get the bubbles out after mixing the pigments in but the only way that i have found that works well is letting it sit for awhile . If you can safely heat the resin it is even better but remember resin is flammable so be careful .
Douglas , adding the MEKP isn't the problem , it's mixing it after when you have to avoid adding bubbles . A slow but complete mix is the only answer , keep the mixing stick on the bottom of the mixing cup and stir slowly .
 
ldb2000 said:
Great job Chris . Glad to see you got it worked out and you are now bubble free . I tried several different ways to get the bubbles out after mixing the pigments in but the only way that i have found that works well is letting it sit for awhile . If you can safely heat the resin it is even better but remember resin is flammable so be careful .
Douglas , adding the MEKP isn't the problem , it's mixing it after when you have to avoid adding bubbles . A slow but complete mix is the only answer , keep the mixing stick on the bottom of the mixing cup and stir slowly .
Click to expand...

Thanks, now I need to work on mixing two colors. What do you use to mix your pr in? The cups I was using would start leaking.
 
I use a HF digital scale and 6 ounce store brand waxed paper cups . They don't melt and are very cheap , just don't scrape the wax coating off when mixing .
As for multi color mixes , time your resin to find the gel time and then pour your colors together just before they gel .
 
lazyguy said:
Just a thought since I have not done any casting but have reading as much as I can but would it help to introduce the MEKP into the resen via a syringe? Thus no bubbles from the pour or would that just be overkill?
Click to expand...

You don't want to contaminate your needle by inserting it in the resin, as you can reuse it with the MEKp. However you are on to a good idea, as that is what some of us use to directly measure the amount of MEKp for the volume of resin we are casting. Then just squirt in on the resin and mix.
 
Hi Chris I cast a lot of PR about 25 ltr's every 3 to 4 weeks, I never have to pressurize unless I have the ribbon effect, my home-made mold will take 2.9 ltr at a time, I use a pigment paste and pearl-ex powder with the pearl-ex only being 30% of 2.9 ltr the rest is the base colour i.e. white, blue is the pearl-ex and flamingo pink is the pearl-ex powder.
I use the big kitchen measuring plastic jugs, these can be used time and time again, now the way I mix my colours are done with two jugs, one say white and the other say blue pearl-ex I also add the right amount of hardener to each jug about 1 in 10 a little less for the summertime.
The hardener and the colours are mixed at the same time with my drill and a wooden spoon but are poured slowly and at random layers until my mold is full, some vibration will be needed but I think the secret is, is to pour slow and that's it! I don't touch, leave it and let it do its own thing.

Hope I have explained this ok and have help in some sort of way.

Mervyn

www.ukpenkits.com

flamingo-pink.jpg


hawaiian-surf.jpg


midnight-reef.jpg
 
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mervyn said:
Hi Chris I cast a lot of PR about 25 ltr's every 3 to 4 weeks, I never have to pressurize unless I have the ribbon effect, my home-made mold will take 2.9 ltr at a time, I use a pigment paste and pearl-ex powder with the pearl-ex only being 30% of 2.9 ltr the rest is the base colour i.e. white, blue is the pearl-ex and flamingo pink is the pearl-ex powder.
I use the big kitchen measuring plastic jugs, these can be used time and time again, now the way I mix my colours are done with two jugs, one say white and the other say blue pearl-ex I also add the right amount of hardener to each jug about 1 in 10 a little less for the summertime.
The hardener and the colours are mixed at the same time with my drill and a wooden spoon but are poured slowly and at random layers until my mold is full, some vibration will be needed but I think the secret is, is to pour slow and that's it! I don't touch, leave it and let it do its own thing.

Hope I have explained this ok and have help in some sort of way.

Mervyn

www.ukpenkits.com

flamingo-pink.jpg


hawaiian-surf.jpg


midnight-reef.jpg
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Yes you have explained it well. Those are some nice blanks I hope to get that good to make some of my own. I have been trying to make a black and gold pen blank. That is the colors of the New Orleans Saints. But I am having problems with the colors. I am using paint and the black gels a lot faster then the gold. Now that I have the bubble thing fixed I need to work on the colors.

Thanks Again for all of the replies
Chris
 
Hi Chris, are you using paint or a pigment paste and what sort of effect are you after?
If say you have a mold that will take 600ml of resin use 200ml of gold pearl-ex and 400ml of black paste mix it separately in two jugs with 2ml of hardener in the pearl-ex jug and 3ml of hardener in the black jug.

pour some of the black in the base of the mold, not much just so that it covers the base and then pour a little of the gold in a figure 8, then the black in a figure 8 until the mold is full and you have used your mixes, pour these reasonably slow like your drawing lines in the mold, don't mix at all, leave it to take its cause, the chemical reaction will do the rest.
If you have the right stuff like I use you should have an effect like my blanks, any problems drop me a line.

Merv
 
Thanks for the reply Merv. I will give it a try. Yes I am using oil base paint I really need to get some more peral-ex colors. Thanks again.
 
ldb2000 said:
Chris , I use the Mica powders from www.coastalscents.com . It works the same as pearl x and costs less . A 1 ounce jar is $3 to $5 for most of the line , and a 1 ounce jar does a ton of blanks . They have some really wild colors and glitters too .
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Totally agree with you Butch. They have such a large selection and you can buy sample baggies mostly for $1 and each baggie is enough for several blanks. They also have very fast shipping that isn't too expensive. Best mica and price I've found thus far!
 
Mervyn, first can i say what great looking blanks you have produced.
Can you tell me what colour pigments you use, and where do you get them. I have tried using the Pearl-ex but the mistake i made was i mixed the colours just a wee bit when i now understand that the chemical reaction is all that is needed.
What do you mean when you say Pearl-ex and Pearl-ex powder??
Also what size of blank do you cast, do you make 1 large blank and then cut it into smaller sizes when set?
Sorry for asking you all the questions, but i think you have made just the type of blank i need, not for pen blanks though. I is good to talk to someone from the UK, most of the time products mentioned in threads are not easy to get over here.

Dermot.
 
New Voice Here

Butch: My Mica was delivered yesterday, my Silmar, today. And I don't know nuttin!!! As a starting guide, what is the recommended amount of Mica per ounce resin for an opaque blank, and what are the variables? I've done a little casting with Michaels Castin Craft but this part is all new. Can I use the Castin Craft pigments, that I have left, with the Silmar. Thanks, in advance, for any and all assistance.

ldb2000 said:
Chris , I use the Mica powders from www.coastalscents.com . It works the same as pearl x and costs less . A 1 ounce jar is $3 to $5 for most of the line , and a 1 ounce jar does a ton of blanks . They have some really wild colors and glitters too .
Click to expand...
 
The nice thing about the Coastal Scents and PearlX powders (and most any dye or colorant) is that you can mix it and tell right away how it will look.

We could give you measurements in precise amounts, but I don't work that way most of the time. I tap some in, mix it up, then pull my stir stick out. The thin amount of resin that adheres to the stick will give you a good idea of the density of the powder. That thin layer can be considered equivalent to the thin layer that remains when a pen is turned. It will give you a good chance to see what the final pen will look like, and allow you to decide whether you've added enough.

Sneak up on the correct amount, though. Too much can make the resin brittle and difficult to turn. Add small amounts at a time until you get the color you want.

Once you've done this several times, you'll start to have a good idea of how much powder goes into the resin. Then the measurements that others will provide will make much more sense.

If you ordered Silmar 41, you ordered at least a gallon then, right? A gallon of Silmar will make a lot of blanks. Particularly if you use molds like NewLondon88's Resin Savers, or pipe molds like I do for most of my casting. Waste some resin and enjoy the process! You never know what will come out of your experiments!
 
joefyffe said:
! As a starting guide, what is the recommended amount of Mica per ounce resin for an opaque blank, and what are the variables? I've done a little casting with Michaels Castin Craft but this part is all new. Can I use the Castin Craft pigments, that I have left, with the Silmar. Thanks, in advance, for any and all assistance.
Click to expand...

For one thing, you probably don't want to use the mica to get an opaque
blank. Use one of the pigments to do that. If the blank is opaque, you
won't see the mica. (except for a little on the surface)
The Casnin Craft pigments will work fine with the Silmar. any PR pigments
will work, but don't use polyurethane pigments. They'll have a tendency to
bleach out when used with PR.

Whatever you have for colors, you'll eventually want to have a bulk
container of white pearl and basic black powders. And you'll want both
opaque and translucent red, green and blue. With those, you can make
the majority of the other colors until you can afford to go hog wild.

Another good one to have from Coastal Scents is UltraSilk. Get a 1# bag
and it will last you forever. It is very fine, very pearly and is probably the
basis for a lot of their other powders anyway.
 
Thanks Don and Charlie, for the info. I picked up a few of the sample colors, but basically don't know how to use them, whether as an addition to pigment or for the total coloring of my resin. Charlie, the Ultra Silk you recommended, what would be the use of this. Thanks again for any and all advice. Joe
 
joefyffe said:
Charlie, the Ultra Silk you recommended, what would be the use of this.
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Joe .. the UltraSilk is a generic pearly silky powder. You can buy pre-tinted
mica powders, but they'll mostly be a pearl with color added. Since you want
to have the color dyes and pigments anyway, why pay someone else to
color them for you? If you have the UltraSilk, you can make your own for
much less. (and it takes up less room!)

Use it to give you resin a pearly look. The UltraSilk is very very fine and gives
a silky look to the blanks. In fact, the only problem I've had with it is that
it is SO fine that it doesn't mix as easily. So I just take a tiny bit of resin
and some ultrasilk and mix those two together before adding it to the mix.
Otherwise, I'm chasing little clumps of powder all over the resin cup :redface:
 
New Voice Here

NewLondon88 said:
joefyffe said:
Charlie, the Ultra Silk you recommended, what would be the use of this.
Click to expand...

Charlie: Makes sense to me. Thanks! I'm sure I'll have more questions as I get into this. the UltraSilk is a generic pearly silky powder. You can buy pre-tinted
mica powders, but they'll mostly be a pearl with color added. Since you want
to have the color dyes and pigments anyway, why pay someone else to
color them for you? If you have the UltraSilk, you can make your own for
much less. (and it takes up less room!)
Click to expand...
 
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