Rookie caster need some help.

[Bobalu]

My casting abilities (if I ever had any) seem to be slipping with each pour. I'd appreciate any advice you can give. Here is the casting method I presently use:

1) Tint resin (Silmar 41) with pigments or micas. I'm using CS micas, Pearl-Ex pigments, and US Composites liquid pigments. The latest casts were with the liquid pigments with a small amount of Pearl-Ex MicroPearl for a little glitter.
2) After thorough mixing I place each cup in my Ultrasonic Cleaner, which is filled with hot tap water.
3) I run the UC one 480 sec cycle with heat turned on. Then two more 480 second cycles with heat turned off.
4) Remove from UC and catalyze with 4 drops MEKP per ounce of resin. I generally catalyze one cup at a time as I work alone. With about 30 seconds of mixing per cup, I'm about 1 1/2 minute out of the UC. I then wait until I feel a slight viscosity change in the PR, usually only 30-45 seconds after mixing.
5) Try to pour, if possible. Usually one or more colors has begun to gel or starts to gel before I get first or second mold cavity filled. Vertical mold.

Am I waiting too long to pour? Should I pour right after catalyzing? Do I need to enlist some extra hands to mix catalyst all at same time? Should I do away with the heat and just use the UC to help remove air bubbles?

 

[PTownSubbie]

Try dropping to 3 drops/oz. It will not kick off as quickly.....

 

[its_virgil]

The warmer the resin the faster is starts to gel. There are several variables with which you must keep track...resin temp, amt of MEKP, amount of resin in the cups(more resin=more heat), ... drop back to 3 drops per ounce.

Try without the heat or don't use hot tap water....just let the heater in the cleaner warm the water. Once you get it down it should work the same each time.
Do a good turn daily!
Don

Am I waiting too long to pour? Should I pour right after catalyzing? Do I need to enlist some extra hands to mix catalyst all at same time? Should I do away with the heat and just use the UC to help remove air bubbles?

 

[DozerMite]

Like Don said, it's about consistancey. Everything has to be the same in order for it to work the same. It's not just the amount of resin or catalyst, but the amount and color of pigments, the temp. of the resin, air temp. and even humidity all affect how the resin reacts. When one variable changes, you have to accomodate.

 

[PenMan1]

Bob:
I agree totally with Don. I use either hot water OR the heater in the UC that starts with room temperature, BUT NOT BOTH.

As hot and humid as it has been here lately, I use 3 drops of MEKP on solid pours and 4 drops on embedded tubes. Any more catalyst and I can't get the warmed resin to the mold before it starts to gel.

AND JUST THINK! As soon as you get your technique perfect, the temp and humidity will drop and change your entire set up.

 

[PenMan1]

AND, this my just be a "Georgia thing", but PearlEx Aztec Gold seems to cure just by "looking at it" - no catalyst required.

That one particular color gives me fits!

 

[Bobalu]

Thanks to all of you for your advise. I'll try another pour tonight and try your suggestions on reducing the amount of MEKP to 3 drops, as well as the suggestion on not using the hot tap water and the UC heater. I'll report my results later.

 

[Drstrangefart]

Thanks to all of you for your advise. I'll try another pour tonight and try your suggestions on reducing the amount of MEKP to 3 drops, as well as the suggestion on not using the hot tap water and the UC heater. I'll report my results later.

Yeah! I'm looking forward to scavenging the "oops" stuff!:biggrin:

 

[Bobalu]

Thanks to all of you for your advise. I'll try another pour tonight and try your suggestions on reducing the amount of MEKP to 3 drops, as well as the suggestion on not using the hot tap water and the UC heater. I'll report my results later.

Yeah! I'm looking forward to scavenging the "oops" stuff!:biggrin:

The "oops" box has gotten so big I might have to get a rental truck to cart it to the meeting next week. See ya' there.

 

[Drstrangefart]

Thanks to all of you for your advise. I'll try another pour tonight and try your suggestions on reducing the amount of MEKP to 3 drops, as well as the suggestion on not using the hot tap water and the UC heater. I'll report my results later.

Yeah! I'm looking forward to scavenging the "oops" stuff!:biggrin:

The "oops" box has gotten so big I might have to get a rental truck to cart it to the meeting next week. See ya' there.

See ya there! And it looks like a lot of blanks will be going to good homes when finished. Win/Win!

 

[Brooks803]

lol...look Allan, you're benefitting from my casting demo more than most! But I'll be elbowing my way to the "oops" with the rest of yall!

Bob, I'll echo what most others have been saying. Try the 3 drops. Find where you can adjust within your comfort zone and build from there. I personally don't heat my resin bc I want as much working time as possible. If you do preheat and know you can maintain a constant temp each time you cast then you can time how fast the resin will gel and you'll have a better feel for when to pour and mix. Right now it doesn't look like you're giving yourself enough time to do more than 1 blank at a time. I'll be at the meeting on the 17th so we can discuss more in depth then. Happy casting!

 

[Bobalu]

I did a second pour last evening. Dropped the MEKP down to 3 drops per ounce of resin. Room temp water in the UC and ran on heat mode for one 480 sec cycle, then two 480 sec cycles without heat. I enlisted the wife to assist in mixing in the catalyst and helping pour the resin into mold. I didn't hold up for signs of setting, but poured immediately after catalyzing, one color at a time, then mixed slightly with my mixing rod. I got all six mold cavities filled this time without issue. That's a big improvement.

I haven't removed the blanks from the mold, but plan to do so later this morning. I might wait for the grandkids to come by. They get a kick out of watching me launch the blanks from the mold with compressed air.:biggrin:

I'll probably need more help down the line, but at least I got part of the process corrected for now. Thanks for all the advise and assistance.

Added comment: The blanks didn't turn out too bad. Hard to say what the finished product will look like until I turn a few. I couldn't resist putting them next to one of Jonathon's blanks blanks just to make comparison. I don't think I'm quite ready for the BIG TIME, yet.

 

[PTownSubbie]

I did a second pour last evening. Dropped the MEKP down to 3 drops per ounce of resin. Room temp water in the UC and ran on heat mode for one 480 sec cycle, then two 480 sec cycles without heat. I enlisted the wife to assist in mixing in the catalyst and helping pour the resin into mold. I didn't hold up for signs of setting, but poured immediately after catalyzing, one color at a time, then mixed slightly with my mixing rod. I got all six mold cavities filled this time without issue. That's a big improvement.

I haven't removed the blanks from the mold, but plan to do so later this morning. I might wait for the grandkids to come by. They get a kick out of watching me launch the blanks from the mold with compressed air.:biggrin:

I'll probably need more help down the line, but at least I got part of the process corrected for now. Thanks for all the advise and assistance.

Added comment: The blanks didn't turn out too bad. Hard to say what the finished product will look like until I turn a few. I couldn't resist putting them next to one of Jonathon's blanks blanks just to make comparison. I don't think I'm quite ready for the BIG TIME, yet.

Bob,

If you think you are not happy with the way it turned out pouring without starting to gel, try this.... You can cut down from the 6 blanks at a time to only 1 or 2. I cast 2 at a time. I may cast 6 of the same colors and such but I do 3 seperate casts of 2 blanks each. This allows me to get the colors to gel slightly but they have not setup too much before I stir them.

I hope that makes sense.....I catalyze the first set, wait 5 mins and catalyze the second set, wait 5 more minutes and catalyze the last set. If I am casting the same colors with the same number of drops of MEKP, the gel time SHOULD be the same for each set allowing 5 mins between each pour.

Just the way I try to do things....might help you too.....

 

[Bobalu]

Bob,

If you think you are not happy with the way it turned out pouring without starting to gel, try this.... You can cut down from the 6 blanks at a time to only 1 or 2. I cast 2 at a time. I may cast 6 of the same colors and such but I do 3 seperate casts of 2 blanks each. This allows me to get the colors to gel slightly but they have not setup too much before I stir them.

I hope that makes sense.....I catalyze the first set, wait 5 mins and catalyze the second set, wait 5 more minutes and catalyze the last set. If I am casting the same colors with the same number of drops of MEKP, the gel time SHOULD be the same for each set allowing 5 mins between each pour.

Just the way I try to do things....might help you too.....

Fred, if I may ask, at what point in the your casting method are you pouring? That wasn't clear, but I got the point on everything else. I can't wait until next weekend to give it another try. Thanks.

 

[DozerMite]

Fred, if I may ask, at what point in the your casting method are you pouring? That wasn't clear, but I got the point on everything else. I can't wait until next weekend to give it another try. Thanks.

What works for Fred, doesn't mean it will work for you.

What is your temp. and humidity? How many ozs. are you pouring? How much catalyst are you using? What colorants and actual colors are you using and how much?

These will all factor into your answer.

Try starting out with just a single blank. Best to start small and remain consistant, then work your way up.:wink:

 

[PenMan1]

Yep, If you wait 5 minutes in our current heat and humidity levels, you'll be trying to pour peanut butter.

This time of year, here it is still too hot and humid to wait very long with thinned resin. Temps are down to the low 90s but the humidity is still above 70 percent.

 

[Craftdiggity]

Bob,

I use a similar method for my casting, but I do not run two additional cycles in the UC without heat. I don't understand what the point of doing that is. My understanding is that the point of the UC is to heat the resin. After 480 secs, the resin is warm. I then add three drops per oz and pour. I don't wait for the gel stage and I am pouring roughly 6 ounces of resin at a time from three different cups. That's two ounces per cup and it is no problem to manage getting it all poured before it kicks.

 

[DozerMite]

Wow, at 90 and 70% humidity, you don't need to heat the resin. Without any heating, the resin will gel in approx. 8 minutes depending on amount of resin, catalyst, and color being used. At 10 minutes...forget it, it's set.

 

[Drstrangefart]

lol...look Allan, you're benefitting from my casting demo more than most! But I'll be elbowing my way to the "oops" with the rest of yall!

And you've been a kind benefactor indeed!

 

[Bobalu]

Fred, if I may ask, at what point in the your casting method are you pouring? That wasn't clear, but I got the point on everything else. I can't wait until next weekend to give it another try. Thanks.

What works for Fred, doesn't mean it will work for you.

What is your temp. and humidity? How many ozs. are you pouring? How much catalyst are you using? What colorants and actual colors are you using and how much?

These will all factor into your answer.

Try starting out with just a single blank. Best to start small and remain consistant, then work your way up.:wink:

Thanks for that good advise. I have a bad habit of jumping into something and trying to do too much, too fast, and often too soon. I have a weeks vacation coming up soon. I believe I'll take some of that time and just make one blank at a time, until I feel comfortable with how I'm doing it.

 

[Bobalu]

Yep, If you wait 5 minutes in our current heat and humidity levels, you'll be trying to pour peanut butter.

This time of year, here it is still too hot and humid to wait very long with thinned resin. Temps are down to the low 90s but the humidity is still above 70 percent.

Funny you should mention that. Someone actually told me they knew how to pour peanut butter.:biggrin::biggrin::biggrin::wink:

 

[Bobalu]

Latest casting results

It's been a couple of weeks since I started this thread. I received a lot of good advice. Here is the result of my latest attempt to cast. This is the finished blank, drilled and mounted on an Electra tube.