The Casting of Flash Juno
- Thread starter PegaZus
- Start date
PegaZus
Stealth Freak
Yeah, I thinking I'm going to be resigned to just having a bit of excessive flash on Flash. Poor guy...
Tonight had three pours, one of which is still in the mold, so no picture yet. And I got the order reversed on them below. The one on the right was with my original resin, which is supposed to be just 1 minute or so of working time before it sets. The hope was that the shorter setting time would reduce the amount of flash getting in by setting up faster. But, even though it was thicker and quicker, it still had the flash. And on top of that, a bubble in the toe. Which was the major reason to go with the slower resin in the first place.
So, faster set time doesn't work. If you notice in the previous pictures, a lot of the flash is around the middle of the mold. Experiment time. I got rid of the two wood pieces that were meant to not concentrate the load in any spot. That may be the problem. It's a pretty thin casting compared to the thickness of the mold, so might be able to withstand a direct clamping action. On goes the spring clamp right over his midsection, and that's the result on the left.
As you can see, the flash was reduced, quite a bit actually. There's still a lot near his legs, so that's the third pour of tonight. I put the big spring clamp on the lower half of the body, then put a smaller clamp over the upper section. I'll post up a picture of what that did tomorrow if I'm not too tired. Got the wife's craft show tomorrow, and last year was so busy she needed help nearly the entire day. Works better with two people anyway, for breaks and whatnot. But, 10 hours in a little 8'x8' area doesn't get any minis painted. Or cast. Or is conducive to a relaxed state. So we'll see.
Tonight had three pours, one of which is still in the mold, so no picture yet. And I got the order reversed on them below. The one on the right was with my original resin, which is supposed to be just 1 minute or so of working time before it sets. The hope was that the shorter setting time would reduce the amount of flash getting in by setting up faster. But, even though it was thicker and quicker, it still had the flash. And on top of that, a bubble in the toe. Which was the major reason to go with the slower resin in the first place.
So, faster set time doesn't work. If you notice in the previous pictures, a lot of the flash is around the middle of the mold. Experiment time. I got rid of the two wood pieces that were meant to not concentrate the load in any spot. That may be the problem. It's a pretty thin casting compared to the thickness of the mold, so might be able to withstand a direct clamping action. On goes the spring clamp right over his midsection, and that's the result on the left.
As you can see, the flash was reduced, quite a bit actually. There's still a lot near his legs, so that's the third pour of tonight. I put the big spring clamp on the lower half of the body, then put a smaller clamp over the upper section. I'll post up a picture of what that did tomorrow if I'm not too tired. Got the wife's craft show tomorrow, and last year was so busy she needed help nearly the entire day. Works better with two people anyway, for breaks and whatnot. But, 10 hours in a little 8'x8' area doesn't get any minis painted. Or cast. Or is conducive to a relaxed state. So we'll see.
PegaZus
Stealth Freak
Well, I was right. Crashed at 8:30 last night and didn't get up for 11 hours. So didn't get a chance to post the picture. He turned out with a LOT less flash! And his head! Well, bubbles happen, right?
Unfortunately, the head did the same thing this morning. Makes me wonder if the clamp on the head area is pinching off things. So, I eased it back for a second as I was vibrating it, and we'll see if that helped the head but hurt the flash. *sigh* So frustrating.
But, I must press on! I wanted to get things progressing and thus started cleaning one of the good ones to prime it grey. A stiff nylon brush that came with the sculpting tools that I bought a while back did a good number on the little flashlings that were all around. Good enough to ship it off with.
And that's when I noticed something. NO NOSE! What?! Checked the second "good" one, and no nose on it, too! It was there on the earlier ones, so I think it may be some debris that is stuck at the tip and keeps getting powdered over. Have to look when I get the next one out of the mold.
EDIT: Found the offending bit stuck in the mold. Gave it a good cleaning. Oh, and third headless Juno in a row, so no more clamp on the head area.
Unfortunately, the head did the same thing this morning. Makes me wonder if the clamp on the head area is pinching off things. So, I eased it back for a second as I was vibrating it, and we'll see if that helped the head but hurt the flash. *sigh* So frustrating.
But, I must press on! I wanted to get things progressing and thus started cleaning one of the good ones to prime it grey. A stiff nylon brush that came with the sculpting tools that I bought a while back did a good number on the little flashlings that were all around. Good enough to ship it off with.
And that's when I noticed something. NO NOSE! What?! Checked the second "good" one, and no nose on it, too! It was there on the earlier ones, so I think it may be some debris that is stuck at the tip and keeps getting powdered over. Have to look when I get the next one out of the mold.
EDIT: Found the offending bit stuck in the mold. Gave it a good cleaning. Oh, and third headless Juno in a row, so no more clamp on the head area.
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PegaZus
Stealth Freak
Halleluiah! I got a mini that's workable! No picture, but that's not important! I was so happy that I poured another!
And pieces of the mold came off with this one. Just strips around the head, and wouldn't really be noticeable, but it looks like this mold is finished. By my count, that's a mere 13 casts before the mold starts to go on me. I think that's about how many I got from the first mold too. That's a bit disturbing, as I'd think that the molds should last quite a bit longer.
And before any advice comes that I need to be careful of the overhangs, as those areas are prone to do that, it wasn't an overhang/thin part that came away with the cast. It was just a chunk of a very solid part of the mold. It's possible that the mold I'm making is too thick, and so is less flexible thus prone to breaking easily. I dunno. At this point, 1 good cast per mold is a horrible rate. I'll have to bone up a bit more on how to avoid those types of issues before I make Mold #3.
And pieces of the mold came off with this one. Just strips around the head, and wouldn't really be noticeable, but it looks like this mold is finished. By my count, that's a mere 13 casts before the mold starts to go on me. I think that's about how many I got from the first mold too. That's a bit disturbing, as I'd think that the molds should last quite a bit longer.
And before any advice comes that I need to be careful of the overhangs, as those areas are prone to do that, it wasn't an overhang/thin part that came away with the cast. It was just a chunk of a very solid part of the mold. It's possible that the mold I'm making is too thick, and so is less flexible thus prone to breaking easily. I dunno. At this point, 1 good cast per mold is a horrible rate. I'll have to bone up a bit more on how to avoid those types of issues before I make Mold #3.
RuneBrush
New member
Love the step by step shots, really nice to be able to see the progress as you improve 
The lump of mold that broke off may have had a tiny flaw in it - perhaps something got into the mold material whilst you were mixing it? From research a while back, a dozen casts sounds reasonable if you're using a fairly soft mold material. I think I recall reading that you have to balance mold flexibility and mold life expectancy. Also make sure you use enough release agent
The lump of mold that broke off may have had a tiny flaw in it - perhaps something got into the mold material whilst you were mixing it? From research a while back, a dozen casts sounds reasonable if you're using a fairly soft mold material. I think I recall reading that you have to balance mold flexibility and mold life expectancy. Also make sure you use enough release agent
PegaZus
Stealth Freak
Bought some Smooth On products (the 30 and some more mold release), headed to Harbor Freight at noon to see about a pressure chamber, and had a brilliant idea this morning for the mold degassing. Unfortunately, through the power of Google, my idea isn't unheard of. I've got one of those food saver vacuums, with the sealing bags. I'm going to use that to degas the mold while its curing. Since I've got the Legos being used for a frame, I can pop a few up on top as supports for the bag. Very similar to what they do for composites forms. Yay! My career is helping my hobby!
Anyway, no pictures to show for a while. Busy weekend again. I need to take time off from work I think just to sit and do hobby stuff. Not sure that would go over well with the family however.
Anyway, no pictures to show for a while. Busy weekend again. I need to take time off from work I think just to sit and do hobby stuff. Not sure that would go over well with the family however.
Bloodshovel
New member
I'd love to see an update on how you plan to construct this thing. I've seen a couple of homebuilt Vacuum chamber builds, but none starting with that.
I've seen a couple of homebuilt Vacuum chamber builds, but none starting with that.
PegaZus
Stealth Freak
Happy to oblige, but it won't really look like much. This is one of those food sealer things that get TV ads some times, so it'll look like some Legos in a ziploc bag. Still, the only place I found it mentioned was on a fishing lure website, and then it was second hand info with no pictures. So I'll be certain to post up what the final thing looks like.I'd love to see an update on how you plan to construct this thing.
BTW, what led me to that solution is that the vacuum set we bought came with some containers that seal via a small hose. Was going to use them but they could be too small. Then realized the bags would do the trick.
Update on the pressure chamber. It was in stock, on sale, and $30 more expensive than I'd thought. And for $80, I'm not sure I can justify it. My hope is to sell enough figures to break even on costs, and I'm thinking the figures aren't going to go for much more than $5 a pop. And buying that chamber would add 16 more I would need to sell. I'm thinking I might try some PVC pipe. Engineer ya know. Figure I can design something that'll not kill me. Or those around me. Can always tap into the mad test lab guys too, see what they think. Pressure chamber, rocket engine; there isn't much difference.
