I finally got a mold... barely! Now, how do I fix issues?
Molding was definitely more challenging than I thought it would be! (They make it look so easy in the videos, don't they?!) It was my first time doing it, too, but I think I at least ended with something mostly useable. I'm just wondering if I can fix some of its issues.
Sculpt before molding:
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The back half turned out pretty good besides a bit of collapse at the bottom of the wall of one side.
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Here's the front, but it had many more issues. I had a really hard time getting it out! I was worried I'd lose the whole thing and my lifecast! I ended up using a heat gun to warm the clay and some popsicle sticks, wooden tools and about an hour of slow digging and prying, digging out the clay all around. I tried to be gentle, but some edges still got dinged.
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Cleaned. But, as you can see...
1) Air bubbles/cavities/peeling: I definitely have some areas with collapsed spaces, a couple of air pockets/bubbles, and it looks like maybe my splash coat started to set too fast and didn't congeal well with the burlap layer? I have spots where it almost seems like that initial detail and splash coat peeled/chipped away in places.
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2) Edge damage, cavities, flaking up close: I have some pretty significant cavities in some spots where you can even see the burlap exposed. I also have spots that seem to have flaked.
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3) When I put the two halves together, I can see some gaps/light. Clearly, if I cast without fixing these issues, the latex would leak. (Sorry, don't have a pic of the gaps currently. My mold pieces are out drying right now from being cleaned.)
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So how do I proceed? Can I patch things up with just epoxy concrete? I thought.. maybe I can fill areas with the epoxy concrete, and then just resculpt in details in those spots (obviously, sculpting the negative version)? Would that work? I'm not sure yet how to fix the mold wall gaps issues. How fast does that epoxy set? Could I maybe use it in between the two halves to sort of mush it to shape, and then take the two halves apart before the epoxy sets?
I have on hand - wed clay, mold wall clay, hydrocal, ultracal, PC epoxy cement
Any ideas, help? How do I save this mold!?
Sculpt before molding:
-------------
The back half turned out pretty good besides a bit of collapse at the bottom of the wall of one side.
------------
Here's the front, but it had many more issues. I had a really hard time getting it out! I was worried I'd lose the whole thing and my lifecast! I ended up using a heat gun to warm the clay and some popsicle sticks, wooden tools and about an hour of slow digging and prying, digging out the clay all around. I tried to be gentle, but some edges still got dinged.
----------------------
Cleaned. But, as you can see...
1) Air bubbles/cavities/peeling: I definitely have some areas with collapsed spaces, a couple of air pockets/bubbles, and it looks like maybe my splash coat started to set too fast and didn't congeal well with the burlap layer? I have spots where it almost seems like that initial detail and splash coat peeled/chipped away in places.
--------
2) Edge damage, cavities, flaking up close: I have some pretty significant cavities in some spots where you can even see the burlap exposed. I also have spots that seem to have flaked.
----------
3) When I put the two halves together, I can see some gaps/light. Clearly, if I cast without fixing these issues, the latex would leak. (Sorry, don't have a pic of the gaps currently. My mold pieces are out drying right now from being cleaned.)
----------
So how do I proceed? Can I patch things up with just epoxy concrete? I thought.. maybe I can fill areas with the epoxy concrete, and then just resculpt in details in those spots (obviously, sculpting the negative version)? Would that work? I'm not sure yet how to fix the mold wall gaps issues. How fast does that epoxy set? Could I maybe use it in between the two halves to sort of mush it to shape, and then take the two halves apart before the epoxy sets?
I have on hand - wed clay, mold wall clay, hydrocal, ultracal, PC epoxy cement
Any ideas, help? How do I save this mold!?
0
Best Answer
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Chris Ellerby AdminYou could patch the defects with a few different materials. I would use Bondo or a 2 part epoxy clay like "Magic Sculpt" or "Apoxie Sculpt" and sculpt back the lost details. That said, I've not run into that type of issue with the mold surface, so my concern would be having more of it cave in over time with use. It looks like the burlap was not super saturated with the stone, allowing pockets of air to form between the burlap layers and the print coat. Mold making can sure be stressful and complicated, but these kinds of issues are part of the learning process. I'm sure with a bit of work you can get that mold up and running!
Anyone else have success patching a mold like this?
/Chris
5
Answers
Lots I would change for next time, but even though I must have watched the part 2 video four times, it's just not the same as doing it with your own hands.
Another question... if I do manage to get the latex to go, would it be wise to do a thinner, first throwaway cast to pick up any loose bits and check for major issues caused by the epoxy? I have a 3 (or maybe it's 5, I'll have to check) gallon bucket of latex.
Back didn't need much.
Front needed a lot. All that prying didn't help.
Seam is much better now.
I could tell the the latex didn't dwell quite as well in spots with a lot of epoxy, but I kept a hair dryer on cool to help dry things that seemed tacky as I pulled it out.
A few rough spots, and loss of depth and detail from epoxy repairs around the eye, but I can live with it, especially for a first time!
Trimmed up a bit.
On to part 3. Can't wait to paint this!