Casting question
Other Forums: Action Figure Chatter, Figure Realm Comments and Questions, Identify Help, Off Topic, Trading Post

Casting question

Posted in Custom Workstation

Ok, so I've been trying to cast six inch heads every once in a while the last couple of years to moderate success. Sometimes I get the Walking Dead results where the lower jaw is missing from the cast, but the most frustrating thing I've noticed is when a cast looks really good except for the dreaded nose bubble at the tip of the nose. Anyone have any suggestions and what to do to stop this from happening? Not sure what I'm doing wrong but it seems like over 50% of the time when the cast hardens I get a nose bubble and other times I don't.

Posted by packerbacker180
on Wednesday, March 2, 2016
User Comments
Truwe 316 -
Thursday, March 3, 2016
This guy made a pretty good video on how to make one.

https://www.youtube.com/watch?v=vO1sD3rvZdA

The only thing different I did is I added a moisture filter that goes between the connections for the compressor and the pot, I guess this helps to make better casts and molds. The last thing I did different is I replaced the bolt on the end with another plug to release air. That way if you do put too much pressure in there (honestly, stop at 50 psis when casting), those plugs will allow the air to escape vs blowing up in your house or garage.

Also, do not use the pressure cookers that some people use on Youtube. I heard that you are saving a little bit of money but don't really last that long.

Good luck. Hit me up if you have any more questions.
Truwe 316 -
Friday, March 4, 2016
325 is the 10 minute demold time, which I don't recommend. The reason being is that after three to five minutes (depending on the temp of the room) it starts to be more of a gel than a liquid and that will no allow the resin to get everywhere.

I recommend 327 which takes 2-4 hours. This allows the resin to settle it and bubble to work their way out. Sucks that it takes to long but the results tend to be better.

Another tip that a fellow caster gave me is putting odor baby powder in your mold before you put the resin. I don't know why but it sucks the resin right in. I just squirt some in the mold, shake it, and then blast the excess out with my airbrush.
Truwe 316 -
Thursday, March 3, 2016
What resin are you using? If it is the stuff that dries in 10 minutes, it's a waste. I use the Clear cast 327 or something. It takes four hours or so to harden but it gives time for all the resin to work it's way into all the nooks and crannies. Even then, my cast success is roughly around 80%. Since I got a pressure pot, I'm at 99% success rate

A pressure pot is going to run you about $800 (last I checked) if you buy one straight off the market. I built one, with the air compressor, for around $200 (the compressor was half the cost if memory serves right) with supplies from Harbor Freight. If you catch them on a decent weekend, Harbor Freight has a some solid sales. I think I had to buy one or two parts from Lowe's but they both totaled for under $10.

The only pain that I had building it was making sure that all the air holes where you seal everything get's sealed up with the tape and such. If you just fill up a squirt bottle with 50% water and 50% dish soap, fill the pot with air, and squirt the water over areas where parts are connected, you should see bubbles forming and that tells you where your leak is.
packerbacker180 -
Thursday, March 3, 2016
I'm using the Alumilite stuff because it was relatively cheap at Hobby Lobby (like $18). Figured it didn't make sense to buy better products until I felt like I could do it successfully. Did you have to buy that online or is it available in stores anywhere?
Truwe 316 -
Thursday, March 3, 2016
I bought that Alumilite before and didn't like the results. Depending on your area, there might be a hobby store that might carry it. I get my at a Barnes and Noble that doubles as a campus book store. You can order it off their website (I usually just buy their trial stuff) but their shipping is around $20. On the plus side, if memory serves me right, you are in Buffalo, NY and they are in PA so you should get it in a day or two.
packerbacker180 -
Thursday, March 3, 2016
Thanks for the info. Is that Smooth-cast 325?
packerbacker180 -
Wednesday, March 2, 2016
Thanks for replying. It's not a bubble so much as an indentation on the nose. I can pour resin into the same mold four times and at least twice it'll have that darn bubble while the other times the cast is perfectly fine. I've tried squeezing and tilting the mold after the resin is poured but I was curious if anyone had any tricks or if this is just something standard if you're not using something like a pressure pot? If I were to look into a pressure pot what do they run and where would I even look?
Henchmen4Hire -
Wednesday, March 2, 2016
Oops, oh right, you're talking about bubbles when casting, not when making the mold

Yeah, it's tough. I've only made a few casts with liquid latex. I don't get bubbles because I brush on the first few layers of latex and let it cure, then I pour the rest since it doesn't matter if that has bubbles because the outer shell is already perfect.

From what I understand, putting the stuff in the pressure pot to cure simply makes any bubbles so tiny that they become microscopic. It also forces the casting material into all the mold's crevices so the bubbles are shoved out. There's another process called "degassing" but you'll have to ask someone like the people at TCP Global for specifics. The pressure pot itself is like $100, and then you need an air compressor too of course.
Henchmen4Hire -
Wednesday, March 2, 2016
Theres a spray you can use on the item before pouring that stops bubbles from sticking to the item.

Aside from that, a pressure pot seems to be the guaranteed way. You can also try getting a strong back or foot massager and pressing it onto the mold so it vibrates the bubbles out.
Write a new Comment
New Comment...
                                                                  Pictures & Links

 

Thundercats on eBay