Removing Smooth Cast 300 Material from backside of mask?

[ERen89]

Hey guys. I just pulled a cast from my very first endeavor of mold making. For Halloween this year, I took on the project of a Babadook costume. I am very happy with my first pull for the mask. The only thing I need some help with is that when I was slush casting, the nose pooled up and I did not think to return any excess resin to a cup right before it cured. So resin built up in the center pretty fast. Something new at least learned for my next slush cast.
So I wanted to ask what you guys think is a good way to remove the material from the back side to re-hollow out the nose so my face can fit nicely? Returning it to more of a shell, like how it should be. What dremel bits if you think dremel? Otherwise, what would you guys suggest?
I used Smooth-On's Smooth Cast 300.
I know I can do another slush cast, but I would rather save the money on material, especially since this one turned out good. Minus the mistake I made of allowing it to pool near the end of the pot life.
Feel free to check out my build. Here is the playlist of my progress all the way up to this pull. I will be continuing on with the entire costume, so I will likely make a new post to show you guys how it turned out closer to Halloween.
Thanks in advance
-E-Ren

How can I carve out material on the backside here?

Here is the front side to show how large the nose is

 

[Egon Spengler]

Carefully dremel it out. That's all I can suggest. I'd personally use a sanding bit that comes to a point.

 

[ERen89]

Carefully dremel it out. That's all I can suggest. I'd personally use a sanding bit that comes to a point.

I was actually just at Menards looking at the Dremel bits. For sanding would you suggest one of the grinding stones? Or do they actually sell Sanding bits with a pointed tip?

 

[Egon Spengler]

I'd just try different bits but it's going to be a lot to remove that. Going to take some time. I was wrong when I said sanding bits. It's actually a grinding stone I used to take out excess plastic on my Casey Jones mask nose inside. Just make sure you wear a mask and do it outside. Dust is going to get everywhere. Could probably even use smaller metal bits similarly shaped. Just be careful.

 

[ERen89]

I'd just try different bits but it's going to be a lot to remove that. Going to take some time. I was wrong when I said sanding bits. It's actually a grinding stone I used to take out excess plastic on my Casey Jones mask nose inside. Just make sure you wear a mask and do it outside. Dust is going to get everywhere. Could probably even use smaller metal bits similarly shaped. Just be careful.

Thanks. Much appreciated.

 

[RacerMachX]

Here's what i like to use.
Heavy Duty Bandfile Belt Sander

5.3 Amp 1/2 in. Heavy Duty Bandfile Belt Sander

5.3 Amp 1/2 in. Heavy Duty Bandfile Belt Sander

www.harborfreight.com

 

[ERen89]

View attachment 1073764
Here's what i like to use.
Heavy Duty Bandfile Belt Sander

5.3 Amp 1/2 in. Heavy Duty Bandfile Belt Sander

5.3 Amp 1/2 in. Heavy Duty Bandfile Belt Sander

www.harborfreight.com

I’ll have to add that to my collection

 

[Psicorp7]

Honestly, that looks REALLY thick. I would do another cast with several small pours to get a more controlled, even layer. I would put this one up as a "wall mount". If you do decide to carve it out, wear a very good respirator and do all your grinding outside. There is going to be a lot of material flying around.

 

[Unseely]

If you want to take it out quickly you can use a 3/4 inch paddle bit. Just be careful.

Use that for the bulk of the work and then finish up with those grinding bits.

 

[ERen89]

I ended up doing another cast. For the sake of time and I definitely used way too much material last time. But that’s how ya learn. Happy I did tho. Who knows how much of a set back it would’ve been if I did truly to grind it down. Now to spend a lot of time sanding away these brush strokes. I’m still learning a lot for sculpting so there are plenty from when I tried smoothing it out with mineral spirits. Probably used a brush that wasn’t soft enough.

 

[Egon Spengler]

I ended up doing another cast. For the sake of time and I definitely used way too much material last time. But that’s how ya learn. Happy I did tho. Who knows how much of a set back it would’ve been if I did truly to grind it down. Now to spend a lot of time sanding away these brush strokes. I’m still learning a lot for sculpting so there are plenty from when I tried smoothing it out with mineral spirits. Probably used a brush that wasn’t soft enough.


View attachment 1075061View attachment 1075062

Looks great! Excellent work!