Hydrocal Bust: how to dry it out and prep it for sculpting

[weaponx82]

I just made my first life cast of my head, shoulders up, in hydrocal. It's actually been a few days and it's still clammy and feels soft.

Any recommendations on how to get this thing to dry out and anything else I should do to it before I start using it for sculpting?

 

[mts]

Well, Seattle is known for being rather damp. But, Plaster dries with an exothermic reaction. It should be dry by now. I think you may have gotten your mix off beam. Especially if it's still mushy.

If you mixed it correctly and it's still not dry, find someone with a kiln (like a school or ceramics joint)and try to dry it out at no more than 120 degrees.

I hope you don't have to try again...Good luck!
M

 

[weaselflinger]

Not sure about hydrocal, but plaster of paris can take more than two weeks to completely dry after it has cured. Putting it in a dry warm place will help speed the process a little.

It really shouldn't be mushy though....

 

[weaponx82]

yeah, it still feels clammy and it can be moved around somewhat when I press on it. I'll see what I can do about finding a place where I can dry it out quicker.

 

[Finhead]

Hydrocal should be very hard after a few hours not days. You may have mixed it wrong, there is a certain way to mix it. If you do it wrong it will dry either very brittle or not at all.

 

[propsculptor]

If you have a Heat Gun then Heating it up with that may do the trick, but generally Hydrocal sets up quickly and does not remain soft.

One thing I highly recommend is getting a thermometer that tells not only the Temp of a room, but also the feature of the Humidity so you know if the Humidity is High you can make certain changes to fix that.

 

[weaponx82]

I picked up Mark Alfrey's Ultimate Life casting Video and followed the steps in there. They used ultra cal 30 instead of hydrocal. They threw a garbage bag over it while it was curing to help the process. So I did the same. Could this be the cause of my problems?

 

[propsculptor]

No I think it was mixed incorrectly. It is also a possibility that you have a Bad batch of Hydrocal. By putting the Plastic Bag over the Ultracal-30/Hydrocal that actually helps it set up and harden faster & with more Heat because you are not allowing the Heat to disperse out of the top of the mold since it's covered.

Was the surface of the Lifecast you made, Dry before you brushed in the Hydrocal?

I picked up Mark Alfrey's Ultimate Life casting Video and followed the steps in there. They used ultra cal 30 instead of hydrocal. They threw a garbage bag over it while it was curing to help the process. So I did the same. Could this be the cause of my problems?

 

[weaponx82]

Was the surface of the Lifecast you made, Dry before you brushed in the Hydrocal?

When you say lifecast, I'm assuming you mean the negative I poured it into?

The negative was plaster bandages and alginate. So basically the front half was damp (alginate) and the back half was dry or near dry(plaster bandages).

I guess I'll have to concede my mixes were wrong. I'm just surprised because I've mixed hydrocal before and never had a problem with it drying and hardening.

 

[propsculptor]

I was referring to your Alginate surface that you brushed in the Hydrocal into, if that was wet and you didn't dab it with a paper towel to dry the surface, then the surface can still be moist.

Here's another question, which I think I already know the answer to...

Is the inside of your lifecast dry but the outside is still not?

 

[weaponx82]

The exterior is close to dry. The interior isn't as dry.

 

[propsculptor]

Here is another suggestion, once it is dry, spray the inside with water, then add a couple of layers of either burlap or Hemp mixed with the Hydrocal to make it stronger.

Why spray it with water on the inside first? Because it helps the Hydrocal stick better.

If the Bust you made is really solid you may not need to bother adding any more material to thicken it up.