HYDROCAL FGR-95 for Molds?

[Atlantisblue]

Has anyone used Hydrocal before for their scale molds? I've been looking into alternatives other than using shell-shock.

[Lily]

I've never used it for silicone but I have used it for other molds. You have to pour it fairly thick or it will break - you might even want to put some plaster bandages on the back as it sets to reinforce it. Also hydrocal and other cements get HOT when they set, so if you've made your scale mold out of clay, that clay could potentially melt before the hydrocal is hard enough to capture the detail. It does degrade a little with each casting. If you're just making a few castings of your scale sheet, it should be fine, but it won't hold up to tons of casting. Be sure to wear a mask and gloves!

PearlieMae is like the mold master, so hopefully she'll weigh in here as well.

[Atlantisblue]

Thanks so much for your response :) I had heard fiberglass resin heats up but wasn't sure about this one.

Which molding material have you found works best?

[ShyMer]

I used hydrocal for my molds. It was the best I could find locally at the time, so I chose to use that instead of ordering ultracal, which was the popular mold making material at the time.
I haven't done a side by side test to see what materials work better, but was satisfied by its performance overall. I did reinforce it with gauze strips.
I made a small scale sheet, so I needed to pull six scale sheets for each tail from the one mold. I've pulled twelve from it so far, and I think it's working just fine still.
I think if you're not planning on using the same molds too many times, it's perfectly fine to use, though there may be better materials available.

[Atlantisblue]

Shymer - did you use foam or clay scales?

[ShyMer]

I used a thick cardboard/chipboard (palet divider from Costco.) I didn't want thick scales- it looks like dropsy to me:(
It ruined my paper cutter... I don't recommend it.

If I had thought of it, I totally would have done clay. I would have loved to shape them and do different size scales.I wouldn't have to deal with undercuts, either.

Are you going to make a process thread once you get started? It's fun to do:)

[Atlantisblue]

I have a thread in the tailmaking forum :) so far I've played around with some designs and made my fluke shape.

I am hoping to pick up my clay next weekend. This weekend is to clean up our work area but we are waiting for someone to fix our heat as its stuck on and impossible to do any type of work.