Using 'normal' (Water Based) Clay With Ultracal For A Mold?

[fredward]

Hi everyone, I've spent many hours on this forum and have finally gotten around to joining! good to be here.
I've got a sculpt that's 95% complete, but there are parts of it I want very smooth, and oil based clay that I've been using for this sculpt is very hard to get really smooth with. I know its possible, but as I've just bought a ton of water based clay (super easy to smooth!), to make the dividing wall for a casting, I suddenly thought -

Can I put a thin coat of water based clay on top of the oil based clay, then apply Ultracal 30 as you would to a normal oil-clay sculpt? has anyone tried this? if it could work it really would save many hours . . .

Hopefully I've struck on something that could benefit many of us making sculpts, but it's late so I think all my ideas are awesome when I'm really tired.

Thankyou
Fred

 

[roninpredator]

Have you tried using 99% alcohol?
it works for me evrytime I need a super smooth surface on a sculpt.

 

[xdmray]

a rubber kidney bean tool and alchohol or mineral sprits with paper towels wiil get you a glass surface. you just have to keep working on it. but yes you can plaster over WED clay. but i never heard of anyone putting a thin layer of WED over oil.

 

[Uratz]

I used medium hard clay that has a high wax content. Using big rakes to smallest rakes I can get a fine smooth surface then finally even using brushes with alcohol can smooth the thing out.

 

[A Hunters Moon]

99% alcohol was hard to come by locally so I've been using mineral spirits. It softens the clay so it can be smoothed out and when it dries the clay turns back to normal.

 

[Darth Pinhead]

With oil based clay, you can also use a heat gun to melt the surface (Just don't touch it, let the heat do the work) or go a step further and pick up a Pen Torch: http://www.homedepot...catalogId=10053.

Isopropyl alcohol at 99% can be difficult to locate. The only place I was able to find it was a local molding supply store. The highest concentration I could find at a Pharmacy was 70%, which works, but takes FOREVER. I've also used the odorless mineral spirits, but prefer the alcohol over them because the alcohol evaporates much faster and you're not forced to sit there and stare at the clay.

Now, in my mind there is a big difference between eliminating hills and valleys to make something flat (Which is what I think you mean) versus making the surface shiny. If you are just going for shiny, you can use cold water or even ice. Using melting ice on the surface will glass it right up and not eliminate your detail, as long as you're not pressing like a mad man, lol. SIDE NOTE: when trying new techniques, I prefer to make a quick sample and mess with it, versus the actual sculpt.

 

[fredward]

thanks for the feedback so far - I do have the Isopropyl alcohol but yes, it is at 70% which is why it appeared to do nothing! I'll check if my safeway has the 99% stuff today. that sounds like it will do it!

 

[ptgreek]

You will not find 99% at a safeway ..it is a specialty item ..you can order it ..or perhaps find it at a hardware store

 

[Darth Pinhead]

I believe Jason found it at CostCo, but that was in Canada, so rules may be different. Personally, I didn't have any luck at Home Depot or Lowes.

 

[xdmray]

just use mineral spirits. that can be found at walmart. and if you only use a little, you are not forced to stare at it waiting for it to evaporate.

 

[fredward]

UPDATE: So my local Safeway chemist counter had the 99% rubbing alcohol (over counter item) and it works a lot better, in fact its good enough for a smooth finish, so thankyou for this information.

A warning to anyone who's going to use it though - it's marked as 'POISON' and my nostrils hurt a little the first time I used it, so I moved outside to the garden and wore gloves / mask / goggles - for splashes as well as vapors Obviously you have to be careful of washing hands, getting on food and not ingesting any! Also found out the health info on Ultracal - which I'd assumed was quite harmless - it can really get funky with your eyes and even rash you badly! - I really recommend everyone reads this:

ULTRACAL HEALTH EFFECTS AND PRECAUTIONS: CLICK HERE (severe cancer warning! yikes!)

Soon I hope to post some photos of what I'm doing, a big thankyou to everyone who's posted here,
Fred

 

[xdmray]

dude, everything we use is hazardous to your health. they are all chemicals that can do harm
to you, which is why you need to use gloves, respirators, and eye protection when doing just
about everything.

 

[Darth Pinhead]

dude, everything we use is hazardous to your health. they are all chemicals that can do harm
to you, which is why you need to use gloves, respirators, and eye protection when doing just
about everything.

So my wife was right about molding in just my banana hammock? Damn it. At least I was wearing my concrete boots...
In all seriousness, though, most of this stuff is hazardous in same way or another. Be smart and wear everything Daman just listed...

 

[Effects Guy]

It is important to point out that only 99% isopropyl alcohol will work, and it only works on oil/wax bases plastilines. Another thing that is even more powerful is naphtha or petroleum ether. I would avoid laying water clay over oil clay. Number one, it is going to give you bad edges, as they will get dry and crumbly, but it is also not going to give you that same level of fine detail that the oil clay will.

Diligence with solvents and tools will totally pay off.