Sculpt finishes. Need help!

[Finnish Spartan]

Okay since i got my Mjolnir Helmet ready: http://405th.com/forums/index.php?showtopic=6704 (Old Images)

I just want to make sure im not going ro screw up the mold im going to make (since it is quite expensive).
I want to be sure that everything will be exactly correct for my helmet.

Heres what i have done so far:

-Add clay to my manique (aka. Legendary edition).
-Add another layer of clay (since it is water based it will crack againgst plastic. so the 2nd layer wont crack).
-Wait for it to dry (2 hours with water based clay)
-Sand it.
-Note i left the "rectangle" area at the bottom of the helmet unfilled (The part where you insert your stand).

So its pretty much perfect right now and precisly as i want it to be, I just want to know should i fill the "rectangle" at the bottom and is there anything else i have forgotten?

Thank you.

PS. Please dont ignore this post.

PPS. HELP!

 

[Sean Bradley]

Water based clay will continue to develop cracks regardless of how many layers you put on. Forming water based clay overtop of any object will cause this...

It's best if you want to use water based clay for this to take your molds before the clay dries with something like plaster... although you will need to break you mold up into many seperate sections for it to come apart.

Oil based clay would have been your best bet if you wanted to make a rubber mold. If you try to make a rubber mold from wet water based clay, the water continues to evaporate and forces airbubbles into your rubber...

Sorry if this is too little too late, but if you had asked prior to starting this, I would have instructed you then.


Hope this helps.

 

[Finnish Spartan]

Water based clay will continue to develop cracks regardless of how many layers you put on. Forming water based clay overtop of any object will cause this...

It's best if you want to use water based clay for this to take your molds before the clay dries with something like plaster... although you will need to break you mold up into many seperate sections for it to come apart.

Oil based clay would have been your best bet if you wanted to make a rubber mold. If you try to make a rubber mold from wet water based clay, the water continues to evaporate and forces airbubbles into your rubber...

Sorry if this is too little too late, but if you had asked prior to starting this, I would have instructed you then.
Hope this helps.

Im sorry i forgot to mention i have this spray thing which forms around the clay and basically acts as a layer of oil based clay (its some sort of resin mix, i have no clue what but it works (atleast for more simple sculpts)...:

Layer of water based clay.
Special spray.
2nd layer of water based clay.
2nd layer of special spray.

 

[cheech92007]

i agree with him /\ but i think i saw a fourm that has this chemical someone found that you can spray onto the water based clay. but i could be wrong.

 

[Finnish Spartan]

i agree with him /\ but i think i saw a fourm that has this chemical someone found that you can spray onto the water based clay. but i could be wrong.

Your not wrong i have that.

 

[Sean Bradley]

Well in my 4 years at the New York State College of Ceramics I never heard of anything like that... hope it works for you.

Still you will need to seal your clay before making a mold... I'd recommend doing a test run with your rubber before you get too far along with your sculpt... I've seen the results of gassing clay on mold rubber, and it's traumatic... the mold will be unusable unless you can seal the clay from dehydration during moldmaking... otherwise it will look like swiss cheese when you pull it off of your model.