I have smooth on products 25 & 30 for mold making.
Wanting to make extra props for a b 36 and some other parts as well.
Would anyone know how to go about this or any helpful hints?
thanks so much
John
There is also a section in Shepherd Paine’s Diorama book on molding parts.
Will it be open faced or a 2 part mold?
Open faced you can tack the part to a flat base with sides that are high enough that the silicon will be able to cover the piece, for small pieces the base of a paper cup may work.
Some folks use Lego’s for building the box and lining the bottom with clay, you can also use foam board or anything that will contain the silicon, you don’t want to make a mold of the table or floor.
A 2 part mold takes more engineering with the piece embedded in the clay with vent lines and registration marks added than once the first part has been molded it gets flipped, the clay removed and a mold release added so the silicon doesn’t stick to it’s self than pour the second side.
Once done open the mold and remove the part and you should be ready to cast.
Depending on the type of silicon and if the proper amount of catalyst is applied the cure time may be in the area of 24 hours, some cure quicker.
Depending on the type of silicon you are using “tin of platinum” based you will have to be careful of the type of clay you use.
See the spec sheets on the Smooth on site.
Eric…
Safety note, WEAR GLOVES.
Silicon will do nasty things to you on contact with your skin.
Once it’s cured your fine but not when in liquid form.
Thanks so very much my man!
It MIGHT irritate skin… What it will do damage to is your eyes…
The stuff I was using with a single drop would freeze up the joints in my hand.
Always use safety goggles when working with chemicals and power tools.
Eric…
Yikes… Might wanna use something a bit less… Nuclear…
Try Alumalite RTV…
I was helping some friends mold a few things, not sure what brand it was, it may have been silpac, it came in a white tub and had a blue catalist.
Aside from the reaction you just don’t want this stuff on you anyway since it’s a pain to wash off.
Eric…
thanks guys
If you are sensitive to some of Smooth-On’s products, then by all means use some plastic gloves. I have gotten both the components and reacted product of Smooth-Cast and Smooth-On’s OOMOO on my hands have had no adverse reactions. YMMV.
As far as casting props, the biggest problem you may need to work out is the method of mounting the master for the RTV pour. Go here for some photos of a resin cast prop - with the pour stub. http://www.hyperscale.com/2009/reviews/accessories/phr48005reviewmd_1.htm
You may find it easier to cast the blades separately from the spinner/hub. Experiment on what works for you.
I see where you’re in Garland. Check with Reynolds Advanced Materials on Harwood in downtown Dallas. They are a Smooth-On distributor. I buy my RTV & resin over the counter from them. They have been helpful in answering questions on mold construction for effective resin pours.
As far as the Aluminite recommended above; my experience is that their resin is ‘coarser’ with more imbedded bubbles than the Smooth-On products. It may be that my procedures have improved since my Aluminite days, but I am satisfied with Smooth-Cast. Again YMMV.
thanks so very much