What Silicone do you use?

[Quail Chick]

Hello Forum,

I just made a decent sized mold (4" by 15" by 9") and the silicone alone cost me a fair amount. I've been using Smooth-On's Oomoo for a while, mostly because I was doing smaller items and I could pick up small quantities at the local Utretch. that and the Oomoo is a good beginner product as it is a 1:1 ratio that doesn't require degassing. Now that I'm making larger items, the Oomoo is getting expensive. At $20 for a 2 pint kit, I'm looking into other options.

What are other good suppliers for larger quantities of silicone mold-making stuff?

 

[MustangGTR1]

Mine runs 115.00 for a 10 pound kit

 

[robstyle]

This s my guy: Mold Making Silicone, moldmaking silicone molds resins hobby moldmaking

I use his 2125 green and have had stellar results without degassing. Of course with any job its about technique so any silicone, if treated and used proper, will have great results unless its contaminated or too fast of a cure time. With the 2125 surfaces are so good its as if it was degassed front and rear. Again, much is in the technique and everyone has their own way of doing things.
Click for pics.
http://i43.tinypic.com/2s61u0k.jpg
http://i40.tinypic.com/flebmu.jpg

 

[MustangGTR1]

It will alll come down to what do you want to use. Mine is high because I use platinum based, and the molds last what seems forever

 

[hansicle]

I work part time for a place. I do odd jobs around the shop, and one of my jobs is disposing of old molds from finished projects. They use the "inexpensive" silicone for most of the work they do, seeing that it's short runs for a customer. They ask that I destroy the molds before I throw them out, and I can pretty much tear them apart with my hands, and the older molds are the consistancy of cheese... just fall apart. This sometimes bites them in the butt when they make a kit that they cast from time t time. The mold starts to tear apart as they do pulls and they have to constantly remold it every year.

If you plan on making something that you will be using over and over again for a while, or maybe put away and store, and might need to use later, invest in a better silicone.

 

[coofunkcurly]

Not gonna find a much cheaper silicone than Oomoo that is easily accessible. Maybe in the USA you guys would have cheaper alternatives than we have in Canada though.

For molds that will experience heavy use, our money goes to Smooth-on's Mold Star for pour molds and Rebound for brush on applications.

 

[slave1pilot]

mrs.slave1pilot uses saline.

 

[clonesix]

Most Silicone RTVs are in the $100/gal range.

The only way to make it less costly is to use it more sparingly, meaning matrix molds. Anytime that you fill up a block with RTV, there is a lot of waste that is just taking up space.

Many people use the "Brush on" approach, where layers are brushed on until a 0.5" - 0.75" is achieved and then a cheaper backer material it use for the remaining space.

 

[robn1]

...Many people use the "Brush on" approach, where layers are brushed on until a 0.5" - 0.75" is achieved and then a cheaper backer material it use for the remaining space.

That's what I'll be doing on my phaser. I got a trial size of Smooth-Sil, I'll brush it on to get it about 1/8 thick. Then I'll back it up with plaster.