In need of a little mold help

[ccobra]

i am trying my first mold for a Resin Body. I am planning on doing a two part mold, should I cut out the windows from the 3D printed body or just slap it into the silicon? The windows are around 0.025" thick right now.

[munter]

If you are doing a two part mould I would cut the windows out. That will give you just some flashing to remove rather than a heavy hack out.
The outside and inside are equally important as are those window inner edges.

[walker]

If you decide to cut the windows out before you pour the silicone for the plug in, don´t forget to isolate the silicone behind the cut out windows with a release agent.

Roland

[ccobra]

Well, I cut out the windows so here it goes.

Only problem so far is that I broke my trusty Hf scales.

[ccobra]

Well I had to get some more silicon and start over. It was kind of like an old 3-Stooges film. I got the first part poured, then poured the inner part of the mold when I soon discovered I didn't have enough silicon to finish the mold. then wait another week so I could get another box of silicon. Anyway for those in the dark wondering about how much is needed to complete a mold, my mold required 3 1-lb. packages of silicon. I also found that a plastic mixing bowl and spatula from the dollar store works great for mixing, pouring, and cleanup. Once the silicon is setup, it just pulls away from the plastic like a skin. The first set of bodies from the mold may have not been perfect but I sure did learn a lot from the experience.
It kind of looks like a sixty year old car. Anyway I need to do some more experimenting with the XTC-3D coating that I used on the latest print. It covers better than the paint but you still need to do a lot of sanding to smooth out the plastic. It does give the 3d Print a good hard shell and I'll be able to reuse this body if I decide to try another Falcon mold.
Thanks for the help on this little project.

[walker]

3 lb silicone for ONE 32nd scale body ????? Really ?

Roland

[HomeRacingWorld]

All of my molds are about 2 1/4. I make my molds with thicker sidewalls so they are very durable and last for many, many pulls.

[ccobra]

I most likely made my mold too large. Even my wife razed me on how much silicon I used. But I am still learning.

[HomeRacingWorld]

The only way to learn is by doing it IMHO. You will find the method that works for you. I know I use more silicone than most, but I like the results so it's worth it.

[mattb]

It's ALWAYS better to use a too much silicone then not enough. A "do over" costs a lot more than an extra $3-$5 worth of silicone.

[ccobra]

[BARC 1]

You can use rice to gauge how much silicone you need. Poor the rice into the mold until it is full, then dump the rice from the mold into a measuring jug and see how much volume you need.

Cheers

Dan

[munter]

[walker]

Another way of learning is using the successful experiences of others. No quote, my experience.

Nevertheless I make my sidewalls quite thin. They are supported by walls, so thick silicone would be wasted. And I can cast a hundred or more bodies without any problem. Maybe it is a matter of silicone quality resp. handling of the moulds, too.

Roland

[mattb]

I also have made the molds not a lot bigger than the subject. I usually cut pieces of wood to put along each side, held in place with a large rubber band all the way around the mold. I find the thinner molds make it easier to remove the body from the mold. The variety of rubber is quite extensive and that is always a factor, too. I have been using the Alumilite high strength from HL for the last 2 years. It is highly flexible and does require side support. It is also very strong. I don't know if there is a limit to how many bodies you can cast in one mold with this rubber. Using some kind of release, of course.

I mentioned a in another thread that a resin caster of sci-fi stuff told me he used baby powder in his molds as a release and to give just a little texture to the finished piece which made it paint easier. I did a couple bodies last week and tried this. I dumped some powder in the mold, tapped it on work surface and then blew out the excess. It actually worked pretty good. Besides being cheap, there is no chemical left on the body.