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[MikaMa]

Thank you all for helping me out. I actually will try to do this in a few days. I will report how things go. There are 9 parts I need to mold, do you guys suggest I do 2 or even 3 molds or only one? If only 1 should I place them in several rows?

[MikaMa]

One more thing:

Since the models are a bit angled in few places, I find it hard to think a easy way to do the blue part



Using plasticard would be tricky, first i would need to cut a small piece and bend it in several places to make it fit the entire lenght of the model. That would take ages and be too tricky.

Any tips how to do the blue channels the easy way?

[mangozac]

Just use styrene strip. It's really not difficult, especially since it doesn't matter how neat it is. Don't bend it; simply cut the lengths needed with angles at the ends so they meet up to the next section.

[MikaMa]

[Blindhorizon]

That little piece that separates the three long pieces i would not add to the connection point. The three long pieces add plenty of ventilation to get bubbles out of, but that piece will add just a little more support to your item to get the shape you want, consistently. Now with working with something so small you won't really run into that issue, but i have noticed on bigger pieces it can really make or break how consistent you get a piece to cast. That being said once i start a practice i like to follow it through even with little pieces to help me better understand how i do my particular craft with future moldings. If the piece i left in comes to hinder me i would just remove it with a razor.

Blind-

[MikaMa]

Well it's been a while and I managed to make my very first split mold. It was easy after all and the cutting wasn't as scary as I thought it would be.

But.. There's always a but. It doesn't work .

I made a mold out of three 6mm scaled tanks with frontal gun and a small siren light on roof (like police cars).

The sprue is like this (yes I draw very well!)



There are 3 of those boxes side by side. The red drawings represent the frontal gun and the siren dome.

I use squeezing while pouring but every time the gun nd the dome fails. Sometimes even the rear end fails because air traps between the rear and the vent..

After 15 failed casts I need help...should I just make a new better mold or what?

And..I have used talcum powder, tried only to cast one at a time and even poured some resin first to the problem areas then closed the mold...but no use. Also I have enlargened the vents.

I use smooth cast 300 with 3min pot life which is too low really.. Will get 305 next time

HEEEELP

[mangozac]

Having separate pour and vent channels will help (so that the resin enters from the underside and the air exits from the top), but with such fine parts I'm doubtful. I'm sure the longer pot life resin will also be better. But ultimately the only way you'll be able to get perfect casts is through the use of vacuum and pressure.

[MikaMa]

thanks mate,

so I am basicly doing the right things and there's not much I can do to make the casts better. What about the angle that I place the vehicles in the sprue? what if they would be something like

\ \ \

hmm.. well I will try to do another mold because if I would manage to get a few clean casts I still would lose too much resin per cast..

anyone want to cast for me ?

[Fleafa]

Honestly, casting without vacuum is barely worth it for me, even for some personal hobby stuff.
You could try tilting the tank a little better, but the small protrusions will still give you trouble.

[MikaMa]

yea, disappointing but not much what I can do. Getting a pressure pot is really not an option atm. No spare room for it and don't want to blow our house up..wife might get mad.

and if someone can help me out and cast for me, PM me please

and to make sure: these are my own minis modeled and printed via shapeways.

[MikaMa]

I made a new mold and casts are good patience is a virtue.

( funny that when I make molds or cast, pearl jam " even flow " plays in my mind :p

[mangozac]