Obliterator Cult progress... Or lack thereof

Well, I've learned some important things about my cutter.  Mainly, it can't do sharp corners very well.  It rounds them off.  It's not a big issue with the larger stuff, but with a 5mm x 2mm piece, it's an issue.  I'll still use it to cut out cardstock vehicles and buildings, but it means the detail stuff will have to find another solution.  It also cuts plastic better then cardstock (which isn't so much a complaint as an interesting thought as it was designed for paper cutting).  Though I guess I can't complain too much about a CNC cutter that only cost $400. 

I learned this trying to cut out the obliterator legs I designed a while back.  they came out kinda bloby and misshapen.  (And due to my own stupidity not cut through all the way.)  I'll just have to resort to more classic ways of making them. *sigh*

All in all, I don't suggest the Cricut series to wargaming modelers. I've never used a robocraft, but from some of the cutouts I've seen it's a better choice and you don't have to buy a $50 third party piece of software to make it cut more then the junk images on the cartridges.

2 Part Mold Making Part 2

2 Part Mold Making Part 2!

Hello again, the silicone from last time has cured so we're going to move on to the next step.

First off, the mold is flipped over to reveal the clay support from last time.


It's carefully peeled off the mold as we want to try and get as much of it as possible with this first removal. Often I'll remove one of the blocks in the wall to get a good starting position.



After it's been removed, look over the mold for any bubbles that had formed against the piece. Be careful to NOT remove the piece from the mold, it needs to stay sealed to the silicone at this point. If there are any obvious bubbles, decide if they're worth redoing the side of the mold. Also while doing this, use a cheap toothpick (the ones that are flat and have a fat end and a skinny end) to gently scrape up any residual clay left behind. I'd probably get better results with the clay if I'd use new (and proper) clay every time, but it's what I have, and it works well enough. A layer of blocks is added to the bottom to form a deeper space to fill with silicone.




Now we need to prevent the silicone we're going to be adding from bonding to the silicone that already exists or we'll end up with a block of silicone with our part trapped inside. I've tried a number of things to do the job. This includes a variety of 'official' mold releases, vasaline, vegtable oil, etc. But what I've found works as well as the official releases and is orders of magnitude cheaper... is Elmer's white school glue. Yes, the cheap stuff you can pick up for a nickel a tube right before school starts each year. Take the school glue and use or transfer to another container about half of it. Then refill the bottle with distilled water (normal water works too, but adds other contaminants which may or may not help) and a drop of liquid detergent. Either dishwashing or clothing detergent work, I use whichever we happen to have for our laundry/dishes at the time.




I have an old brush I have dedicated to being used with waterbased glues. I use it for making bases and terrain as well, so it's not only for mold making. But a brush should be dedicated as the glue changes how the bristles on the brush react making it hard to paint with it later. Anyway, put a few drops of the 1-1 glue we made someplace and then brush it over the silicone rubber surface of the mold. Try to avoid getting it on the model itself, but make sure the rubber by the model is covered. It doesn't take a thick layer, just some. I've found mine tends to want to puddle a bit while it's trying to dry. Just use the brush (damp with water or 1-1 glue still) to pull the wet glue back out to the higher points of the mold.




After this glue has dried. We repeat the procedure last time and hmm... aparently I didn't take a lot of pictures of that stage, so I'll do a quick synopsis with more pictures.

I didn't get a picture of it, but first I weigh the inner cup that I'll be putting the silicone in. This gives me the offset I need for calculating how much catalyst I need. I use a 2 cup measuring system. It's made by taking 2 cups and sticking one inside the other. Water is then added in known incremements to the inner container, and the outer is marked for each incremement. This way I can replace the inner cup and not have to relabel my cup every time. I can't remember where I learned of this idea, but it's not originally mine. After measuring out volume of silicone I want, I remove the marked cup (as I didn't weigh it too,) and weigh the silicone.




After calculating the needed amount of catalyst ({silicone+cup} - {cup}) * 0.03. I add the catalyst to it and mix.




The pouring is identical to the before and is hard to take a picture of while doing it, so I don't have any pictures of that.

I'll probably do a post on casting with the mold sometime in the near future as well.

Female Fire Warrior Mold Making

Having neglected to take pictures at good times of the last few stages of the female firewarrior project, I had decided to not even mention them on the blog. I'm regretting that as now I have to play catch-up. I finished up the initial scuplt and made a mold of it. Which took three or four days (most of which was spent waiting on silicone to cure). Then a handful of casts. This is the stage where I learn a lot about my sculpt and usually where I do a lot of revising on it. The image at the start of this post is the mold of the first cast.

As usual, I decided I didn't like a large chunk of it and using one of the cast pieces as the base, chopped off large chunks of it and redid them. I tried getting some pictures of the new scuplt, but it kept ending up with greenstuff work on a white blob. The lighting was just unable to pick up any definition on the unpainted white resin.

So instead as I mention casting relatively regularly, so I figured people might be interested in my particular methods. I use 2 different methods depending on if I'm making a one part or two part mold. I'll plobably cover one part molds later, but as I need to cast the reworked FWF torso I'll start there. I build an interlocking brick box (I think these ones are megablocks) and then roll out a blob of clay.



I press the part in the clay, press the building brick box around the part, and lastly add some divets using the 'wrong' end of a paintbrush to work as keys. I would use some other method besides clay, but I'm poor and haven't gotten around to hunting down and pricing out some of the temporary mold materials.



The silicone I'm currently using is made by GE Silicones and is "RTV426" with catalyst "Beta 26". I got a 5 gallon pail of it as a sample from them a while back. I'm assuming they're used to dealing with people that use multiple gallons per cast as that's a LOT of silicone. Their datasheet suggests 3 different mixes, and I aim for the 100 parts silicone to 3 parts catalyst as I almost always add too much catalyst (bringing making the actual ratio about 100 to 4) which is halfway between 2 of the suggested ratios. I mix it up and drizzle a tiny dab onto the part which I carefully spread into the cracks of the model (sorry, forgot to snap a picture at this stage) before slowly filling the mold with the rest of the silicone. This helps us poor mold makers without vacuum chambers avoid bubbles.



It then sits for 24 hours to cure. And that's the first half of the 2 part mold. I'll cover the second part as i do it.

Airbrush, Airbrush!

Well, it's been almost 2 weeks sense my last post >.< Sadly RL issues have been plaguing my life and I hadn't come up with anything to post about. However, just recently (yesterday, I believe) I got an airbrush! They are beyond nice. I test painted the basecoat for a devilfish earlier today. Including setting up the air compressor, fiddling with the airbrush before trying to actually paint, and clean up, I painted it to a nicer, smoother coat in a quarter to an eight the time. It's amazing.

The airbrush is a Badger 150, Dual Action, Internal Mix Airbrush. Which is nice as I have a number of Badger brand paint pots which fit perfectly onto the nozzle attachment thingie. I should probably find another regulator as the ones on the compressor are higher then the airbrush's recommended. The compressor fills the tank to 100 psi. the outlet regulator can be set between about 60 psi to something higher then 100. The airbrush manual on the other hand says that regulated pressure should be set someplace between 15 and 50 psi with normal operating pressure at 30 psi. Now there are some pressure sources that it says are alright to use that are unregulated that are up in the 70 psi and 80 psi ranges when new, so I'm undecided as the airbrush will only be attached and under pressure while I'm using it. The compressor has a cute 2 gallon tank so if I get a regulator that provides 30-35 psi, then the 2 gallons at 70-100 psi should give me lots of painting time.


It'll take some practice before I can start airbrushing designs on things, but as a vehicle basecoat painter, it's amazing. I'll have to try it on my crisis suits too.

Sorry the picture is a stock instead of an actual of my brush, but eh.
Image pulled off the Badger website, used without permission.
And woo, finally figured out there was a built in image uploader thing for images >.>