Tuesday, August 25, 2009

not much progress to report lately

I didn't do much this weekend.

A few weeks ago I bought some Sentinel Walkers off a kid in the gaming club and stripped the paint off them and broke them down into base components as much as possible so I can reconfigure them as part of the Adeptis Mechanicus army I want to build.

The pilot is just a seated guy molded as mostly one piece (torso, pelvis, legs). I decided to fill in the back surface of the lower half with Green Stuff (GS) to give it all substance; this will make it easier to cast it in resin.

I took some heads from a box of IG infantry and with a little bit of carving and GS sculpting made three variations of modern aircraft pilot heads. I cast all of these in silicon to make a two-part mold so I can do a handful of resin casts for the Mechanicus army and some other future projects. I ended up with a few bubbles in the silicon that I had to repair last night, but I think the mold will be usable with just a smidge of trimming with a razor blade.

Friday, August 14, 2009

corner pieces

I went home at lunch yesterday and did a first layer pour on my sons corner sculpt, then after work I finished the mold in a couple of separate pours.

I stripped the Lego mold box off this morning when I woke up and did a first run resin cast before morning sabbatical.

I think I pulled the piece out of the mold too soon because a few spots were squishy, but that pour was more to clean the mold of clay residue and silicon flash. I wouldn't try to sell that first cast anyway, so it doesn't matter if it failed.

I poured a second cast before leaving for work, it should be fully cured by the time my son rolls out of bed to go to work.

Thursday, August 13, 2009

A night of casting

As it turns out, the repairs I made to my mold yesterday morning took and the mold is very close to "perfect". It hard to accept anything short of "exactly what I wanted" and balance that against something that "works". I want to think that the imperfections in the mold give the cast pieces "character", but I find that to be difficult to sell.

My son must be as cheap as I tend to be. When I asked him what he would pay for one of the castings, it was like pulling teeth to get him above $5; I'm thinking of asking $15.

I managed to get three casts last night and two more before leaving for work this morning.

My son used the first two casts I made (which I wouldn't sell because of shrinkage making the edges very thin) as templates to make a 90 degree corner piece. He was laying the tile for the decking when I left for work this morning; I asked him to wait to pour the mold so I can take a final look at the original and make any tweaks that come to mind.

We were talking last night and I am thinking of donating a set of the terrain pieces to my local gaming club to be a prize at the next tourney. I'm not sure right now what I am going to consider "a set" - a minimum of 4 straight pieces (each is 5 inches long), probably two 90 degree inside corners (I think they will be 4inches by 4 inches) and two 90 degree outside corners (I think they will be 5 inches by 5 inches) - I THINK a GW Bastion will sit inside of that, I need to check.

My son thinks I should cut the length down. Each straight piece has crenelations that give 3 firing rests. If I cut one down to just one positions it would be about 1 2/3 inches long, two positions would be about 3 1/3 inches long... Those sizes would work better with smaller angled corner pieces to make a snaking defense line but would be easy to knock out of position. If I had a wide blade on my band saw, I wouldn't have to make a new mold for each size...

Wednesday, August 12, 2009

casting mis-adventures

When I got home last night I tried to use a piece of glass to give my casting a FLAT base, it did NOT go well....!

Using my big open topped block mold, given a little shrinkage in the resin, yields very thin edges where the original sculpt tapers down to "ground" level. To try and reduce this effect I sprayed a bright, shiny, NEW piece of glass with silicon lubricant thinking that would let me just slide the resin casting off and have a wonderfully smooth bottom.

To my dismay and GREAT irritation, the resin clung to the glass and wouldn't even consider letting go.

I managed to slice a chunk of skin off the back of my middle finger on the edge of the glass... Ouchy!! And this not even a minute after saying "I know I'm going to hurt myself doing this..."

And then, just to be mean, while cooling, the resin shrank and cracked the glass into 8 or 10 pieces...

But amazingly, the glass was still adhered to the resin! I ended up smashing the glass into tiny bits and still some is attached to the resin!! I have even dragged it along a concrete sidewalk and all that did was smooth out most of the sharp glass edges....

Needless to say, that cast is ruined and useless!
I might be able to salvage it as a painted example...

The gooey part of the mold had not completely cured so I cut into the side of the mold and scrubbed out the unset silicon and refilled the cavity with a new batch. That fixed two separate spots, but I discovered this morning that it did not fix the one that was causing a serious problem in the finished pieces (right where models would be placed!).

I did a little more surgery this morning before leaving for work and I hope that solves the problem, if not I'll have to remake this mold and lose probably $30 in materials! If the mold comes out usable, I plan to turn it into a two part mold that will give it a little more thickness at the taper points and pour it from a side. If I go this route I am going figure out a way to have my name and the copyright symbol integrated into the mold so it comes out on all the finished casts.

Tuesday, August 11, 2009

more casting

When I got home from gaming last night the silicon mold I had trouble with seemed to be less soupy and then this morning it seemed a bit more firm as well. So I measured how much liquid it would hold and figured out where half of that would fill a dixie cup and mixed a batch of resin and poured it in.

The resin sets up in about 15 minutes, so I was able to demold the cast before leaving for work and it looks mostly good.
There are some deformations around the still gooey areas, but they look almost intentional and give the piece a little character.
You can't see finger marks in the clay original, but it doesn't look as smooth and professional as I would like...

I'm going to try to do 3 or 4 more casts tonight when I get home and maybe prime and paint one.

Monday, August 10, 2009

silicon casting

This weekend I made my first foray into the wonderful world of silicon molds and resin casting!!

I picked up some supplies from JGreer.com and have so far found the guy to be helpful.

While waiting for the supplies to be delivered (UPS ground – I expected the full 10 days, but they really only took 3 or 4!), I made a few mold boxes with Legos and based some multi-piece metal model parts in clay as a foundation; these Legos will be forevermore dedicated to molds and casting, I bought lime green and orange so I remember to NOT mix them with the others I have collected over the years and plan to hand off to my grandchildren some day

I went out Saturday and bought several different sized dixie cups for measuring and mixing and poured the first halves of 2 two-part molds Saturday afternoon. The silicon I am using sets up in just over an hour, so I was able to strip the mold box down enough to pull off the clay base layer, swab the silicon with petroleum jelly, rebuild the box and pour the remaining half around mid evening. On the weekends I tend to stay up until 1am and actually managed to do my first resin cast in the molds before going to bed.

I was casting copies of a grav-bike from the game Void, which is a pretty spiffy model in my opinion. I plan to convert it over for use as a Tau Tetra for Warhammer 40,000, but I didn’t want to mangle the original because the company (i-Kore) has shut down (I’ll try to paint it up good enough to display).

I was also trying to make a copy of mini tank treads from an old GW Imperial Guard heavy weapon platform ( forget the name). This too is a multi-piece metal figure I’d like to NOT mangle, the casts are going to become the treads of an Adeptus Mechanicus heavy weapon servitor conversion.

The grav-bike pieces came out pretty good. I discovered that I got some bubbles in the mold, but the resin piece cleaned up nicely with a new X-Acto blade. I also discovered that the silicon mold picked up brush marks from where I used a large artists brush to swab petroleum jelly around between pours. The first cast picked up all the residual clay and petroleum jelly that was left in the mold and a second cast I did on Sunday came out nearly perfect. I need to find a way to patch the bubbles in the mold; I have an idea, but I am waiting for the guy from the supplier to get back to me about it. The brush marks that are in the mold should sand off the cast no problem.

The mini treads did NOT come out well at all!!! The way I set the mold up caused air bubbles to get trapped at critical points and I lost entire sections of the cast! I tried to clean up (expand) the air channels in the mold, but the second cast came out as bad as the first! If I can fix the bubbles in the grav-bike mold the way I think I can, I’ll do similar to fill in the pour spout on the treads mold and then cut new ones. The problem is that I did this as a tall, vertical mold where the resin is supposed to flow down through one piece and fill the other and continue to the top. Sounds great on paper, but didn’t work out well in practice. If I can plug the fill spout, I’ll cut new fill spouts and air channels so that I am filling the mold from a side; otherwise I’ll have to redo the mold.

Late last night I bit the bullet and tried to pour the silicon for a big block mold around an original defense barrier made from clay sculpted over Legos. The first batch of silicon only filled the mold box about half way, so I quickly made another batch and poured it in as well. The second batch left the mold about a quarter of an inch from the top and I knew that would mean there is less than a quarter of an inch of silicon over the highest point of the sculpt so I made up a little more and poured that in as well. I used my stirring stick (a popsicle stick) to try and integrate the three layers of still semi-liquid silicon.

This pour proved that I am having trouble getting a consistent mix with my current methods… By the time I got to the bottom of the mixing cup I saw that I needed to mix the two parts more and that showed consistently across all three portions of the pour.

I stripped the mold box off this morning before heading to work and I found that there were still several pockets of liquid silicon inside the mold. Fortunately, the skin of the mold didn’t tear and gush out the gooey liquid silicon! I put the mold out on the railing of the stairs to my apartment in hopes that the 90 plus temps today will help the mold finish curing. I’m hoping to get at least one good resin cast from this mold so that it isn’t a total failure that used about 3/8 of the silicon I paid $100 for… It doesn’t help that I had to destroy the original clay sculpt to get it out of the mold (this is a failing do to inexperience on my part, not the casting/mold making process – I have seen YouTube videos of other people where this doesn’t happen).

If things turn out well, I'll be fleshing the defense barrier out into a full line of terrain to sell. Then I am going to move on to sculpting an actual trench piece based on some photos from the first World War that will mount in a gaming board rather just sit on top of it.

I might do some scenic bases to sell as well, but I'm not sure yet... There is a ton of competition in that arena and I know a guy that does that already and wouldn't want to step on his toes.

I had planned to do some 15mm buildings for Flames of War, but I haven't gotten around to building the originals yet.