Grimstuff's Scratch Build Journal (building, casting, painting)
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Grimstuff
Active Hunter
Thanks. My gauge is only in inches mercury so I couldn't say the exact psai, but it maxes out the gauge at 29 point whatever, so it's definitely sub-1psai range. It can get most the way there fairly quick too (though those last few inches of mercury do naturally take a little bit). A lot of it of course will be dependent on how large your chamber is, and how much CFM the piping allows. Even though mine works fantastically, I'd probably go with the 8qt pot if I had to make another as I haven't degassed anything that needs the extra space and it would would work a little quicker.
As for a shop vac, not exactly sure. I see a guy on Youtube who used one, but he doesn't seem to measure the vacuum it achieves and the comments seem pretty critical of it, so hard to know how effective it is. A shop-vac would certainly have the CFM down, but I'd question how much actual vacuum one could pull; silicone and urethane definitely need full-vacuum to degas. Also iirc shopvacs use the airflow they pull to cool the motor, so it'd probably burn up for a use like this too.
As for a shop vac, not exactly sure. I see a guy on Youtube who used one, but he doesn't seem to measure the vacuum it achieves and the comments seem pretty critical of it, so hard to know how effective it is. A shop-vac would certainly have the CFM down, but I'd question how much actual vacuum one could pull; silicone and urethane definitely need full-vacuum to degas. Also iirc shopvacs use the airflow they pull to cool the motor, so it'd probably burn up for a use like this too.
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Grimstuff
Active Hunter
Been pumping out some rangefinder casts lately.
First few sets had some bubble issues from trapped air, easy enough to fix with some filler, but a few modifications to the air-channels on the molds and some improved casting techniques let them start coming out perfect.
Pretty much when casting into block molds you want to think about the flow path that the urethane is going to make. Any little crevice that the urethane can't flow into or out of will create a void and capture bubbles in the casting. It's like filling an underground cave with water, anything that doesn't have an outflow for the air is going to create a pocket. Since the rangefinder stalk and ear cap are both sorta complex shapes that needed 2-part molds, I had to give some thought to how my resin would flow through them. Here's them both with their flow channels highlighted.
Each had their own little challenges that had to be overcome. The 1st image, the earcap, is pretty much a big hollow space so it didn't need any fancy inflow channels or anything like the 2nd did, the resin could just pool upwards. It's red highlighted 90degree sections towards the top create some air trap risk, but rocking the mold back and forth a little bit while injecting seems enough to escape them. The 2nd image, the rangefinder, was too tight and thin to really pour from the top, so instead I had to create an inflow channel that would allow the urethane to enter from the bottom and flow upwards. I also cast it at a slight angle so the bubbles don't get trapped in any of the flat 90degree sections.
The perplex block is cast with a different resin than the others, Smooth-cast 325, which cures to a transparent slightly-yellowed look. The only problem though is that it cures incredibly fast with a 2.5 min pot life, which makes degassing it very difficult. In the future I'll use the longer-setting 326 instead.
The stalk's mold is a little long and wobbly, so I made a cheap little mothermold for it by casting some plaster around it.
Some images of the masters next to their cast replicas:
First few sets had some bubble issues from trapped air, easy enough to fix with some filler, but a few modifications to the air-channels on the molds and some improved casting techniques let them start coming out perfect.
Pretty much when casting into block molds you want to think about the flow path that the urethane is going to make. Any little crevice that the urethane can't flow into or out of will create a void and capture bubbles in the casting. It's like filling an underground cave with water, anything that doesn't have an outflow for the air is going to create a pocket. Since the rangefinder stalk and ear cap are both sorta complex shapes that needed 2-part molds, I had to give some thought to how my resin would flow through them. Here's them both with their flow channels highlighted.
Each had their own little challenges that had to be overcome. The 1st image, the earcap, is pretty much a big hollow space so it didn't need any fancy inflow channels or anything like the 2nd did, the resin could just pool upwards. It's red highlighted 90degree sections towards the top create some air trap risk, but rocking the mold back and forth a little bit while injecting seems enough to escape them. The 2nd image, the rangefinder, was too tight and thin to really pour from the top, so instead I had to create an inflow channel that would allow the urethane to enter from the bottom and flow upwards. I also cast it at a slight angle so the bubbles don't get trapped in any of the flat 90degree sections.
The perplex block is cast with a different resin than the others, Smooth-cast 325, which cures to a transparent slightly-yellowed look. The only problem though is that it cures incredibly fast with a 2.5 min pot life, which makes degassing it very difficult. In the future I'll use the longer-setting 326 instead.
The stalk's mold is a little long and wobbly, so I made a cheap little mothermold for it by casting some plaster around it.
Some images of the masters next to their cast replicas:
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Grimstuff
Active Hunter
Just some quick lil updates. Been doing a lot of research into painting over the past few days as I start getting close to hopefully actually getting one of these buckets done up. Painting and weathering is actually one of my weaker skillsets though, and you can't get much more advanced than the ESB Fett helmet, so I've been checking out a lot of your guy's paint threads to hopefully get ready for it. Biggest hurdle so far has been getting a solid paint list together. I've seen the Humbrol list referenced around quite a bit, but I wasn't sure how hard they'd be able to get here in the states. I actually did a whole bunch of research into converting the colors into other brands or even mixing my own before I found a seller on ebay with the entire Humbrol line for pretty cheap shipping, so that problem ended up solving itself. Now just to wait for em to arrive all the way from Poland.
While I've been waiting on that, I got the buckets all primed. Dunce on left, and two production helms in-case I mess one up, one happy little family.
Also tried to make some visors, but it seems the 0.09 inch acrylic I got at Lowes is too thick to thermoform well. I just can't get enough heat to stay into it to evenly bend, so it comes out barely curved and kinda wavy.
I'll have to try to find something thinner I guess, but not so much it's paper-like. Suppose worse comes to worse I'll scavenge from some cheap face shields.
While I've been waiting on that, I got the buckets all primed. Dunce on left, and two production helms in-case I mess one up, one happy little family.
Also tried to make some visors, but it seems the 0.09 inch acrylic I got at Lowes is too thick to thermoform well. I just can't get enough heat to stay into it to evenly bend, so it comes out barely curved and kinda wavy.
I'll have to try to find something thinner I guess, but not so much it's paper-like. Suppose worse comes to worse I'll scavenge from some cheap face shields.
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Grimstuff
Active Hunter
Ahh nevermind, when in doubt, apply more heat I guess.
Instead of the heat gun I tried using an oven instead, ~10 min @ 300 degrees, and it forms much much nicer. I'm generally very apprehensive about heat-forming any plastics indoors, let a lone in an oven, but it seems the fume danger of acrylic is more of a debatable worry rather than a critical one like heating something like PVC is, so hopefully it doesn't kill me.
Now just to get it tinted up. Current plan is to go for the dye method, but I might experiment with some film tints too.
Instead of the heat gun I tried using an oven instead, ~10 min @ 300 degrees, and it forms much much nicer. I'm generally very apprehensive about heat-forming any plastics indoors, let a lone in an oven, but it seems the fume danger of acrylic is more of a debatable worry rather than a critical one like heating something like PVC is, so hopefully it doesn't kill me.
Now just to get it tinted up. Current plan is to go for the dye method, but I might experiment with some film tints too.
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Grimstuff
Active Hunter
Ayyy signed package from Polan arrived.
Might take me a bit to start derping around with these with what all the Christmas and stuff going on right now, but I'm glad to finally have them in-hand though. They all look very wonderfully desaturated.
Wonder if he's ever curious why people buy these exact sets of colors so often.
Might take me a bit to start derping around with these with what all the Christmas and stuff going on right now, but I'm glad to finally have them in-hand though. They all look very wonderfully desaturated.
Wonder if he's ever curious why people buy these exact sets of colors so often.
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I personally prefer Vallejo. About to start my own Jodo Kast paint-up with those 
Grimstuff
Active Hunter
Yeah, I'd prolly prefer to do it in acrylics, lot easier to work with and quicker drying. The ease of not having to convert colors and the combined shipping from that ebay seller sorta won me over to the Humbrol list though.
But anyway, been spending the past few days playing around with them on the dunce helm, mostly just some experiments to see what can be sprayed over what and getting some practice in layer masking.
I actually got a whole ear roughly done up (just quickly eyeballed the patterns), but two major problems lead me to end up stripping it. First was the matte clear coat I used which came out hazy, I believe due to the humidity on the day I sprayed it. I didn't mind that too much since it's just the dunce helm and it seemed to be clearing up as it cured more, but the final nail got set in the coffin while I was masking out the white decal. The Rustoleum metallic aluminum I used as the base-coat just doesn't offer enough adherence for things above it, and the masking tape ended lifting off big huge chunks of all the layers. There wasn't too much left after the tape was all off.
I expected I might have some difficulty with the metallic base. I was hoping the steel-wool scuffing and soap wash I gave it would make it work, but I guess not. I'll have to experiment with some alternatives; the Humbrol silver would prolly work as the paintjobs I've been referencing use it, but it seems wasteful to use the model paints as base-coats, especially on the dunce. I might even just paint-on the metallic bits instead of having them as an under-layer, dunno, like I said this sorta effects-heavy painting is still kinda new to me, so I'll prolly have a few more mistakes to learn from before it's all said and done.
For now though I got the entire silver base all stripped off and a new layer of primer curing on it.
But anyway, been spending the past few days playing around with them on the dunce helm, mostly just some experiments to see what can be sprayed over what and getting some practice in layer masking.
I actually got a whole ear roughly done up (just quickly eyeballed the patterns), but two major problems lead me to end up stripping it. First was the matte clear coat I used which came out hazy, I believe due to the humidity on the day I sprayed it. I didn't mind that too much since it's just the dunce helm and it seemed to be clearing up as it cured more, but the final nail got set in the coffin while I was masking out the white decal. The Rustoleum metallic aluminum I used as the base-coat just doesn't offer enough adherence for things above it, and the masking tape ended lifting off big huge chunks of all the layers. There wasn't too much left after the tape was all off.
I expected I might have some difficulty with the metallic base. I was hoping the steel-wool scuffing and soap wash I gave it would make it work, but I guess not. I'll have to experiment with some alternatives; the Humbrol silver would prolly work as the paintjobs I've been referencing use it, but it seems wasteful to use the model paints as base-coats, especially on the dunce. I might even just paint-on the metallic bits instead of having them as an under-layer, dunno, like I said this sorta effects-heavy painting is still kinda new to me, so I'll prolly have a few more mistakes to learn from before it's all said and done.
For now though I got the entire silver base all stripped off and a new layer of primer curing on it.
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Grimstuff
Active Hunter
Ayy, i'm back!
No posts in a while since I had only really been doing more paint tests and template cutting since the last update, boring stuff. During that process though I did end up painting the whole rear section on the dunce helm too, but it was a pain due to the crappy small nozzle detail brush I've been using so far which gave it some really thin spotty layers.
Combined with the rough sanded helm and bubbles holes... it looks a little yucky.
Since then though I finally invested in an airbrush that costs more than 15 dollars and got a Paasche-H. Tons more easy to work with, I really should have just gotten one to start with, it's not like it's even that much more money than the cheapos.
Anywho, with it, and the knowledge I gained working on the dunce,I've finally started working on the proper bucket imma send off to my friend. So far I got it all layered on the back up to the green.
I'm pretty happy with all the under layers, but the final green there came out a little rough textured and splotchy though, and got a little mineral spirits splash on it, whoops. I'll prolly see if I can give it a light steel wooling without lifting the latex mask then give it another coat tommorow. I'm not completely sold on it's color anyway.
No posts in a while since I had only really been doing more paint tests and template cutting since the last update, boring stuff. During that process though I did end up painting the whole rear section on the dunce helm too, but it was a pain due to the crappy small nozzle detail brush I've been using so far which gave it some really thin spotty layers.
Combined with the rough sanded helm and bubbles holes... it looks a little yucky.
Since then though I finally invested in an airbrush that costs more than 15 dollars and got a Paasche-H. Tons more easy to work with, I really should have just gotten one to start with, it's not like it's even that much more money than the cheapos.
Anywho, with it, and the knowledge I gained working on the dunce,I've finally started working on the proper bucket imma send off to my friend. So far I got it all layered on the back up to the green.
I'm pretty happy with all the under layers, but the final green there came out a little rough textured and splotchy though, and got a little mineral spirits splash on it, whoops. I'll prolly see if I can give it a light steel wooling without lifting the latex mask then give it another coat tommorow. I'm not completely sold on it's color anyway.
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Grimstuff
Active Hunter
Got the back all steel wooled, re-coated, and finally peeled.
It looks pretty cartoony with the colors so flat like that, but that seems to be pretty normal from the paintups I've seen, I expect it'll come into it's own after the weathering.
With the back mostly done for now, I began on the face.
The initial grey layer came out a little rough due to Florida's humidity, so it got a steel wool pass too. After that on went the red, then the lower cheek's green. I figured it'll be best to do the upper cheek's black last as it'll cover the red and green much better than the other way around.
While starting to remove the masking to prepare for the black layer though I ran into a bit of a problem.. some paint chipping. It goes all the way down to the resin, so it seems the primer had a weak bond in this area. It's a bit of a crevice, so I guess I missed doing any prep here and it still had the release agent oils on it from the casting process. whoops.
For now I re-taped it and peeled it a few times to get it to fully-chip. I didn't wanna repaint it just for it to chip again. Tommorow I'm gonna try to sand down the surrounding red a little to flatten the layer ridge, then carefully repaint the area. Luckily it's only chipped in the red, and not the actual layered damage much, so it'll hopefully be an easy touchup.
Grimstuff
Active Hunter
Some more bits done.
Repairing the lift-up:
I also got the upper cheeks blackened out, but didn't get any photos.
Finishing the back band:
I already had the silver and grays laid down from the earlier steps, so it just needed a quick red layer now. It looks a bit.. sparse after the peeling, but it's a really heavily weathered spot in the references, so I suspect that's a lot of the difference.
Lower Right Ear:
While prepping to get the right ear's sand color on, I got some more lifting on the back side, ugh. I sanded down the whole side and re-grey'd it. After that got on all solid, I masked out the grey and got the actual sand on.
It was only later that I discovered that the sides of the lower piece are actually silver instead of grey.. I don't know what reference I was using that lead me to believe otherwise. Instead of repainting it though, I just took a silver sharpie to it, which will get the job done without risk that trying to repaint just that bit would give.
Dome:
The dome went about pretty routinely. I'm starting to run low on my dark grey, so I tried to spray it conservatively in only the spots it'd show. I never peeled my masking fluid between the layers, so it was a bit tough to finally get off after the green was dried, you can see a few roughing marks from the process in the last shot. They cleared up after a quick steel wooling and soap bath though.
The masking fluid I'm using actually isn't Maskol despite the purple appearance, but rather just simple cheap liquid latex I watered down some and added purple acrylic to.
Repairing the lift-up:
I also got the upper cheeks blackened out, but didn't get any photos.
Finishing the back band:
I already had the silver and grays laid down from the earlier steps, so it just needed a quick red layer now. It looks a bit.. sparse after the peeling, but it's a really heavily weathered spot in the references, so I suspect that's a lot of the difference.
Lower Right Ear:
While prepping to get the right ear's sand color on, I got some more lifting on the back side, ugh. I sanded down the whole side and re-grey'd it. After that got on all solid, I masked out the grey and got the actual sand on.
It was only later that I discovered that the sides of the lower piece are actually silver instead of grey.. I don't know what reference I was using that lead me to believe otherwise. Instead of repainting it though, I just took a silver sharpie to it, which will get the job done without risk that trying to repaint just that bit would give.
Dome:
The dome went about pretty routinely. I'm starting to run low on my dark grey, so I tried to spray it conservatively in only the spots it'd show. I never peeled my masking fluid between the layers, so it was a bit tough to finally get off after the green was dried, you can see a few roughing marks from the process in the last shot. They cleared up after a quick steel wooling and soap bath though.
The masking fluid I'm using actually isn't Maskol despite the purple appearance, but rather just simple cheap liquid latex I watered down some and added purple acrylic to.
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Grimstuff
Active Hunter
Welp, while taking off some more masking tape. I got some more lifting around the ears. :facepalm
At this point, I got pretty fed up with dealing with this problem, so I decided to just completely sand the areas on both ears all the way down to the plastic, and properly re-prime and paint them. This time using some high-stick primer.
Re-doing all that was a pretty big setback timewise, but hopefully it solves these lifting issues once and for all.
From there I got that left ear done up so I could finally have all the major sections painted up,
The white decal is kinda rough looking, the liquid mask didn't do too good for masking straight lines. I might touch up the edges with some proper masking tape stencils instead. For now though, it's nice to just have everything on.
From here I just have to paint the rear keyholes, the maroon on the red parts, the rangefinder and earcap, and then do some detail passes. Then we'll finally be ready to weather it and get the visor in.
At this point, I got pretty fed up with dealing with this problem, so I decided to just completely sand the areas on both ears all the way down to the plastic, and properly re-prime and paint them. This time using some high-stick primer.
Re-doing all that was a pretty big setback timewise, but hopefully it solves these lifting issues once and for all.
From there I got that left ear done up so I could finally have all the major sections painted up,
The white decal is kinda rough looking, the liquid mask didn't do too good for masking straight lines. I might touch up the edges with some proper masking tape stencils instead. For now though, it's nice to just have everything on.
From here I just have to paint the rear keyholes, the maroon on the red parts, the rangefinder and earcap, and then do some detail passes. Then we'll finally be ready to weather it and get the visor in.
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Grimstuff
Active Hunter
Thanks @MoogMan. I really should have just gone ahead and redone it all the first time it happened, trying to just patch them up as long as I did was dumb. Worst possible thing would be for me to get it all done and shipped out, only for another big chunk to flake off on arrival. Fortunately though, this new primer seems to be gripped on there tight, survived some tape tests just fine. Next time I'll do double the prep work I did for this, and use that primer from the start. Those cheap regular paint-aisle primers are pretty much just flat normal paint (same exact dry times and everything), you really have to go for the industrial and automotive stuff for true proper bonds.
Grimstuff
Active Hunter
Also, some more lil updates. Got the final red layer on the rear keyholes done, also the killstripes.
The old grey that was on there from the original painting of that area was a little rough textured, so I steel wooled it a bit. Doing so made the layers spot through each other a little more than I like though, but it's probably not worth the bother and risk of messing things up to try to micro-mask and repaint them. This is intended to be a pretty economy paint-up, so a few smaller issues like that are ok as long as the general aesthetic isn't hurt.
The killstripes were a challenge to get masked up. I ended up getting a little two stripe template card made up which made things easier.
The white layer was a primer layer as I didn't want to have to do 100 layers of yellow to keep the green from showing through. For the yellow/orange gradient I tried to keep it pretty subtle, as it seems that way in most references. I'm pretty sure for the actual original prop they only used 1 color for the stripes, and the gradient comes from how thickly they painted it over the green, but it's a challenge to replicate an effect like that without knowing the exact colors and weathering they used. Also, I'm still a pretty inexperienced painter, so simple is better.
There's a few chips of bright yellow showing through the orange, due to me de-masking the stripes before the orange layer had dried and bonded properly. Not really any way to fix them unfortunatly as that's now a unique mixed orange/yellow shade that I'll never be able to approximate. Bob Ross would call it a happy accident though, as it fits alright with the chipped damage theme.
Another little thing I did was give a metallic effect to my Borden connector.
Since the Borden is supposed to be an actual metal piece that gets glued in, I didn't want it to just use the same fakey looking Silver 11 the rest of the helmet has. So to make it look distinct like it does in the references, I painted it with some Alclad II metallic lacquer, which gives some very realistic effects. The picture doesn't give it too much justice, as it has quite a realistic sheen in person.
The old grey that was on there from the original painting of that area was a little rough textured, so I steel wooled it a bit. Doing so made the layers spot through each other a little more than I like though, but it's probably not worth the bother and risk of messing things up to try to micro-mask and repaint them. This is intended to be a pretty economy paint-up, so a few smaller issues like that are ok as long as the general aesthetic isn't hurt.
The killstripes were a challenge to get masked up. I ended up getting a little two stripe template card made up which made things easier.
The white layer was a primer layer as I didn't want to have to do 100 layers of yellow to keep the green from showing through. For the yellow/orange gradient I tried to keep it pretty subtle, as it seems that way in most references. I'm pretty sure for the actual original prop they only used 1 color for the stripes, and the gradient comes from how thickly they painted it over the green, but it's a challenge to replicate an effect like that without knowing the exact colors and weathering they used. Also, I'm still a pretty inexperienced painter, so simple is better.
There's a few chips of bright yellow showing through the orange, due to me de-masking the stripes before the orange layer had dried and bonded properly. Not really any way to fix them unfortunatly as that's now a unique mixed orange/yellow shade that I'll never be able to approximate. Bob Ross would call it a happy accident though, as it fits alright with the chipped damage theme.
Another little thing I did was give a metallic effect to my Borden connector.
Since the Borden is supposed to be an actual metal piece that gets glued in, I didn't want it to just use the same fakey looking Silver 11 the rest of the helmet has. So to make it look distinct like it does in the references, I painted it with some Alclad II metallic lacquer, which gives some very realistic effects. The picture doesn't give it too much justice, as it has quite a realistic sheen in person.
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Grimstuff
Active Hunter
Time for some visor dying.
For this, I used the very popular product iDye Poly. I got mine from a lady on ebay who attached a comically insane amount of stamps on the envelope.
There's a few video guides on how to use this stuff on visors, plus I'm sure plenty of guides around here and mandomercs;
The general gist though is to heat up some water, add dye, stir it, let it cool to 140-150F, then dunk your plastic for ~5 mins.
I suspect my thick acrylic visors probably could have handled higher heat than the thin PETG in those videos, but I didn't wanna risk it.
This was a pretty interesting and fun process. You feel sorta like an early century oil worker.
I did a few test sheets like you can see in the second image. I found about 2-3 dunks gave a good solid tint. The last image is a pretty good approximation of what it's like to look through it, if your eye was a camera sensor at least.
I few things I learned for the next time I do this ever:
Overall though, I'm pretty impressed I didn't make a huge mess. I'll probably just buy pre-tinted plastic in the future, but this was fun.
Now to just get it actually mounted in, instead of me holding it there for the photo.
For this, I used the very popular product iDye Poly. I got mine from a lady on ebay who attached a comically insane amount of stamps on the envelope.
There's a few video guides on how to use this stuff on visors, plus I'm sure plenty of guides around here and mandomercs;
The general gist though is to heat up some water, add dye, stir it, let it cool to 140-150F, then dunk your plastic for ~5 mins.
I suspect my thick acrylic visors probably could have handled higher heat than the thin PETG in those videos, but I didn't wanna risk it.
This was a pretty interesting and fun process. You feel sorta like an early century oil worker.
I did a few test sheets like you can see in the second image. I found about 2-3 dunks gave a good solid tint. The last image is a pretty good approximation of what it's like to look through it, if your eye was a camera sensor at least.
I few things I learned for the next time I do this ever:
- Probably use 2 packets instead of just the 1 I used, dunkings were getting less effective towards the end and it was getting a little grainy. My initial test piece came out better than my final visor.
- Get very cold water for the quenching step, and don't touch any of the dyed part until after a solid minute or so in there. Otherwise you can smear and fingerprint the dye.
- Don't use a thermometer with a plastic clip, as it'll get dyed too.
Overall though, I'm pretty impressed I didn't make a huge mess. I'll probably just buy pre-tinted plastic in the future, but this was fun.
Now to just get it actually mounted in, instead of me holding it there for the photo.
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