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  1. Member Since
    Aug 2008
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    Dec 3, 2008, 3:26 PM - few questions abt casting method and products #1

    right been reading several thread over the last few days here and on RPB. also reading the TDH wiki.

    my question has to do with slush casting a lid. most of my projects are at he planning stages only but already doing research into the next stage and methods

    I will be referencing the smooth on products just cos then I have some reference frame for comparison and its available in UK

    I know abt the silicone vs latex argument; and making mother molds then a outer case with plastikote/FG

    I'd like to thank stormtrooper guy, stormrider, FP, asok, evan... and DangerRuss for their threads. ANd every1 else who has posted over the last 2-3yrs whose names I may have forgotten.

    my question are really abt the casting part.

    from wot I gather FG used to be the only material availble in the past; but is a pain to use and not that great for ur lungs. WIth new liquid plastics - slush casting seems to be the way forward.

    question 1 - does any1 still do gel-coat/FG for surface + resin (ie rotocasting) backing? reason I ask is yrs ago; before I knew better, bought stuff off the internet which was FG only (main item is a imperial guard lid). Want to work on these bad casts but the FG alone feels really flimsy. I alos like the smooth finish of roto cast on skin. would it be advisable then to put in 1-2 layers of smoothcast320 between the FG and roto? Also - the FG is well cured stuff, will smooth on roto-cast stick to the FG, or will there delaminatin problems?

    question 2 - was following DangerRuss Briareos lid build. his layering involved sandable surface, shell shock, 2 layers resin, then 2 layers FG. Would lover to use this methods as it sounds like a really sound belt-and-braces method. But wot would u other more experienced prop builders think? is this be overkill?

    question 3 - some people were going to experiment with shell shock; but heard it was too brittle. has every1 given up the idea of using shell shock then?

    question 4 - is the accepted standard slush cast method (i understad diff people have diff products, no. of layers and methods of doing this) - mix something like smooth cast 320 in a required volume. Swirl it round. build layers up. Heard 1/8" smooth cast 320 and finishing off with rotocast should be strong enough for a helmet.

    question 5 - of the smooth on products - wot do lid makers use? I hear the smoth cast 320 is strong but flexible and holds paint well. would that be a (very) genral gist of it? I have heard that some UK guys recommend that stuff from Tiranti (forgotten name)

    question 6 - was following asok's cold cast DP WIP, and he mentioned cold-cast layer, then 3-4 rotocast layers to the lid. Wot are peoples opionion regarding roto-cast vs standard smooth cast?

    question 7 - Does any1 like using FG alone still? Or is FG more or less relegated to fixes and re-inforcement to lid interiors then? only minor exposure to FG with car repair, and dont like the stuff tbh. And being in UK with horrible weather, small garage and little kids abt would rather not use it.

    I guess at the end of the day I will have to experiment myself; but just afew questions that swirl abt my head. Hope I havent bored every1 and thanks for looking

    Nate
  2. stormtrooperguy's Avatar
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    Dec 3, 2008, 3:43 PM - Re: few questions abt casting method and products #2

    the shell shock is very very brittle. smoothon says it's one of the more durable materials when it's thick, but having it thin like you would for a helmet, i think it would break if you look at it funny.

    I use smoothcast roto for my stuff.

    i've been doing 5 coats in my clone helmets, about 8oz. per coat. that seems to be a good balance between thick and thin. the thing with smoothcast roto is that it's classed as a semi-rigid. i've had a fett helmet, no visor, fall 3 feet onto concrete and not break. but, it can warp in high heat. so it's sort of a tradeoff. where i live, falling is a more likely source of damage than heat, so i'm ok with that.

    and we are talking high heat... like leave it in your car in the summer sort of high.

    i have done rotocasting with the 320 (maybe 321, i forget which). it takes a bit longer to set than the roto, but otherwise it worked out fine.
  3. DangerRuss's Avatar
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    Dec 3, 2008, 6:16 PM - Re: few questions abt casting method and products #3

    Hey Nate, great thread with good questions. I hope you are satisfied with my Bri lid. The shell shock is brittle in thin layers, that's why I back it with FG. I also use smooth cast-roto for my Iron Man lids. 5 layers, 8 oz. each which produces a perfect casting. I guess it depends on your mold, application, and just your preferance. For people who don't like Fg inside, I recently did a Briareos helmet and coated the inside with shell-shock as well. This sealed up the hairs real good.
    These two methods are my favorite choice. I have had issues with sagging with the smoth cast-roto. Once while painting outside on a sunny hot day I had it on a pole and it sagged. However i was able to repair it back to shape with a heat gun. So do be careful leaving it in your car on hot days.
    Russell
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  4. Member Since
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    Dec 3, 2008, 6:43 PM - Re: few questions abt casting method and products #4

    hey russ - absolutely love the Bri lid man; it had pride of place in my collection!

    working on another lid to cut my teeth on something else 1st. The way u coated the FG is very neat, and no way I could achieve with much less time I have with it. In fact I am happy that its got that much re-enforcement as it does have lots of built up areas on it.
    I heard abt rotocast saggin as well - hence was a bit worried abt using it. thats why I thought some smooth cast 320 and with a roto cast interior for the smoothness. Still waiting for holiday spending to settle fore I hit u up for the LED lights and an IM lid in the new year mate!

    stromtrooper guy - love the new CW forearms btw mate. I know wot u mean abt flexibility (softness) vs harness (brittle). dont think it ever really gets that hot in UK rofl. is smooth cast harder then? was wondering if I use smooth cast 2-3 and roto-cast 2-3 layers to get the right mix of hardness with flexibility. prob heading towards 1/8" thickness as a general rule.

    like I have said - its kinda out there to ask a few question, and I guess I will eventually have to have a go and see wots fits best for wot I am intending it for. THink I may not use the shell shock though. for my FG re-enforcement I will prob use some roto cast.
    For a lid - smoothcast 320 with a rotocast interior; still under-decided on the FG layer on the inside; but not sure if I have the ability or opportunity to use it. Although with that new stuff Aqua Resin on the horizon - I might do!

    keep opinions coming in pls. any feedback is appreciated. I must have loked through those smoothon vids so many times; my wife is just sitting next to me shaking her head.

    Nate
  5. Jaiden's Avatar
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    Dec 3, 2008, 9:45 PM - Re: few questions abt casting method and products #5

    Sorry, I have nothing constructive to add right now. I'm in the same position you are in, my friend...getting ready to do some casting work myself. So, I'm interested in how this thread progresses. I'll be watching it closely.

    David.
  6. stormtrooperguy's Avatar
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    Dec 3, 2008, 11:11 PM - Re: few questions abt casting method and products #6

    i've never tried mixing the 2 materials, but my guess is that as long as you did it while the layers were all still curing you'd be fine.

    i know that if you pour 1 layer of roto on top of another one that's still a bit tacky, they bond forever. but if you pour a layer over something that's fully cured they pull apart.

    i've got a jug of both in the basement... if an opportunity presents itself i might give it a try to see how it goes. i think i still have some shellshock too.

    did i mention how nice it is being able to walk into a store and buy this stuff by the gallon?
  7. Member Since
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    Dec 4, 2008, 4:40 AM - Re: few questions abt casting method and products #7

    ta for that tip TK-guy. was wondering abt the delamination issue. unfortuantely - we arent up to that yet in the UK (ie smooth on retail outlets), and I live is a small village in North East England?! great for the kids and wife, not so good for sourcing prop making materials.

    I guess its the same with Briareos lid - that right Russ? in effect u had 3 diff materials (4 if u count the sandable layer). So it was shell shock, 'normal' resin then FG. All layers put down before full cure? Or is it ok to lay the FG layers after the resin as cured?

    Nate
  8. DangerRuss's Avatar
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    Dec 5, 2008, 7:34 PM - Re: few questions abt casting method and products #8

    Quote Heatshock said: View Post
    ta for that tip TK-guy. was wondering abt the delamination issue. unfortuantely - we arent up to that yet in the UK (ie smooth on retail outlets), and I live is a small village in North East England?! great for the kids and wife, not so good for sourcing prop making materials.

    I guess its the same with Briareos lid - that right Russ? in effect u had 3 diff materials (4 if u count the sandable layer). So it was shell shock, 'normal' resin then FG. All layers put down before full cure? Or is it ok to lay the FG layers after the resin as cured?

    Nate
    With the Briareos lid, I primed the mold first with sandable primer, then layed in the shell-shock, it is best to lay in the fiberglass while the shellshock is still green, but it'll still bond even if the shell-shock is cured. I mixed polyester resin and cabosil filler and smeared in a paste coat, then added two layers of fiberglass. The shell-shock is brushable, but you have to stay on it til gets firm or it will pool in the low spots.
    You can't get materials shipped in reasonably?
    Smooth cast will delaminate if you let it fully cure between layers.
    Russell
  9. Member Since
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    Dec 5, 2008, 7:46 PM - Re: few questions abt casting method and products #9

    I can - but I hear there are simple retail outlets in US.
    UK post is also notoriously expensive.

    Using Smooth cast as a base - as both US and UK peeps kinda know wot we are talking abt. But there is also a local compnay called Tiranti that does decent stuff.

    ta for tip Russ - hope its isnt revealin too many of ur secrets mate. wow ur method seems very skill intensive. Diff resins mixed, plus FG inbetween... hmm I may have to go for a simple roto-cast for my 1st time for me. gonna try to avoid FG for the time being

    Nate

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