Help - strengthening a slush cast made with smoothcast?

[mizuno hadouken]

Hi all. Just wondering if anyone out there has experience creating a strong lightweight slush cast using any of the smoothcast products, and what method did you use to strengthen? I was told by a smoothon rep on the phone that fiberglass and polyester/epoxy would not work with the urethane resin that the smoothcast products are made from.

Previously, I've slushcast an Iron Man helmet with smoothcast 65D but over time I noticed it would warp (plus it is pretty heavy). I have recently made a fiberglass cast with epoxy resin, but I have issues getting a nice complete initial gelcoat in the corners so I was thinking to get the best of both worlds I could slush cast a smoothcast product into the mold, then use some product to strengthen with fiberglass.

 

[nachtinis]

I have used fiberglass resin to strengthen an already cured piece, but the problem there is that they dont adhere and so you have to get a mechanical lock to get it to work properly otherwise you get delamination.

You can use more smoothcast if thats what you are aiming at.

If you are having problems getting resins and whatnot into the corners of a mould, you should try using baby powder (talc) to powser your mould, just be sure to blow out the excess powder.

I guess i might not also be understanging exactly what you are referring to, i have had some REALLY good luck with loctite 5min epoxy and smooth cast onyx. But I havent ever used epoxy as a substitute for fiberglass resin before, that seems expensive.

 

[Tigerblood]

You can technically use fiberglass mat with the Smoothcast, but you will be better off switching to the Task 4 by Smooth-On.

 

[mizuno hadouken]

I have used fiberglass resin to strengthen an already cured piece, but the problem there is that they dont adhere and so you have to get a mechanical lock to get it to work properly otherwise you get delamination.

You can use more smoothcast if thats what you are aiming at.

If you are having problems getting resins and whatnot into the corners of a mould, you should try using baby powder (talc) to powser your mould, just be sure to blow out the excess powder.

I guess i might not also be understanging exactly what you are referring to, i have had some REALLY good luck with loctite 5min epoxy and smooth cast onyx. But I havent ever used epoxy as a substitute for fiberglass resin before, that seems expensive.

Thanks man. I was also told by the smoothcast rep that the smoothcast resin doesn't wet down fiberglass though... have you had better experiences wetting down fiberglass cloth/mat with smoothcast?

What does the tacl actually do with getting the corners of the mold?

The last cast I made is made from SmoothOn ExpoAcoat Red as a gelcoat, then layed down fiberglass mat wetted down with SmoothOn Epoxamite.

I'll post some pictures later when I get home of the corners that I've missed with the gel coat.

 

[mizuno hadouken]

You can technically use fiberglass mat with the Smoothcast, but you will be better off switching to the Task 4 by Smooth-On.

Are you saying using task 4 to wet down mat, or to brush in the inside as a "strength" coat?

 

[The Ronin]

Are you saying using task 4 to wet down mat, or to brush in the inside as a "strength" coat?

You can put fiberglass mat into the smoothcast and create a fiber reinforced plastic. It's the polyester resin that's usually associated with fiberglass that isn't compatable with the smoothcast.

 

[nachtinis]

Thanks man. I was also told by the smoothcast rep that the smoothcast resin doesn't wet down fiberglass though... have you had better experiences wetting down fiberglass cloth/mat with smoothcast?

I see what you are asking now.
Ok so fiberglass from most retail stores that arent for industrial uses is a polyester resin and polyester fiber that works very well together, the problem is that the resins out there are usually polyurethanes and wont saturate the fiber properly, so to strengthen those, you would go with what we call a "filler" there are all types of fillers like ceramics and metal powders and such.

Or you could switch to one of the task series like poster above me says, its a far stronger resin.

What does the tacl actually do with getting the corners of the mold?

Capillary effect, draws your gelcoat into the nooks and crannies of the mould, helps to get rid of bubbles.

The last cast I made is made from SmoothOn ExpoAcoat Red as a gelcoat, then layed down fiberglass mat wetted down with SmoothOn Epoxamite.

I'll post some pictures later when I get home of the corners that I've missed with the gel coat.

Ok so it was the epoxy that was doing the fiber wetting, you might switch to a non polyester fiber, or a natural fiber if you really want that kind of str.

I have some props that are simply onyx fast at about 3-4mm thick and they are super sturdy.

YMMV.

 

[mizuno hadouken]

I see what you are asking now.
Ok so fiberglass from most retail stores that arent for industrial uses is a polyester resin and polyester fiber that works very well together, the problem is that the resins out there are usually polyurethanes and wont saturate the fiber properly, so to strengthen those, you would go with what we call a "filler" there are all types of fillers like ceramics and metal powders and such.

Or you could switch to one of the task series like poster above me says, its a far stronger resin.

Capillary effect, draws your gelcoat into the nooks and crannies of the mould, helps to get rid of bubbles.

Ok so it was the epoxy that was doing the fiber wetting, you might switch to a non polyester fiber, or a natural fiber if you really want that kind of str.

I have some props that are simply onyx fast at about 3-4mm thick and they are super sturdy.

YMMV.

Awesome man, thanks for the tips. I'll try out the baby powder on my next cast. I googled it real quick and found a quick step by step from smoothon that shows the use of talc.

How's the weight on your onyx props? I'm probably going to cast an entire Iron Man armor and want to make sure it's light enough to not die while wearing for a day hahah.

 

[nachtinis]

Awesome man, thanks for the tips. I'll try out the baby powder on my next cast. I googled it real quick and found a quick step by step from smoothon that shows the use of talc.

How's the weight on your onyx props? I'm probably going to cast an entire Iron Man armor and want to make sure it's light enough to not die while wearing for a day hahah.

I have RacerMachX's magneto helmet and it is super sturdy, made from onyx and no fiber fill. Its "light" to me, I am not sure of the exact weight but its not much more than a construction helmet, imo.

As for making entire armor parts from it, it should be doable, the reasons folks would want to re-inforce with fiberglass are mainly in parts that are pron to being struck, flexed, or abused, like in torso areas, cod peices, butt plates, jointed areas, shins and ankles, so its about half of what you might want to be building.

Keep in mind that the strength of the resin is just the resin, all the fiber will do is prevent it from shattering, or at least that is what it is supposed to be doing.

 

[mizuno hadouken]

I have RacerMachX's magneto helmet and it is super sturdy, made from onyx and no fiber fill. Its "light" to me, I am not sure of the exact weight but its not much more than a construction helmet, imo.

As for making entire armor parts from it, it should be doable, the reasons folks would want to re-inforce with fiberglass are mainly in parts that are pron to being struck, flexed, or abused, like in torso areas, cod peices, butt plates, jointed areas, shins and ankles, so its about half of what you might want to be building.

Keep in mind that the strength of the resin is just the resin, all the fiber will do is prevent it from shattering, or at least that is what it is supposed to be doing.

Thanks man... I appreciate all the followups to my questions