Making a Calf Casts

[Andrea Ferrara]

as the son of an orthopedist (cast maker) i can say this. you can easily replace cast molding cloth with sprained ankle wraps. I would wrap it trice around (one layer for your bulging muscles, one for the cloth, and one for the growth of muscles later down the line

[Mac]

as the son of an orthopedist (cast maker) i can say this. you can easily replace cast molding cloth with sprained ankle wraps. I would wrap it trice around (one layer for your bulging muscles, one for the cloth, and one for the growth of muscles later down the line

Andrea,

If I understand you correctly, you are expecting the armorer to work over the *outside* of the cast.

As an armorer, I have to disagree. It is much better to work from an exact copy of the client's leg, rather than some padded up interpretation of it.

The best thing to do with the resulting "cast" from any the methods discussed above, is to grease the inside and pour it full of plaster of Paris to make a "positive". I like to cast a piece of "rebar" into the ankle to for strength, and glue the resulting positive casts onto plywood bases so that they will stand up on the bench.

Mac

[Tom B.]

Of course Mac is correct, do not pad up your legs!
You want a close fit up on your calves, this is what holds the greaves up.
If they are too loose they will either painfully ride on the top of your foot or pull down on your upper leg harness.

Tom

[Tom B.]

For my gauntlets I made an alginate mold and cast the positive in Hydrocal.
The detail was unbelievable.
The hydrocal is much stronger that normal plaster of Paris.



For my legs I bought some plaster bandages a a local medical supply place. They are much cheaper and better suited to the this usage than the hobby shop variety. Due to the prohibitive cost of shipping (my armourer was in the Czech Republic) I did not make a positive casting. A gypsum based cement / plaster casting of my whole body from the waist down would have required a wooden crate & cost hundreds of dollars to ship. I will not go into details as to my method, due to the many possible disastrous pit falls. I did get a good result but it was probably due to both good luck and the OCD type of detailed measurement and assembly only possible by a mechanical engineer.

Tom

[Giles de Bois Guilbert]

make the the STS cast - make a positive from the STS cast. put the turn-shoe on the positive voila. really you could use that "expanding" or insulating foam from Home Despot or even mix concrete. it depends on how durable you want it to be. Foam will give you form and substance which is more than adequate for fitting.
If you wanted to be innovative you could even use the socks to cast forearms and I definitely wouldn't mind "defraying" some expenses here in the UK if some other members were interested in getting a syndicate together

[Mac]

really you could use that "expanding" or insulating foam from Home Despot or even mix concrete. it depends on how durable you want it to be. Foam will give you form and substance which is more than adequate for fitting.

Giles,

In my experience, plaster is really the best thing for greaves. It rubs off onto the inside of the work, and thus tells you exactly where it is making contact.... something a live model could not even tell you.

Mac

[Aussie Yeoman]

Giles,

In my experience, plaster is really the best thing for greaves. It rubs off onto the inside of the work, and thus tells you exactly where it is making contact.... something a live model could not even tell you.

Mac

Brilliant! So even if the client lived next door, a plaster cast would stand better stead than the leg in the flesh!

Or am I taking it too far?

[Arrakis]

Makes me wonder about scanning the leg in question with a range scanner (KinectFusion) and just sending the resultant point cloud...

If only large 3D printers/rapid prototypers were more common...

[Alec]

I so wish I had done this step for the greaves I am working on. It would have sped things up considerably. I am definately saving this thread for future use.

Is there any evidence of cast use historically? It seems an obvious technique from this discussion, but so does the use of power tools . . . Any hints from the actual pieces that folks have examined?

[Sean Powell]

Makes me wonder about scanning the leg in question with a range scanner (KinectFusion) and just sending the resultant point cloud...

If only large 3D printers/rapid prototypers were more common...

3D printing I can handle. Large 3D scanners not so much. I'll look into the KinectFusion. Do they do outsourcing?

Sean

[Mac]

Giles,

In my experience, plaster is really the best thing for greaves. It rubs off onto the inside of the work, and thus tells you exactly where it is making contact.... something a live model could not even tell you.

Mac

Brilliant! So even if the client lived next door, a plaster cast would stand better stead than the leg in the flesh!

Or am I taking it too far?

Not at all!

The casts are patient. They don't complain that the greaves are still hot from the torch, or wet from the slack tub. They never fidget or complain that they are getting pinched between the plates. They don't talk. They never wonder off when you need them. They don't take a lunch break.

If the client lived next door, I would have him by periodically to check the progress, but first I would cast his legs.

Mac

[Dmitriy]

Hey Aaron, I'd be willing to split the cost of ordering a 10-pack of those with you.

D

[Giles de Bois Guilbert]

Giles,

In my experience, plaster is really the best thing for greaves. It rubs off onto the inside of the work, and thus tells you exactly where it is making contact.... something a live model could not even tell you.

Mac

Mac, of course your right on this but you could also do the same by soot blackening any positive type mold. Acetylene is pretty handy for this

[Vermillion]

Another option.

Say you want to cover your cast with a layer of fiber glass for durability. Too achieve the same result as Mac gets with plaster go to the hardware store and buy a refill for a chalk line in your favorite color, coat the cast lightly, and voila ! Same affect

[Mac]

Mac, of course your right on this but you could also do the same by soot blackening any positive type mold. Acetylene is pretty handy for this

Giles,

The acetylene flame certainly produces soot of the finest quality, but plaster shows up very nicely against the dark oxides on the inside of a hot worked piece.

Mac

[Mac]

Another option.

Say you want to cover your cast with a layer of fiber glass for durability. Too achieve the same result as Mac gets with plaster go to the hardware store and buy a refill for a chalk line in your favorite color, coat the cast lightly, and voila ! Same affect

Vermilion,

The chalk sounds like it would be worth trying if you already had a plastic cast of some sort.

Beware of adding fiberglass to your casts, though, lest you make them bigger than the client's legs.

Mac

[Vermillion]

Mac,

Understand totally. I was envisioning an extremely thin layer to protect the plaster from breakage in the shop.

I'm in the process of making a torso cast of myself, and I'm at the plaster gauze stage. We did the gauze wraps last weekend, let them dry thoroughly, and in some places they were very fragile. I've reinforced them as needed without changed the dimensions, but the plaster of paris is still fragile by nature. I've considered laying down some fiberglass on my gauze to make my molds more durable.

[Mac]

Mac,

Understand totally. I was envisioning an extremely thin layer to protect the plaster from breakage in the shop.

I'm in the process of making a torso cast of myself, and I'm at the plaster gauze stage. We did the gauze wraps last weekend, let them dry thoroughly, and in some places they were very fragile. I've reinforced them as needed without changed the dimensions, but the plaster of paris is still fragile by nature. I've considered laying down some fiberglass on my gauze to make my molds more durable.

V,

In my experience, it takes a lot of plaster gauze bandage to make a thing that is dimensionally stable enough to serve. You would do well to incorporate stiffeners made of wood, iron or whatever else you like to work with. Since these will be on the outside of the mold, they can take any form you please.

Mac

[Roger_de_Gilbert]

I just picked up some stuff from a local medical supply store for casts. I am going to give it a try and see what I get.

I will let you all know how it comes out.

Unna's Boot Dressing, is the name of the product.

Roger

[Roger_de_Gilbert]

Ok. Fail. The stuff is not a casting material.

Sigh.

[Chris Gilman]

Vermillion,
For a torso, you would want to make a fiberglass positive. For lower legs you can use hydrocal or ultracal, both are high strength gypsums. Plaster of Paris is the weakest of the gypsums. When casting the lower legs, put a piece of rebar or broom handle down the center of the cast to reinforce the ankle. I use a piece of steel pipe that is open on the bottom of the foot so I can slide the leg cast over a rod attached to the table or a baseplate to hold the leg cast up.

[Vermillion]

Chris,

That is my basic plan on the torso.

This was the first time we've ever done the plaster gauze bandage forms, we being my wife, teenage stepson, and me the castee. It really didn't go that bad, but it took about an hour and 45 minutes, was pretty messy, and my wife swears she would never do it again. Of course we now see many ways that would have made it much easier and faster. And to get a better result overall.

I am just using regular plaster of paris to fill in the places where the plaster gauze has irregularities in the mold surface, or to help stiffen the edges where we didn't get enough layers of gauze or didn't get a good bond between layers of gauze. I'll then sand it down lightly to get a consistent mold surface. My father use to own an automotive paint and body shop, so I'm pretty confident in my skills there I think I will coat the mold surface with a thin layer of polyester fiberglass resin ( with minimal or no glass reinforcement ) just for durability. I'm thinking that I will do a full 3-4 layers of fiberglass on the backside of the plaster gauze, so that my molds will be durable enough to do multiple positive casts in the future if I want them. I figure to put them on stands and use them as handy armor stands.

My current plan is to make the positives from wood pulp paper mache (which I have not had a chance to experiment with yet) with an overlay of fiberglass.

Arms and Legs will then be on the "To Do List" at some point.

[Chris Gilman]

We almost always make a fiberglass positive from the plaster bandage mold and it rarely lasts more than one part.
Although if you use paper mache’ you may be able to do more pieces and then you will want the plaster to be able to pull moisture from the paper mache’ so coating the outside only would be better.
An episode of “How it’s made” showed making cardboard dress forms; you may be able to do something along this line.
We almost always use drywall joint compound to “surface” the inside of the plaster bandage mold to smooth out the surface. This material sands faster than the plaster bandage so you are less likely to sand too much off the bandage mold. Then we use 2 to 3 coats of paste wax and a brushed in coat of PVA (Polyvinyl alcohol) as a release agent. Make a fiberglass layup an two halves being careful to keep the two joining edges of the plaster bandage mold clean, then put the 2 halves together and mix some polyester resin in with Bondo to make a pourable mixture (Use both catalysts to set it off) and pour this down the seams to join the front and back of the fiberglass pieces together. I most often will use an initial “gel coat” of this same Bondo resin to give me a nice sandable surface on the finished positive. We then take the finished part and sand it and make a master fiberglass mold so we can run multiple fiberglass parts.

[Vermillion]

Make a fiberglass layup an two halves being careful to keep the two joining edges of the plaster bandage mold clean, then put the 2 halves together and mix some polyester resin in with Bondo to make a pourable mixture (Use both catalysts to set it off) and pour this down the seams to join the front and back of the fiberglass pieces together. I most often will use an initial “gel coat” of this same Bondo resin to give me a nice sandable surface on the finished positive. We then take the finished part and sand it and make a master fiberglass mold so we can run multiple fiberglass parts.

How many layers of fiberglass do you use, and what weight cloth do you use? (Both for the Master Fiberglass Mold, and the fiberglass parts)

I know how to repair Corvette body panels, or repair minor damage to boat hulls, but I've never built something like this from scratch. So I don't have a feel for how many layers to use and how much cloth to use.

[Chris Gilman]

I use mat, not cloth. It is plenty strong for this application. I aim for 1/8th inch thick, so depending on your mat, 2 to 3 layers for the body, 3 to 4 layers for the mold.

[uwhguy]

am i understanding this correctly... are you actually hammering on the cast of the legs like its an anvil?

[wcallen]

am i understanding this correctly... are you actually hammering on the cast of the legs like its an anvil?

If you are referring to Mac's comments about the plaster marking the work, no. He is just "test fitting" the pieces on the cast and that rubs.

The metal is worked on normal stakes.

We did make "greave stakes" many, many years ago. They worked to get the general shape right, but we didn't work hard enough to have custom ones for every pair of greaves. I guess you could make a positive, then build up the areas where you want the crease and some wiggle room, then have them cast is cast iron... but that would get crazy for each greave.

Wade

[Aaron]

Rick and I made casts of my arms and now Gruber has them to make arms for me. Tonight we make calfs of my sabatons, calves and knees to send to another good armourer to make shaped greaves in spring stainless. The next week I might be able to get a cast of my head, neck and shoulders done to send to Ice Falcon so he can make me a stainless armet or sallet that is BotN worthy.

[Aaron]

The storm knocked out the power and Rick and I opted not to do the casts last night. The idea of having a cast on my leg, and Maureen trying to cut it off in the dark while our toddler runs amuck...just sounded like a bad sitcom plot and a possible chance to do self-aid for severe bleeding.

[Vermillion]

LOL!

I feel your pain Aaron. A couple of weeks ago, I was doing a body cast, with my 16yr old stepson as an assistant.

He got the fiberglass casting tape too high up my throat, and too deep up my armpits. So when it hardened (which is very rapid) it started cutting into my air supply and made it almost impossible to cut the cast up the side and get me out of the damn thing.

It took less than 20 minutes to apply. Almost 2.5 hours to cut off. And I got the ever living crap cut out of me from the dremel tool we were using to cut the cast off.

At one point, I was seriously considering calling 911 to cut me out of the thing No kidding.

[WinterTreeCrafts]

So has anyone actually tried these nifty sock things?

These would be *REALLY* handy to send to customers who want greaves and aren't in traveling distance... (if they are any good and fairly user friendly)