Substitute for Vermiculite
Hummel Matthew T SSgt 81 MSGS/SGCQOA
Description
Collection
Title:
Substitute for Vermiculite
Creator:
Hummel Matthew T SSgt 81 MSGS/SGCQOA
Date:
6/23/2003
Text:
Many of you were interested in the replies that I received about my post on
vermiculite substitutes. Here are the replies that I have received so far.
If I get any more I will be sure to share them. Thank's to all who have
replied.
Matt Hummel, BOC Orthotist
Take a look at this post on the technician forum:
<URL Redacted>
The only reason I use vermiculite is to help keep the sureform from clogging
up.
If you don't want to use it, just wait until your mold is the hardness you
like.
In summary, I don't know another substitute that is as good, once you have a
light fill and put a nylon over the mold.
You can use swimming pool agrigate.It is usually found in a fine grain at
the same supplier of vermiculite.It works and looks very simular to
vermiculite.
Corn starch softens the plaster and makes it much more workable. I have
also heard of folks using Pearl Starch which is a feed grade corn
starch. It's cheaper but I've not had any luck finding a local source. We
get our corn starch from a local restaurant supply house. It comes in 50
lb bags and is very nearly the same price as plaster. We use about four
parts plaster to one part corn starch. Too much starch and thin casts will
break too easily. Mold does not occur until the casts have sat around for
a few weeks so it really isn't a problem. It's not a fuzzy sot of mold
either, kind of a purple blotch within the surface on the material. It
doesn't create any problem so I don't worry about it. Some people object
to the idea so I mention it. A weak bleach soln. applied to the cast after
it molded would cure the problem, if it was one.
Corn starch also does not have a respiratory hazard associated with it. If
you do inhale some your body will just absorb and digest it.
What is it you're trying to do? If it's simply to lighten the weight of the
mold, add a tablespoon or two of baking soda to the water prior to mixing in
the plaster. This will give a 'foamy' effect to the plaster. I did this a
lot with hip disarticulation casts as well as body jackets. You should first
put at least an inch or so of straight plaster into the mold just to anchor
the mandrel. Even a slurry mix around the entire cast will give you
something sturdy to modify.
We use a material called zonolite. I don't know how -or if - it differs
from Vermiculite, but it looks different and is finer grained.
I'd be interested to knoiw if you come up with anything.
Corn starch, it's cheap, doesn't show visibly and actually improves the
texture of the plaster. Wet molds stored too long can get some mold growth
but this is rarely a problem and does not affect the usability of the cast.
vermiculite substitutes. Here are the replies that I have received so far.
If I get any more I will be sure to share them. Thank's to all who have
replied.
Matt Hummel, BOC Orthotist
Take a look at this post on the technician forum:
<URL Redacted>
The only reason I use vermiculite is to help keep the sureform from clogging
up.
If you don't want to use it, just wait until your mold is the hardness you
like.
In summary, I don't know another substitute that is as good, once you have a
light fill and put a nylon over the mold.
You can use swimming pool agrigate.It is usually found in a fine grain at
the same supplier of vermiculite.It works and looks very simular to
vermiculite.
Corn starch softens the plaster and makes it much more workable. I have
also heard of folks using Pearl Starch which is a feed grade corn
starch. It's cheaper but I've not had any luck finding a local source. We
get our corn starch from a local restaurant supply house. It comes in 50
lb bags and is very nearly the same price as plaster. We use about four
parts plaster to one part corn starch. Too much starch and thin casts will
break too easily. Mold does not occur until the casts have sat around for
a few weeks so it really isn't a problem. It's not a fuzzy sot of mold
either, kind of a purple blotch within the surface on the material. It
doesn't create any problem so I don't worry about it. Some people object
to the idea so I mention it. A weak bleach soln. applied to the cast after
it molded would cure the problem, if it was one.
Corn starch also does not have a respiratory hazard associated with it. If
you do inhale some your body will just absorb and digest it.
What is it you're trying to do? If it's simply to lighten the weight of the
mold, add a tablespoon or two of baking soda to the water prior to mixing in
the plaster. This will give a 'foamy' effect to the plaster. I did this a
lot with hip disarticulation casts as well as body jackets. You should first
put at least an inch or so of straight plaster into the mold just to anchor
the mandrel. Even a slurry mix around the entire cast will give you
something sturdy to modify.
We use a material called zonolite. I don't know how -or if - it differs
from Vermiculite, but it looks different and is finer grained.
I'd be interested to knoiw if you come up with anything.
Corn starch, it's cheap, doesn't show visibly and actually improves the
texture of the plaster. Wet molds stored too long can get some mold growth
but this is rarely a problem and does not affect the usability of the cast.
Citation
Hummel Matthew T SSgt 81 MSGS/SGCQOA, “Substitute for Vermiculite,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 25, 2024, https://library.drfop.org/items/show/221416.
