File puptcrit/puptcrit.0811, message 481

Date: Sat, 29 Nov 2008 13:31:41 -0500
Subject: Re: [Puptcrit] thermalplastics

Hmm. 10 years is not a long time. I know thermaplastic has been around 
for a while, but how long has "Veraform" been on the market? If it was 
a fairly new product 10 years ago, perhaps it was a problem with the 
early product and it has been improved since then. I would think the 
materials were planned to have a longer lifetime. Were these puppets, 
by chance, some of the first you made using the mesh? The reason I ask 
is that, perhaps, you did not get the mating of the materials done as 
well as should be. I say this not to question your building abilities, 
but because I have found that as I learn to use a material better, 
particularly one that requires some sort of melding, my earliest work 
with the material often has weaknesses that I introduced through my 
lack of experience in working the material. For me this certainly is 
the case with fiberglass, some epoxies, to a lesser extent neoprene, 
and even wood/carpentry or paper mache.. A joint is almost always the 
weakest point. Learning ways to make the bond between like materials 
definitely has a learning curve. Dissimilar materials is even trickier. 
Some things I have gotten the hang of quickly, others only after a long 
while, some other I still don't have the hang of.

Extreme temperatures can be catalysts for joint failure as the 
expansion rate varies for different materials. If you are binding two 
different materials you may have three different expansion and 
contraction rates: material A, material B, and the Bider.

  Often people (including myself) use too much of the binder, or don't 
mix the binder completely, or in the case of two part binders don't use 
the correct portions. "Looks about right" is one of my favorite 
measuring devices. As an educated guess this can work, but the less 
education (or experience with the material) the greater chances of only 
getting it almost right. Rushing (that darn deadline looming!) often 
leads to almost right weakness. When it is two parts of a material that 
are melded, as I believe thermopastic can be, often the joint area is 
not thoroughly melded. When melded properly it is often stronger than 
the other parts of the material. A lapped joint properly glued or 
melded only at the edge of the lap is not a very strong joint, 
certainly not as strong as a fully glued or melded joint. My very 
limited experience with thermoplastics showed me that the edge is not 
too hard to meld while, depending on the structure, deeper into the 
joined area can be difficult to really meld.

As to neoprene, I found that quite a bit of the joint weakness came 
from things I did (or didn't do) early on. The first project I used 
neoprene on was "Jungle Book" where we created a LOT of puppets. When 
we started on the puppets, I had only been exposed to the product 
through a hands on workshop. Through the process of building many 
puppets I learned where I was creating joint weakness in my molding 
process and how to build or reinforce joints where things had to be put 
together. So, while there was nothing wrong with the product or in the 
use of the puppets, the "fault" lay in the building stages primarily 
because of my inexperience with the product. Same can be inferred about 
almost all of my "early stages" work - the longer I work at something 
the better I get at it. Funny how that works.

Just some thoughts.


On Nov 29, 2008, at 9:41 AM, wrote:

> I've just recently discovered a problem with thermalplastic mesh -- 
> marketed as "varaform" a while back. The adhereing qualities break 
> down after about ten years.=A0
> Heads made out of the mesh ten years ago started having problems -- 
> pieces from inside started breaking off. One head almost collapsed & 
> needed to be carefully sewed & glued back into place. Difficult when 
> mechs are involved.=A0
> I need to go back and re-examine all the pieces I've used it in, and 
> see if they are okay.
> While ten years seems like a long time, it's still disappointing to 
> see something fall apart through no fault of the user --
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