15 Sep
2006
15 Sep
'06
7:05 a.m.
[Mixing part kits of 2-pack stuff]
That makes sense as one possible reason. I'd prefer not to have to
assume, though.
Well, apart from that, and the 'business' reason (that they sell more
kits if you waste most of them), can you think of any other reasons?
I've worked with a number of 2-part molding and casting supplies, mostly
urethanes and variations on RTV rubber, and they're often sensitive to
oxygen and/or atmospheric moisture: once you open the factory seal, they
start a slow chemical change unless you can stop the effect (say by
displacing the air: http://www.smooth-on.com/rubbaccess.asp#xtend for
example). I'd suspect the company's saying "mix the entire product all at
once" may be based on something like this. (The fact that you end up
using it up faster is doubtless a benefit in their eyes, too.)
But, yes, unless the manufacturer will _tell_ you what's going on, this
would only be a guess. :)
...ObClassicCmp: If you're looking at casting replicas of various small
plastic pieces for no-longer-manufactured items, a look through
smooth-on.com will likely give you useful ideas and a place to buy useful
materials. I _like_ toys which give you the capability of building more
toys. :) :)
-O.-
I'd feel a
whole lot better about taking some company's word that
this is necessary if they'd say _why_ it is.
I would assume it's because at least one part is not totally
homogeneous and may partially separate in storage. If you take, say,
half of the contents of the container you might not be getting half
of everything.