Just a word of caution for those of you using Electronic Scales.
So far I have not seen a electronic scale under many hundreds of dollars that
maintains
accuracy if you add to cup when cup is on scale!!!!!!
What happens is the scale has some sort of threshold level. If it is not reached
then the scale resets.
What this means if you are trying to target something exact, and are adding
small
amounts, the scale may be resetting and giving you false measurements!!!!!!!
Simple test
Zero out scale.
Put on a piece of 8.5x11 paper and note weight
Now cut up paper into pieces 2 times the size of a postage stamp.
Now zero out scale, and place 1 piece of paper on the scale at a time, waiting
a few seconds between adding. You will get quite the shock after you added a few
full sized pieces of paper and the scale reads zero!!!!!
I take off cup between adding, this way when you place it back, since you are
way
beyond threshold accuracy remains intact.
I also do a little test to catch if i forgot to tare the scale or it reset. I
first
zero scale. then weigh the empty cup and note its weight. then i tare the
scale with cup. Then add resin and hardener. Now I rezero scale and weigh the
cup/resin and hardener. On your mini worksheet you added the cup/resin and
hardener.
If it is not the same on paper as what you are reading on scale, then
either you forgot to tare the cup, or the scale reset, in other words trash that
mix.
I called Aeropoxy. For structural mixes, keep proportions within 5%. For non
structural
mixes keep within 10%. Please note that it will harden if off by more
than 25%!!!! The problem is the glass transition temperature really falls off.
Another tip was if you need to be off, make it resin rich not hardener rich.
Just figured I would mention.
Just for general knowledge, please post type of scale that can pass the copy
paper
test.
Ron Parigoris
Another note: probably an excellent idea to not keep redux measurement sheet
anywhere
near the Resin mix sheet. I keep mine with redux, and have it outlined
in green. If you have it on the other side of the Epoxy sheet, and you are
having
a bad day..... Lets see 40 to 100, compared to aeropoxy 27 to 100,,OK 27 -
40 / 27 = 48% So that mix is 48% off target. far cry from the 5% max.
structural
target if you used redux scale for Aeropoxy. But then again you were probably
adding hardener on the scale, which brought the mix just perfect ;-)
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