Re: Digital scale for Epo

Posted by Steve Miller on Dec 1, 2004

Mark, note that the ratio by weight is not the same exactly as by volume. I used a scale for a while doing exactly 2:1 for System 3 then read in their info about the difference when doing weight ratios.

I zero the scale with the cup on it. Then I pump hardener and note the weight. I add the resin from a ketsup bottle so I can drizzle it in slowly until the total weight is correct based on my chart. One drop registers as .1 grams so I can get close enough. The other day I mixed a batch with 2 pumps of hardener which weighed 7.7 grams so I added 17.9 grams of resin for a total on the scale of 25.6 grams. I use a calculator and a note pad to do this. If you do many batches in a row you will get confused. Anal I know but one bad batch several years ago made me that way.

Here is my chart that I hang in the shop. Note that doing the goo by weight at 2:1 always seemed to work but so it must be ok to be a bit heavy on the hardener. If my math is wrong on the info below someone please correct me!


Resin to Hardner Chart by Weight

System 3 Epoxy (2:1 mix ratio by volume)

"Use 100 parts Resin to 43 parts Hardener by weight"

Grams R Grams H Total Mix Weight 7.0 3.0 10.0 12.5 5.4 17.9 15.0 6.5 21.5 20.0 8.6 28.6 25.0 10.8 35.8 27.9 12.0 39.9 29.1 12.5 41.6 50.0 21.5 71.5 100.0 43.0 143.0

Multiply amount of Resin X .43

Resin is 2.33 X Hardner (multiply amount of hardner X 2.33)

In Response to: Digital scale for Epoxy by Mark Camp on Dec 1, 2004