EPOXYWORKS

Zhivago Balance Page 4 (continued)
page 1 2 3 4

Both the resin and catalyst weights in these pictures were cut to proportional lengths from the same 2x3, so they were already close to the correct weight ratios. I added wooden matchsticks (Figure 30) to the underweight weights to bring them into balance and get a sense of how much wood to remove from the over-weight weights, allowing for the effect of the different lever arms for the two weights. Three matches at 10 inches is the same as fifteen matches at 2 inches (thirty inch-matches each).

After two very light chopsaw cuts off the bottom and a little sanding, the over-weight resin weight balanced the 3.5-to-1 catalyst weight. Then a couple of swipes on the beltsander brought the slightly overweight 5-to-1 catalyst weight into balance with the corrected resin weight. I checked the weights on a fairly accurate commercial beam balance made for kitchen use, and found one weight was within 3% of exact proportion and the other was within less than 1%. And I can’t say for sure which balance had the error.

Mark the catalyst weights to remind your helper to use the correct propor-tions for the catalyst in use (Figures on left and right). The fancy typog-raphy is obvious overkill. A rough marking pen scribble would have been more appropriate.

Using the Balance
To mix a batch, pump the amount of resin you expect to need into the cup. I usually drop the cup into the loop first, but it doesn’t matter. Position the resin weight to balance the resin in the cup. It helps to support the out-of-balance rod with your last three fingers. Resting the pivot block on your index finger and putting your thumb on top of the pivot block makes it easier to handle the out-of-balance rod while you position the resin weight
Once the weight is close to the right spot, switch to suspending the balance by the hook (Figure 35 and 36). The threads provide a nice increment of adjustment. Give the hook a little wiggle to overcome the pivot friction when you’ve got it close. Positioning the weight in the nearest notch to balance is plenty close. Grasp the balance by the pivot block again and place the correct catalyst weight on top of the resin weight. Begin pumping in catalyst. You should be able to tell when you are getting close to the right amount by the feel of the balance in your hand, and by eyeball estimate in the cup. Switch to the hook again and add the last little bit of catalyst to bring the balance to zero. The proportions are now correct. Mix and use.

Odds and Ends
		An optional coupling nut, as shown here, can serve as an adjustment weight, making it easy to accommodate different weights of epoxy vessels. Just bring the balance to zero with the vessel only, by spinning the nut toward the high end. No adjustment is necessary when you are using cups from the same package, so normally there is no need for it.
		An optional coupling nut, as shown here, can serve as an adjustment weight, making it easy to accommodate different weights of epoxy vessels (Figure 37). Just bring the balance to zero with the vessel only, by spinning the nut toward the high end. No adjustment is necessary when you are using cups from the same package, so normally there is no need for it.



Zhivago Balance page 1 2 3 4

Epoxyworks 20 / Fall 2002

Copyright © 2002, Gougeon Brothers, Inc. All rights reserved.
This page is maintained by Gougeon Brothers, Inc. Last Modified on 10/28/02.
Reproduction in any form, in whole or in part, is expressly forbidden without the consent of the publisher. EPOXYWORKS, Gougeon Brothers, WEST SYSTEM, Episize, Scarffer and Microlight as used throughout this publication, are trademarks of Gougeon Brothers, Inc., Bay City, Michigan, USA.