Adding weight to counterweight, how to set vtf?

Hello everyone,

I recently upgraded my cartridge from the stock ortofon om5e on my project debut iii to a 2m red, which weighs 2g more. I didnt buy the heavier cw, but rather added weight to the standard cw via a thick rubber washer. So, when setting vtf, am I right in assuming that the weight numbered ring will not be accurate if Ive added weight to the cw and I therefore have to use a scale to set it? Is there any reson not to use an electronic scale such as those sold for jewelry with a metalic tray? The magnet inside the cartridge shouldnt affect the reading much, or will it? Thanks.
No the cart magnetic field will not affect a scale.

If you use a scale with a metla tray, slip a piece of thin plastic, or hard paper on the metal scale tray. so the cart tip is not harmed. then reset the scale calibration to include the paper at zero grams.
Arrange the scale tray to be at the same height as the arm would be playing LPs... to set the arm weight.

My scale wears out the battery when not used for a long time. So maybe take the battery out when finished if not using for awhile again.
Elizabeth is correct, but you will also want to make sure anti-skate is zero and repeat the measurement a few times to make sure you don't have any scale drift. Good luck and happy listening!