The way that i weighed my bike was to weigh my self then weigh my self with me holding the bike, then just take my weight away from it and there, you have your bikes rough weight!
Clean the rotor, make sure there isn't any crap on the pads. Then Bed it in again, ride around with the brake on, get it really hot then chuck water over it, do this again and once it has dryed off it would work better
I weight my bike today an found it was 25.8 lb, i was just wondering if this was an average weight for a trials bike! So how heavy is your bike?, I hope my bike isn't fat!
I robbed a big torpedo of tar from same road works years ago, it worked really well. However as i said it got hot one day and the whole thing melted all over my mate garage floor.