Does anyone have any tips that might help me avoid ripping up my fingers on my bass strings when practicing for more than a couple of hours?
Practice more. The more you practice the tougher the skin on your fingers will get--don't necessarily start with 2 hour long sessions, work up to it. You could also try a couple of tricks: nose grease-that stuff that makes your nose so greasy also makes your fingers slick and helps to keep them from getting eaten alive; wipe your fingers on your nose and then play. Hempseed Oil- available at your local health-food store it does the same thing nose grease does; put some on a napkin, put the napkin in a plastic baggie, and the plastic baggie in your pocket periodically wipe some hempseed oil onto your fingers and it will help. There was an old myth about Jaco keeping a chicken wing in his bass case for a similar purpose. Like Jaco needed it.
First of all, let them heal at least a bit before you play again. I think you should use a lighter touch, I don't really have a callous anymore, the skin is just a little thicker.
have you tried using different strings? i first started with steel-wound, but they ate my hand so i switched to nickel-wound, luckily for me i prefered the sound anyway!! but yea, play "softly" and for several short periods instead of one long session. then slowly build up the time you play and then you will be able to do those long-a$$ sessions without harm, and your fingers will get thicker and you can bare a lot more! Jason.
I wouldn't recommend this, it will make your strings sound very old. http://community.webshots.com/user/pistoleroace