I normally don't mess with tires. I'd rather slime most leaks and wait till I'm in the shop for other service. (Yes I apologize for it, the stuff is NASTY). Replacing a 20" x 8" tire (old one had a sidewall puncture), here is my dumb question -- how do I get the new tire to seal to the rim when it is decidedly limp. I've used vasalene before to help seal smaller tires. Yes, it works, and has allowed 'field repairs.' Is it bad for the tire? I don't know. It's a rain day and I was trying to do it on the mower. Have done it successfully before with smaller tires (and a bit of vasalene) but this one has me stumped. I'm ready to go buy a tube... Any suggestions?