i use a lighter and just keep it moving.

 

Get a heat gun. Harbor freight has one for $9.99. It looks identical to the sears unit for $69.

The longer you keep heat on to shrink the tubing you run the risk of damaging the insulation of the adjacent wiring. With an open flame this problem is multiplied.

 

yes i know...insulation breaks down under excessive heat. you'd think i would have a heat gun, being an electrician, but i have only done heat shrink once on my bike. we always had 1 or 2 heat guns on the boat.

 

Second the vote for Harbor Freight, 2 settings, real cheap. If you only use it once and a while, it is a great bargain. I don't know how it would stand up to everyday use, but I've had one for a year now and so far, so good.

Butt splice? What's that? Sounds like a transplant operation you don't want to have