I have better luck prepping them like this. It sets the joint a more consistent size all the way around to start with. It's obvious in the photo at a glance where it should end up considering what the burn in will end up at on the outside. I start these from the tack, to the outside corner first, before it gets too hot and washes the works away. By the time you get to the crotch, it is hot enough to penetrate the extra material.
![Image](https://sphotos-b.xx.fbcdn.net/hphotos-ash3/68482_4749778656522_436279019_n.jpg)
Ends up looking more like a uniform band with controlled penetration and is more user friendly with regard to no sharp edges.
![Image](https://sphotos-b.xx.fbcdn.net/hphotos-prn1/59545_4749778416516_701423817_n.jpg)
A neater, overall picture. All welds are 'nearly' flush with the pipe so you don't have to have additional slack elsewhere for such allowance. This is sched 40 pipe. The welds with the inclusive interior penetration, end up at somewhere around sched 50+ on the outside corner, and more like sched 60+ in the crotch.
![Image](https://sphotos-a.xx.fbcdn.net/hphotos-ash3/67908_4749776136459_1439937618_n.jpg)