Marty if you could narrow it down to what you are wanting to do with your slide playing, that would help a lot with regard to making a recommendation.
6-string Slide Guitar (electric guitar), Lap Steel, and raised-nut Acoustic slide of whatever form (acoustic guitar, Dobro, Resonator), are all like their own separate universes.
Slide is extremely hard.
It is the most likely instrument to make the whole band sound out of tune.
Guys who are really good slide players have literally spent hundreds/thousands of hours practicing/perfecting their touch, tone, and intonation.
First you have to choose an instrument, with x-number of strings, and a tuning to tune the strings to.
If you are playing Lap Steel it is probably not tuned the same as a standard 6-string guitar like Bobby played slide on, and you are probably playing it with your bar hand over the neck with a bar in your hand, not under the neck with a slide on your finger.
Concerning 6-string guitar neck radius, you could probably look up the neck radius of guys like Jeff Beck, Ry Cooder, Duane Allman, Derek Trucks, etc, and see what they are playing.
I personally have never given a thought to neck radius, but with regard to slide-guitar, I really only play on stock Strat and Les Paul style guitars with the action high enough to play aggressive slide without touching the frets.
One commonly overlooked technique that 6-string-electric slide guitar players could explore to enhance their playing (while playing slide on a standard 6-string guitar tuning, EADGBE) is, if you get a slide that fits good on your pinky, you can use your fingers to fret notes BEHIND the slide bar, to attain different chords and/or single note runs, to enhance your slide solos and/or background slide-vibrato chord textures.
The Key to the technique: When you push the string down behind the bar, the string drops below the bar and onto the fret behind the bar.
For example, There are a lot of blues songs that go from the 1-chord to the 1(7th) chord, then the 4-chord goes to a 4-minor.
So if you are playing in the Key of D, and you have the bar over strings 2,3,4 at fret 7 to form a D-triad (like a typical D barre cord), you play the D chord with the slide, then push down the 3rd string at the 5th fret to get the 7th chord while you are still playing strings 2 and 4 with the bar at fret7.
Then, you then slide to G at the 12th fret with the bar still over strings 2,3,4... now to get the Gminor, just push the second string down onto fret 11 with your finger, and it comes off of the bar at the 12th fret, and goes on to the 11th fret making the G-minor chord.
So you are now playing a G-minor with the bar over strings 2,3,4 at the 12th fret, but string 2 is actually going under the bar and being fretted behind the bar on fret 11, and the bar is playing strings 3 and 4 with a nice vibrato.
You can expand on this technique to create single note runs by playing one or two frets behind/under the bar to add cool passing notes to your slide chords and solos.
You have to have at least a relatively high action for this to work easily, but that is the jist of it.
It works perfectly on the Blue Strat that you setup for me.
Last edited by Pete B.
on Sat Feb 22, 2014 8:31 am, edited 1 time in total.