Lap-Slide.

First we will start with a couple of definitions : a lap guitar is a guitar which we play put on the knees.A lap-slide is an acoustic guitar whereas a a lap-steel is an electric guitar. The most famous lap-slide Ben Harper uses is of course the Weissenborn, a specific section is dedicadted to the Weissenborn and I invite you to read it for more details. Then he uses as a lap-steel a Rickenbacker Electro from the 30's as for example on the song "Less". However most of the time on stage he uses two guitars especially designed for him, te first one by Maton , an australian firm and the second one by an american luthier Bill Asher, who created the Bill Asher Ben Harper Model.

About the Maton model, there is a very good article written by Emmanuel and I invite you to read it if you are interested in : http://www.swer.net/english.guitars.maton.html . You can learn that the conception has been done by computer and that the guitar is done with three different australian species of timber.(You can also look at Maton's website: http://www.maton.com.au )

Then the Bill Asher Ben Harper Model : Ben Harper : "Since a long time, I had the idea to make build a guitar between a Les Paul and a Weissenborn. People said me that this luthier in Santa Monica (Bill Asher) could probably do that (he makes and repairs vintage guitars since 1983). We started from my idea, from sounds that I would like to obtain and I should say that the result is good. I control volume, sustain and feedback like with a solid body. I can also filter the echo of the hollow elements."

Ben Harper : "Manufacturing is similar for an Asher and a Weissenborn, but a little thicker.The body is Honduras Mahogany (like the old Les Paul). Solid body in the middle and hollow body on the sides -there are eight honeycomb hollow chambers- capped with Koa.This is the main difference between an Asher and a Les Paul, echo is deeper.Bill Asher had built several prototypes, with and without graphite inside. It seems that graphite allows a better vibrations transmission from the neck to the body.It's a fretless guitar but there are maple fret lines on the neck. Fretboard is in Koa.The important action (of strings) allows to obtain a better slide sound. The Asher, like the Weissenborn, has a 25 inch scale, while traditional Lap-steel have a 22,75 inch scale.Pickups are custom single-coil. The pickup selector allows to switch between low, medium and high pickups and to make combinations. Sound is more agressive than on a Weissenborn but stays very melodious. Bill Lawrence pickups avoid feedback. The sound crosses a vintage pedal Ibanez tube screamer. I experiment all the time. I've no definitive configuration. I experiment in studio trying to find the better sound."

For more details, you can also look at the "techniques" section. Finally here is Bill Asher's website : www.guitartraditions.com/benh.html

And the interview done for Guitar Player Magazine about this guitar :

(Guitar Player Magazine)The Musical diversity of your youth still seems to drive you creatively...For instance, your feedback-laced, Weissenborn-through-Marshall riffs have given way to an even heavier distortion.
(Ben Harper)You're hearing my Asher guitar. On the previous record, Will to Live, I think I pushed an acoustic lap guitar as loud as it could go with the crunch stuff on "Faded" and "Will to Live." Those old Weissenborns are only held together with hide glue, and I could feel them vibrating in a dangerous way.....
So I went to [luthier] Billy Asher and said, "How can we translate acoustic lap guitar into something that's a cross between a Weissenborn and a Les Paul? He came up with the instrument I played on Burn to Shine. It's built of Honduras mahogany--like and old Les Paul--but it's a neck-through-body design. The wings are honeycombed with nine hollow chambers and covered with a koa top. Billy also hollows out the neck and fills it with graphite. He built several prototypes--with and without the graphite--but somehow the graphite connects the resonance to the rest of the body, so we settled on that. The Asher also has a brass saddle, which seems to enhance sustain. I was excited when Billy built this guitar--it gets such a mad tone. Finally I could get solid body volume and sustain, control feedback, and still have some hollow resonance that filters up through the pickups instead of through the open hole.
(GP)The Asher sounds very different from a traditional lap steel, and it obviously led you down a new sonic road.
(BH)One reason the Asher sounds different is because it has a full, 25" scale length--like the Weissenborn. Typical lap steels have a 22.75" scale.
(GP)What other guitars and amps did you use on Burn to Shine?
(BH)All the crunch slide is the Asher........

Some pictures for you to see these guitars :