I have done it twice no problems, but my LA (Innova) is a real work horse and can handle anything I throw at her. Here are links to the two I have done and posted. One was made by someone else and the other I did. Both had regular quilting cotton used as sashing/background. Which I would consider a must. Doing nothing but sewn together T-shirts front and back is probably a recipe for disaster.
http://www.quiltingboard.com/picture...ts-t95274.html
http://www.quiltingboard.com/picture...t-t209647.html