Would this work?

[la79al]

I was thinking about sewing some velcro onto a prefold so I don't need the Snappi and sewing in a doubler as well. I think this would be the cheapest way to make an easier diaper for when we go out.

[retro.mama]

I would only sew the doubler in along one side, so when you dry it, there weren't as many layers on top of one another. Does that make sense?

There was another thread not too long ago about sewing snap tape on prefolds, so I would think velcro would work. I turned some prefolds into fitteds and used velcro. The material has held up to the pull of using velcro, if that was your concern.

HTH

[Teddy'sMom]

I don't see why not... but if you would like to make something a little more like a fitted from your prefold check this link out...

http://www.diapersewing.com/prefold_to_fitted.htm

I have not actually done it, but it looks cool.

[lifeguard]

I would just be concerned with the velcro that the "rough" side might rub the baby. As well, velcro can so icky with stuff stuck to it over time.

[love2bmom]

I recommend using either Aplix or Touch Tape instead of Velcro. The Velcro brand hook & loop is just not tough enough to stand up to diaper use.
As long as you sew the hook & loop so that there is a bit of space between the edge (top) of the diaper and the hook/loop you shouldn't have any trouble with it rubbing on baby.
As far as "icky stuff" being stuck in the hook - it's usually just threads/fluff but you can always pluck it out if it bothers you. The rigors of diaper washing are not going to leave you with raisins stuck to the hook & loop.