I haven't done any scraping in a long time but though I'd share how I made my own power scraper. The whole project is based on a variable speed Harbor Freight sawzall where the saw blade is replaced by a carbide tipped insert. The only difficult part is modifying the reciprocating mechanism to make the stroke adjustable. After disassembling and cleaning I decided to remove the fixed post and milled a dovetail slot so I could add an adjustable bearing post in its place. The inset is brazed onto a mild steel flat bar ad ground just as you would for hand scraping. - - - Updated - - - At first it was a little choppy until I settled on an 1/8" stroke and learned to cradle the sawzall on top of my forearm with the handle resting against the inside of my elbow. I use my free hand to help guide the blade while the hand underneath is supporting the weight. After a little experimenting it became natural and what took days by hand was done in a couple of hours. There used to be a video of me using it online somewhere, not sure where it is now.