Giok -

I've got a fistful of scrapers very similar to your Skarsten, and can disagree (mildly) on the "do the same job." Also, it's quite easy to sharpen your bit of glass. You just break a quarter inch off the end and you have a new sharp edge. Or with window glass, just whack it against the nearest hard object, and you've got lots of new sharp edges.

There are some tasks where a good handle is helpful, and others where one needs a shaped blade and a "built tool" is preferable. I'll use my hunk of window glass for many of the rest. I'll even concede that I fairly often just flip the switch on the power sander when the glass would work better, but that's just because I'm lazy.

Rowan -

With thin sheet glass knapping isn't really needed. I probably should break a couple of bottles and get me some thicker chunks to give that a try. As a scraper for smoothing things, a fairly long straight or gently curved edge is best, and knapping tends to produce short - but not straight - cutting edges. A knapped edge strikes me as more suitable for a knife or gouge(?).

Some "plate glass" may present another problem for the knapper. Most "modern" commercial plate sold here is ¹tempered, and if you release the surface stress I'm told it sort of "explodes" like the auto windshield stuff.

¹ At least that's the story I got from the supplier when I replaced a broken top pane on LiK's 1920s drug store display case (family heirloom). He debated whether I could take surface scratches out of the other pane, but eventually conceded that it was probably from the "pre-tempering" era and wouldn't blow up on me. (The abrasives that he and several others recommended wouldn't touch the old stuff, so I'll probably never know whether that was safe to do.)

John