Thread: Bad Idea?

The long awaited "Sheer scraping tutorial" is not far off, so you may not need to do it this way soon. Although I guess there is always the recalcitrant piece of wood that demands the unorthodox approach.

Originally Posted by tea lady

Although I guess there is always the recalcitrant piece of wood

.or recalcitrant turner...

.....

It's true that the old hacksaw blade does not hold a good scraping edge for long, but one is only making a few light cuts on a piece to smooth the curvature so it's not a problem. My last cut(s) on a piece (before "hacksawing" if needed) are always shear scrapes with the bowl gouge. As mentioned in the other thread, shear scraping anywhere near the nose of the bowl gouge can leave ridges (hills and valleys), especially if your tool control is imperfect like mine. The hacksaw blade smooths/levels these irregularities.

Seems like a small, kidney shaped scraper would be great for the inside of bowls. May have something in my junk pile to make one of these.

For removing small ridges in soft or med density woods they may have a role. For leveling down to groove bottoms I'd reach for a real scraper.

On harder woods I can't see the burr lasting long.

But Ern, your tool control is better than mine. With a real scraper I would still have a few hills and valleys. By hills and valleys I mean stuff to maybe .005" (.13 mm) total variation that may not be obvious to the eye from a short distance, but can easily be felt by the fingers.

Agreed the burr would certainly not last long on some of your hard Aussie woods.

5 thou? ... power sanding wld be quicker than scraping doncha reckon?

It is on little pieces. Maybe those flat spots on larger pieces are bigger/deeper than I thought. Seems to help get smooth curvature with no palpable irregularities.

For what its worth, I made a couple of scrapers out of an old handsaw blade a few years ago after we saw them demonstrated at a Guild meeting - one with straight edges and corners just under and just over 90 degrees, and one with various curves. I'm guessing it was reasonable quality carbon steel. They seemed to work well if you kept the edges burnished, but I didn't persist with them.

cheers, Colin

I use a number of curved scrapers from my past life as a luthier. Used Japanese pull saw blades, and taping knife blades work well. The thin scrapers are often ground with a 45 deg. edge then lightly burnished (something like one light pass with a burnisher) Thicker less flexible blades are sharpened square edge.

In a lathe situation the edge will only last for a few seconds. The last time I used one was on the wings of a natural edge bowl turned wet, out on the wing tips where a few tool marks remained.

Note that the trusty hacksaw blade is held in a concave curve for smoothing the O.D. of a piece. More interesting thread than inticipated.