Card Scraper Use
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- This topic has 7 replies, 4 voices, and was last updated 3 years, 3 months ago by Bill Epstein.
17 December 2019 at 1:54 am #637193
I’m new to card scraper use and have not been getting the glass smooth finish I’ve heard referenced consistently across a piece.
I am getting a good edge and can achieve a good surface on straight grain.
What considerations are there for working “trouble” spots with a scraper to achieve a good result?17 December 2019 at 2:21 am #637198
What species wood have you tried?17 December 2019 at 2:35 am #637208
Primarily American Black Walnut as it’s what I have on hand.
I have a piece of soft maple I could try as well.17 December 2019 at 7:36 am #637252
Any of the close grained American temperate forest hardwoods will scrape well (walnut, cherry, maple, oak, beech, etc.)
most pines don’t scrape very well, and spalted woods sometimes don’t scrape well.
Joseph did a nice video on card scrapers if you haven’t seen it
Note that he starts with a filed edge to avoid any issues with work hardened steel, if you skip that step you can be trying to turn an edge that is too hard to be maleable enough to turn.
and you might find it a little easier to ensure a square edge in the stoning steps to use a block of wood to register the card scraper vertically. I think Paul uses honing compounds to polish the faces, but that isn’t always necessary with the better scrapers and only really needs to be done once. My old Sanvik scrapers came polished, I’m not sure if the Bahko ones do.
The two most common mistakes I see is that people turn too much of an edge, which can remove a lot of material but won’t leave as smooth a surface. The goal is the surface, not the shavings. Four or five careful swipes with the burnisher is often enough. The second is that they hold the scraper at too steep an angle.
And lastly Make sure your burnished is harder than the scraper steel and well polished.
Follow all of Joseph’s steps and see how you do.17 December 2019 at 12:30 pm #637304
Thank you Larry, that’s helpful.
Are considerations such as going with the grain still applicable for scraper use?
Are you aware of anything (picture/video) that shows what the results of proper scraping are? I have no real idea what I’m looking for.
I’m wondering about expectations, “have not been getting the glass smooth finish I’ve heard referenced consistently across a piece.” Scraped surfaces look scraped. They look different than planed surfaces. I’d say planed surfaces are closer to glass smooth. Once finish is on, both look great. I know a craftsman, though, that sands ever square inch to make all the surfaces look the same before putting on finish, but I’m not sure that is needed. If the surface looks scratched, e.g., with lines, one possibility is that you are raising a burr with the file and not getting that burr off before proceeding to turn the edge.
Regarding grain direction, with or against makes a subtle difference, but not usually enough to matter. Going *across* the grain, though, must be done with care because some woods will splinter out, oak for example.17 December 2019 at 1:59 pm #637350
Thanks Ed. I was expecting something similar to a planed surface.
Perhaps I’m doing better than I thought.
I have noticed a few scratched areas however. I’ll pay closer attention to my sharpening17 February 2020 at 2:17 am #649369
I think one needs to keep in mind the progressive order of preparation: jack planing to remove highs and lows, smooth planing to remove planing ridges, scraping to remove the marks left by the smooth plane, sandpaper in progressive grits to make finer and finer scratches. The scraper is part of, not the end of the process. On wild grain as you describe, the scraper is turned in every direction until the imperfections are gone, something you can’t do and avoid tear out with a smooth plane.
I was trained in the Pleistocene era accept that planes and especially scrapers burnish the wood, closing the pores. After scraping, the wood is moistened, not wetted, then sanded with 220 Garnet paper so that the wood will accept the finish uniformly. For oil finishes, you’re done. For surface finishes you may want to go to finer grits.
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