That final emphasis is mine. I get that sanding can create fuzz due to tearing. That makes sense. Scrapers are supposed to avoid that by slicing the wood instead of gouging it.
Yes in theory, but this is a case where the wood is unusually prone to tearing so scraping can't always give the results it would otherwise.
Are you not suppose to use scrapers on "fuzzy" wood?
It depends on the exact circumstances as much as on the scraper — both the size and the amount of hook on the scraper can have a large effect on the success of scraping (more on this below).
You may have read elsewhere that softwoods shouldn't be, or can't be, scraped. The reason for this is the fuzz, where the very soft earlywood on some species is extremely prone to tearing or lifting. But as I mention in passing here I've scraped softwoods. In fact I'd like to think I've had quite a bit of success doing it and that is partly because I won't just scrape in one way and if that doesn't work I give up.
Sometimes it's not enough to sand "in the direction of the grain", or parallel to the grain to put it more accurately, there are times when you want to sand only in one direction. Where you're getting tearing of fibres you can sometimes get much better results sanding forwards or backwards only, and not back and forth.
Variations in scraping
Very broadly there are three edges that are used to scrape with:
- card scraper with a large, heavily turned burr (e.g. 10°)
- card scraper with a small, lightly turned burr (3-5°)
- a knife edge (using an actual knife, single-edged razor, or the edge of a chisel held upright)
On the same piece of wood you can notice quite a difference between scraping with each of these. As a result it's worth having all three on hand to try out when situations crop up and you're not getting the uniformly good results you expect.
Harden the wood surface
I was going to mention a similar workaround/solution to the problem as aaron has already provided, in applying a light coat of finish to harden the surface wood. But in my case I would suggest either dilute shellac or lacquer (in essence, using the equivalent of many commercial 'sanding sealers' one of whose jobs is exactly this). While varnish works as well or better for this purpose shellac and lacquer dry much much faster so you can continue work on the board with far less waiting.
This will improve results with both sanding or scraping, but if you remove too much wood you'll expose untreated wood fibres and the problem will recur.
I think the bottom line here is that problem areas in a given piece of wood are problem areas, and it can be difficult to deal with them 100% successfully. I'm sure nearly everyone has experienced that one patch on a board, that overall smooth-planes or scrapes well, which tears out and spoils the otherwise pristine surface. Occasionally in seems that no matter what direction you go at it the problem won't go away entirely and you eventually have to just do the best you can with it as time and the material allows, accepting it's not ending up perfect.
Incidentally, you'll hear people express their surprise that others are having this problem much/at all in a given species that they're very familiar with, as in, "I use [x species] all the time and I never experience this etc.". There's one major reason for the different experiences: wood varies. As blindingly obvious as this is it's surprising how often it goes unacknowledged. It's not just that wood itself varies so much, local humidity (and therefore wood moisture content) obviously can be anywhere from dry as a bone to like a sauna. Last but not least whether the wood was air-dried or kiln-dried can have a marked effect on workability. Just ask fans of air-dried black walnut what they think of the kiln-dried version!
But there's another major reason that often gets overlooked which can play a major role here and that is whether one guy is processing their stock by hand planing and the other using machine planing. There's almost an assumption that planed wood = planed wood, which is very much not the case.
I never use dummies.com as a solid information resource
That's wise. But to be fair, I take that attitude with everything I hear and read in woodworking, no matter how unimpeachable the source is supposed to be :-)