Hello,
As part of my learning process I am making something simple, a clipboard for my wife. I laminated it from pieces of cherry, hard (bird’s eye) maple and walnut. Things went well but now I’m preparing the surface for finishing. I decided to have a go with scrapers because I like the tool and I don’t like sanding. I gave a good scraping to both faces of the board.
I like what the scraper does. It leaves a surface that reflects light and has depth.
However…the walnut doesn’t take it very well. It *looks* almost as nice as the other woods (except I don’t like that white-ish dust that’s filling up the pores and can be very visible at some angles, or is that a characteristic of the wood?) but it still feels kinda rough. You can feel the grain. I am not sure if that’s bad yet, but that’s what I get.
On a piece of scrap from the same walnut board, I tried a comparison between scraping and sanding. The scraping makes the wood look beautiful, shiny, and brings out the curls, but it’s still a bit rough to the touch. The sanding makes it *very* smooth to the touch (or would it be dust filling up the pores?), but it’s dull (I went up to 320 grit). I much prefer the looks of the scraped surface.
Anyway, my question is: is this typical? Can I get the walnut smoother with the scraper and keep the lustrous surface? What is causing the roughness? Is it some kind of tearout (I do see, on one of the walnut pieces, some cross grain lines that look like tearout)? Even if they have a bit dulled by now and probably need a resharpen, I think my scrapers were sharp, and I could get shavings with them (although I think I turned the burr too much and have to angle them a lot to get them to start cutting). The maple is super smooth.
Any tips welcome!
Replies
A scraper shouldn't be creating dust, it should be making curely shavings. Walnut does have open pores, that will be more open under scraping than with sanding. You shouldn't need to sand after scraping unless you have some surfaces than you can't scrape, and which will be stained along with the scraped surfaces. The scraped surface has sharp surfaces, sanding just rounds things over. Perhaps this feels smoother, but when you apply the finish, the clarity to the scraped surface will stand out.
But, one shouldn't make too much of the difference between scraped and sanded. This is mostly an aesthetic difference seen only by the maker. Once you start applying finish, the differences become much, much more subtle. Even with a very revealing finish such as French polish (which I assert is the finest finish possible) the difference between a scraped and a sanded surface will be hard to discern. Even the change that occurs with a good planed or scraped surface just sitting overnight eliminates the wonder of the clear surface. The shimer and clarity of a planed or scraped surface is seen only by the craftsman, and wonderous in that rarity.
I know you will wipe your work down with mineral spirits prior to your finishing. This will give you a good idea of what a clear finish will look like.
Most likely you have used too much pressure when turning your burr on your scraper. Possibly also at too much angle. This is a very common mistake for the inexperienced and will turn the burr too far fracturing the edges and creating a saw like surface that will still scrape but leaves a rougher ridged surface than a properly turned scraper would. You should only need to tilt your scraper about 15 to 20 degrees from perpendicular to your wood surface. Fairly light hand pressure is all that is needed... usually much less than beginners guess would be required. Refile your scraper and reburnish the edge using about one half pound of pressure at about 2 to 4 degrees from perpendicular to your scraper edge. That really is all that it takes, the round surface of the burnisher applies the force to a very small area at a time and easily does the job. Normally the first burnishing (after refiling) will give you a fairly aggressive scraper edge that is good for coarser removal while the second and (possibly) third burnishings will give a more refined (but slower) cut which is nice for final surfacing. I never sand or stone my scraper edges... filing and burnishing keep them working nicely. You can actually get a finer (smoother) cut by dressing the edges more than I do... but in my experience it slows the process to the point of making it rather useless. I do prefer a fine cut file for filing my edges but have often worked with regular bastard cut files too. A double cut file is less desirable but I have made them work reasonably well too.
Thanks all for your feedback. I knew that my scrapers had too much of a burr, but I didn't think it could have such an effect beyond just the problem of having to tilt it more. First thing I'll do when I can get back into the workshop is resharpen them properly.
You may have more than one problem. It takes only very light pressure to make the scraper burr, as someone else pointed out. A better burr may give a smoother surface.
The white dust in walnut pores probably comes from the maple. Scraping can create some dust. I make turnings mixing these woods & have the same problem. You may vacuum the dust out or blow it out with compressed air.
How will you finish the clipboard? Will you want to leave the pores of the walnut open? I haven't figured out how to fill them when mixing these woods.
Cadiddlehopper
I am not very experienced with finishing but I have worked out something that I like out of a couple coats of Watco Danish Oil followed by some Minwas wipe-on poly, a few coats. That's something I have available right now and I've managed to get pleasing results on some small pieces. With the poly, I usually got a plastic look and treaks if I followed the prescribed method of wiping it on, so I do something that is more flooding, let sit a few minutes and wipe. It takes longer to build a film (and probably waste more product) but I find the result pretty nice and natural. I recently used the poly on a piece of marquetry from my father that I needed to refinish.
I've put wipe-on poly over tung oil varnish (Behr brand) with pleasing results. I got a great finish with it over a Minwax stain. I found that wipe-on poly does not work well if the temperature is high, maybe over 70 F. I suppose it sets too fast.Cadiddlehopper
Here in Tucson it gets hot of course, but I'm lucky enough to have a small A/C unit in my tiny workshop. Before I decided to put some poly on the marquetry, I tried with simple paste wax, but I was unable to apply it without streaking. No matter what I tried, short, medium or long drying time, thin coat or thick coat, wiping hard, doing one or several applications etc. Tried several times and ended up removing it each time with mineral spirits to finally decide to go ahead and put some poly, which looks real nice after 3 thin coats with the flooding method.
Re-do the edge of the scraper and only angle your burnisher 10 degrees when putting on the burr. As stated in this post, use a light touch when using the scraper. Think, a light caress to check the surface for smoothness with your hand, use this same gentle caress with the scraper. Tear out can be remedied by scrapeing in the opposite direction. On inlays the more uniform your inlay to the adjoining wood the better. Small gaps really show up when you put your finish on. As to a finish that I use all the time, I use poly cut 50/50 with mineral spirits and hand wipe this on. It creates a smooth thin coat and another can usually be applied after 2 hours dry time. A system you check out for the future is one by the Woodsmith Shop. It is all in one unit and I have had good results with it. Sandvik makes an excellent scraper and will give you many years of faithful service. Hope this helps!
Well, this walnut scraping thing is still puzzling me.I have resharpened my scrapers (I have a thick and a thin one), filed, honed them on 2 waterstones (using a block of wood to keep them straight, burnished them at the correct angle until I had a nice small burr, then they were sharp enough to take thin shavings without much pressure. Still, the scraped walnut looks very nice with a glassy surface, but the pores are still rought to the touch. The version where I sanded to 220 and 320 grit after scraping is *much* smooth (without much effort with the sandpaper) but seems duller. However, after putting some finish on the strip, the part that was sanding still looks a tad less shimmery as the other piece but the difference is very much reduced.It's weird. How could the scraped surface look shinier and yet rougher to the touch?
Sometimes the pores are closed with sanding dust and therefore when scraping these are not touched to the full depth of the wood. It is something that I have encountered in the past, but if the piece looks ok to the intended recipient and they think the thought behind it was in their own interest, the job has accomplished it's purpose. Don't be so hyper-critical about the process, the admiration of the person receiving it is the true reward. Even if you did everything possible to get it perfect, the end result is it's final test. Perfection is not what you want all the time, the gift is more important.
This forum post is now archived. Commenting has been disabled