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Scott Winners
02-21-2022, 12:55 AM
I have three pretty fair solutions now, figured I would mention. I recently flipped the knives in my DeWalt 734 to a fresh edge, less than a month ago. I still see washboard on the surfaces coming out of the planer. Possibly 1/64 height x 1/64 wavelength, but I can see them on bare wood in raking light and clear finishes just magnify them.

One inexpensive option to make these go away is a card scraper ($15). I finally learned to sharpen my card scraper: https://sawmillcreek.org/showthread.php?296222-Who-is-really-ecstatically-happy-with-their-cabinet-scrapers
with my new upgraded card scraper sharpening technique I can take poplar out of the planer, 4 passes with the card scraper at angles to the washboard, gorgeous.

I have also used a Polissoir from Don's barn ($27)and been able to make planer knife washboard go away on poplar, but I am not sure if it is a permanent solution. I guess I will find out in a few months/ years.

Finally, I made a burnisher from tropical hardwood (Sapele here) as described on Don Williams' DVD($0.25?). The DVD is 3.5 hours and about 30 bucks, I am claiming a quarter dollar for the Sapele scrap. I have seen most, but not all of the DVD. Anyroad, with the burnisher which cost me a piece of scrap I can make the planer washboard go away on poplar with fresh planer knives. I think Don used rosewood for his.

FWIW I respect that 'French Polish' is an American term for ever thinner layers of shellac on a surface with a pad, but also must respect Don's experience as a furniture conservator at the Smithsonian that what we call 'French Polish' was primarily an English technique. Going forward I will mention pad/shellac polish when I use that technique and wax/water when I use the wax/water technique as practiced by the French +/- CE 1775.

I have the most long term confidence in a surface I first clipped the washboard off with a card scraper and then burnished with the Sapele. I have taken to trimming down pin knots with a small chisel before burnishing. I find the burnisher leaves a high spot on the end grain of the pin knot, and then with continued burnishing eventually makes a ditch around the knot with radius equal to burnisher width. Better to have a small pit over the knot I think.

For $42.25, if planer knife washboard on flat surfaces with clear finish is bugging you, skip the polissoir. Use the $27 to buy a burnisher for the card scraper instead. I have, I think, every card scraper in every shape and thickness ever offered by LN, a Two Cherries, and I will in the future buy from Lee Valley with confidence. If you got a Dremel, some free time, and an old handsaw blade, sky is the limit. Start with a thick and thin rectangle, figure out what works for you, and then stock up.

FWIW the sapele scrap was 4/4 x 1.5 x 4.0. I cut the primary bevel by eye and then used a rasp to make a shape that doesn't hurt the palm of my hand. I am losing track of how many small scraper/burnishers I have made from nominal 1/2 x 3/4 x 8 inch hardwood scrap this weekend. Just cut a bevel at one end on the wide part, flip it, cut a bevel on the narrow part at the other end. Plane it flat with whatever you got, #3 Bailey, #4, maybe a #2. I have one for scraping wet glue out of inside corners now, works great.

FWIW I have found multiple thin coats of milk paint will fill/erase planer knife washboard, but for clear finish surfaces I have had to step up my game. I should mention I did fill the pores on my sapele burnisher with beeswax using a tack iron, like a clothes iron only smaller. I am not sure that is necessary as tropical hardwoods tend to be oily. But I had the heater and the wax, so I went ahead.

Back in the good old days, formerly known as 'these trying times,' everything I took out of the planer needed attention from the handplanes to make the washboard go away. I may still need to do that on primary woods like hickory and white oak, but on poplar I can move from the electric donkey to the card scraper to the burnisher to the varnish brush. There are some rags involved of course.

474345

Rob Luter
02-21-2022, 6:01 AM
I have a lunchbox planer (Ridgid) that leaves the same marks (see below). This is not a new thing. We always called them Mill Marks. I use the planer to thickness the wood but have no expectation it will leave a final finish. I always just hit the surface with a sharp smoothing plane set to a super fine cut. Sanding works too but takes too long. A few strokes with a smoother followed by a little fine sanding goes quick and leaves a surface that takes finish well.

https://s3.amazonaws.com/finewoodworking.s3.tauntoncloud.com/app/uploads/2021/11/22115751/planer-marks-700x755.jpg

https://www.thewoodwhisperer.com/wp-content/uploads/planer_marks.jpg

Brian Runau
02-21-2022, 7:36 AM
Could I see a picture of the marks you refer too. Is there some reason sanding with random orbital sander 120 up to 220 is not proper technique? Thanks brian

Phillip Mitchell
02-21-2022, 10:40 AM
Sanding?

.

Jared Sankovich
02-21-2022, 11:18 AM
I always just sand those out. If they are deeper than sanding will solve (its usually a planer issue in my experience) I'll hit it with a #4 plane then sand.

Zachary Hoyt
02-21-2022, 11:20 AM
My old DeWalt 733 leaves a clean enough surface to go straight to 220 grit on a ROS, unless there's figured grain tearout.

Phillip Mitchell
02-21-2022, 12:21 PM
Yep, I typically start at 150 or 180 grit on the orbital right off the planer unless it’s some skanky wood that did not fare well (tear out) during the planing process and then it’s a different approach, but that’s more than milling marks from the planer knives. Sanding goes very quick - those marks disappear quickly even at 180 grit. Depends on how well set up your planer is and how sharp the knives are, I suppose.

Brian Runau
02-21-2022, 6:05 PM
I have a lunchbox planer (Ridgid) that leaves the same marks (see below). This is not a new thing. We always called them Mill Marks. I use the planer to thickness the wood but have no expectation it will leave a final finish. I always just hit the surface with a sharp smoothing plane set to a super fine cut. Sanding works too but takes too long. A few strokes with a smoother followed by a little fine sanding goes quick and leaves a surface that takes finish well.

https://s3.amazonaws.com/finewoodworking.s3.tauntoncloud.com/app/uploads/2021/11/22115751/planer-marks-700x755.jpg

https://www.thewoodwhisperer.com/wp-content/uploads/planer_marks.jpg

Could this be caused by dull blades, blade at wrong angle to wood, height variations in blades? Brian

Bill Dufour
02-21-2022, 7:14 PM
I have read the human eye can see a 1/1000 inch difference in a flat surface. Like at a joint.
Bill D

Scott Winners
02-21-2022, 9:01 PM
With fresh knives, the mill marks coming out of my 734 were small enough I can't see them with raking light, or when the surface is wet with isopropyl. Get some wax or shellac on there - Surprise! We are still here!

There is nothing wrong with sanding, I just don't want the dust in my shop. I will look for a usable pic. My circa 2008 SLR has given up the ghost, and I don't seem to have manual controls on the camera in my phone.

johnny means
02-21-2022, 9:16 PM
It's unrealistic to think that material can come out of a planer without scallops. Every machining process leaves its mark. Even a wide belt sander leaves chatter. The only solution is to have patience and do the necessary sanding or scraping.

Mark Wooden
02-22-2022, 8:57 AM
It's unrealistic to think that material can come out of a planer without scallops. Every machining process leaves its mark. Even a wide belt sander leaves chatter. The only solution is to have patience and do the necessary sanding or scraping.

+1
Mill marks are a fact of life when sawing, jointing, planing, wide belt sanding lumber. Very smooth planing is of course achievable, 'glass' smooth is is a misnomer IMO- look with a loupe, the ridges are still there. and with a helical head (all that i've seen), the ridges just go the other way. With regards to planing, the ridges can be higher due to a knife being a little higher than the others; the marks will be farther apart as feed rate increases. Well adjusted knives obviously are the solution to a smoother finish from the machine and it can be made even smoother with a slowed feed rate- you're giving the machine a chance to cut the peaks off. If a machine has a smooth or rubber infeed roller, a second pass through the planer at the finish dimension can also reduce them- a serrated infeed roller may dent the wood and then you'd have to steam those out.
As to burnishing them out, well, you're compressing the ridges, not removing them as per scraping and/or sanding and since the material is still there, my concern that the ridges would swell back out over time. I may be wrong, but is wood;)
I usually sand with 150 to 220 grit in softwoods and most often use a scraper on hardwoods (I'd rather scrape all day than sand for an hour) followed by a touch hand sanding with the grain with some 220 to 320 garnet paper.
But, everyone is different and theres almost a million ways to get to the finish in woodworking, and most work.