losing my mind over sanding swirls

[Bob Riefer]

Please read before diagnosing... I have watched so many instructional videos, read so many threads and magazine articles, and continue to experience ongoing struggles with "swirls" or "pig tails" after sanding my projects. I thought explaining my current approach might help the crew here give me some ideas as to what to try next.

Let's suppose I'm building a table top:

- After rough lumber has acclimated to my shop and has been surfaced/prepared

- As I clamp/glue, I use shop-made cauls to help ensure close alignment between the edges of each board

- An hour after clamp/glue, I carefully/gently scrape squeeze out on both sides of the table (I find that glue is easy to remove this way.. I temporarily move a clamp, scrape that area, replace the clamp for overnight, and so on...)

- The next day, after clamps are removed, I use a combination of card scrapers and hand planes to blend joints as needed. This typically results in a surface that has only minor imperfections that I can detect with my fingers.

- For large surfaces (e.g. a dining table top) I then get busy sanding using my larger sander which is a Bosch 6" ROS, model ROS65VC-6. I usually run it on speed 5 or 6 (which are faster settings on this tool).

- I begin around 100 grit and progress to mid-200's, never skipping a grit along the way. I have tried multiple types of Aluminum Oxide discs.

- I progress about 1 linear inch in about 5 seconds, with the grain, overlapping passes, and the sanding disc sitting flat (not tipped). I typically do 2 such passes per section before incrementing to the next overlapping section. To give you an idea, to sand my current table top (measures 3.5 feet wide x 7.5 feet long), it took me about 2 full, non-stop hours to progress through the grits.

- I have good vacuum suction pulling through the sander the entire time for all grits

- I brush the surface clean each time I change grits

- In terms of downwards pressure, I am barely pushing downwards at all... Just enough pressure to keep control and guide the sander. The disc spins freely across the surface and I am not bearing down aggressively.

- I have changed the pad on the sander, and also tried a much softer pad.


After all of this, and without fail, I find widespread swirls across my work. Sometimes what I would consider "very noticeable" and other times "probably only noticeable to a woodworker". I either choose to live with it at that point or spend hours and hours and hours (literally 5-6 hours) painstakingly trying anything under the sun to resolve the issues (more card scraping work, hand sanding, endless power sanding with 300 grit, etc.).


As two points of reference:
- As a much less-experienced woodworker, I used an old Porter Cable 5" ROS and took none of the care noted above to achieve flawless results (even when judged by my current eye)

- For smaller pieces, I use my smaller BOSCH ROS20VSC and follow all the same steps as noted above.... and get swirls galore.



At this point, I really must wonder:
- Am I missing something extremely obvious?

- Are my expectations out of line? That is, should I expect that it truly takes every woodworker 10+ hours to sand a table top?

- Is it possible that 6 different brands of sand paper are all a problem? Is alum oxide not an ok choice?

- Are my Bosch sanders to blame? (I am 150% willing to write a check right this minute to buy 2 new Festool sanders [or whatever the group thinks is best] if that will help me past this issue)


I'm open to anything.. I'll even video tape me working on a table top if that would help. I'm going absolutely mad over this :)

Thanks!!

Bob R.

[Derek Cohen]

Why sand after hand planing? If you do a good job of planing, then sanding cannot come near the finish. This is my usual go-to.

When I do sand, I go to 400 grit with Abranet on a Mirka Ceros or very old Festo (forerunner of the Festool 150/3). If there are any swirls (not usually), I would use a card scraper or hand sand with the grain.

Regards from Perth

Derek

[Andrew Hughes]

I agree with Derek after handplaning a surface I will sometimes go over the surface with 400 grit that
I rub with the grain. You don’t mention what wood your working with closed grading hardmaple or open red oak. My suggestion sand with the grain when get to 220 raise the grain with water and grind it smooth again.
Good Luck

[Mark Rainey]

Bob, you are not alone. Because most woodworkers on this forum work in isolation, they are their own worse critics, and do not have a solid concept of "good enough". In my hand plane courage thread (https://sawmillcreek.org/showthread.php?293028-Handplane-courage&highlight=) almost all admitted to sandpaper. And yes, after sandpaper, I can still see "defects". I suspect your table is fine.

[Tom M King]

Try 320.,,

[Lee Schierer]

Try 320.,,

Our switch to a belt sander which will only sand in line with the grain.

[Tom M King]

It's hard not to have to do a little hand sanding if you want something perfect.

[David M Peters]

My guess is that the table top isn't terribly flat even after hand-planing, and that the ROS is snagging the high spots causing those swirls. Check for flatness using a long straightedge.

I recently finished a dining table where I had to a good amount of cross-grain flattening with my biggest plane (5-1/2), and then with-the-grain planing and scraping to get it ready for sanding. My cheap 5" Makita ROS then didn't leave any swirls.

[Brian Holcombe]

Turn the vacuum pull down if you are using a vacuum. If not, the follow up with hand sanding.

[Patrick Kane]

Depending on the finish being used, I dont know that a purely planed surface is the 'best' surface. I would double check that against my planned finish schedule, but yeah, a planed surface finish is preferable to many in terms of aesthetics. I dont know that it is preferred by contemporary finish manufacturers.

Bob, my first instinct is to say "its the sander", but lets not jump to spending your money too quickly. You mention multiple types of abrasives, what brand specifically? Is your sander connected to a variable suction vacuum?

If i had to guess, i would say you are not sanding away the original 80-100 grit swirls. By the time you make it to 220+ its already too late, and you would be there for 5 hours trying to sand out the 80 grit swirls. Your sander has a very small stroke(2mm), which means its not that aggressive at removing material. Conversely, it should be less likely to have big noticeable pigtails. They will still be there, but tighter packed and less noticeable. My guess is you are damaging the surface with the coarse grit that your sander cannot adequately remove as you step up into the grits. I see this with my Festool rotex switching to my Festool ETS ec. The 3mm stroke ETS cannot undo the swirl pattern off the aggressive rotex in a reasonable amount of time. I would go back to the basics and lay down a light pencil hatch across your surface. Sand till there is no more pencil. Repeat the pencil hatch. Change grits and sand. Rinse/repeat.

I can all but guarantee a new Mirka/Festool sander would solve your issues. If they dont, then send the sucker back for a refund within the trial period.

[Bob Riefer]

Thanks everyone!

Brian - do you mean to try reducing the shop vac suction a bit? I was just now reading that some felt that too much suction could result in swirls.


I also read some suggestions to start at a higher grit (say, 150 grit rather than 100 that I start at now). My table tops have been nice and flat (the cauls help a lot on that).


Here, from left to right are 4 recent efforts that all had the "swirl battle"... Ash, Hickory, Pine, Walnut. My current table top I'm working on is actually just poplar, but had the same issue.

483769 483770 483771 483772

[John TenEyck]

I have both those sanders and neither leaves swirl marks, so save your money on thinking new ones are the solution. The thing that really caught my eye in your work description is that you move the sander "1 linear inch in about 5 seconds". Really? That's incredibly slow. No wonder you are having problems, especially with the coarser grits. I would typically move about 12" in 5 seconds. You also said you move with the grain. When sanding a big table top I almost always start going directly across the grain, then diagonally, first one way, then the other, and then with the grain. I do that through 80 grit, then switch to sanding only with the grain. On rough glue ups I've started with 36 grit in order to get the top flat, then 60, 80, etc. up to whatever the final grit is. I almost never hand sand. That's how good I think the Bosch ROS65VC-6 is. I do not use a vacuum hookup with it, just the onboard dust cannister.

I did this tabletop from a biscuit aligned glue up at my friend's house. I used a #6 handplane to get the joints fairly flush and then spent 2 hours to sand it flat, as you see it. I started with 36 grit and followed the sequence above up to 150 grit. I used a hard pad on the sander.

https://lh3.googleusercontent.com/pw/AL9nZEXDGDcKzQ2h0wQV1NQWsCkbiq273WxcG-vOLM_IWYUiD2j5gbZIEbBylS5WqbD6ZyMnqLTIFhVkRCTW4o9_ MEhftaYSbScAlQ1CsXupglO3PCLla7FtVG2ZaNXpgO8x2hC8gY c3BNVohmAxmDdZjcp49A=w1470-h828-no?authuser=1

John

[Jim Becker]

Brian - do you mean to try reducing the shop vac suction a bit? I was just now reading that some felt that too much suction could result in swirls.


It's a good idea to reduce the vacuum air flow more and more as you get up to finer grits simply because there's less space between the "grains of abrasive" which in turn can make the sander "stick" to the workpiece. That can cause issues and may make any swirling worse. Make sure you are also thoroughly cleaning the workpiece between sanding grits to avoid a "bigger" piece of broken away grit from getting caught on the new, finer abrasive and causing the swirls. If you do see them...carefully inspect the abrasive pad that's on the sander. You will likely fine something; either debris or "corn" where some wood fiber got "glued" to the abrasive and is now cutting patterns in your fresh wood surface.

[Bob McBreen]

My only suggestion is to wipe down with mineral spirits after you believe that you have removed of the previous grit and are ready for the next grit. This will highlight any swirl marks.

This will help determine where in the process you start seeing the marks.

[Steve Jenkins]

I agree with Patrick about using a pencil to draw a light cross hatch pattern and sand until it’s gone. Do that every grit. Clean thoroughly between grits. Inspect the results every grit. It’s nearly impossible to remove 80grit scratches with 220 paper.

[Randy Heinemann]

I'm not a big hand plane woodworker but I would guess that, if you get a smooth level surface with a hand-plane, starting with 100 grit sandpaper is not necessary. I would use 80 or 100 grit only if I were trying get rid of imperfections or slight glue joint inconsistencies. Handplaning should get rid of those. Using 100 grit at that point would be like sanding veneered plywood with grits coarser than 120 since that is what most ply is sanded to from the factory. I would probably start with 220 grit or even 320. If you're staining the surface then you would run into problems of absorption of the stain but if you're doing a natural finish, then the smoother the better.

I think the suggestion of turning down the suction of the vac is excellent. I use Festool vacs and find that on a large flat surface the vac can be turned down to its lowest setting and the dust will still be sucked up.

Maybe you're moving the sander too slow. After all the surface is already smooth. As I said I'm not a hand plane guy. Since I began using Festool sanders and vacs I almost never get swirls. If I do, I know I'm unknowingly doing something wrong.

[Bob Riefer]

This is wonderful, thank you everyone!


Jon E. - about moving too slow... This was my attempt to remedy that I thought I was going too fast in the past, so perhaps the happy medium is the ticket. Also, very glad to hear that my existing sanders ought to be fine - I had invested in those after a fair amount of reading and am happy to hear they aren't the likely issue.

Jim B. and Randy - Thanks for confirming idea on the vacuum suction. I think I saw a simple "bleeder" design that Glenn B. posted awhile back and will try that.

Bob M. - Good idea on the mineral spirits after each grit... Will do that on my next project.

Patrick / Steve - great idea on the pencil marks... I do that when planing and can see the logic here too


I'll report back on my next project soon! Thanks again!!

[Richard Coers]

I hope I didn't miss it, but how much pressure are you pushing down on the sander? Your hand should only move the sander, not pushing down on it. You should not hear the sander change rpm when doing the work. Next, how often do you change abrasive? Use sandpaper like you stole it, replace it often! I use two grits on a belt sander before moving to a random orbit. It's not easy to keep a flat surface with a round disc. I stop sanding with 220 before finishing and use 320 between coats of finish.

[Bradley Gray]

The only thing I can think of that hasn't been mentioned is wetting the surface then repeating the final grit.

[Maurice Mcmurry]

My random orbit and orbital sanding starts at 120. Pryor to 120 all sanding is done with the grain. Bigger RO sanders leave bigger swirls.

[Alan Lightstone]

I also start at 120 grit. Personally, I think starting with 100 grit risks scratches that the higher grits won't work out, as has been said above.

Almost all of my sanding is done with my Festool 150/3. So not changing sanders. Suction turned down most of the way. Start against the grain, then diagonal, then with the grain. Seems to work and not leave swirls. I fortunately haven't faced this issue.

[Don Stephan]

Experiment with different movement speeds as mentioned a couple times. A "raking" light (low angle) should highlight swirl marks There's nothing to gain moving up to the third grit if swirl marks from the first grit still present.

[Maurice Mcmurry]

Swirls from fresh 100 git on a R.O. go deep. It is very difficult to get rid of them. I am sure they can be measured, A few ten thousands of an inch... they do not go away when followed by finer grits.

[Mike King]

https://www.youtube.com/watch?v=rZZyypf-Qqk

[Thomas McCurnin]

No one has mentioned card scrapers. After a couple quick passes with a No. 4-5 Plane, try using a card scraper. You might find that you don't need sandpaper below 150g.

[Jeff Roltgen]

My main concern:
Once that coarse (36-80)grain is implanted in the pores, it can easily camp there, only to be dislodged during later courses. Maybe vacuuming after each course will grab every last spec - maybe washing down with mineral spirits would help.
IMHO: Don't go that coarse to begin with.

Unless I'm grinding finish off the floor of a deck outdoors, I never reach for anything less than 120 grit for the R/O.
Max out at 150 - 180.

Secondary consideration:
May have missed it, but I've seen little mention of hand sanding. Final sand with the grain using a large block (EG:3"x14") and hand pads for a final dressing before finishing.
I've read other's advice to do this with 1 grit higher than last grit run on the R/O, though I've always done well with a final R/O at 180 and matching it for the hand sanding.
Incidentally, that block and a series of pencil lines can help spot/conquer high spots in the early stages, much like a hand plane, if an inordinate amount of levelling is needed and you're not adept with the hand tools.

Swirls suck. Don't let them suck the enjoyment out of your woodworking.

jeff

[John TenEyck]

My main concern:
Once that coarse (36-80)grain is implanted in the pores, it can easily camp there, only to be dislodged during later courses. Maybe vacuuming after each course will grab every last spec - maybe washing down with mineral spirits would help.
IMHO: Don't go that coarse to begin with.

Unless I'm grinding finish off the floor of a deck outdoors, I never reach for anything less than 120 grit for the R/O.
Max out at 150 - 180.

Secondary consideration:
May have missed it, but I've seen little mention of hand sanding. Final sand with the grain using a large block (EG:3"x14") and hand pads for a final dressing before finishing.
I've read other's advice to do this with 1 grit higher than last grit run on the R/O, though I've always done well with a final R/O at 180 and matching it for the hand sanding.
Incidentally, that block and a series of pencil lines can help spot/conquer high spots in the early stages, much like a hand plane, if an inordinate amount of levelling is needed and you're not adept with the hand tools.

Swirls suck. Don't let them suck the enjoyment out of your woodworking.

jeff


I have routinely used 60 grit (and sometimes 36 grit) on tabletops that have a lot of cleanup required to get uniformly flat. I use a hand plane to take off the worst of it, but once I'm down to fingernail catch close I prefer to sand because it eliminates the chance for tearout. I've never had a problem with coarse grit getting lodged in the pores. The tabletop I showed above was red oak and Sapele. If anything is going to capture loose grit it's red oak. It just doesn't happen. When I did that tabletop I didn't even have access to a shop vac. I just brushed it off between grits, then wiped it with my bare hand. You will feel large grains of grit with your hand. Any little shards that are stuck in the grain that you can't feel aren't going to be a problem with the next grit. I'm not suggesting what I do is the right way, only that it works and is more efficient for me with no worry of tearout.

John

[George Yetka]

When you say you get swirls, is it a few like seen in the link? I will get these once the paper starts to were. If you are starting with new paper and sanding tables you may get to a point where the paper wears out before the end of the grit your on. If you were sanding coasters id be scratching my head. I would visually inspect each grit sanded. If they have appeared you will have to drop back to get rid of them. Dont progress you will get even more frustrated. I would suggest Mirka Abranet It lasts a long time and they are very consistant.
If you are using hand tools to smooth the joints/glue starting at 120,180,240(I use the dont progress by more than 1/2 current grit rule) with the abranet should be sufficient.


Found this while I was looking for a picture of swirls
https://www.abrasiveboss.com/blogs/info/eliminating-swirl-marks-in-wood-sanding

[Pat Germain]

Did the videos you watched include the sanding video from Stumpy Nubs? I recently watched his sanding video and multiple times he talked about avoiding pigtails.

In my experience, I tend to get pigtails if I'm not keeping the sander flat.

[Bradley Gray]

I'm not suggesting what I do is the right way, only that it works and is more efficient for me with no worry of tearout.

Who hasn't taken "one last pass" with a plane only to muck it up?

[Mark Rainey]

Yes Brad…and that one pass causes tearout that requires 80 grit to repair��

[Bob Riefer]

Thanks again everyone!

Someone used the term "fingernail catch" to describe the slightest deviation between to adjacent boards... Even with cauls I have found it difficult to entirely eliminate such deviations so I use a hand plane and card scraper to knock down the worst of them.... but I think I must be tilting the sander to more quickly smooth such areas, thus causing my swirls.

I am due for new sandpaper anyways, so I have an assortment pack of Abranet on the way, and will give the Bosch routers more opportunities to succeed as I use the new paper and carefully watch my technique.

I will also look to spend more time with card scraper and hand planes.

AND, starting with higher grit.

I'll report back :)