Can't get the scratches out of walnut!

[Cheryl A. Prince]

Greetings all. I am another "background sulker" who's going crazy trying to sand a black walnut bowl. I'm electric sanding through the grits with the bowl turning on the lathe. It seems like everytime I think I've finished with a grit I see new marks, tearout or scratches that I swear wern't there when I finished with the previous grit! I sand two grits forward and then have to go back a grit or two to get out some new marks. I've tried putting down the right angle drill/sander and going through the grits hand sanding using abralon. That seems to work a little better then, BAM...some new set of scratches seems to appear. I tried putting a set screw in the chuck and reverse sanding (only to create a whole new set of scratches going a different direction!:eek:). For the sake of my sanity I'm walking away from the power tools. I am a frugal sort and sometimes I try to extend the life of my sandpaper long after it's "given up the ghost...dust? After dinner I'm going back out and will only use new, clean paper. Any suggestions might stop this bowl from becoming a frisbee!:confused:

[David DeCristoforo]

Don't power sand with the bowl spinning!!!

[Thom Sturgill]

Use sandpaper like some one else is buying. Do not allow build-up on the paper.

Also, get one of the man made abrasive pads (fake steel wool?) and use that to back up the sandpaper. It will help prevent heat build-up and that is your enemy.

Don't let the piece turn too fast - 400 rpm on a six inch bowl is plenty fast - again speed causes heat build-up.

If hand sanding, after sanding with one grit with the bowl spinning, lightly sand with the grain with the lathe stopped. Do this with each grit change. This is to remove concentric rings that may occur.

Once above about 150 grit, each sanding should be light and fairly quick. You should not be sanding out defects as those should already have been taken care of. Above about 400 grit you are really polishing not sanding depending on the wood. Depending on the type of finish, apply sealer at 320 or above - after that you are sanding finish not wood.

Hope that helps, as I've been there - done that ;)

[Scott Hackler]

Don't power sand with the bowl spinning!!!


??? Thats the only way I power sand. And a lot of the time I power sand at high speed just keeping watchful attension to heat buildup. I dunno, works pretty darn good for me.

[Pete Jordan]

Cheryl,

You might try adding a little water or oil but it does eat up the paper.

[Scott Hackler]

Greetings all. I am another "background sulker" who's going crazy trying to sand a black walnut bowl. I'm electric sanding through the grits with the bowl turning on the lathe. It seems like everytime I think I've finished with a grit I see new marks, tearout or scratches that I swear wern't there when I finished with the previous grit! I sand two grits forward and then have to go back a grit or two to get out some new marks. I've tried putting down the right angle drill/sander and going through the grits hand sanding using abralon. That seems to work a little better then, BAM...some new set of scratches seems to appear. I tried putting a set screw in the chuck and reverse sanding (only to create a whole new set of scratches going a different direction!:eek:). For the sake of my sanity I'm walking away from the power tools. I am a frugal sort and sometimes I try to extend the life of my sandpaper long after it's "given up the ghost...dust? After dinner I'm going back out and will only use new, clean paper. Any suggestions might stop this bowl from becoming a frisbee!:confused:

Walnut (black Walnut expecially) is particular to showing scratches. Make sure the contact point of the sand paper to wood is ALWAYS moving. You might look at the quality of the sand paper. They are not all equal. Some cheaper pads will have non-consistant grains of sand .... causing scratches. Also its a good idea to blow off the piece with the air hose in between grits, to remove any remaining larger grits.

Hope this helps.

[Curt Fuller]

I've been turning for several years now and I still can't avoid those two little areas of tear out in a face grain bowl. I'm talking about those two spots 180 degrees apart where the grain makes the transition from 'with the grain to against the grain'. I've learned tricks to minimalize the tear out but it's still there. The thing I've found is that when you're power sanding with the bowl turning you have to sand the entire bowl down that fraction of smidgen to get rid of the tear out. But if you stop and just work those two small areas, it takes a lot less sanding. Another thing is that when you change grits, wipe the bowl clean with a paper towel to remove the sanding dust and any sandpaper grit that might be lurking in it. And lastly, when all else has failed to give you the surface you're looking for, spray it with some wd40 and wet sand. Hope that helps.

[Kyle Iwamoto]

+1 on sandpaper quality. You didn't mention what you use, but I've bought cheap sandpaper, and it seemed to have no quality control. Probably had 30 grit rocks on it, so it always left scratches.... Since then, I only buy "quality" sandpaper. I too am "frugal" and use my sandpaper until it is no longer servicable, hence even more so requiring buying good sandpaper. Good sandpaper cuts for a very long time.

Just my $0.02.

[Karl Card]

One thing that I have noticed is that certain sanding marks in walnut will absolutely not come out. More times than not I have had to go back and get the tools out and barely touch it up with a turning tools and the go back to sanding.

But you all have to understand that I am still learning how to sand and I have a bad problem with putting to much pressure on the sanding material. My fingers are getting tired of getting burnt..

I have though adapted some new ways and I will post some pics of what I use now to sand bowls with.

[David DeCristoforo]

"...certain sanding marks in walnut will absolutely not come out..."

It's not just in walnut. The "problem" with sanding on the lathe is that you can never be sanding "with the grain" which is a basic rule of sanding. Power sanding a spinning piece can exacerbate the problem. I know lots of people do it and sometimes I do it too. But I stop the lathe after each grit to hand sand with the grain to be sure there are no marks before proceeding to the next finer grit.

[Bill Wilcox]

I don't have any problem with sanding my BW. However I do go down to 600 G. I also use a woven scotchbrite type pad to sand also. One trick I also do is use sanding sealer and when I use sandpaper, I go slow, sand in both directions and use a pad of steel wool between the folded sandpaper.
I think using a sanding sealer on the bowl first helps stiffen the fibers so they shear off better.
+1 on the quality paper too.

P.S. I also burnish the wood with the shavings I get from turning the bowl too. That seems to really help.

[Chris Colman]

Walnut is notorious for showing sand marks. Sometimes they do not show themselves until the first coat of finish or sanding sealer (which is why I love sanding sealer).

I try to make my last cuts as smooth as possible, shear scraping or riding the bevel and shear cutting. I do not usually start below 150 grit, especially with walnut, unless I need to REALLY reshape or work down an area. I usually stop at 320 or 400 for most woods.

Watch out for steel wool. It can leave small particles of steel in the grain of walnut, and, because of the color, you may not see them. They can wreak havoc with certain finishes. Sometimes a wipe down with a rag can get them out.

Walnut is certainly worth the work. I especially like the application of the first laquer coat, when the wood color changes and the chatoyance starts. Magic transformation from firewood to beautiful wood.

[Barry Elder]

Would suggest that you "Google" Russ Fairfield and go to his website and read his material on sanding and finishing. It is quite an education!

[Bernie Weishapl]

One thing I would suggest is when sanding before going on to the next grit is to take your Air Compressor and blow off the piece before going on. Clean the wood off before going on to next grit. If you don't you will not get rid of your sanding marks.

[Art Kelly]

...it's like turning rope.:mad:
...it smells bad.:mad:
...it gives me contact dermatitis if it's green.:mad:
...it turns my hands black if it's green.:mad:
...it takes forever to sand.:mad:
...I hate it right up to the moment I rub some oil on it.:mad:

Then I love it.:)

Sand it with the lathe spinning, blow it off, then sand by hand with the grain, then blow it off again.

Don't skip grits.

Don't use anything you don't want staying in the pores of the wood.

$0.02
Art

(I quit using steel wool after the first time I used it on some mockernut hickory, which has open grain sorta like walnut (they're related). All the little pores got filled with steel-wool dust and wouldn't come out except with vigorous :eek: sanding and blowing.)

[Carl Miller]

Do all the things that Curt said. Especially wipe the bowl between each grit to get rid of grit. I do all that, and then I hand sand with the grain for final and hand sand with the grain in particularly troubling spots.

[Leo Van Der Loo]

Greetings all. I am another "background sulker" who's going crazy trying to sand a black walnut bowl. I'm electric sanding through the grits with the bowl turning on the lathe. It seems like everytime I think I've finished with a grit I see new marks, tearout or scratches that I swear wern't there when I finished with the previous grit! I sand two grits forward and then have to go back a grit or two to get out some new marks. I've tried putting down the right angle drill/sander and going through the grits hand sanding using abralon. That seems to work a little better then, BAM...some new set of scratches seems to appear. I tried putting a set screw in the chuck and reverse sanding (only to create a whole new set of scratches going a different direction!:eek:). For the sake of my sanity I'm walking away from the power tools. I am a frugal sort and sometimes I try to extend the life of my sandpaper long after it's "given up the ghost...dust? After dinner I'm going back out and will only use new, clean paper. Any suggestions might stop this bowl from becoming a frisbee!:confused:

Don't start with too small particle sandpaper, the first paper you choose is the most important one in removing all the tool marks and any rough grain, all the sandpapers after that have only to remove the sandpaper scratches from the previous paper.

Good sharp tools and cutting makes for less sanding and less rough spots, though sometimes we can't avoid them, and it is pretty hard and time and sandpaper consuming to take the amount of wood all around the bowl down for just a small rough spot.

I normally sand powered with the lathe running very slowly, and the drill with the sanding pad also slowly, it just works better in most cases, there's less heat and work hardening and/or heat-cracks, sandpaper last longer as well.

And yes good and sharp sandpaper makes all the difference in the world, I think we all tend to keep using paper that doesn't cut well anymore, and than create the problems I was referring too.

On a stubborn spot I will stop the lathe and power sand the spot, very good lighting is also important, so you can see if all the spots and scratches are gone

[David E Keller]

Lots of good advice so far. I powersand with the lathe on a slow speed and keep the pads moving with a light touch. I hand sand with the grain with the lathe off between grits. I blow the piece off with the air compressor between grits when I remember to. Sometimes I'll sand with my finish(usually tung oil) with the final grit(usually 500 for me).

One thing I didn't see mentioned are compression marks... Usually concentric rings caused by the bevel rubbing too hard. I see them most often at the transition from side to bottom on the inside of a bowl. I wouldn't say that they can't be sanded out, but I think they can be cut out much more easily. YMMV.

[Cheryl A. Prince]

Thanks everyone for your great insights! I'll head out to the shop later on and try some of the many suggestions I've received. I think my biggest problems are sanding with the lathe running too fast and not cleaning off the previous grit before moving up. I'll give it a go and post a picture of the final piece for critique. Thanks again everyone!:p

[Nathan Hawkes]

Don't start with too small particle sandpaper, the first paper you choose is the most important one in removing all the tool marks and any rough grain, all the sandpapers after that have only to remove the sandpaper scratches from the previous paper
Good sharp tools and cutting makes for less sanding and less rough spots, though sometimes we can't avoid them, and it is pretty hard and time and sandpaper consuming to take the amount of wood all around the bowl down for just a small rough spot.
I normally sand powered with the lathe running very slowly, and the drill with the sanding pad also slowly, it just works better in most cases, there's less heat and work hardening and/or heat-cracks, sandpaper last longer as well.
And yes good and sharp sandpaper makes all the difference in the world, I think we all tend to keep using paper that doesn't cut well anymore, and than create the problems I was referring too.
On a stubborn spot I will stop the lathe and power sand the spot, very good lighting is also important, so you can see if all the spots and scratches are gone


Leo has given great advice here! Too many people start at a fine grit when a coarser grit would do the job much more quickly to remove tool marks. Don't be afraid to get out the coarse paper if you have tearout. I have two moffat lights that help finding compression marks and any grooves left by the tools. I always sand with the lathe stopped, only because my Powermatic won't go slow enough. Anything above the slowest speed---50rpm, is too fast to see where you might need more sanding. I make my own foam mandrels, which catch on the wood less and create less compression problems. Like Leo said, sometimes stopping is the best possible thing you can do when sanding; why sand the whole bowl with 80 or 120 grit when really only the torn spots need a coarse grit--quite often I can get away with 150 in one or two spots, then 220 or 320 for most of a bowl to start. I do take my time with shear cuts to clean up the surface, but for me, its a lot more fun to cut than to sand!!!

I have to disagree with comments made about fine grit sandpaper, but with a couple qualifying remarks. I switched to abranet for above 400 grit sanding, for a couple reasons; the paper I was using was inconsistent, and it clogs too easily. If you have clogged or worn paper, it WILL burnish the surface of the wood, and not do you any help at all. I throw away a lot of paper that "still has life left in it". Sandpaper is cheaper to me than my wasted time and frustration!!!!! If you are careful about how much pressure you use, and always always with a foam backed mandrel, you can sand up to 800 or higher quite effectively. Not every wood needs this, but some, like walnut, do. As already stated, walnut is particularly bad about heat cracking, IMHO.

[Reed Gray]

I think the biggest problem with sanding at high speeds is skipping. The bowl is never perfectly round, and you will hit the high spots, and skip over the low spots. If you have 'spots' that show the scratches, and they are on opposite sides of the bowl, like tear out, than that is the problem. For some reason, cutting with tools works better at higher speeds, but cutting with sand paper doesn't. If you want your sand paper to cut, you need fresh paper. As far as I know, there is no way to sharpen your abrasives. I power sand at slow drill speeds, and slow lathe speeds. Some abrasive discs are good for the outside of a bigger bowl (14 inch range), and some will last for a couple of bowls. Depends on the abrasive.

robo hippy