Describe your bowl sanding technique

[Mike Vickery]

I have been getting better but still am not quite where I would like to be on my bowl sanding technique would some of you like to detail your technique includeing grits used, power or no power, use of contour pads, ect.

For background here is what I am currently using. I power sand using a 2 inch hook and loop disk holder in a regular cordless drill. I do not use any of the contour pads and neither the drill or my lathe have a reverse. I run my lathe very slow and the drill slow (no digital readout but it is an electronic variable speed lathe and it is going pretty slow.) I sand useing 80, 100, 150, 220, 320, 400 and 600 grits. If you are faceing the headstock I usually sand on the right of the inside of the bowl (opposite side you cut from). I lightly sand by hand with the grain after power sanding each grit. I am useing DNA on paper towel to clean between grits. When I am done it looks pretty good but I am still getting slight sanding marks on the inside where the bottom transitions to the walls of the bowls. Nothing that is very obvious but I can see them.

I would appreciate either advice on where I am going wrong or your sanding method. Or even better give me both.

Thanks

[Frank Kobilsek]

Mike

Lathe slow - drill fast, it is too bad your drill doesn't reverse because the you want the sand paper rotating against the rotation of the piece and sometimes it helps to reverse the drill/sander.

I don't like the pads either.

Try stopping at 320 with the power sanding and just lighty hand sand with 400. I don't think most woods, especially domestic benefit from power all the way to 600. BUT ... it depends on finish. A walnut plate that I plan to put a flat or low gloss oil on I definate stop a 320 and suspect 240 would have been plenty good.

That corner your talking about. Try a 3" pad instead. It surprized me but it was a little easier. Although I learned that about the same time I learn a bigger radius in that area looks better anyway.

One of the question in the interveiw is: if you won the Irish Lottery, I'd hire a 'sander'.

Frank

[Jim Ketron]

I have posted this a few times so I keep it handy hope it helps!

Sanding is an art in itself! There are many methods of achieving the same result, some turnings take a long time some don't. Some woods sands easily and some take forever to get right. Also a lot depends on what type of finish you are wanting to achieve, and how much time you want to spend on a particular piece. Gallery type of finish or utility type finish? It took me a while to learn how to sand properly and to get a good finish on my work! I was not satisfied with my finishes for a while and got plenty of help from friends and forums but reading and doing are two different things, it takes time to develop your techniques just like turning does.

I'm a Sanding nut I have been known to spend hours sanding on one piece!
I try my best to have no sanding scratches in my work, The way I see it why spend time to cut the wood, cut it into turning blanks, seal it with Anchorseal, rough turn it, let it dry, finish turn it, and then not take the time to give it a proper finish to show off your hard work?

I use the Souix angle drill for power sanding, the 2" and 3" pro Velcro disk holders from Packard Woodworks. I use Rhynogrip hook and loop sandpaper I cut to size, I have these grits 80,120,240,320,400,600, I start on the highest grit that the finished turned piece will allow. I run my lathe around 300 rpm and the drill medium speed to fast and use light pressure with the sanding pad. Remember heat is your enemy while sanding light pressure is best and it will cut faster and wont burnish your tuning from the heat which is not good because it makes the wood hard and will take you longer on the next grit. Everyone has their own ideas about speed and technique but this is how I sand mine. when you pick the starting grit and if it's not cutting fast enough, drop down one grit and start over. I try my best to get all the tool marks and tearout with my first grit. IMO this is where a lot of people make mistakes buy moving up to the next grit before getting them all out this was my main problem while I was developing my sanding technique! If you have tool marks and tearout after the first grit you will either spend lots of time trying to fix them a few grits down, or when you get to your last grit and get it off the lathe and think you are finished and admiring your work and it sticks out like a sore thumb! but some times you will miss one and you can get it with the next grit, but its best to give it a good look over before switching to the next grit. Be sure to wipe the previous sanding dust and grit off good before going to the next grit it leaves the residue from the previous grit and if you don't get it out it will leave sanding scratches.
Have fun sanding
Jim

[Keith Burns]

I can attest to Jim's method. It works. Now if I can just get the most important part, patience, to work for me I might attain the quality of finish that Jim produces.

[Mark Pruitt]

Yep, Jim pretty much said it all. The only thing I could possibly add to his comments is, be sure your lighting is (1) adequate and (2) oriented toward the workpiece so as to reflect any imperfections present.

[Mike Vickery]

Thanks guys.
Frank - By running the drill and the lathe forward and sanding on the right side of the bowl the drill is running opposite to the pieces rotation.
Jim - I agree with everything you said. If fact it is almost exactly what I am doing. Though maybe I just need to use a lighter touch and speed up the drill a little. Would you care to expand on you technique by letting me know what direction you sander and lathe are going and what side of the bowl you are sanding the walls on?

[Richard Madison]

Mike,
Your grit selection is good, and you are sanding in the right place inside the bowl. About 75% of your total sanding is done with the 80 grit to remove tool marks, tear-out, humps and bumps. Suggest just using the shop vac between grits. Something to try- I sometimes alternate between power sanding and hand sanding as follows: power sand with 80 grit at 75-100 rpm, hand sand with 100 at 600-800 rpm and check for scratches, power sand with 120 at 75-100 rpm, and so on. This sometimes helps to see if there are scratches left from the previous grit. I do most of the early (through 150) sanding on the outside by hand (at 600-800 rpm), just cause sheets are cheaper than those little discs. And--- after thorough power sanding with 80 you still have some bad spots, maybe in the endgrain areas; spindle lock and lightly go over those areas til they are cleaned up, being careful not to create serious hollows and lumps.

[Dennis Peacock]

One thing I learned about sanding....sanding to "hard" or heavy-handed will leave some pretty serious sanding scratches that takes a LONG time to get out on the next higher grit.

There are times when I pull up a stool, slow the lathe down and just sit-n-sand for several hours. Shoot, I even sanded on a single bowl for 3 evenings after work.

Jim K. has got ya covered......he's got it all down pat and it shows in the quality of his work.

[Reed Gray]

I feel like I could just about write a book on the subject. One rule that I have is to sand until you think you have all the marks out, and then hit it one more time. There is as big of a learning curve in sanding as there is in turning.

Don't skip a grit. If you start at 80, then you move to 120, then 180, then 220, then 320, 400 and up. I go a bit redundant, and add 100 and 150 grit. Most of the time I am able to start at 120. I have yet to turn a bowl that doesn't need some sanding, but I still keep trying.

I prefer the Sioux/Milwaukee angle drills. They are a bit better at getting all the way into bigger and deeper bowls than the right angle and in line drills, at least if you are working the disc flat rather than up on an edge. The handle doesn't get in the way of the rim of the bowl as much. I like the slow speed models better than the high speed models. There is a cheap ($30) angle drill available. The S/M drills last me about 6 months before the bearings go. Most other people will get a year or three out of them. I tried a Sioux pneumatic drill and it lasted about 4 months before it failed. I have 4 drills, which each have been rebuilt 3 or so times each. I have worn out 2 drill casings. The cheap drill lasted me about a month, and it was the casing that failed. I am very hard on my drills, mostly because I use the 3 inch pads.They are much faster if you can fit them inside of the bowl you are sanding, rather than the 2 inch discs.

I just had 2 drills rebuilt. I have a friend who works at Kaman Bearing, and was asking about the Koyo bearing that some people have recomended. He called an engineer and told him what I was doing to the poor drill, and the engineer recomended other bearings for the rebuild that are supposed to be better than the Koyo. I am now in the process of attempting to wear out these bearings, and will let you know how they last. I am hard on my drills. I do blow them out a couple of times a day if I am sanding a lot.

I have my lathe at almost the slowest speed that it will go (PM3520A). I turn green to final thickness, let them dry and warp, then sand them so even if I wanted, I couldn't sand at higher speeds. I like the warped shapes. High lathe and high drill speeds do not make the process go faster. The sanding discs load up more, glaze over more, burn and crack the wood more, you lose the backing, and both the discs and pads wear out faster.

I prefer the blue sanding discs from VincesWoodNWonders. They are soft and flexable, and cut 3/8 inch over size. This helps to cover all the hooks so there are no marks from them, and there are no marks from the edges of the paper. They also outlast anything else I have tried about 2 to 1. They are priced right also. Do keep one of the crepe/eraser sticks handy and clean the paper often. I like his pads better also. I prefer the softer pads because they conform to the inside of the bowl better than the firm pads. The firm pads work fine on the outside, but I don't want to change back and forth between the pads. I like his soft pad better than the other ones on the market. I would call them medium compared to the others that I always thought were to soft. It is cheaper to replace a pad than it is to replace the whole mandril.

When beginning, I will usually start on the outside. At slow speed, I can get all of the marks out (well most of the time) without having to stop the lathe and work on problem spots. When doing the inside, I may start with the lathe on but almost always have to stop and work on those problem areas which are mostly ridges, and minimal tearout. After I am done with the coarsest grit, I usually don't stop the lathe to work on problem spots because I got them out the first time. I do stop and give a visual inspection at every 2nd or 3rd grit. When I am sanding without the lathe turned on, I often find that I am letting the drill spin the bowl, and letting one hand hold the drill and the other acts as a brake. I do this mostly on the inside. One of the learning steps I took to help see if I was getting all the scratches from the previous grit out was to switch from power to hand sanding. They leave 2 different scratch patterns, straight scratches will show up any circular scratches, or the other way around. I used to switch almost every other grit, then went to changing at 150, and 320. Now I power sand all the way through to 400. I apply oil with a grey synthetic steel wool pad. The method that I use to check for scratches now is to hand rub out the dust between grits when I think I am done with that grit. The finer sandind dust will sit in the scratches from the coarser grit and high light them. Of course you need good light. Again, I do this every 2nd or 3rd grit.

If you are hand sanding you have to reverse sand the bowl, even if you have to turn the bowl by hand, because the fibers will lay down. I haven't noticed the necessity of this at all with the sanding discs. As near as I can tell, especially if you sand with the disc more flat rather than up on an edge, the circular motion of the disc does this (the top of the disc is spinning towards the edge of the bowl, and the bottom of it is spinning away). I don't wet the wood to raise the grain, it doesn't seem to need it.

On my last sanding run, I sanded and finished (Mike Mahoney's oil) 20 bowls in about 8 1/2 to 9 hours (over 2 days). The bowls ranged in size from 5 inches to 16 inches, with the majority being bigger bowls. I seem to spend almost as much time sanding as I do turning, some times more, and sometimes less.

I soak all of my bowls in LDD before drying and sanding. The soap really makes the sanding easier compared to bowls that are just air dried or DNA soaked. If you turn thick, dry, and then return, I don't think this makes a difference.

robo hippy

[Glenn C Roberts]

LDD? Liquid dishwashing detergent? Do you use it straight? How long do you soak them for? Do they just drip dry? Anything else I need to know before I try it? So many questions, so little time. (!)

Glenn

[Justin Stephen]

I sand at 50rpm, the slowest my lathe will go, and with the drill (a Neiko) at medium speed. As far as I am concerned, slower is better and I would sand even slower than 50 if I could. I apply diluted sanding sealer after 220 on most woods and usually stop at 320 or 400 (400 usually by hand). Rather than holding on the same area for a long time to get rid of any potential trouble spots, I'll stop the lathe and get rid of them by slowly rotating the piece by hand. I probably spend more time sanding than a lot of people but 1), I don't dislike it and 2), it is darn critical. I stop often and inspect visually and by running my hands over everything again and again and again.

In my opinion, many a perfectly good piece has been ruined (or at least substantially harmed) by insufficient or poor sanding. There is too much focus on avoiding sanding ("I start at 220, etc., etc.") and not enough on sanding well, especially among turners who don't have thousands of pieces under their belts. In my mind, tools are for shape, sanding is for surface. I certainly try and leave the best surface I can off the tool (and spend a lot of time carefully sheer scraping to do just that), but I stop when the shape is just right and correct small imperfections with sandpaper.

I agree with Reed that there doesn't seem to be much reason to reverse between grits if power sanding. I do anyway out of habit most of the time, but can't really tell the difference if I don't.

[Steve Schlumpf]

I hope everyone realizes that this thread is 10 years old! If you think the topic has something new to offer - then please start a new thread.

[Glen Blanchard]

I realized the age of this thread when I saw Reed's reference to his PM 3520A. LOL.

[Reed Gray]

LDD, Liquid Dishwashing Detergent, 50/50 mix with water, 24 or more hour soak, rinse off surface soap, dry. Since this thread started, all the new lathes turn off at 50 rpm. They can be programmed to go slower, which is necessary for my warped bowls. The soap is a big help in sanding, but really messy, a process I need to refine. Slower drill speed + slow lathe speed = faster cutting.

robo hippy