Tips and techniques to more effective sanding of 16" bowls

[Breck Whitworth]

I have been doing production rough turning of a lot of large nesting bowl sets, with the largest bowl mostly 16" the next 13" then 10" respectively. I have always used an angle drill with H&L sanding discs and intend to continue the practice in the finishing of all these bowls when dry. What I would like from those of you who have done similiar large sanding jobs, is any tips, or techniques that you found to make the job more effective or easier. I have found that there is usually someone who knows something I don't or a tip they found to make a job easier or more effective. I have 2" disc's and 3" disc's but any tips or methods gained from experience will be appreciated greatly.

[Bob Bergstrom]

When I turn larger bowls, I use a 3/8 Millwaukee drill that runs at 2600 rpms. My close quarters drill is more than a thousand resolutions per minute slower.

[Malcolm Tibbetts]

Breck, if you are doing a lot of large bowls, you should seriously consider stepping up to 5" sanding pads.

[Prashun Patel]

The best tip I ever got was learning to finish turn better so you can skip the tedium of sanding at 80.

I also switched to sanding the outside with a 5" ros and a soft backing pad.

[Bernie Weishapl]

I just use 3" disc on my big bowls. As you start getting to higher grits slow the lathe down and if you have a variable speed drill slow it down also. At 320, 400 and 600 grit my lathe is down to 200 rpm and my drill at half speed or less. I had a long talk with Vince at VincesWoodNWonders. He gave me a lot of good info.

[Kyle Iwamoto]

Breck, if you are doing a lot of large bowls, you should seriously consider stepping up to 5" sanding pads.

+1. It may not be "better" but I think it's a whole lot faster. You can still use the smaller H&L for the higher grits.

Since I'm really cheap, I use the PSA discs. Since the inside bowl sanding uses only the edges of the disc, I take it off, fold it in half, now I have a really stiff hand sanding disc. Now you can use the center of the disc which is still relatively fresh. And you don't need to buy more paper since you already will have all the grits......

If you use the PSA, I don't reccomend leaving it on the pad and using it until it doesn't cut anymore. If you do that, the glue REALY sticks the disc on the pad, and you'll have to waste a lot of time scraping the disc off the pad. I have a pad for all the grits I use. Took me a day to get the pads clean....

Since I suck at turning, I have to be a pro at sanding.

Did I mention I'm cheap?

[Mike Cruz]

Breck, I use an angle sander and hook and loop disks. First and foremost, make sure you don't over use the discs...as with any sanding.

Second, I sand on the lathe with the lathe running at about 500 rpm.

Thirdly, sand with the direction of your sander spinning in the opposite direction of the spinning wood. Otherwise, your grit is basically following the wood. You may have to change the direction (forward and reverse) of your angle sander for different areas on the bowl.

Fourth, unless you are "shaping" with your sander, try not to sand against (sideways or crossways) the grain.

Fifth, blow the dust off the bowl after each grit.

Sixth, save yourself some time by stopping the lathe after sanding and blowing it off after each grit to make sure you aren't missing sanding or tool marks. Otherwise, you'll get down to 600 grit, turn off the lathe, see marks, and have to start all over again.

[Harry Robinette]

Breck
Check out Bill Neddow Woodturner. Bill sands with a 4" angle grinder a router speed control and a adapter that is on his web site also. I've been using this system for awhile on all my big bowls say from 13" to 24" and it works great. I made the adapters and can use 2"3"5" disc I can sand about 4 times faster.

[Nathan Hawkes]

Hi Breck. I'm a semi-production oriented turner, and make a decent amount of my living from turning. I turn green however, and end up with warped bowls; some a little, some a lot. I use a high-speed drill, 2400-2800rpm depending on which one I'm using; I have a Makita, Sioux, and Hitachi that are all around the same rpm. For my style of turning, I prefer a higher speed drill and a very light touch, with very soft 1" thick foam backed pads that I make myself. I use Vince's pink discs which are 3 1/2". I've been seriously considering making a few mandrels for PSA 5" discs for my larger bowls, just to stay efficient. Big discs won't fit inside a smaller bowl, so I've been using smaller discs. PSA is cheaper, I believe.

My system consists of a 1/4" x 20 tpi bolt, from which I remove the bolt head with a small cutoff wheel. Using a threaded insert mounted into a disc of MDF, I then glue soft foam to the MDF, and attach velcro hook material. A quick trim at speed with a utility knife and voila, I have a bunch of shop-made mandrels, one for each grit which are easily removed and replaced with the next higher or lower grit as necessary. This way, with average sized bowls anyway, I may get two bowls worth of sanding from some grits. (some bowls require more than one disc of a given grit depending on how dry I've let the bowl get, what type of wood, etc.) Starting with whatever grit you deem necessary to remove tool marks or tearout, I go to a minimum of 400, or as high as 800 with black walnut. The soft back doesn't dig in and leave more marks, so I can afford to use it on a higher speed drill. The same can NOT be said for other mandrels, which dont' work well at higher speeds IME.

Your methods may vary!~ In other words, try what you will, and stick with what works for you! Happy turning~!

[Thomas Canfield]

You can use a 1/4" drill bit extension from Ace Hardware or similar and a piece of 1/2" PVC for sleeve to give extension to the 1/4" mount for the sanding pads. I also agree with the use of 5" ROS for exterior work. I wish that there was an electric ROS that would work on the inside. There was a 3" Metabo ROS suggested to be used with soft pad mount as a possible use inside, but the handle gives me some concern.

I strongly recommend getting a 12" buffing adapter from Don Pencil to use to buff the interior of the larger bowls and hollow form, and buffing with Tripoli.

[neil mackay]

Well I use all the above with power sanding and also use inertia or self powered sanders [random orbital type] Of these I have about five 4 DIY all work just fine, although you will need to run the lathe quickly in order to get revs out of the sander.

[Bill Hensley]

What Malcolm said, 5" RO sander.

[Michelle Rich]

I start on large items with an angle grinder with sanding pads..it is faster than lightening..