Tools for sanding inside bowls

[Terry Jay]

So what tools are effective for sanding bowls, especially the inside? The Random Orbit sander works well on the outside to maintain a consistent profile. Most of the spindle sanders are too short to work on the inside, unless you look at the Jet or Grizzly 9" spindles. They are over 300lbs and $750. Is there a 9" or so drum for a drill press? Any ideas? Seyco has foam backed drums which work well for a lot of things but not for a consistent internal profile. King Aurthur has pneumatic drums in long and short but leave you guessing as to what that means. On smaller bowls a 3" drum is to big for the bottom opening, so a smaller drum would be needed, and also for the oval and scalloped bowls.
Terry

[handibunny]

Terry,

Check out the video on making a basic bowl. You can access it from the video link on the sidebar. That should give you some ideas. Also, check out my blog for posts dealing with sanding.

For bowls with scallops, I use the King Arthur round inflatable sander for the inside, and a 2" pad sander for the outside, each chucked into the drill press. The drums are not suitable for insides because they are not rounded on the bottom and can gouge.

For straight sided round bowls, a vertical belt sander works quickly, but you may risk sanding away too much wood on your gluing edges.

Hope this helps.

[Terry Jay]

Thanks, Carole.

I looked at the videos, painful as it plays a few seconds and loads and plays and loads. Those are some wonderful tools in that shop, but I don't have them or have access to them. The small spindle sanders are nice as long as there are only 3 rings. I'm looking for something that will do 5 to 7 rings on the inside and maintain a constant even profile from top to bottom. The obvious answer is the 9" spindle sander. Does anyone make a 9" drum that can be used on a drill press? I have managed to make around 31 bowls so far but I see inside sanding as an area needing a lot of improvement.
Thanks,
Terry

[handibunny]

Terry,

The only long spindles that I've seen are for the larger floor mounted spindle sanders. A 9" drum chucked into a drill press might create forces as it rotated that could loosen the quill and make the drill press imprecise for drilling. I tried an extension once, and it thrust itself right off the drill press and went flying through the room. A day later, the quill and chuck dropped out. Fortunately, the drill press seemed OK, but that was not something to repeat.

Even if you could get a 9" spindle that you could use safely, unless your rings really line up well, it will be difficult to get them perfectly even and still have enough wood left to attach the bottom. Or, if you've already attached the bottom, you might have a problem sanding through the sides of the bowl.

One trick I found useful when doing projects where access to the inside was limited was to glue up the rings in stages. If you glued them up 3 at a time, you might be able to sand them separately and get them to match well enough so when you glued the two sets together there was just a little sanding to do. The only way I can think of to get inside a bowl as deep as the once you're making, unless the bowl has a very large diameter, is to use the round inflatable sander on a flex shaft.

With practice, the round inflatable and the pad sander can get a finish that is almost perfect. If you ever want to do bowls that have curved sides, you'd have to use those anyway.

Might not be a bad idea to post pictures of what you're doing. There are now quite a few folks who do bowls, and they might very well have other suggestions. Good luck!

[Terry Jay]

Thanks, Carole. Nice private conversation we are carrying on here. Smile!!

Never have taken pics of work in progress, oh well. But some of them are translucent on the sides by the time I am done with them. I think the largest was about 13.5" dia and 6 rings high. Millie called it the fruit bowl. Sold several. All are native Alaska Birch, no glue-ups, and most boards are 3/4" to a bit over 1" thick after sanding. Most were made with a compass and now use Dave's Polydraw. The smallest was 3 rings and around 3" in dia. You do works of art, I do things I can sell and use the funds for more tools to do it better. Wish I had access to that community shop you have. I have to transport all the tools up and back, or decide to leave some in Alaska for seasonal use.

Looks like the next step is a KAT pneumatic sanding system and some practice. My drill press is a Shop fox 14" table top oscillating and it is stout. Have a Craftsman floor model in Alaska that I can wrestle outside for dust control and it worked well with the Seyco 9" soft drums, foam rather than pneumatic. The only issue I had was getting the hard spots sanded down to be even with the soft spots. A lot of my boards are lightly to heavily spalted which makes for vast differences in hardness. I really need a 9" drum to profile the interior. And you are absolutely correct about sanding off the bottom glue ring. I even have the T-shirt for that one.

I really like using the ROS with the bowl in one hand and the sander in the other, but it is a strength and grip issue. I can take the outside surface down evenly and do so to as fine as 600 grit. I am struggling with the even inside surface at any grit.

Love your book and inspiration, and really like making bowls and the customers love them as well. Am going to do Alder and Maple this winter, as well as the birch. Just need to solve the inside sanding.
Many thanks,
Terry

[sqrlalrt]

I know I am new to all of this but I made my own sanding ball to use with my little drill press. I epoxyed a cheap racquet ball to a 3" sanding disc holder that has a 1/4" shank. Then I glued velcro dots on the ball.( the hook side of the velcro) I got 5" hook and loop sanding discs and cut them like a pin wheel leaving about 1" on the center of the disc uncut. Center the disc to the bottom of the ball, arrange the wheels to attach to the velcro on the ball, and pop it on the drill press. Works great for me!

[handibunny]

Tammy, the book I referenced in your post describes making sanding balls from sponge rubber balls. That was long before the inflatable sanders hit the scene.

It's very much like what you described, just more elaborate. Congratulations on your ingenuity!