• It's time to cast your vote in the January 2025 Turning Challenge. (click here for details)
  • Conversations are now Direct Messages (click here for details)
  • Congratulations to Alan Weinberg for "Elm Burl Bowl" being selected as Turning of the Week for January 27, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Safe sanding a hollow form

Emiliano Achaval

Emiliano Achaval

Administrator
Staff member
Beta Tester
TOTW Team
Joined
Dec 14, 2015
Messages
3,346
Likes
4,414
Location
Maui, Hawaii
Website
hawaiiankoaturner.com
I'm writing an article. All I can say for now is, it's a hollow form, with a maybe 2 to 2 1/2 in opening. It might not be safe, but, I usually just sand as far as my fingers will go in, carefully.. So far, I never broke a finger...
For the article, I have to do some sanding in a 100% safe and responsible manner, like a serious adult would... This hollow form is going to have a shoulder... Even an undercut... What's a good and SAFE sanding gizmo to do this... I have heard of people using surgical clippers, bending them and holding the sand paper with them... I have use your average stick with a velcro ball, a stick with just velcro... Have to admit, always feels dicey sticking your fingers in there. What do you guys use? Thanks in advance... Aloha
 
I use large hemostats. I have a couple, one straight and one curved. Never never put your fingers in the handles. If you are going to do very much sanding of this kind of form it would make more sense to make one of the homemade jigs that uses a sort of ball with Velco attached. There have been several articles or tips over the years in American Woodturner. Doing closed forms you need some sort of sander. Sticking your hand in is not wise. Some people have even made the jigs I mentioned above so they fit on drill extensions. One even put a piece of copper pipe over the drill extension so you could use 2 hands (one with a glove on the copper of course) to help you control the sanding. Of course if your really serious go this route. I''ve been drooling over one of these for years to speed up the sanding of my carving.
https://www.amazon.com/King-Arthurs...=1521196994&sr=8-2&keywords=guinevere+sanding
 
I have been drooling over that amazing tool for years too! Do you think a large hemostat without my fingers in the handles will Be a safe practice? Or would it be better a stick with velcro? Thanks for the help John.
 
Last edited:
I sometimes use a home made flap wheel. Buy a cutoff wheel mandrel and cut several strips of sandpaper about one in wide by 4 or 5 inches. Then cut a hole in the center of the paper the size of the screw and randomly arrange the paper on the mandrel. The mandrel are cheap enough that you can have a few different grits set up.

73E5D46B-EBCD-462A-B175-85CB37C0D4E0.jpeg 2C6EE823-ECA3-4EFC-8D26-6A0F04FFF359.jpeg
 
hockenbery said:
You might give equal time to the the idea that the inside of a hollow form needs no sanding.
Many folks don’t sand inside at all.
I just use a scraper to smooth the inside walls.
Click to expand...
That's why people use collars, keeps the fingers out.
Using a wider scraper with a light touch can get the ridges smooth enough. A little black gesso goes a long way.....
 
Emiliano Achaval said:
Thank you Guy. Good idea! Is that cloth backed Sandpaper? Not sure what brand available in the US has cloth...
Click to expand...

It is klingspor paper, and it is excellent. I don't know what specific type it is or what name they use for it. I actually buy it by the pound at their local store here in NC. They have a big bin of scraps you can dig through to find the grits and sizes you want. I think they sell a bargain box of this type of paper, but I couldn't find it on their website. I would recommend you call the Hickory, NC store if you are interested in it. www.woodworkingshop.com
 
Years ago I used the 3M sanding blocks glued onto a wood stick to get inside a vessel. They now make Scotch Brite Polishing Scuff Balls in different grits that can be mounted onto a drill. You can use an extension on your power tool and extend the scuff ball into the vessel. Depending on the extension you can make a handle that slides over the shaft of the extension so you have something to hang onto while sanding the inside of the vessel. You can also use these scuff balls mounted on the end of a shaft and just use the rotation of the vessel to do the sanding with and not use a power tool.
 
When I was a beginner I dislocated a finger while sanding the underside of the interior of a shallow calabash bowl. In an instant my finger was twisted around and was suddenly pointing backwards. The pain really started after I was home from the ER and the local anesthesia started to wear off. I learned from the occupational therapist that hand injuries are the slowest to heal and there is always some residual effect. That turned out to be very true in my case. It took about a year for the injury to heal and even now, fourteen years later, there is still some residual limited range of motion in that finger.

There's a lesson or two to be learned from my experience.
  • I'm not exempt from following safe practices
  • Being nominated for a Darwin Award doesn't have the same status as being nominated for an Oscar.
  • Give somebody else a chance to be the poster child of why you shouldn't do something dumb.
  • Being inconvenienced lasts just a little while ... Regret is forever.
 
hockenbery said:
You might give equal time to the the idea that the inside of a hollow form needs no sanding.
Many folks don’t sand inside at all.
I just use a scraper to smooth the inside walls.
Click to expand...
I have turn my mini scraper that goes on the boring bar into a mini NRS. I finish a Koa urn today, the NRS did a great job on the inside... I'm thinking just have to do one picture, one safe way of sanding the inside, thats all...
 
Guy Scronce said:
It is klingspor paper, and it is excellent. I don't know what specific type it is or what name they use for it. I actually buy it by the pound at their local store here in NC. They have a big bin of scraps you can dig through to find the grits and sizes you want. I think they sell a bargain box of this type of paper, but I couldn't find it on their website. I would recommend you call the Hickory, NC store if you are interested in it. www.woodworkingshop.com
Click to expand...
Thank you Guy!
 
Mike Johnson said:
Years ago I used the 3M sanding blocks glued onto a wood stick to get inside a vessel. They now make Scotch Brite Polishing Scuff Balls in different grits that can be mounted onto a drill. You can use an extension on your power tool and extend the scuff ball into the vessel. Depending on the extension you can make a handle that slides over the shaft of the extension so you have something to hang onto while sanding the inside of the vessel. You can also use these scuff balls mounted on the end of a shaft and just use the rotation of the vessel to do the sanding with and not use a power tool.
Click to expand...
I like this idea! Thank you...
 
Bill Boehme said:
When I was a beginner I dislocated a finger while sanding the underside of the interior of a shallow calabash bowl. In an instant my finger was twisted around and pointing backwards. The pain really started after I was home from the ER and the local anesthesia started to wear off. I learned from the occupational therapist that hand injuries are the slowest to heal and there is always some residual effect. That turned out to be very true in my case. It took about a year for the injury to heal and even now, fourteen years later, there is still some residual limited range of motion in that finger.

There's a lesson or two to be learned from my experience.
  • I wasn't exempt from following safe practices
  • Being nominated for a Darwin Award doesn't have the same status as being nominated for an Oscar.
  • Give somebody else a chance to be the poster child of why you shouldn't do something dumb.
  • Being inconvenienced lasts just a little while ... Regret is forever.
Click to expand...
We try very hard to do things the right way, a lot beginners read it, can't show unsafe practices... I have been lucky with the lathe, no so much with the bandsaw, almost lost a finger years ago...
Doesn't look like there is one predominant way of sanding the inside of a hollow form, only consensus about do not stick your fingers inside. I will make something with an angle that will hold either a scotch write ball or some sandpaper... Thanks for the help.
 
Last edited:
Years ago Thesandingglove came out with a glove that has velcro on the fingers. The thought was that you can stick the velcro backed sandpaper on the fingers and sand without having to grip the paper. Works great however the urge is there to sand the inside of bowls and vessels while it's spinning. Not a good idea. It is a good to sand carvings with the lathe off however. I think for sanding the inside it's hard to beat a styrafoam ball glue to a stick and velcro stuck on that. Then wrap the sandpaper around it. Simple to build and you can alter the shape if necessary to be able to sand odd shaped vessels.
 
Have you had a look at the Vermec sander made in Australia. It is supposed to work a treat. Or else make ypu own by cutting a Scotch Brite type pad into 2"squares and mounting on some threaded rod to get what they call an "Abrasive Ball" It works well mounted in a drill. I have a couple made this way. saw the idea on the net , can't remember whose idea it was but it works. I used Mirka Miralon sheets to make mine
 
john lucas said:
Years ago Thesandingglove came out with a glove that has velcro on the fingers. The thought was that you can stick the velcro backed sandpaper on the fingers and sand without having to grip the paper. Works great however the urge is there to sand the inside of bowls and vessels while it's spinning. Not a good idea. It is a good to sand carvings with the lathe off however. I think for sanding the inside it's hard to beat a styrafoam ball glue to a stick and velcro stuck on that. Then wrap the sandpaper around it. Simple to build and you can alter the shape if necessary to be able to sand odd shaped vessels.
Click to expand...
Guilio Marcolongo told me that someone gave him a sanding glove as a joke at the Utah woodturning symposium. The very next year someone that didn't know it was a joke or tought it was a good idea, made them available commercially!! Lol. I like the idea of Styrofoam ball. I need something available to the masses or easy to build, cheap, or both.
 
Richard Hodsdon said:
Have you had a look at the Vermec sander made in Australia. It is supposed to work a treat. Or else make ypu own by cutting a Scotch Brite type pad into 2"squares and mounting on some threaded rod to get what they call an "Abrasive Ball" It works well mounted in a drill. I have a couple made this way. saw the idea on the net , can't remember whose idea it was but it works. I used Mirka Miralon sheets to make mine
Click to expand...
Would you mind taking a picture of your home made one. Thank you for your help. Aloha
 
john lucas said:
Years ago Thesandingglove came out with a glove that has velcro on the fingers. The thought was that you can stick the velcro backed sandpaper on the fingers and sand without having to grip the paper. Works great however the urge is there to sand the inside of bowls and vessels while it's spinning. Not a good idea. It is a good to sand carvings with the lathe off however. I think for sanding the inside it's hard to beat a styrafoam ball glue to a stick and velcro stuck on that. Then wrap the sandpaper around it. Simple to build and you can alter the shape if necessary to be able to sand odd shaped vessels.
Click to expand...

There is a warning printed in BOLD RED letters directly on the sanding glove that tells you not to use the glove with the lathe running, but I'm sure that there are people who prefer to regret making bad decisions.

Emiliano, here is my ball-on-a-stick that I use for sanding the interior of deep hollowforms. You could make balls of various shapes to reach around the corner. The stick on this one is ¾" diameter and 46" long. The ball was made by first wrapping 3M Coban self adhesive bandage around one end of the dowel. Next, I wrap strips of adhesive backed Velcro hook material.. On top of that I applied the yellow 80 grit Velcro backed sanding pad. I used that for a while, but it wasn't nearly as aggressive as I wanted so I cut strips of 80 grit Abranet which has a Velcro like backing that adhered nicely to the sanding pad without the need to do anything to hold it in place. I bought the Abranet in ten foot lengths from @Steve Worcester at TurningWood.com. You can buy a whole roll or he will cut it to whatever length you want.

image.jpeg
 
DSC_5342 copy.jpg DSC_5341 copy.jpg DSC_5340.JPG Emiliano here are some shots of the abrasive balls I made as requested. I cut 50mm squares of the Scotch brite pads forcesd them onto some 6mm threaded rod. I put each 50mm sq at 45 degrees to the previousone and locked them all onto the rod with nat and washer top and bottom. Tighten them down tight and lock the nuts with some Loctite or superglue. Trim the edges to get the shape you want and you are good to go.
 
Gemtex makes various grit Scotchbrite type sanding and polishing balls used for various industrial uses.
There are several types listed on Ebay right now for a box of 5 for $12.00 in several different sizes.
 
Pete Blair said:
Emiliano here is a link to the safest way to sand the inside of a hollow form but I do agree that there is no need to sand the inside unless of course you are trying to impress other wood turners which I have personally given up on.

https://woodbowlsandthings.wordpress.com/2014/06/16/sanding-the-insi…of-a-hollow-form/
Click to expand...

Great idea. When we made small parts like knobs, etc on my automatic lathe we sanded them in a rock tumbler barrel. I made a wooden barrel identical to the standard rubber lined metal barrel. Small irregular pieces of wood had sand paper glued all over them and the insides of the barrel were also lined with sand paper. The parts were tumbled for an hour or so with the abrasive and came out well sanded.

The rock tumbler rotates much slower than the lowest speed on most lathes, maybe 30 to 60 rpm at a guess. It'd take some clever arrangement to slow the lathe down enough otherwise the parts and abrasive blocks won't "tumble" like necessary to accomplish the sanding action. Of course you'd have to plug the hollow form's top opening.

Another odd thing we did with the rock tumbler was applying finishes to parts. We used the standard metal barrel with the rubber liner removed. The sanded parts were put in the open ended barrel. Start the barrel rotating, pour the finish material into the barrel. We used a relatively quick drying lacquer based finish, either colored or clear (a local paint making company formulated the finish material, I don't recall if they slowed down or accelerated the drying time).. The magic is ALL the paint finish ends up on the parts with only the very slightest trace left in the barrel's inside corners, not enough left in the barrel to need bothering to clean the barrel between color changes.. After the part's finish was thoroughly dry some were tumbled in another metal barrel with chunks of hard carnuba wax to put a shine on.
 
Bill Boehme said:
There is a warning printed in BOLD RED letters directly on the sanding glove that tells you not to use the glove with the lathe running, but I'm sure that there are people who prefer to regret making bad decisions.

Emiliano, here is my ball-on-a-stick that I use for sanding the interior of deep hollowforms. You could make balls of various shapes to reach around the corner. The stick on this one is ¾" diameter and 46" long. The ball was made by first wrapping 3M Coban self adhesive bandage around one end of the dowel. Next, I wrap strips of adhesive backed Velcro hook material.. On top of that I applied the yellow 80 grit Velcro backed sanding pad. I used that for a while, but it wasn't nearly as aggressive as I wanted so I cut strips of 80 grit Abranet which has a Velcro like backing that adhered nicely to the sanding pad without the need to do anything to hold it in place. I bought the Abranet in ten foot lengths from @Steve Worcester at TurningWood.com. You can buy a whole roll or he will cut it to whatever length you want.

View attachment 24842
Click to expand...
Now we talking !!! That sure looks like an Argentinian solution to me a John! Thanks!
 
Doug Rasmussen said:
Great idea. When we made small parts like knobs, etc on my automatic lathe we sanded them in a rock tumbler barrel. I made a wooden barrel identical to the standard rubber lined metal barrel. Small irregular pieces of wood had sand paper glued all over them and the insides of the barrel were also lined with sand paper. The parts were tumbled for an hour or so with the abrasive and came out well sanded.

The rock tumbler rotates much slower than the lowest speed on most lathes, maybe 30 to 60 rpm at a guess. It'd take some clever arrangement to slow the lathe down enough otherwise the parts and abrasive blocks won't "tumble" like necessary to accomplish the sanding action. Of course you'd have to plug the hollow form's top opening.

Another odd thing we did with the rock tumbler was applying finishes to parts. We used the standard metal barrel with the rubber liner removed. The sanded parts were put in the open ended barrel. Start the barrel rotating, pour the finish material into the barrel. We used a relatively quick drying lacquer based finish, either colored or clear (a local paint making company formulated the finish material, I don't recall if they slowed down or accelerated the drying time).. The magic is ALL the paint finish ends up on the parts with only the very slightest trace left in the barrel's inside corners, not enough left in the barrel to need bothering to clean the barrel between color changes.. After the part's finish was thoroughly dry some were tumbled in another metal barrel with chunks of hard carnuba wax to put a shine on.
Click to expand...
Thank you Doug!
 
Richard Hodsdon said:
View attachment 24844 View attachment 24845 View attachment 24846 Emiliano here are some shots of the abrasive balls I made as requested. I cut 50mm squares of the Scotch brite pads forcesd them onto some 6mm threaded rod. I put each 50mm sq at 45 degrees to the previousone and locked them all onto the rod with nat and washer top and bottom. Tighten them down tight and lock the nuts with some Loctite or superglue. Trim the edges to get the shape you want and you are good to go.
Click to expand...
Another great , simple solution. I actually can buy those locally, cut them and make one for the picture! A little more professional looking that my second option... How about a longer screw, then bending it a little to catch the shoulder? Too much torque? Thank you again!
 
I was going to mention abrasive balls...they can go from 60 grit to 320 and even higher

https://www.ptreeusa.com/images/10933_scuff_ball_green_300.jpg
10933_scuff_ball_green_300.jpg
 
Mike Johnson said:
Gemtex makes various grit Scotchbrite type sanding and polishing balls used for various industrial uses.
There are several types listed on Ebay right now for a box of 5 for $12.00 in several different sizes.
Click to expand...
Simply amazing! SO many great ideas!! This one is great!! Big thank you! Aloha
 
Emiliano Achaval said:
Excellent choice. They are not cheap, how do they hold up? Do they last? Thank you, Aloha
Click to expand...
Emiliano, they do hold up pretty well. I have used them a few times, and have them available when needed, but to be honest, I have learned to use the Hunter cupped carbide tools on the inside of hollow forms in a shear scraping angle, and a few passes makes all the ridges from the hollowing bits go away, and leaves a surface comparable to perhaps 180, maybe 220 on some woods. For me, that is more than adequate for inside hollow forms. I know David Ellsworth leaves the ridges from the tool bits inside his hollow forms! ;)
 
I think Richard is onto the right track, as another member stated those are available from 3M in different grits of Scotchbrite--I have used one on a flexible extension to get deep into a couple vases that I did--another DIY idea is to use an appropriate sized soft rubber ball with velcro strips adhered to it, and mount it onto a piece of flexible rod of some type--perhaps this: https://www.amazon.com/DR-Machinist...s&keywords=flexible+drill+bit+extension&psc=1 and this looks like another option: https://www.amazon.com/Whitelotous-...=flexible+drill+bit+extension#customerReviews I ran across a lot of options with an Amazon search....this is one of the scotchbrite balls I mentioned: https://www.amazon.com/inch-Scuff-B...=1521759412&sr=8-6&keywords=flap+wheels+balls
and another one: https://www.amazon.com/inch-Scuff-B...1521759506&sr=8-31&keywords=flap+wheels+balls
And of course you could put a traditional Flap Wheel on the appropriate extension and sand a lot of things: https://www.amazon.com/Shank-Mounte...21759795&sr=8-52&keywords=flap+wheels+sanding
 
Last edited:
Roger Chandler said:
Emiliano, they do hold up pretty well. I have used them a few times, and have them available when needed, but to be honest, I have learned to use the Hunter cupped carbide tools on the inside of hollow forms in a shear scraping angle, and a few passes makes all the ridges from the hollowing bits go away, and leaves a surface comparable to perhaps 180, maybe 220 on some woods. For me, that is more than adequate for inside hollow forms. I know David Ellsworth leaves the ridges from the tool bits inside his hollow forms! ;)
Click to expand...
I can leave a decent enough surface.. It's tempting not to sand, but I have to make the effort... Thank you for the reply. Aloha
 
Alan Trout demoed his deep hollowing technique at our club last night. He buys round craft wooden balls, drills a hole in the, and glues them to a wooden dowel. He places one on each side of the dowel. He then reshapes the balls to give it softer radius on belt sander and glues foam backed Velcro to the balls. He uses different sizes for different size openings, and sands on the lathe with the lathe turned off. The long dowel gives him leverage.
 
Last edited:
Fadi Zeidan said:
Alan Trout demoed his deep hollowing technique at our club last night. He buys round craft wooden balls, drills a hall in the, and glues them to a wooden dowel. He places one on each side of the dowel. He then reshapes the balls to give it softer radius on belt sander and glues foam backed Velcro to the balls. He uses different sizes for different size openings, and sands on the lathe with the lathe turned off. The long dowel gives him leverage.
Click to expand...
Excellent and very inexpensive idea. Thank you.
 
Derek Lane said:
I did ask this question not too long back on the English AWGB site which is the same as this site but for the UK. There were some ideas on there which may be of little help take a look HERE
I hope this does not break any rules
Click to expand...
I do not think this is against the rules. Thank you for taking the time to post this. Aloha
 
You must log in or register to reply here.
Back
Top