robutacion
Member
Hi everyone,
Again, this is an issue that I have mention many times at many forums, but never actually taken pics of it, there is, the precise type of sanding disks that I was referring to. While on the subject, I decided to document the rounding process of one of the many very soft blanks that I'm working on at the moment.
The particular blank that is on the lathe, is one of the recently stabilized Golden Wattle blanks and I though that it was already dry (stabilized the day before) but it was not. Apart from messing up my sanding disc a bit with the hardener stuff getting stuck to it, it did prove the point that these discs can cut and shape the softest of woods, including those that are nearly disintegrating close to a total cell separation.
Some of these blanks before hardening, are as soft as the white foam used on packing, rubbing the wood with your fingers would totally "grind"/brake the blank into shreds. I have actually tested rounding this white/light syntactic foam (can't thing of the name of it...!!!), by cutting it on the bandsaw, same size as a normal pen blank, then mount it between centers on the lathe.
Using a normal 4" grinder and these discs (various grits available), you can cut and shape materials that are impossible to cut and shaped on the lathe,with normal gouges, regardless of speed and type of gouge. Any attempt, will simply "rip" chunks and blow the blank material into pieces. These tests were made with a full pen blank material, normal size and with the square corner on it. Material used were, cork, white foam, extremely spalted wood (untreated),cardboard glued together, radiata pine bark, hard and splintery woods, some of the hardest timbers I could find, normal acrylic, plastic, and some of the hardest/treated acrylics used as friction points in lots of machinery and on trucks sliding trays!
There is just no comparison and effectiveness, when these discs are used on turning materials. The most common grits are 40, 60 and 80, there isn't much the 40 grit wouldn't cut/sand, most certainly the one to use when a lot of material needs to come out very quickly, in either soft or hard materials. The other grits work also very well, just a little slower in removing material but with the advantage of leaving behind a smoother surface.
There is nearly no pressure (well, it shouldn't be...!) put into the material being sanded, from the grinder/disc, the discs work effectively with a gentle touch, particularly on soft to very soft materials, reason why it is possible to round and have a smooth finish on a piece of white foam, mounted on the lathe in between centers, there is, with no support inside of it from tubes or anything!
I used only the 40 grit on the wood that I used for the pics, demonstrating what type of surface/finish it leaves behind. Obviously, this grit is very "aggressive" on soft materials, removing lots of stuff in a flash so, sometimes is better to use a higher grit number, if you are not to experienced doing this or you don't want to risk taking more than what you want, before you have time to say, sugar...!
For someone that does a lot of pens and see the advantage of using this sanding process, the best way to set yourself at it is with 3 cheap grinders, one with each grip, plugged and ready to go. A sort of "bracket" can be made near the lathe where these 3 machines are mounted on, easy to reach and swap when needed! In our days, you can find 4" grinders on sale for as low as $25!:biggrin:
The only down side I can see of using these discs is, the bushes in the mandrels are probably going to need replacement more often than using a gouge would, there is off-course, depending of how careful you will be, getting close to the final shape and before the hand sanding process begins.
Don't believe me...??? OK, go and try if for yourself, come back and tell me what you think now!
OK, I'm done here, for now...!:wink:
Make no mistake, I have no association and or business interests, including commission, from any manufacture of grinders and/or sanding discs, my information is based on freedom of speech, free advice and demonstrations on what I come up with...!:biggrin:
Cheers
George
Again, this is an issue that I have mention many times at many forums, but never actually taken pics of it, there is, the precise type of sanding disks that I was referring to. While on the subject, I decided to document the rounding process of one of the many very soft blanks that I'm working on at the moment.
The particular blank that is on the lathe, is one of the recently stabilized Golden Wattle blanks and I though that it was already dry (stabilized the day before) but it was not. Apart from messing up my sanding disc a bit with the hardener stuff getting stuck to it, it did prove the point that these discs can cut and shape the softest of woods, including those that are nearly disintegrating close to a total cell separation.
Some of these blanks before hardening, are as soft as the white foam used on packing, rubbing the wood with your fingers would totally "grind"/brake the blank into shreds. I have actually tested rounding this white/light syntactic foam (can't thing of the name of it...!!!), by cutting it on the bandsaw, same size as a normal pen blank, then mount it between centers on the lathe.
Using a normal 4" grinder and these discs (various grits available), you can cut and shape materials that are impossible to cut and shaped on the lathe,with normal gouges, regardless of speed and type of gouge. Any attempt, will simply "rip" chunks and blow the blank material into pieces. These tests were made with a full pen blank material, normal size and with the square corner on it. Material used were, cork, white foam, extremely spalted wood (untreated),cardboard glued together, radiata pine bark, hard and splintery woods, some of the hardest timbers I could find, normal acrylic, plastic, and some of the hardest/treated acrylics used as friction points in lots of machinery and on trucks sliding trays!
There is just no comparison and effectiveness, when these discs are used on turning materials. The most common grits are 40, 60 and 80, there isn't much the 40 grit wouldn't cut/sand, most certainly the one to use when a lot of material needs to come out very quickly, in either soft or hard materials. The other grits work also very well, just a little slower in removing material but with the advantage of leaving behind a smoother surface.
There is nearly no pressure (well, it shouldn't be...!) put into the material being sanded, from the grinder/disc, the discs work effectively with a gentle touch, particularly on soft to very soft materials, reason why it is possible to round and have a smooth finish on a piece of white foam, mounted on the lathe in between centers, there is, with no support inside of it from tubes or anything!
I used only the 40 grit on the wood that I used for the pics, demonstrating what type of surface/finish it leaves behind. Obviously, this grit is very "aggressive" on soft materials, removing lots of stuff in a flash so, sometimes is better to use a higher grit number, if you are not to experienced doing this or you don't want to risk taking more than what you want, before you have time to say, sugar...!
For someone that does a lot of pens and see the advantage of using this sanding process, the best way to set yourself at it is with 3 cheap grinders, one with each grip, plugged and ready to go. A sort of "bracket" can be made near the lathe where these 3 machines are mounted on, easy to reach and swap when needed! In our days, you can find 4" grinders on sale for as low as $25!:biggrin:
The only down side I can see of using these discs is, the bushes in the mandrels are probably going to need replacement more often than using a gouge would, there is off-course, depending of how careful you will be, getting close to the final shape and before the hand sanding process begins.
Don't believe me...??? OK, go and try if for yourself, come back and tell me what you think now!
OK, I'm done here, for now...!:wink:
Make no mistake, I have no association and or business interests, including commission, from any manufacture of grinders and/or sanding discs, my information is based on freedom of speech, free advice and demonstrations on what I come up with...!
:biggrin: Cheers
George
Attachments
Last edited: