Sanding disk on lathe

In message , Bart V writes

Have you tried Spray mount or similar, the spray used for mounting photographs. From memory there are temporary and permanent versions but from what I remember if has good adhesion against sheer.

Well, you could try something like this:

Please remove splinters before emailing

Why not switch to PSA (Pressure Sensitive Adhesive)

---"sticky-back"disks? They have the adhesive on the backside and it stays there when you remove it. There are also several kinds of temporary fastening systems like Hook-it, etc.

After offering this advice, I note that I still use that old fashioned system with the hard-to-remove adhesive on my 9" disk sander just because I have bunch of the old style disks left. Maybe I will go out to the shop right now and toss out those disks. Then I will probably change disks a lot more often rather than using them when mostly worn out!

Pete Stanaitis

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Bart V wrote:

or you can get 5 faceplates from Bill Noble for $25 + $10 shipping. Make a sanding disk for each one.

i just use a 12" psa disk and a crepe stick to clean the disk. Haven't had to change the paper yet

jc

carrying it one step further, have you guys built some kind of support around this configuration or just talking about a hand held setup?

I have a Jet 1236, and the ways are square. I glued together some

The top just fits a small miter gauge fence I have.

I glued two pieces of 3/4" ply to the bottom into the two dados, after cutting them so they "just" fit the ways of my lathe.

I can 1) screw on the sanding disk (using Bill Noble faceplates) 2) Drop the platform on the lathe 3) push it snug (it doesn't wobble) 4) Add the miter fence

It was a fast project to do, other than waiting for glue to dry. It's easy to put on and take off.

You can buy sanding disks with adhesive already on the back.

My advise though would be to use the best possible abrasive you can find so that they don't need changing often. You need something designed for machine use, probably not something you use for hand sanding.

I have a disk permanently mounted on an old lathe. I use abrasive on some real heavy duty backing. It came off of one of those big wide sanders they use in cabinet shops. It doesn't get a whole lot of use, but it's been years since I changed it. I use the same stuff flat on the bench to hone skew chisels.

Thanks for all the suggestions folks, greatly appreciated. The woods I sand are all hard, hard woods. A lot of it is teak and it's as rough on the paper as it it on the sawblade and chisels... Yes, I do use the crepe stick as well but the sanding paper gets "shiney" after a while. I use the Norton 3X aluminum oxide paper and I found it really does last a lot longer than the standard paper. The normal self-adhesive round paper just don't cut it on the woods I use. They're only small pieces of wood and the final dimensions for them are quite delicate and important so the coursest I can use safely is

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I think if I were to do this on my lathe, I'd find a backer pad for adhesive discs with an arbor, and then mount it in the machine with a jacob's chuck. I do a lot of buffing like that, and it works well- and it would also allow you to mount spindle sander drums in there, if you decided you needed them at some future point.

Hi Bart, I can tell by your web site that you know this, but someone might not. Used fractional hp motors are so easy to come by that to tie up a lathe seems counter productive. Motors for washing machines, furnace blowers, etc are often available for a gifted turning at a shop or free at the curb. A Harbor Freight work arbor with washers and a Jacob's chuck threaded to fit and you're set up.

I enjoyed your site and learned from it. Banjo bridges. Now that's a speciality, you ought to add drumsticks and batons. :)

I'm musing several electron rings outside the nucleus, but I wonder if the wave form & frequency transmitting characteristics of different timbers and of different physical states of the same timber affect turning characterisics. Could a variable frequency & waveform generator and an O-scope tell us something useful about turning blanks that personal experience, asking rcw and common sense doesn't? I doubt it, but wondering on rcw is still tax free ...for now. :)

Turn to Safety, Arch Fortiter

Bart V wrote:

Bart: I do segmented vessels and after gluing up segments, sand each ring to within a few thousandths of an inch (or the rings don't stack well in the vertical glue up). I have a 24" disc made up of double thickness of

As most of the rings I sand are Koa, I tent to use coarser grits on mine (150 grit is a real chore, it's on the lathe right now, while I wait for delivery of new discs from Supergrit). I usually use their blue zirconia discs because they last a really long time compared to any other aluminum oxide (AO) discs. Other manufacturers and distributors also sell similar products, but Supergrits seems to be one of the relatively few that ship USPS priority mail automatically to Hawaii, which helps keep the costs down for me (UPS ground to here is typically as much as "second day air" which really takes three or four days, and Prioiry mail is a small fraction of the cost and gets here reliably in 4 to 5 days.) Of course, once you burn a hunk of wood on an AO disc, it glazes over the grit and even the crepe stick doesn't help much, because it can't break the bond between the grit and the burned wood... When I changed from AO to blue zirconia, I at least tripled the life of the discs I use (for the same grit sizes). I just changed out the 80 grit disc (to the only spare I had, a 150) after over 6 months of service. Previously, an 80 grit disc only got me through 1 or at most 2 months before it was just not worth the time. Given that a 24" blue disc is aroung $20 and an AO disc is still nearly $15, it's easy to see the blue discs are worth the extra bucks for me. I don't know if it's just a feeling, but I really think they cut faster too, but haven't done a real side by side comparison to check. I use the same blue zirconia on my belt sanders too, and they really cut well. If you really need to hog off a lot of wood, a 24 or 36 grit belt will rip it off in no time. If you ever use anything this coarse, make sure you keep fingers away, these grits can sand through a fingernail before you even know you touched the belt!

A couple of tips: TO prevent loading, you can spray the (new) disk with a little "Pam" (anti-fat frypan coating that replaces oil or butter). I spray the disk, then "daub" it with a cotton shop towel to soak up the excess. Got this tip from a sandpaper manufacturer, and it seemes to help, particulary on the nastier woods.

In a pinch, if you have glazed the disc and just can't replace it right now, you can sort of "scrape" the crap off by sanding a hunk of mild steel. It tends to break down some of the grit as well, so an 80 grit disc cuts slower, sort of like a 150 grit disc. Not a wonderful thing to do all of the time, but in a pinch, it can keep you working. Don't think you can turn an 80 grit disc into a 150 grit by doing this, the grains are still pretty big, but it really slows down the "cutting action" so it sands much slower, like a 150 grit disc... It will also load up faster the second time, but if you just gotta get it done tonight and don't have replacement disc on hand, it still beats hand sanding.

To glue the discs on, you can either purchase them with "peel and stick" adhesive already on them (it looks like double stick tape, but it's really wide...) or use some sort of cement. When I worked in a body shop, we used a sanding disc adhesive that remained tacky and didn't set up as much as typical contact cement, but I haven't found any of it for years. Now, I typically use 3M #77 adhesive (comes in a black spray can, there's a high strength version as well but not needed for sanding discs.) Spray it on each part and spread it out with your finger, then wait for it to dry and apply the disc like you are using contact cement.

Don't use paper backed sanding discs, unless you're using 5" or smaller, use good cloth backed discs instead. They last forever in comparison to paper backing, even heavy paper backing. If you have difficulty getting the old disc off, you can use a propane torch or heat gun to warm up the disc (and the underlying cement) and it will peel off a lot easier. With paper backed discs, they tend to turn nearly black and bubble up, but the cloth backed discs tend to stay a little more intact when applying heat. Of course, you're not going to be able to re-mount the disc after this treatment... If you want to remount to change discs, you probably want hook-n-loop discs anyway.

If your parts are all small enough to use 5" discs, just use the standard psa (pressure sensitive adhesive) discs and a hard backer like MDF on a faceplate. A couple of coats of lacquer or shellac to seal the MDF, and the discs will stick just fine. You can use the torch/heat gun trick to get the discs off if you wait too long before changing them. Even buying good quality 5" discs at 150 grit in 100pc box/roll won't set you back too much. If you do use paper backed discs, buy them from one of the suppliers already pre-cut, instead of cutting them from hardware store AO paper sheets. The hardware store stuff just isn't the same quality, and they shed grit pretty fast.

Also, you may wish to look at using stearated discs. (they have a sort of soapy coating applied during manufacture and don't load up as fast)

At 150 grit, most of the paper you're getting is probably closed coat, which definitely loads up faster than open coat, which has the same sized grains, just farther apart. Though it looks like it is "cheap" because there appears to be less grit on the sheet, in a quality paper, it will actually last longer because it doesn't glaze as quickly.

Good Luck

--Rick