Jet 12" Disc sander problem

[llucas]

A while back i got a 12" Jet disc sander and picked up some 12" replacement discs at Woodcraft for future changes.
The original disc worked great, but I am having a problem with the replacements staying stuck flat on the metal disc.
I have cleaned the bejugies out of the disc surface and had no trouble getting the new disc centered and plastered flat. But the outer 3/4" or so keeps buckling up. I have burnished the disc back flat by running some oak against the spinning disc to the point of heating it up in hopes it would activate the adhesive better....it stays flat for a few hours and then re-buckles...I have even used a heat gun to try make it stick better...no dice.
I am on my third replacement disc with the same problem.
I am hoping I just have just some bad discs.

Anyone have any ideas for more successful adhesion?....Where do you get your discs?

 

[Michael Mathews]

I'd get some spray adhesive like Super 77 or equal and use the "temporary" bond technique. Of course if you were to use the permanent bond, I believe a heat gun will still soften the adhesive well enough to remove the old disc.

 

[Tarhead]

How old are the discs? I've gotten all of mine at Klingspor.

 

[Charlie]

I'm having the same problem with 20" from Klingspor. I even had one fall off overnight.

 

[llucas]

Charlie,
How do you usually stick the sanding disc to the metal wheel? Is the peel and stick adhesive usually good enough? Is there a prep regimen for the wheel prior to putting on a new disc?
I figure with as much sanding you do, you would have the process down pat.

 

[BKHam]

i had the same problem with a disc over the winter. i have a garage shop. during the coldest snap of the year the disc came off. that is the first time i've had it happen. since that disc has not stayed on. i'm hoping that when i add a new one it will not be so annoying. i've tried spray adhesive to augment the sitcky back and it hasn't helped. i thought about adding some pieces of double stick tape but haven't tried yet.

its really annoying.

 

[Charlie]

Luke, Fortunately the old discs peel off leaving very little adhesive on the plate. I remove the remaining adhesive with lacquer thinner.
The adhesive on the new discs is not adequate, especially around the edges.
I had one disc that wouldn't stick at all. I ended up covering the whole plate with double sided turners tape. Very time consuming and expensive, but at $20 a disc, (and the last one on hand), I had no choice.
There always is an area around the edge that delaminates over time. I have even clamped those areas overnight and they still lift.
I have only used Klingspor discs because if you order by mail I'm sure they will arrive rolled up and that loosens the protective plastic layer on the adhesive.
Fortunately I only change discs every few months.
I think on the next one I will put turners tape around the edge.

 

[Jeff]

I'm a casual observer who doesn't have a 12" disc sander but I'm curious nonetheless.

The original disc worked great, but I am having a problem with the replacements staying stuck flat on the metal disc.

Sounds like a common problem for many disc sander users and the 3/4"-1" perimeter edges buckle and peel back. Even with that, is it a show stopper when sanding right out to the very edge of the disc when there is still 10" of flat surface to work with? Maybe the Klingspor replacement discs use a different adhesive than the OEM discs? :eusa_thin

 

[llucas]

Charlie
Thanks for your feedback...I guess this is a common problem for which I was hoping for a reliable solution...I'm still searching for something other than turners tape as I think just putting it around the outer rim will result in creating a not flat profile to the sanding surface. Thanks for chiming in.

Jeff
You are correct that the center 8-9ish inches of the disc stays pretty much flat...but then again I paid for a 12" machine. For the most part I do use the flat center portion, but on those occasions that I need a longer sanding surface, I really feel cheated.

The observation that the newly purchased discs are rolled at the edge is correct...even in the store they are that way.

I guess another solution is to purchase a 20" machine...but that seems like a manufacturers poke in the eye to me.

 

[Jeff]

It's an inconvenience and a PITA but apparently not a show stopper for everyday use even on the outer edges!

The observation that the newly purchased discs are rolled at the edge is correct...even in the store they are that way.

Was the original disc that worked ok from Jet already installed on the disc or in the package flat as a pancake without curling up. Are the Klingspor replacements rolled up in a tube?

I have only used Klingspor discs because if you order by mail I'm sure they will arrive rolled up and that loosens the protective plastic layer on the adhesive.

So Charlie's discs are flat, but you purchased yours from Klingspor on line? He's still had the same problem.

 

[Pop Golden]

had the same problem with my new Woodcraft sander. I found that lacquer thinner leaves a film on the disk. I clean my disk with alcohol. I also lightly sanded the disk with 120 and that seemed to help. I get my disk from Farris Belt & Saw that come flat and farris is less than a 1/2 mile from my shop so if I have a problem I take it to them. If you call them and explain your problem I'll bet they can ship flat & work on your glue problem. Good folks.

Pop

 

[Tarhead]

Could this be a QC issue w/Klingspor? Any discussion with them? I've not had this issue but their customer svc staff have always bent over backwards when I've had a problem.

 

[llucas]

May be a QC issue, but I believe I bought the discs I am using from Woodcraft a few years back...it was from the closing Greensboro store...they may have been old stock. In any case I plan a new start with new discs and an intensified plan for cleaning and a light sanding of the metal surface. I will re-post if/when I find a suitable approach.
In the meantime, I will welcome any further suggestions.

 

[JohnnyR]

Back in the days of licking postage stamps my father had a Shopsmith. I remember him using a thick, hard, round black stick of some kind of adhesive that he put on the plate while it was spinning. Don't know if the product is still available but it seemed to work for non-psa discs.

 

[junquecol]

The problem is your disks came from Woodcraft, and are several years old. Because I burn thru so many disks when making Toys for Tot's Cars (10 -12 per year,) I make my own. Check in the sandpaper bin at Klingspor, and get the slick backed paper that is redish brown on back side. Using a drywall circle cutter, cut out disk, cutting from backside. Get a can of Sprayway adhesive from Klingspor, spray back of disk. While it's drying, clean disk plate on sander with naptha, or mineral spirits. Run a piece of clean toweling over spinning plate to remove any residue. Attach new disk, burnishing it in place. DON"T SPRAY both plate and disk. DAMHIK!

 

[Jim Wallace]

These adhesive discs are expensive, so I make my own like Bruce. I've been using 3M spray adhesive - medium bond. Works great, but I'm going to try Sprayway.

 

[llucas]

OK Update! I followed Bruce's suggestion, went to Klingspor bought the remnants he mentioned, got some Sprayway there as well. Cut a 12" circle using the old disc as a pattern, cleaned the metal disc with MS. Then sprayed the Sprayway directly on the metal (so I wouldn't get the paper stuck to my clumsy fingers), let it dry 5 min then placed the new paper in place without difficulty. I burnished the surface with some hardwood while the disc was spinning and Bob's your uncle. So far after 4 days and some moderate use the paper is staying in place with no buckling. Hopefully it stays put longterm and will be easy enough to remove later.
Thanks all for the suggestions. I am pleased with how this technique works and it is MUCH Cheaper than the commercially available discs.