Sharpening a tape dispenser blade

Hi folks,
I bought this really cool 3M tape dispenser recently. It's cast iron and weighs a ton: http://www.mythic-beasts.com/~cdt22/3m_tape_dispenser.jpg
But the blade's a little blunt and I can't find anyone who supplies replacements. It's not incredibly blunt - it still cuts tape with a bit of effort - but ideally it would be sharper.
Anyone got an idea for a good way to sharpen the blade? I was thinking of carefully sharpening the teeth individually using a good quality, half-round needle file.
Any thoughts would be appreciated.
Best wishes,
Chris

Christopher Tidy wrote:
  Quoted Text Here  
Chris,
Do you have a picture of the blade, IIRC the blade is usually a seperate piece with serrated teeth, I would have thought using a sharpening stone on the working face of the teeth would be the best method to restore the cutting edges.

On Sep 11, 11:30 pm, David Billington
  Quoted Text Here  
Hi David,
Thanks for that suggestion. I hadn't thought of using a sharpening stone, and it would avoid changing the shape of the teeth - it would only change their thickness.
I don't have a picture of the blade to hand, but I can take one tomorrow if it would be useful. The blade is a separate piece of steel. It's L-shaped. But turn the L upside down and bend the horizontal tip of the letter upwards, and that's where the teeth are.
Did someone in this group once suggest acid as a means of sharpening?
Best wishes,
Chris

  Quoted Text Here  
IF IT WAS ME .................
I'd take some cleaner and make sure I had gotten all the goo off the blade. May or may not be the problem.
Then I'd take the right file from my six pack of mini Nicholson files and stroke it in the right direction to sharpen it. There's even a triangular file in there that might fit the grooves.
Those little six packs of Nicholsons are awesome. Not cheap, but handy in a lot of situations.
Steve

replying to SteveB, TamGaCap wrote: This just worked with my stapler blade. Looking for how to sharpen it, got no real tips, saw this and though, “no way, it’s clean, I can see it, it’s not dirty.” Put some alcohol on a few qtips and gave it a rub.
It finally works again! I kept pulling off pieces easily over and over thinking it was a fluke. I looked like such a dork gasping with surprise and joy every time a piece ripped off easily.
It’s nerdy, but this made my day.

replying to SteveB, Shada wrote: Cleaning the blade was excellent advice. I was doubtful it would work. I?ve had my tape dispenser for years. Great advice. You were right, don?t over think it.

  Quoted Text Here  
At a food processing plant I worked at, the corugated blades were sharpenned on a buffer, parallel to the wave. Advantage of this method is not only was it sharp, it was slick and was less likely jam... --Glenn Lyford

Christopher Tidy wrote:
  Quoted Text Here  
If it is removable, replace with a piece of bandsaw blade?

I had the same question with my meat slicer blade. Finaly I started it up and put a diamond hone on the side that had the origional grind and it slices like new. I'm guessing the teeth were punched out so take it off the base if possible and sharpen it from the bottom by laying it flat on a fine file, whetstone or diamond hone (you can even use a slight angle if you wish) and it will be good for another 50 years. Karl
wrote:
  Quoted Text Here  

wrote:
  Quoted Text Here  
Thanks for all the suggestions. Sorry about the delay in replying. I replied to David a couple of nights ago but Google Groups must have lost my post. I need to go back to using Netscape for Usenet as soon as I get my Unix box sorted out.
The blade is a pressed steel L shape (in cross section), mounted upside down with the horizontal tip of the L turned upwards. Teeth are cut into the part which is turned up, and the vertical part of the L is screwed to the cast iron dispenser body.
I don't think goo is a problem, but rust might be.
Sharpening against a stone is an idea I hadn't thought of. My only concern is how to hold that tiny turned up part of the blade at the right angle. It would be easier if the blade was a flat piece of steel, but it isn't. Any ideas?
I have some Bahco needle files. The closest to the profile of the teeth is the half round, not the triangular. The advantage of using a needle file is that I can clamp the L to the bench, but the disadvantage is that I need to be careful and precise!
Thanks for the suggestions.
Best wishes,
Chris

replying to Christopher Tidy, indchemist wrote: Tried small files didn't work. I used ambersil fux remover fixed it perfectly.

replying to Christopher Tidy, Manish chandra wrote: Hi ! this is Manish , like see i also had the same problem too which you are having , so i tried in many ways one you can do is use* acid* but that may be very dangerous , so instead *you can use the fire up technique* in which you can heat up the blunt blade to a very hingh temperature and then rub it against a hard plain surface which will make it sharpen (*/_THIS IS ONLY FOR ADULTS KIDS DO NOT TRY THIS_/* !!!) Regards Manish.

replying to SteveB, TamGaCap wrote: This just worked with my stapler blade. Looking for how to sharpen it, got no real tips, saw this and though, “no way, it’s clean, I can see it, it’s not dirty.” Put some alcohol on a few qtips and gave it a rub.
It finally works again! I kept pulling off pieces easily over and over thinking it was a fluke. I looked like such a dork gasping with surprise and joy every time a piece ripped off easily.
It’s nerdy, but this made my day.

replying to SteveB, Shada wrote: Cleaning the blade was excellent advice. I was doubtful it would work. I’ve had my tape dispenser for years. Great advice. You were right, don’t over think it.

replying to Christopher Tidy, Gayle Frust wrote: I have the same predicament. It seems ridiculous to have to purchase a whole new unit just because the blade is dull and can easily be removed.

replying to Christopher Tidy, Gayle Frust wrote: I have the same predicament. It seems ridiculous to have to purchase a whole new unit just because the blade is dull and can easily be removed.

replying to Christopher Tidy, Manish chandra wrote: Hi ! this is Manish , like see i also had the same problem too which you are having , so i tried in many ways one you can do is use* acid* but that may be very dangerous , so instead *you can use the fire up technique* in which you can heat up the blunt blade to a very hingh temperature and then rub it against a hard plain surface which will make it sharpen (*/_THIS IS ONLY FOR ADULTS KIDS DO NOT TRY THIS_/* !!!) Regards Manish.

I've found, in most cases, that the apparent dullnes is caused by a build up of adhesive along the cutting edge. This can usually be removed with a petrolium base solvent. Another approach would be to touch up the cutting edge by deepening the notches in the metal cutting strip with a fine sharp cornered needle file or a dremel cutting wheel.