Rasp question

[Rick Fisher]

I have a couple of good cabinet makers rasps.. both are tapered at the end, one is a #6 and the other is a #9.

Looking at rasps, I wonder about the square end raps which can have different " grit " on each side.. What would the downside be to that style rasp ?

Most of what I have used them for is a bit of tennon work, and some shaping of detail pieces on furniture.. I want something finer than #9 and was thinking .. why not get a #10 on one side and a #12 on the other ?

Originally planned to just get a #11 or #12 Cabinet makers rasp ..

[Mike Holbrook]

Rick as you may be guessing by now, rasps, like many other hand tools, can be an extensive topic. I too am learning about them and I thought I would mention some places that sell rasps and or provide information on them. I am not familiar with the rasp numbers you refer to, maybe they are Nicholson numbers? I think the video, done by one of our own members (John Coloccia, see SMC link below), is a good place to get started learning about various types of rasps/files and how they work. Highland Woodworking carries Auriou rasps & rifflers & the Iwasaki Japaneses float/files, Tools for making wood has good information and makes a line of hand made Gramercy rasps and also carries rasp from makers like Auriou, Stewart-MacDonald carries the Dragon rasps John uses.

http://www.sawmillcreek.org/showthread.php?173548-Traditional-Rasps-vs-Dragon-Rasps-vs-Iwasaki-carving-files&highlight=rasp+test

[Bill White]

Not to be meant as a hijack, but I seem to remember that there was a way to chemically sharpen rasps. Any clues as to what the chem was/is. I keep thinking that here was a phosphoric acid solution.
As far as your initial question, I would contact Lee Valley for a reasonable value.
Bill

[Rick Fisher]

Hey Mike.. Those are not codes I used.. those are just my descriptions.. The #6 and #9 is the roughness or points per inch ?

I have an Auriou 12" long cabinet rasp, 6 points per inch.. It hogs off material but leaves a rough finish.. I appreciate you posting a link to John's video's.. I realize now that my technique is wrong and could be adding to the rough finish.

[Rick Fisher]

Not to be meant as a hijack, but I seem to remember that there was a way to chemically sharpen rasps. Any clues as to what the chem was/is. I keep thinking that here was a phosphoric acid solution.
As far as your initial question, I would contact Lee Valley for a reasonable value.
Bill


Bill, the Ferrier site I read suggested using Hydrochloric Acid which is the same as Muriatic Acid. It can be bought in different strengths, usually 25% - 33% .. They dipped them for 4-6 hours.. which seemed bizarre to me.. I would research it a bit more before trying.. lol

I have used it to clean driveways and we cut it 1:10 with water.. it hissed and smoked at that concentration.. Don't try it based on this post.. I found that the Horse hoof guys are a good place for this type of info.

[Bill Moser]

Rick - I checked out those videos (Mikes link) that John made a few weeks ago -- and ended up buying several of the Iwasakis. I've used them to make a plane recently, and I really liked them. Only about 1/3 the price of an Auriou rasp, but a HUGE step above the borg-rasps that I had. I think they'd work really well as floats for easing tenons, and I'm planning on testing that theory pretty soon. FWIW, I'm pretty happy with the micro-plane "cheese-graters" also for rough work

[Jack Curtis]

... I think they'd work really well as floats for easing tenons, and I'm planning on testing that theory pretty soon...

Be sure and look for rasps that aren't toothed on the sides, otherwise you'll muck up the shoulders.

Jack