Thread: RASPS - COATED verses UNCOATED - simple test comparison

What is the difference in Cost?
TM

I am sorry but until you put the results in a chart and post them on at least 4 forums I am unable to accept these results

Originally Posted by TermiMonster

What is the difference in Cost?
TM

About 40% Mike.

Sorry Brett I'll go against you on this one. I have several coated and several uncoated, I have used them all extensivly and I have had zero clogging effects where I have had to stop and clean the rasp. I find that once the blue stuff has been roughed up a bit the clogging looks similar and I don't remember having one look that dirty coated or uncoated when I have stopped rasping (?) and I have used them non stop for hours on end sometimes. I still like the feel of the sharpness of my untreated and if I was to buy more (which I will) I will only buy untreated Just had a look at mu untreated rasps under the big light magnifier and a 10x loup and after all the hours of work I have done on hardwood, various softwoods and a sh_-t load of Huon they don't show any signs of wear. I think you must have been rubbing that one on the steel vice. UNLESS the quality of the rasps has dropped like the files I have a very little touch of corrossion but then I haven't looked after them as well as I could have. How long since I purchased them Brett?? 2years and 20,000 miles?

Ban the Blue, stick to steel

Yeah, it comes down to personal preference Mark. As I said I've been curious to see if there was any difference as far as I can tell. It was your comments, and also Ian's that got me wondering.

Originally Posted by Claw Hama

..... and I have had zero clogging effects where I have had to stop and clean the rasp. Yes, I don't say that it was a problem at all, and may well have been caused by the oil (I think you can see some oil soaked dust on the uncoated one - this would go away in time, unless of course you re-oil it, as I know you do. It didn't feel any different to when it was unloaded.

How long since I purchased them Brett?? 2years and 20,000 miles? Starting from about 2 years ago.

I think the difference in performance was only in the "feel" not in timber removed. That is a valid enough case for some people, such as yourself. There's a guy in France that prefers to use them without a handle simply because he gets a better feel for what's going on. And hey, a 40% price difference is certainly something to be considered when one needs quite a few rasps, as you do.

Nice pics but the experimental design leaves a bit to be desired in that the testing simply does not address the original objective.
The clogging aspect is a bit of red herring and is not a away to assess sharpness anyway.

The experiment aim might be better achieved if
1) the rasps were cut and shaped so that the same amount of rasp area and profile is in contact with the wood.
2) The rasps are used with a constant applied force device for some maybe thousands of strokes
3) the weight of wood removed was graphed as a function of number of strokes.

The better rasps should maintain a more consistent rate of chip removal over time compared to those of poorer quality, but whether one could quantify anything out of this sort of experiment is another matter.

If the X4 was correct the area under the graph for the better raps should approach 4 x that of the poorer rasp.

However, since I do not believe it is possible to quantitatively define what is meant by a sharp "sharp working life" (for any tool) this means that any quantitative value assigned to a rasp being X time better is some what bogus.

Ok, here is my 300mm Cabinet Makers #8 after something like a minimum of 30,000 strokes (at around 100/min), (probably more like 300,000). Under the magnifier it looks good, the camera does pick up a few little shiny tops but it still feels very sharp to your hand and on the wood. Sorry if my photos are not as good as FF's.
30 000 plus strokes.jpgOur lady of the Rasp.jpg

Originally Posted by BobL

Nice pics but the experimental design leaves a bit to be desired in that the testing simply does not address the original objective.
The clogging aspect is a bit of red herring and is not a away to assess sharpness anyway.

The experiment aim might be better achieved if
1) the rasps were cut and shaped so that the same amount of rasp area and profile is in contact with the wood.
2) The rasps are used with a constant applied force device for some maybe thousands of strokes
3) the weight of wood removed was graphed as a function of number of strokes.

The better rasps should maintain a more consistent rate of chip removal over time compared to those of poorer quality, but whether one could quantify anything out of this sort of experiment is another matter.

If the X4 was correct the area under the graph for the better raps should approach 4 x that of the poorer rasp.

However, since I do not believe it is possible to quantitatively define what is meant by a sharp "sharp working life" (for any tool) this means that any quantitative value assigned to a rasp being X time better is some what bogus.

It appears that you have not read what I said very carefully. I can't see how you could describe the clogging as a red herring when I went to some length to say that it hadn't impacted performance, and may have only been caused by the manufacturer applied oil (note that I pointed out that there appeared to be oil soaked dust). Furthermore, I point to this comment that I made:
"and may result in more regular cleaning being necessary for a given number of strokes" See the word "may"?

As far as the rasps not being identical I pointed out the differences and put several caveats on that. Should someone want to stump up the cost of two rasps of identical specs apart from the coating (around $300 from the webstore) then I'll be happy to repeat the experiment. Or perhaps it needs to be done by someone in a lab with all of the equipment that is available. Would you like to volunteer for the task?

As for applying constant force - as close as I could get. Being so pedantic about issues such as this is a little fruitless, because Joe Average in a workshop doesn't work like that. JA is going to base their assessment of a tool on how it feels to them, with their hands. I can't see how thousands of strokes are necessary when a mere thirty (plus uncounted strokes afterwards, but no more than another 20-30) has already revealed a wear pattern on the uncoated rasp. As I said, this is far more obvious in the flesh with a loupe.

Yes I thought about weighing the dust removal, but I figured that a fair person could see that the right hand rasp had removed a bit more timber (the dust pile is longer and thicker). As I also said there was a difference in the number of teeth in contact with the timber. All of those factors were against the coated rasp, and yet it had little to no signs of wear (remembering that it was not new, like the coated one was).

I am not stating an "up to 4x life" - this is the manufacturer's claim. I'm simply trying to find out if there is ANY evidence to support this claim, and the results make me think that there is. Others can draw their own conclusions. Claw Hama has different opinion to me and probably IanW does too. So what? This is my opinion and was quite clearly stated as such. Surely it is better to have at least some information, qualified and caveated as it has been, than none at all, isn't it Bob???

If I had laboratory equipment at my disposal the results would have been more empirical. At least I had the motivation to spend 4-5 hours conducting the tests, editing photos, uploading them and writing a short report full of qualifications and caveats.

Hey man, I'm just trying to put some information out there that may help someone decide if the rasp they are about to purchase NOW should be coated or not. My conclusion for my usage is that the coating is worthwhile. Someone who is about to purchase a rasp quite clearly doesn't want to wait for some years before a user can say that over a long period of time the coated rasp was or was not worth the extra purchase cost.