Scraper question or Help me save me some $

Ned Bulken

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Hi gang! Since I have a literal pile of fresh wet maple out in the yard, I'm busily roughing out bowls on a daily (or nearly daily) basis. My two bowl gouges are naturally enough my 'favorite tools' of my arsenal at the moment. I'm looking down the road however, and from what I've seen on videos and learned through turning articles here there and everywhere, I may want/need a scraper at some point to smooth out the bottom/interior of a bowl.

Now, I've got two main sets of gouges and other implements of destruction, one came with my lathe, and is your basic HSS Harbor Freight starter set. The other is one I picked up from Jim Capozzi, which is an older set of mahogany handled Disston (sp?) and they're not HSS. I'm slowly working my way through both sets, learning how each tool works. I've got 4 however which are either factory ground or ground such that I'm thinking they need to be re-done, or I'm not sure what to use them for and am perfectly willing to re-grind them into a scraper instead of their 'designed' use.

First off, I have one tool in each set which are similar to a parting tool; except they're not tapered in the cross section. they each come to a point at about a 45° angle looking at the tip, with a relatively steep grind on them:


Vf8uFw5l.png


pardon the fuzzy images, but you get the rough idea of the shape. I look at these tools (this happens to be from the disston set) as a pointy scraper. Which I don't see a need for. I am thinking of re-grinding that as a round nosed (approximately 1/2") scraper. (more likely I'll do that on the HF version as it is HSS, this is carbon steel)

speaking of scrapers, This is what the disston carbon scraper is angled at the moment:

I"m thinking of regrinding that to a steeper angle, about 70° to 80° vs the 30° it is now (and it is very 'catchy' as it sits now).

and finally there is one tool in the HF set which has me puzzled.. it seems to be a skew which wasn't sharpened right:


I'm thinking that needs to be re-worked as well. though whether as a skew or a scraper, I'm not sure.


what say ye turning gurus? (and 'take better photos' is a given, It was raining and I didn't want to drag the nikon out to the shop just now)


edit: Oh, and I'm looking at a 1" bowl scraper from PSI as well...
 
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Ned, I don't claim to be a turner, so take it for what it's worth, I have found that a 30º angle or less is better than a steep angle. I am sure that someone with MUCH more experience will chime in here. I have found the the edge holds up better with the lower angle grind V/S the steeper grind, and I have found the edge less grabby.
 
Keeping in mind that these are strictly personal opinions, here are my answers to your questions:

The pointy scrapers are great candidates to be reground into something useful. I ended up regrinding mine into a special shape for making dovetail tenons for my chuck. The angle is slightly less than 90º so that when one edge (the left edge in this sketch) is perpendicular with the lathe bed, the other edge (the one on the right) is forming the slight dovetail shape my Nova chucks need. I like this shape better than the other dovetail scrapers that are commercially available, since it allows me to approach the cut from an angle instead of directly in line with the lathe bed.

Dovetail Tenon Scraper 600.jpg

I agree with you about the Diston scraper. :thumb: It needs to be a much steeper angle. (More blunt, as it were.) Right now it's shaped like a gouge, not a scraper. Here's an example of the angle all of my scrapers are at. I have no idea what the actual angle is...I've never measured it. This is the cutting tip for a hollowing tool, but I use the exact same angle on my 1 1/2" bowl scraper and every other scraper in between. That tool rest angle hasn't been changed in years:

Hollowing Cutter Setup 02 - 800.jpg Hollowing Cutter Setup 03 - 800.jpg

(BTW Charles, it sounds like you're trying to get a cutting edge on your scraper, not a scraping edge. On a scraper, it's not the angled edge making the cut, it's the burr that gets raised along that edge that's actually doing the cutting. To reduce the amount of "grabbiness" and catches, you need to take lighter cuts and be certain the tool is level and anchored well on your tool rest. I used to get spectacular catches with my bowl scrapers, but once I got the feel for it, the catches stopped. It's been years now since I had a scraper catch.)

Ned, the HF skew you showed can be reworked into a better skew shape or into a scraper. As a skew, the steel won't hold an edge very long. As a scraper, it's a bit thin. You'll find that heavy (thick) scrapers are a lot easier to control. The additional mass reduces or eliminates chatter. My two main scrapers are a 1" square nose (for outside curves) and a 1 1/2" round nose (for inside curves). The square one is 3/8" thick and I believe the round one is heavier, at 7/16" thick. I also have a 1/2" wide scraper that's 1/2" thick. If it chatters, it's only because I'm doing something horribly wrong, lol. Even though I'm very comfortable and confident with my scraper technique, I still run into chatter problems when I use scrapers that are less than about 3/8" thick. The link to the PSI bowl scraper didn't work for me, but I'll strongly suggest that you make sure whichever one you buy is at least 3/8" thick. :thumb:
 
Thanks Vaughn, Like I said I'm definitely not a turner, so I'll take all the good advise I can get :rofl: I am aware that the burr does the cutting. I know just enough about turning to get me in trouble. I do it when I have to, and surely not for the fun of it, like so many others do.
 
The V shaped scrapers are old school, I'm told. Some of my books still have things to say about them. I took some tools to a turner to learn how to sharpen once. They were a basic HF set, and my friend ground the V scraper down to a round edge scraper.

I hae a round edge scraper now, of better quality, with a little burr on the edge, and it is very useful for smooting inside curves.
 
I don't use scrapers a lot, just never got the hang of them plus they were thin. I do now have three 3/8 X 1-1/2 tools and I will regrind one into a radius curve scraper and give it an honest try.
If using for bowls I suggest going to youtube and look up "robo hippy", he does a lot of bowl work with scrapers and has very informed videos.
 
I agree with Vaughn I do use scrapers for the inside with lot of hard figured woods but they work best with the spalted soft woods better an its more of a blunt edge with a nice small burr.
 
Can't tell for sure what the top of that fellow looks like, but you might want to take that part to a stone and polish it up a little if it's as rough as the one picture shows the bottom being. Remember the cutting part is an intersection between two smooth surfaces. A lot of the time I'll take the scraper to the stone and knock off the grinding burr as well, the edge lasts longer and is more forgiving of my general incompetence at the lathe :D If I decide I really wanted a burr I'll add it by burnishing on a hard steel rod (a good screwdriver works well enough), the but you get that way is both sharper and a lot longer lasting than the grinder burr, for most uses it seems worth the effort for the better cut (if I'm roughing sometimes I stay lazy and just use the grinder burr).
 
On the "grinder burr" vs. the "burnished burr" debate, I'm the opposite of Ryan. I've had better results and success with a burr off the grinder (120 grit dry wheel, not the Tormek) as opposed to one that's been burnished. I seldom use scrapers for bulk material removal like Robo Hippy does. I use a bowl gouge to remove most of the material then use the scraper to take very light cuts to remove any tool marks and refine the curves. The shavings that come off the scraper are like angel dandruff...very light, translucent wisps of wood. And I'm using he scraper flat on the tool rest, not angled to make a shearing cut. (A lot of good turners turn the scraper at an angle to make shearing cuts. I've not mastered that approach and get better results with a true scraping cut...but it has to be super light.)

So my suggestion, Ned, is to try several different approaches and see which gives you the best results. One of the great things about woodturning is that you can get from point A to point B via a whole bunch of different routes. ;)
 
Ned, I don't claim to be a turner, so take it for what it's worth, I have found that a 30º angle or less is better than a steep angle. I am sure that someone with MUCH more experience will chime in here. I have found the the edge holds up better with the lower angle grind V/S the steeper grind, and I have found the edge less grabby.
Charles, thanks, I'm pretty much in the same boat, but willing to learn! I'll see what the lower angle does for me for sure!


Keeping in mind that these are strictly personal opinions, here are my answers to your questions:

The pointy scrapers are great candidates to be reground into something useful. I ended up regrinding mine into a special shape for making dovetail tenons for my chuck. The angle is slightly less than 90º so that when one edge (the left edge in this sketch) is perpendicular with the lathe bed, the other edge (the one on the right) is forming the slight dovetail shape my Nova chucks need. I like this shape better than the other dovetail scrapers that are commercially available, since it allows me to approach the cut from an angle instead of directly in line with the lathe bed.

View attachment 86148

I agree with you about the Diston scraper. :thumb: It needs to be a much steeper angle. (More blunt, as it were.) Right now it's shaped like a gouge, not a scraper. Here's an example of the angle all of my scrapers are at. I have no idea what the actual angle is...I've never measured it. This is the cutting tip for a hollowing tool, but I use the exact same angle on my 1 1/2" bowl scraper and every other scraper in between. That tool rest angle hasn't been changed in years:

View attachment 86149 View attachment 86150

(BTW Charles, it sounds like you're trying to get a cutting edge on your scraper, not a scraping edge. On a scraper, it's not the angled edge making the cut, it's the burr that gets raised along that edge that's actually doing the cutting. To reduce the amount of "grabbiness" and catches, you need to take lighter cuts and be certain the tool is level and anchored well on your tool rest. I used to get spectacular catches with my bowl scrapers, but once I got the feel for it, the catches stopped. It's been years now since I had a scraper catch.)

Ned, the HF skew you showed can be reworked into a better skew shape or into a scraper. As a skew, the steel won't hold an edge very long. As a scraper, it's a bit thin. You'll find that heavy (thick) scrapers are a lot easier to control. The additional mass reduces or eliminates chatter. My two main scrapers are a 1" square nose (for outside curves) and a 1 1/2" round nose (for inside curves). The square one is 3/8" thick and I believe the round one is heavier, at 7/16" thick. I also have a 1/2" wide scraper that's 1/2" thick. If it chatters, it's only because I'm doing something horribly wrong, lol. Even though I'm very comfortable and confident with my scraper technique, I still run into chatter problems when I use scrapers that are less than about 3/8" thick. The link to the PSI bowl scraper didn't work for me, but I'll strongly suggest that you make sure whichever one you buy is at least 3/8" thick. :thumb:


Vaughn, Thanks, I've got options (as you refer to 'later' in the thread)! I'm more than willing to experiment. I'll likely tear into the HF tools first, and then the Diston since they're carbon steel vs HSS. I like the nova dedicated scraper, since my one and only chuck is a nova product.

The V shaped scrapers are old school, I'm told. Some of my books still have things to say about them. I took some tools to a turner to learn how to sharpen once. They were a basic HF set, and my friend ground the V scraper down to a round edge scraper.

I hae a round edge scraper now, of better quality, with a little burr on the edge, and it is very useful for smooting inside curves.

Roger, that's my plan as well, the v-nose scrapers are definitely getting re-worked. I have a natural edge bowl on the chuck at the moment, but after I get that done this morning I'm planning on some serious clean up and grinder time this afternoon before work.

I don't use scrapers a lot, just never got the hang of them plus they were thin. I do now have three 3/8 X 1-1/2 tools and I will regrind one into a radius curve scraper and give it an honest try.
If using for bowls I suggest going to youtube and look up "robo hippy", he does a lot of bowl work with scrapers and has very informed videos.
Mike, thanks for the tip on robohippy. I've added him to my playlist and will be going to school on his body of work soon!

I agree with Vaughn I do use scrapers for the inside with lot of hard figured woods but they work best with the spalted soft woods better an its more of a blunt edge with a nice small burr.
Roy I'm planning on using these scrapers (and a better thicker one when the tool budget allows...) for those finishing touches on the inside of bowls and boxes (I still can't adjust to thinking of a turned shape with lids as a 'box').

Can't tell for sure what the top of that fellow looks like, but you might want to take that part to a stone and polish it up a little if it's as rough as the one picture shows the bottom being. Remember the cutting part is an intersection between two smooth surfaces. A lot of the time I'll take the scraper to the stone and knock off the grinding burr as well, the edge lasts longer and is more forgiving of my general incompetence at the lathe :D If I decide I really wanted a burr I'll add it by burnishing on a hard steel rod (a good screwdriver works well enough), the but you get that way is both sharper and a lot longer lasting than the grinder burr, for most uses it seems worth the effort for the better cut (if I'm roughing sometimes I stay lazy and just use the grinder burr).
Ryan, my shop generated a lot of surface rust last year... I'm going to be cleaning up tools for quite some time.

On the "grinder burr" vs. the "burnished burr" debate, I'm the opposite of Ryan. I've had better results and success with a burr off the grinder (120 grit dry wheel, not the Tormek) as opposed to one that's been burnished. I seldom use scrapers for bulk material removal like Robo Hippy does. I use a bowl gouge to remove most of the material then use the scraper to take very light cuts to remove any tool marks and refine the curves. The shavings that come off the scraper are like angel dandruff...very light, translucent wisps of wood. And I'm using he scraper flat on the tool rest, not angled to make a shearing cut. (A lot of good turners turn the scraper at an angle to make shearing cuts. I've not mastered that approach and get better results with a true scraping cut...but it has to be super light.)

So my suggestion, Ned, is to try several different approaches and see which gives you the best results. One of the great things about woodturning is that you can get from point A to point B via a whole bunch of different routes. ;)
To my way of thinking, the scraper is for when I can't get in to do a shear scrape cut with the bowl gouge. Since you and Bill G straightened me out on my two bowl gouges (which I'm very thankful to a) own and b) finally be able to use!), I'm doing my level best to master their use. I'm in 'bowl' mode right now since I have that pile of wet stock out there. Eventually I'll try some more spindle work. I think you'll agree that my 'path' has to be one of the most unique possible!

Absolutely agree with this!! :thumb:
Thanks Jeff, we're all rugged individualists at heart I suppose!
 
Mike, wow, I just dove into the robohippy youtube rabbit hole... what a great source of information!

Reed (Robo Hippy) is a good guy. I knew him on another forum a few years ago. Sometimes a bit unconventional in his methods, but he's a production bowl turner, so he's got a lot of 'em under his belt.
 
Some turners scoff at scrapers, but they are fantastic in certain applications. The v-point can be reground to a spear point scraper which is great for getting into tight areas to clean up (bowl foot, beads, bowl rim, etc). And I think it was Vaughn that pointed out the ability to clean up tool marks. Learn to shear scrape (with in on an edge instead of flat) and you can get an almost mirror finish and eliminate most of your sanding. A small round nose scraper is nice for cleaning up the inside rim of a bowl, especially if slightly undercut (shear scraping, not flat). They are quite versatile and are a great use of chisels that would otherwise gather dust.
 
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