Inboard NR scraper recommendation?

[Scott Luallin]

Hi all!

I have been working on the Bird's Beak natural edge bowl I posted in "what's on your lathe" thread. The outside is done, sanded to 320 and will be finished with Tried and True. Looks like it will be a nice piece.

The inside, however, is deep. Bowl is too narrow for my current bowl gouges. I am WAY WAY WAY out over my rest for carbides (which I am trying to avoid), which keep grabbing like hell. I am a newbie - 8 months on the lathe.

Seems like a good use for an inside NR scraper??? Any recommendations under $100? I have a slow speed grinder and CBN so can shape and sharpen.

--Scott

 

[Scott Luallin]

Bowl in question. Mineral oil sneak peak on the outside is awesome. (this pic is unfinished, of course)

 

[Kent Reisdorph]

I use a 5/8" bowl gouge ground to a micro bevel (aka bottom feeder). You can read about it here: https://turnawoodbowl.com/micro-bevel-gouge-wood-bowl-secret-weapon/ . The 5/8 shaft helps with stability. I also turn my long tool rest sideways to get inside the bowl. I have tried to use curved tool rests but I just can't get used to them.

 

[Mark Jundanian]

Yes, turn your tool rest to get it farther into the bowl. I prefer a "J" shaped tool rest for this sort of application. (But lately I've been loving the "Finial Rest" from Advanced Lathe Tools for deep, light work).

A NRS is most commonly used to smooth the surface, very like a cabinet scraper in flat work. But a NRS still needs tool rest support near the action. If I was trying to remove material, a NRS would not be the first tool I would think of.

If you had one, a hollowing rig could really help here.

 

[robo hippy]

NRSs are for very minimal clean up, and not for heavy stock removal like roughing cuts on bowls. For me, I use the 40/40 grind for most of my bowl stock removal, well, after the scrapers have done the job, and then clean up cuts with gouges. Since that one is deep, it may not be easy. A more pointed nose gouge could go down the side fairly well, but you would need a BOB (bottom of bowl) gouge to make the transition and across the bottom. The carbide scrapers will only get you so far. If you have some of Mike Hunt's cup shaped carbide cutters, they can do the job.

robo hippy

 

[Scott Luallin]

Thanks guys!

I was to use my swept back gouge and a bottom feeder for 80% of the inside of the bowl. I had to go to round carbide for the last 20% or so, mostly smoothing out the bottom of the bowl transition. The wings on the bowl make it almost impossible to get a nice, smooth, complete cut all of the way down the side.

So I am done removing bulk material, I just want to remove some tool marks and smooth the inside out a bit more before I start sanding.

thanks for the feedback!

--Scott

 

[Mark Jundanian]

, I just want to remove some tool marks and smooth the inside out a bit more before I start sanding.

Then a NRS could be a good choice.

 

[Dean Center]

And you don't have to spend $100. You can take an inexpensive M2 skew or scraper and reshape/regrind it into a very serviceable NRS. M2 will not keep a burr very long, but you probably won't appreciate the difference from more expensive steel at this point in your journey, and the saved few seconds will probably not be worth the doubled or tripled price for the tool.

 

[Darryn Achall]

For something that deep I sometimes set up the articulating arm captured hollower with a negative rake scraper on the bar. Takes a few minutes to set it up but eliminates almost all the risk.

 

[Doug Freeman]

This is the type of application I made this tool for. Uses 5/8” mild steel square stock. Uses a teardrop tungsten steel teardrop (and hss instert will work). Its designed to hold the insert at 45*, but The edges of the square stock are rounded so the angle is adj as needed. As others said, get a tool rest down in the bowl for support.

 

[John K Jordan]

Uses a teardrop tungsten steel teardrop (and hss instert will work).

I also use one of those inside a bowl or wide-rim form - I have the set of scrapers that cam with the Sorby set, teardrop, round, and crwe (can't remember what else). I also made another scraper for it by grinding a cabinet scraper to a oval shape and making a hole for the screw. (Used a diamond bit on a Dremel for the hole).

By mine are held tilted, are not really negative rake as @Scott Luallin asked, but held titled.

For the insides and outside of bowls my go-to NRS are these - I grind them with equal angles sort of like a skew, burnish a burr on one side. These are amazing for curved or flat:



For a deep form I'd probably grind one with a similar curve, cut off the end and mount it to a handled shaft like the flat/curved Sorby (I keep both the straight and curved versions.)

With a proper burr these scrapers will remove "whisper" shavings on a variety of turnings. Here smoothing "air".


Also, if not aware, several companies including Best Wood Tools and Robust, sell box rests that mount in banjo and extend inside the box to support tools including scraper with very little overhang. I have both of these and each has certain advantages.

If I did a lot of deep forms or deep bowls I might make one of these to extend even deeper into the bowl - just need some 1" steel round rod and weld a piece of flat steel stock on top. These is arguably better for NRS since they are flat on the top and fairly wide - good for support and stability. The robust version is nicely beveled for clearance. The roll pin can be easily removed if desired. Good for both conventional and negative rake scrapers.

Robust Box Tool Rest, 6" Long, Long Post, BOXR-LO - Woodturning Tool Store

The Robust Box Tool Rest allows for easy access into boxes and other deep forms. This shortens the tool overhang and reduces vibration.

woodturningtoolstore.com

JKJ