Hollowing out End Grain Box - help

[wassaw998]

I am having a horrible time trying to learn how to hollow out an end grain box, or any end grain anything. What I normally get is a huge catch that knocks the wood off my chuck. I have seen the method on a Raffan Video I own, and when I see it it looks so easy, but...well, I keep not being able to do it (always get a catch). Is there a special grind I need on my gouge to start with ? Should I use a bowl gouge or a spindle gouge, and, from what I read, I start in the middle - make a hole, and work my way out, rubbing the bevel, the tool working out of the hole towards on the top back end of the "bowl" ?

ps. If it helps, the tools I own (that may be for this) are the HF HSS set, and I have several of the PSI's Benj Best bowl and spindle gouges, and a big round nosed scraper.

Thanks.

[kwgeorge]

Chris, what you are trying to do is what Richard Rafan refers to as his “Back Hollowing Technique” This even he admits is very hard to learn. I would practice this on only strait grain wet wood until you get it down if that is what you want to do.

I suggest however that you start a bit easier. Drill a depth hole with a drill bit to get you started. Now if you are doing a box I suggest a scraper with a side grind on it. PSI has 2 that work very well. They have a round one Part# LX150 and a Square one Part# LX160 that I think you will find gets you were you want to be. I have several box tutorials on my site if perhaps they can help also.

[wassaw998]

Thanks Ken ! After posting, I read some of the articles on boxes on your site and decided to use a Forstner bit and then a scraper. Worked very nice. I'll also order the 2 scrapers from PSI you recommend.

(ps. You'll never know how helpful your site and your advice on this forum is - Thanks !)

[mater]

quote:Originally posted by wassaw998


(ps. You'll never know how helpful your site and your advice on this forum is - Thanks !)

I second that.

[boblon]

quoteps. You'll never know how helpful your site and your advice on this forum is - Thanks !)

I whole heartedly third this.

BobL.

[gerti]

A little over a year ago I made an almost identical post... What helped me most was looking over the shoulders of other turners, and a box-turning class at Woodcraft, and then practice. Stick with it, in time it becomes a lot easier.

My set of HF HSS tools do not hold an edge very well. When I bit the bullet and bought a Sorby scraper, I was amazed how much better that tool worked! I guess any good quality scraper will make a big difference to the HF tools.

Tool handling was another matter. For some reason I understood 'riding the bevel' as 'riding the bevel AND it should be supporting the cutting edge'. That works for some spindle work, but for a lot of operations the bevel rides 'sideways', which also happens to greatly reduce the danger of a catch.

IMHO the Raffan videos are not well suited for a beginner. Raffan is a production turner of many years, and that shows in the videos. And I think it is best to forget about Raffan's 'back hollowing technique'. At least for the first few years.

Scrapers: There seem to be two schools of thought. Most people use it flat on the tool rest. That works fine and is easy to learn, but leaves a rather course finish as the scraper basically just breaks of the ends of the fibers. For this technique you do not want a burr on the scraper, that would make it catch a lot.

The way I learned it from Alan Lacer is to have a burr on the scraper, and angle the scraper. For this it is best to round over the sides of the scraper slightly so it does not dig into the tool rest. The tool rest is fairly high for this, and the scraper angled downwar a bit. The burr on the angled scraper slices the wood and can produce a very fine finish. Held slightly different and with a tad more pressure it can also cut quite aggressive.

The fastest way to learn is by having some first-hand instructions. Join the local wood turners club, or take a class.

Gerd

[kwgeorge]

Thanks everyone for the kind words as it keeps me creating and trying.

quote:
My set of HF HSS tools do not hold an edge very well. When I bit the bullet and bought a Sorby scraper, I was amazed how much better that tool worked! I guess any good quality scraper will make a big difference to the HF tools.

Gerd; I currently own Sorby, Crown, Henry Taylor, P&N , PSI and quite a few homemade tools. I have found that the greatest difference between these tools is the final finishing on them. With Henry Taylor being by far the best finished and edge holding tools of them all. I own several Sorby scrapers and find myself making no more trips to the grinder with the PSI scrapers than I do with the Sorby. Even so I see nothing wrong with taking a tool to the grinder often that cost $20 versus one that cost $80 while learning to grind ones tools. Most of my turnings have a PSI tool used while creating them and I find no ill effects or problems in the turnings. With that said however I do prefer more expensive tools for my gouges and again this goes back to the finish on the steel. (BTW, Grizzly is now carrying Sorby tools much cheaper than Woodcraft or Rockler)

quote:
Tool handling was another matter. For some reason I understood 'riding the bevel' as 'riding the bevel AND it should be supporting the cutting edge'. That works for some spindle work, but for a lot of operations the bevel rides 'sideways', which also happens to greatly reduce the danger of a catch.

Ok, ya got me on this one. I agree on the premises that people believe that in order for them to “Ride” or “Rub” the bevel the entire bevel must be in contact with the wood and we both know that in most cases only a portion of the bevel can touch the wood. I always thought that “Rubbing the Bevel” was a better way to say it as the whole purpose is to support the cutting edge as you say. Where you got me is the “That works for some spindle work” When I am using a bowl gouge working on the interior of a bowl or what not I can assure you I have as much of the bevel rubbing as possible and probably all of it with a conventional grind bowl gouge. I also assume by “Sideways” you are referring to using the scraper in a “Shear” scraping mode.

quote:
IMHO the Raffan videos are not well suited for a beginner. Raffan is a production turner of many years, and that shows in the videos. And I think it is best to forget about Raffan's 'back hollowing technique'. At least for the first few years.

I agree with you totally on this. It is not only difficult to emulate him but it also can be dangerous.

quote:
Scrapers: There seem to be two schools of thought. Most people use it flat on the tool rest. That works fine and is easy to learn, but leaves a rather course finish as the scraper basically just breaks of the ends of the fibers. For this technique you do not want a burr on the scraper, that would make it catch a lot.

I disagree; the scraper with a bur can be a very aggressive cutting tool that will allow the removable of a lot of wood quickly. When cutting like this I like my tool rest a bit high so if I do have a catch it will just pull the tool down and cause little damage.

quote:
The way I learned it from Alan Lacer is to have a burr on the scraper, and angle the scraper. For this it is best to round over the sides of the scraper slightly so it does not dig into the tool rest. The tool rest is fairly high for this, and the scraper angled downwar a bit. The burr on the angled scraper slices the wood and can produce a very fine finish. Held slightly different and with a tad more pressure it can also cut quite aggressive.

I also like to take all the sharp edges off the non-cutting parts of my tools as they will slide on the tool rest much better and also are less apt to mar it. I don’t know about the “Bur used for Shear scraping” though. When I am close to making my final passes I always knock the bur off with a diamond hone and shear scrape. Which is basically what you are describing but a bur will still make the cut too aggressive for me to achieve the best possible tool finish. The funny thing is that Sorby came out with a “Hardwood” scraper that is basically simulating shear scraping without raising the tool rest and bring the tip back to center line.

quote:
The fastest way to learn is by having some first-hand instructions. Join the local wood turners club, or take a class.

Can’t disagree with you on this one, unfortunately classes are normally very expensive and the closest Woodcraft is 60 miles away from me. Clubs are another issue and again I would have to travel from 50 to 80 miles to make meetings. For me it was a mater of finding, digesting and trying information from all sources available. This is the whole idea and reason I put up my site so I could perhaps help people out who were in the same situation as me. In turning there are many ways to do everything and the trick is to find what is comfortable, safe and efficient. Personally if I find a better way to do something than I will change to that way quickly. Turning is very subjective and everyone has there own habits and processes.