Box Scraper

[celt40]

I bought a 3/8th box scraper, and i tried it out today, it could not cut butter!!!!!! I removed more timber using my small parting tool. Will i have to do some reshaping before it will be ready for use?
It is shaped like a " D " shape or a half circle with a square face. Can someone please advise me to what i should do with this scraper apart from throw it into the bin:U

[hughie]

Dermot,

A couple of questions. Is it not cutting due to the quality of the steel etc? Most tools come with a reasonably sharp edge to start with.

Before you grind away have a look at the cutting edge. Can you see any polished shiny areas to it? If so it may well be too soft, Carbon steel perhaps instead of HSS.

Pick up a small file and see if you can file it. If so, take it back to the supplier, unless you bought carbon steel to start with.

A pic would be good.Who is the maker of the scraper?

[OGYT]

I've always had to sharpen new tools before they would perform satisfactorily... Exceptions to this are the tools I've gotten from Hughie, and Doug Thompson.

[joe greiner]

If you could cut successfully with a parting tool, you probably have appropriate presentation to the work. So, the next suspect would be the relief angle on the cutting edge. Like Hughie said, a pic would help. I've used relief angles of 45 to 65 degrees without drama, but there's surely more authoritative information about.

Joe

[celt40]

Hi Not to good at the photo side but i will have a go and try and post a pic soon.
The tool is HSS, and the face is straight no angle at all. As OGYT said i to have always had to get my new tools ground before they can be used. This will need an angle ground into it but i am not sure what angle this would be.:(

[hughie]

Dermot have a go at 5-7 degrees, would not go over 10' to start with. Play around with the angles a bit till you settle on one the does the job for you.

For me its around 5-7 or so, don't like allot of angle its get a bit vicious other wise. Some keep it at 90 and cant the scraper over, For me I tend to shear scrape, find it does the job.

[Sawdust Maker]

According to Carol Rix the angle for round nose and square nose scrapers is 30 - 40 degrees
cheers

after reading Hughie's response I don't think mine are much more then 10 or so
I'll have to have a look

[TTIT]

According to Carol Rix the angle for round nose and square nose scrapers is 30 - 40 degrees
cheers

after reading Hughie's response I don't think mine are much more then 10 or so
I'll have to have a lookIMHO, 30 - 40 degrees is an 'emergency spindle brake'!!!:o I'll stick to about 5 -10 like Hughie :U

[rsser]

LOL. Nice facility to have Vern from time to time :-{

Dermot, as the others have said, you may need to regrind the tool to raise a burr. On endgrain, the burr will do the cutting.

But that's easier said than done on your tool. Terms are a bit of a problem here - if memory serves your tool is also sometimes called a hook tool. But that can mean something very different too.

Any case, you'll find it hard to get all of the edge of yours to a grinder. May I suggest two options:

Regrind with a metal grinding wheel on a 4" angle grinder, or
Use a coarse diamond file running across the round face of the 'D'.

And before trying either, lap the top on an oilstone.

And if I may suggest another approach altogether, assuming you are hollowing a box or pencil jar so are trying to cut endgrain:

Box scrapers are used to deal with both end and sidegrain. I've found that they shred side grain on the way down, so instead I use a (nearly) square end scraper to do the hollowing and then finish the wall side with a drill-mounted drum sander.

The square scraper I grind to about 87 degrees included angle or even less (that is, seen from the top down) so as to get a crisp corner at the bottom and avoid the whole scraper edge contacting the base of the form (which will likely give you a disaster).

That means you are just cutting end grain, and you do it in stages, both sideways and heading in. The harder the wood, the less width you take out with each pass. Regrind regularly.

Now you don't need a crisp corner at the bottom. Raffan does his pencil jars with a rounded bottom and that would prob. avoid having too thin a base which is prone to cracking, even with dry wood.

Good luck, and let us know how you go.

[Sawdust Maker]

IMHO, 30 - 40 degrees is an 'emergency spindle brake'!!!:o I'll stick to about 5 -10 like Hughie :U

Maybe I shouldn't quote books :B
but happened to have this one sitting here from local library
thanks for setting us straight Vern :2tsup: