Thread: more scraped planes

Pics are on Michael's blog.

Re float glass and W&D or Alox, there's a natural tendency for convexity as the sole is differentially exposed to fresh (or fresher) abrasive. The only way to reduce this is to go for flats that are much longer than the sole and widths that are the same, plus v. even pressure.

That pressure can be hard to achieve on a jointer as one hand will drive via the knob but the other has to be at the heel, using the fingers.

Michael's blog postings on scraping start here

Yep as Ian says, it can be faster than sandpaper, I can really hog off a fair bit of material with the tc scraper.
Here's a link to a video of the process:
YouTube - Broadcast Yourself.


Yes and no, a plane needs to be that flat. We all know you can get away with a flat at the toe, heel and in front of the mouth. It's just in the case of these two planes, in bringing everything down to achieve those 3 flats the whole surface became flat. If you have a look at the plane I did in my blog, you'll see I stopped when I achieved these flats and that was before the whole sole was flat. In fact, it may be advantageous to create a hollow like that to reduce friction. Easily done with scraping, impossible with lapping.
As Ian says, lapping dubbs the edges. In fact, it's pretty bloody easy to make a sole convex by lapping even if you are aware of the correct method. I know, I've done it. When I restored my planes initially, I lapped. Spent a lot of time doing it. Wasted time. All the soles were convex (may have been they started out convex). I put a straight edge along a plane an expert had lapped - convex heel to toe. Heaps of literature says lapping makes soles - convex. I think people see a nice shiny sole and think flat, I wonder how many put a good straight edge to it and check and are prepared to admit to wasted time - I know I would not for a long time. Can you use these planes - yes- to a point.
So what happened? I took one of my lovely sharp smoothers #4 I think to a board to put a planed finish on it, taking really thin shavings. Tracks everywhere - huh? Iron was prepared properly with relieved corners, in fact a gentle convex across, maybe the thickness of a shaving high. Thing was the sole was convex across the plane more than the blade and exposed the corners. Doesn't take much convex on a smoother to get abysmal results. With a jointer, convex heel to toe is more of the problem, pretty easy to achieve with lapping.
I'd like all you lappers to go out to the shed, put a good straight edge on your planes and be honest whether you can see daylight at the edges. Whichever way you move a plane on sandpaper, the edges "see" fresh grit first and get eaten up, wearing the paper and leaving swarf, the centre of the planes "see" the swarf and relatively worn abrasive and wears a bit less.. Bingo, it's begun. This has nothing to do with rocking the plane, you can even jig it in a holder (people have) and this will happen. Once it's started, it become vitually impossible to prevent a small rocking, you're probably not even aware of it, which just adds to the wear on the edges. And if you happen to start with a convex sole its very hard to get it flat by lapping.
Sorry for rambling. Now I only wish I could find half the literature references for you

Oh, I forgot to add another problem, you may think cast iron is homogenous, it is not. There are hard and soft areas, caused by variable cooling rates wwhen the casting cools and perhaps by case hardening. Scraping doesn't mind this, lapping will wwear the softer stuff quicker.

Cheers
Michael

My experiences exactly, Michael.

And it's the same with sharpening chisels & plane blades by the 'scary-sharp' method - you end up with duffed edges. A sharp edge, yes, but useless for paring or any situation where you need a dead-flat back.

Apart from the surface 'seeing' fresh abrasive as it moves forward, paper 'piles up' in front of and behind the material being lapped. No matter how well you glue it down, it's a compliant material, and even a half a thou will make a lot of extra material removed over hundreds of strokes. (And have you counted how many strokes it takes to lap a plane sole??)

I don't panic about having plane soles within a smillionth of a thou all over, but they do work best if flat at the critical points & DEFINITELY NOT convex, either laterally or end to end.

Slight concavity between toe & mouth flat, and mouth & heel is ok, & may reduce friction. If you want to feel a truly dramatic reduction in friction, wipe a block of paraffin wax (bee's wax tends to be sticky) over the sole every 40-50 strokes - magic!

Cheers,

If you go to the Maleny Wood Show, go see and support Curt Swenson a local woodworker and Windsor chair maker. You'll be able to see these planes at Curt's stall.

Cheers
Michael

That YouTube vid appears to have vanished it seems.

But here's one:

[ame="http://www.youtube.com/watch?v=AkYyWcflMy8"]YouTube- Imants Gorbants teaches scraping[/ame]

and another:

[ame="http://www.youtube.com/watch?v=R3Bc1-VZ__s&feature=related"]YouTube- Kitamura Machinery - Handscraping Techniques on a Vertical Machining Center[/ame]

Originally Posted by rsser

That YouTube vid appears to have vanished it seems.

hmmm, link works for me Ern.


how 'bout this one:
http://www.youtube.com/watch#!v=uHF7...eature=related

Mic

I don't seem to be able to get any leads on someone who can sell the Sandvik scraper you used - the carbide insert looks like a great idea. I have even gone to the Sandvik Coromant website and I can't find it listed.

Any leads?

hmmm, link works for me Ern. how 'bout this one:
http://www.youtube.com/watch#!v=uHF7...eature=related

Ja. Gut. Danke.

Originally Posted by jmk89

Mic

I don't seem to be able to get any leads on someone who can sell the Sandvik scraper you used - the carbide insert looks like a great idea. I have even gone to the Sandvik Coromant website and I can't find it listed.

Any leads?

Ring a place like Total Tools or Ideal Tools. Special order from Singapore IIRC. About $180 inc a spare tip.

Originally Posted by rsser

Ring a place like Total Tools or Ideal Tools. Special order from Singapore IIRC. About $180 inc a spare tip.

Ahhh

Originally Posted by jmk89

Mic

I don't seem to be able to get any leads on someone who can sell the Sandvik scraper you used - the carbide insert looks like a great idea. I have even gone to the Sandvik Coromant website and I can't find it listed.

Any leads?

Hi Jeremy, sorry I didn't find out before. I had a dig through my receipts (wasn't that hard was it) and it was ordered from bolt and industrial:
https://www.bolt.com.au/
as Ern said, comes from Singapore, about the $180 mark (they might throw gst on top of this)

Cheers
Michael

Thanks ern and mic.
I looked at the website and it isn't there. So I've sent an email off to Sandvik to see what they have to say for themselves. Will report back.
If worse comes to worst, I may just buy an Eclipse scraper from Blackwoods and learn how to sharpen it (which is what I have done with most of my metalworking - I still use HSS rather than carbide for lathe tools).

Check your PM box Jeremy. If nothing there from me, email me at ern

at

reeders

dot

net