tapping out disaster

[Noah Wagener]

In a thread of the same name David Wong had described tapping the middle of his plane blade from the bevel side to get the back flat which i guess is expected of a blade user in Japan. I have a blade that was humped across the back so i thought i could tap the corners down flat. It worked but i chipped some small dogears onto the corners.

sawmillcreek 173.jpg

I think i'll just round the chipbreaker corners to match rather than grind off the 1/32" or so. It is not really a disaster as it just makes the blade a little narrower.

I just wanted to know if this is done by others and what the danger is of ruining the lamination? I have a Sheffield blade that is humped the same and also pitted on the low spots and would be quite a lot of work to lap and would leave a much thinner blade.

[george wilson]

Don't worry about the chipped corners. Don't Japanese blades have beveled corners anyway?

Don't try tapping the Sheffield blade. It is hardened steel all the way through,and will crack if you go hammering on it. You have to lap it flat.

[Noah Wagener]

Thanks George,

That blade was actually from a coffin smoother. It was just David's post and the chat about the Japanese practice that gave me the idea to try hammering that blade flat. I'm the kind of guy who needs to be told it's ok to do something and it has been done in the past. Not exactly Dick Fosbury.

I believe the blade from Sheffield Tool co. is also laminated in that manner. A file will skate across the back but dig in to the bevel side. I thought all those old "warranted cast steel" blades were laminated in thickness while the thinner Stanley blades were just welded lengthwise at the end of the slot?

Am I correct in interpreting what you wrote thinking that the soft backing will bend while the hard steel does not but moves with it? Thus it would crack if it was hard all the way through?

About those corners being clipped, do you camber the corners on your smoothers at all?

[David Weaver]

Camber the corners on the smoother and leave the cap iron untouched. If the iron itself isn't in the cut, it will not hurt to have the chipbreaker suspended there because it won't be contacting chips, but you may wish later to have it back.

A cap iron set moderately close on a jack iron is doing the same thing (working suspended over nothing), but any cap iron over open space cannot by definition end up in the cut or the cap iron would have to project past the mouth - something that would yield a pretty awful situation.

[Noah Wagener]

thanks,

i thought for sure i would get shavings stuck under the corners despite there being no blade there but it seems to work fine.

All the old blades i get tend to have a hump in the middle of the back and the old stones are dished to facilitate these humps. I do not see how they could use a chipbreaker. If you sharpened the breakers on same stone you would magnify the problem. It is like the users were brought up in the single iron tradition and just backed the breaker off to avoid jams. Or naive people got a hold of them after the craftspeople.