Plane Sole Flatening

[jfynyson]

I have a Stanley No. 4 Type 10 and the tote cracked during my last project so afterwards I epoxyed it and decided to restore the plane. I really liked the old patina but like the look of being semi-restored as well. I decided to check the flatness of the sole (not that I've had any noticeable issues) and it seems the front, before and after the mouth back to ~3/4 of the way to the back of the bottom are flat but it's not quite touching on the back (slight hollow that includes the very back).

I got tired of trying to flatten on the 120grit stuck to a quartz slab then switched to my 325grit (course) diamond plate. With fluid applied I can pick up the diamond plate via suction and this tells be it's flat enough.

Questions
1. Is the bottom indeed flat enough or should I continue until the back portion of the sole is also flat ?
2. If I was flattening a No. 7 or 8 would this be any different need ?

Thanks for your input in advance !

 

[Mike Davis]

I usually want the toe, mouth, and tail touching. I check by rubbing on fine sand paper on a flat surface.
If the space between the toe and mouth or between the mouth and tail are hollow I don't worry about that.

Are you saying there is a hollow from behind the mouth all the way to the tail? Are the sides touching all the way back?

Can you touch the tail with your fingers and make the plane rock?

I think sometimes folks are too critical of the sole.

 

[jfynyson]

Here's some Sharpie marks along each edge and a few passes w/ 120grit. See a few scratches on the front & back and sides but the mouth area immediately removed the markings. Do I need to continue flatening or is this good enough ?

Mike - this is the plane I got in a trade with you for a router bit. It's been great learning. I added the Veritas PM-V11 iron & chip breaker.

 

[Mike Davis]

Looks like it was rocked a little during flattening at some point in its life.

Probably not too bad. Can you slip a feeler gage under one end when you hold down the other?

I wouldn't be too concerned but I can't really tell how much crown is here, if only a few 1000th then it's plenty good.

 

[jfynyson]

Ok, I'll check that ad see how many thou it's out and make a call from there. In the end the results matter most and I've not had any major issues getting it to perform. Just trying to optimize a little more now.

 

[jfynyson]

The worst offending areas are the very front and very back right edges and they are only 0.005"...several other nearby areas are 0.004" and the rest I didn't bother checking. I'd say that's good enough wouldn't you ?

Would this also be the case (out 0.005" good enough) for a No. 7 or 8 when trying to flatten a long edge for joining table tops ?

I've started my search for a No. 7 or 8 (non-corrugated)...if you know anyone (other than eBay)

 

[jlimey]

I would not spare the Sharpie and put some lines across the entire sole. Right now, it looks like it isn't flat all the way around the edges - but is that only around the very edge?

 

[jlimey]

The worst offending areas are the very front and very back right edges and they are only 0.005"...several other nearby areas are 0.004" and the rest I didn't bother checking. I'd say that's good enough wouldn't you ?

Would this also be the case (out 0.005" good enough) for a No. 7 or 8 when trying to flatten a long edge for joining table tops ?

I've started my search for a No. 7 or 8 (non-corrugated)...if you know anyone (other than eBay)

I would say that is good enough, especially if it is working for you. I wouldn't want my smoother to be that out of flat near the mouth, but yours looks good in that vicinity. FWIW, Lie-Nielsen promises flat within 0.0015, regardless of length. That is impressive on a #8, at least in woodworking (caveat for the rocket engineers out there!).

I would think your tolerance would work for a jointer. There is a lot of metal to remove in flattening one of those (DAMHIKT), so I would joint a couple of boards before deciding that nearly flat is not flat enough. BTW, my jointer's performance did improve a little with flattening, but a LN would have been a good choice.