Flattening a plane sole.

[AESamuel]

Hi,

I recently bought a Faithfull No.4 hand plane, and I like it but checking the sole with a straight edge, it doesn't seem very flat (I don't have any feeler gauges so I don't know hoe much, but a lot of light is coming through). It is convex along the length of the sole, and convex across the sole - all apart from a slight hollow in the middle about 1cm in diameter.

I've been trying to flatten it with some silverline 80 grit sandpaper (roll, not sheet) on some 4mm float glass backed with a tile. I change the sandpaper when it seems to lose the "bite" which is probably about 10-15 minutes. It seems to be taking forever though, I've spent many hours trying to make it flat, but I don't really seem to be making much difference. I can see by the scratch pattern that I've not yet made it down to the hollow in the middle, and while I'm not bothered by such a small hollow, it does show that I'm not making any progress.
I understand that the plane sole doesn't have to be perfectly flat (for example, a slight hollow behind the mouth wouldn't make a difference) but as the plane is convex and what seems considerably so, I would really like to flatten it out.

Does anyone have any suggestions on how I can get the sole flat?

Many thanks!

 

[SimonT]

Not really any suggestions but there is a good video by paul sellers on youtube on how to flatten the sole of a plane.

 

[wizard]

i do mine on a belt linisher with 80 grit

 

[Rhossydd]

flattening-the-sole-of-my-new-smoothing-plane-t85950.html

 

[RogerP]

i do mine on a belt linisher with 80 grit

ditto - takes only a few minutes with a zirconia belt.

 

[AESamuel]

Thanks very much for the replies.

Unfortunately I don't have a linisher - it would probably be the first thing I tried if I did have one.

 

[dp341]

convex is an issue, you need to be careful that you're not rocking the plane as you try to smooth it. if you do you'll get a lovely, smooth convex plane. You'll need to put all your effort into keeping it level and only removing the metal in the centre.

Personally, if you're having to change paper because it's worn i'd be thinking about getting another cheap plane, that's largely flat or concave to start with.

 

[bridger]

Shift the bulk of the metal with a large flat file. Check with straightedges every few strokes.

 

[Phil Pascoe]

Bin the thing and spend a £5 at a car boot for an older Stanley or Record? They might not be perfect but they'll be better. And worth correcting.

 

[mouppe]

Make sure the blade is tightened in the plane as if you were using it (and retracted of course!) as this can affect the flatness of the sole.

 

[bugbear]

Make sure the blade is tightened in the plane as if you were using it (and retracted of course!) as this can affect the flatness of the sole.

No - the fixing of the frog to the sole flexes it a little, but the blade (lever cap, really) doesn't flex the sole. I've checked this against my surface plate.

If you think about it, the blade would have to flex the sole by flexing the frog enough to flex the sole, which would be remarkable.

In a wooden plane, fixing the blade does flex the sole.

BugBear

 

[wizard]

depending where you are in Cornwall just fished this out of my scrap bin may have the screws as well if you want it its free to a good home. and its very flat.

 

[mouppe]

Make sure the blade is tightened in the plane as if you were using it (and retracted of course!) as this can affect the flatness of the sole.

No - the fixing of the frog to the sole flexes it a little, but the blade (lever cap, really) doesn't flex the sole. I've checked this against my surface plate.

If you think about it, the blade would have to flex the sole by flexing the frog enough to flex the sole, which would be remarkable.

In a wooden plane, fixing the blade does flex the sole.

BugBear

Ok thanks for the clarification. I have always inserted the blade in all planes because I was shown to do so when flattening a shoulder plane, so I just assumed it was the same for all planes.

 

[Vann]

...and its very flat.

No it isn't :!: I can see a whole lot of hollows both in front of, and behind the mouth :mrgreen:

Cheers, Vann.

 

[bugbear]

Ok thanks for the clarification. I have always inserted the blade in all planes because I was shown to do so when flattening a shoulder plane, so I just assumed it was the same for all planes.

Yeah, shoulder planes are notorious for this, to the extent that having a fairly constant lever cap tension is important, otherwise you can have a convex or concave sole everytime you sharpen the blade.

BugBear

 

[JohnPW]

convex is an issue, you need to be careful that you're not rocking the plane as you try to smooth it. if you do you'll get a lovely, smooth convex plane. You'll need to put all your effort into keeping it level and only removing the metal in the centre.

I agree that trying to remove convexity by rubbing the plane on a large piece of sandpaper is a problem. But I don't see how is it possible to hold the plane so that only the centre is touching the paper, I think you will rock it whatever you do, and you will either maintain the convexity or make it worse.

Therefore, you need to only abrade the centre, ie the high points. I guess by using a smaller piece of sandpaper or use the scraping method.

 

[mouppe]

Ok thanks for the clarification. I have always inserted the blade in all planes because I was shown to do so when flattening a shoulder plane, so I just assumed it was the same for all planes.

Yeah, shoulder planes are notorious for this, to the extent that having a fairly constant lever cap tension is important, otherwise you can have a convex or concave sole everytime you sharpen the blade.

BugBear

Yes, I learnt from David Charlesworth to put a mark with a felt-tip pen on the lever cap knob so I know where to tighten it to.

 

[Bedrock]

I agree with JohnPW, file or scrape the centre 'til you are flat or even slightly convex, then back to the abrasive on a flat surface. I cannot think of any way you can remove a convex cross section by hand. I have a Norris 5 with exactly this problem which is overdue for treatment, so if anyone has a better method than the above, please enlighten me.

Mike

 

[bridger]

http://www.practicalmachinist.com/vb/ge ... ole-96628/

 

[matthewwh]

convex is an issue, you need to be careful that you're not rocking the plane as you try to smooth it. if you do you'll get a lovely, smooth convex plane. You'll need to put all your effort into keeping it level and only removing the metal in the centre.

I agree that trying to remove convexity by rubbing the plane on a large piece of sandpaper is a problem. But I don't see how is it possible to hold the plane so that only the centre is touching the paper, I think you will rock it whatever you do, and you will either maintain the convexity or make it worse.

Therefore, you need to only abrade the centre, ie the high points. I guess by using a smaller piece of sandpaper or use the scraping method.

Spot on!

When working by hand you can only approach flat from concave.

First you need to hollow it out, then you can start with a larger abrasive surface to bring it back to flat - nightmare!

I'd suggest cutting your losses and buying a plane that is flat to begin with.