No5 Jack How much is too much

[Trafalgar]

I'd certainly love to see a plane sole with a regular curve, convex or concave. It would be my first time for sure.

I would also love to know how you make the distinction, bump(s) vs. a regular convexity or concavity, through a section of the sole.

Grinding to a regular curve would seem a more miraculous manufacturing feat than grinding them dead flat. I've found no evidence that they ever did either on a consistent basis. Obviously, the goal was a flat sole. How that morphed into ones with regular curves is interesting, to say the least. Do you have any theories on how this could have happened, regular curve that is? And how a disproportionate number of them have apparently come your way?

 

[Phil Pascoe]

Unusually, I agree with Jacob. I've done a few of mine this way and not had any problem whatsoever.

 

[Trafalgar]

Unusually, I agree with Jacob. I've done a few of mine this way and not had any problem whatsoever.

My sense is that we would all have much trouble with one over a millimeter out if we went straight to the lapping table. That, or have an unusually sensitive hand to be able to balance the sole on the high point and grind it down. It usually sits on the high point, settles on a low point at the other end and while the high point is taken down the low point is too so the plane stays, on a net basis, at best as out of truth as it was when one got started.

 

[GLFaria]

With the sandpaper or polishing paper I use, no matter what the grit, I found out that with baby oil instead of water the sandpaper doesn't have the tendency to curl it has with water. But it does slip on my glass plate, so... clamping... heck, Pete, how do you manage to do any kind of work on so cluttered a table (or whatever that so-calles surface is)? Plainly nightmarish! :wink:

I only use spray adhesive for "heavier" work - hence almost never; much as I would like ito, I don't buy that many used (or new for that matter) planes. And it's just too much trouble cleaning the plate afterwards... (ok, call me lazy)

 

[Phil Pascoe]

Surely it can't settle on a low point? For the end to be a low point, there would have to be two high points - in which case it wouldn't settle on the low point.

 

[Jacob]

Unusually, I agree with Jacob. I've done a few of mine this way and not had any problem whatsoever.

My sense is that we would all have much trouble with one over a millimeter out if we went straight to the lapping table. That, or have an unusually sensitive hand to be able to balance the sole on the high point and grind it down. It usually sits on the high point, settles on a low point at the other end and while the high point is taken down the low point is too so the plane stays, on a net basis, at best as out of truth as it was when one got started.

It will (can only) settle on high points only. There will be at least 3 of these. They will all be diminished until the thing is flat. You could always put more pressure towards one rather than another if you want to.
A level of over-thinking going on here! As usual it's much simpler if you go at it brain-off head-down.

 

[Jacob]

With the sandpaper or polishing paper I use, no matter what the grit, I found out that with baby oil instead of water the sandpaper doesn't have the tendency to curl it has with water. But it does slip on my glass plate, .....

If you use thin paper and just wet it thoroughly it won't slip, once it's nicely flattened out

 

[bugbear]

If a high point is truly localised, it will be abraded very aggressively, compared to a less localised "mean plane".

Thought experiment: Consider a case, where an other wise flat plane (of either type ) has a localised bump, a 1 mm hemisphere, projecting above the plane.

I don't think anyone would be too worried about removed this with abrasive - although there will be "some" unwanted abrasion in areas other than the bump, it will be slight. The action of the abrasive is moderated by the size of the features being worked on - large features lead to lower pressures leading to lower removal rates. For once, the laws of nature are on our side, at least at the level of precision we're discussing.

The only time this joyous thing doesn't happen is a uniformly convex banana.

BugBear

 

[Trafalgar]

Unusually, I agree with Jacob. I've done a few of mine this way and not had any problem whatsoever.

My sense is that we would all have much trouble with one over a millimeter out if we went straight to the lapping table. That, or have an unusually sensitive hand to be able to balance the sole on the high point and grind it down. It usually sits on the high point, settles on a low point at the other end and while the high point is taken down the low point is too so the plane stays, on a net basis, at best as out of truth as it was when one got started.

It will (can only) settle on high points only. There will be at least 3 of these. They will all be diminished until the thing is flat. You could always put more pressure towards one rather than another if you want to.
A level of over-thinking going on here! As usual it's much simpler if you go at it brain-off head-down.

When well-meaning woodworkers speak of lapping and lapping and the out-of-flat situation not improving it is this phenomenon in play: the high spot is coming down but a low spot is coming down right along with it. If the high spots are at both ends of the plane, and they are pretty much the same 'height' then all will be fine. If not, then trouble lies ahead.

Some planes have no more than a heel bump, right under where the handle attaches. You can lap fore and aft the rest of your life and it won't improve one millionth of an inch. Just scrape or sand down under the handle and, voila', flatness. Some have a bump under the front knob and back handle. These usually will lap out fine all at once but you have to compare the height of each bump to another spot on the plane, doesn't matter where but you have to use the same spot. If the bumps are the same height, then lap away. If not, work on the highest one first.

It's no different than working wood. You have to figure out where the highest spot is first and work on that area to the exclusion of all others until it comes down in height to the 2nd highest spot, etc. etc. At some point with wood you can then just take through shavings and the truth of your long plane will do the rest of the work. And this is the same thing the lapping table does. But you have to get to that point first. The fact that you were able to go straight to the lapping table is proof that the sole was close to true to begin with. It isn't so with all planes.

 

[bugbear]

It will (can only) settle on high points only. There will be at least 3 of these.

If the sole is either a good old Sheffield banana (curved in 1 direction, common) or domed (curved in 2 directions, not common) that's not true.

BugBear

 

[Jacob]

Oh all right! I was thinking more of the typical flatness with blemishes, rather than the avocado or other special shape.

 

[woodbrains]

Hello,

There seems to be an awful lot of advice about plane flattening from the 'just use it as it is' and the 'planes weren't flat when they were made of wood' crowd. (hammer)

Mike.

 

[GLFaria]

With the sandpaper or polishing paper I use, no matter what the grit, I found out that with baby oil instead of water the sandpaper doesn't have the tendency to curl it has with water. But it does slip on my glass plate, .....

If you use thin paper and just wet it thoroughly it won't slip, once it's nicely flattened out

"Thin" being a relative notion, I don't know if the paper I can get and use is thin or not according to your references. But I know for sure that it curls a lot if I use it with water and no adhesive.
On the other side, if you mean "wet it thoroughly" with oil, I guarantee it is usually fully soaked - those d***d baby oil bottles never have a decent spout, and most of the time when I just want a couple of drops I usually get a full - big - spoon of it... Does anyone know a trick for modifying these stoppers so one can get a reasonably metered amount instead?

 

[JimB]

Going back to the original question, "how much is too much?", I'd say this one was too much if you wanted it for a tool, just right if you wished to learn the esoteric arts of flattening metal and, pretty cheap if you merely wanted to display the downfall of a once proud trademark.

 

[lanemaux]

Hi GL , if you want a better bottle for spreading baby oil (pleasantly scented mineral oil) you might try a lighter fluid bottle . Even if you don't smoke dollar store lighter fluid can be had cheap , the fluid removed for other purposes like the BBQ and the bottle makes a very precise dispenser , one drop or many. I wind a band of electrician tape on mine so it stands apart from real lighter fluid. Make sure to use a funnel to transfer though or you just exchange one mess for another , DON'T ASK.

 

[bugbear]

Oh all right! I was thinking more of the typical flatness with blemishes, rather than the avocado or other special shape.

Yes - the more uniform defects tend be residual stress from poor manufacture, the more localised defects are normally the result of wear. Both are common enough.

BugBear

 

[GLFaria]

Hi GL , if you want a better bottle for spreading baby oil (pleasantly scented mineral oil) you might try a lighter fluid bottle . Even if you don't smoke dollar store lighter fluid can be had cheap , the fluid removed for other purposes like the BBQ and the bottle makes a very precise dispenser , one drop or many. I wind a band of electrician tape on mine so it stands apart from real lighter fluid. Make sure to use a funnel to transfer though or you just exchange one mess for another , DON'T ASK.

Thanks, lanemaux, I'll look for one. Anything must be better than those slippery, messy, oil-spilling Johnson Baby Oil bottles (being just a very lousy amateur working mostly very soft woods and not having to sharpen all that much, I can afford the luxury; and besides, that's what they stock at my local drugstore...)

 

[Phil Pascoe]

I used a Zippo for 30 yrs, and I didn't see fluid in a bottle.

 

[GLFaria]

And I don't smoke, so I have no idea at what the fluid comes in...

 

[Jacob]

With the sandpaper or polishing paper I use, no matter what the grit, I found out that with baby oil instead of water the sandpaper doesn't have the tendency to curl it has with water. But it does slip on my glass plate, .....

If you use thin paper and just wet it thoroughly it won't slip, once it's nicely flattened out

"Thin" being a relative notion, I don't know if the paper I can get and use is thin or not according to your references. But I know for sure that it curls a lot if I use it with water and no adhesive......

Then it's (absolutely) not thin enough.
Has to be paper backed (not cloth - wrong material altogether for flattening). Though I notice "latex" backed in some ads - don't know if this is the same stuff, probably is - makes sense - the water (or white spirit) helps it stick by "suction".