Flattening a secondhand plane

[normanW]

I have just bought a Stanley 4 1\2 smoother secondhand,the sole is concave in the centre highest points heel and toe,what equipment do I need to flatten the sole please.

 

[Gary]

How much is the plane out of true by? Place a straight edge on the base and measrue the gap with a set of feeler guages. Knowing how much work is needed is a good start. Too much and your best tool may be the bin.

 

[Philly]

Norman
Some great tips here from our friend Bugbear.
Hope this helps
Philly

 

[Paul Chapman]

With smaller planes (block planes, bull nose shoulder plane and #4 bench plane) I've had success using a large DMT diamond sharpening stone (coarse, then fine then extra fine) using 3-in-1 oil or WD40 as a lubricant. I mark the sole with a waterproof felt tip pen so that I can check frequently how the flattening is going. It's important to hold the plane firmly and keep it very flat on the stone. For anything bigger I would use a piece of float glass fixed to some thick MDF (say two layers of 18mm) and abrasive paper. I think the important thing is to keep marking the sole and keep checking frequently so as to ensure you are in fact making the sole flatter and that you don't end up with something worse than you started with.

Hope this helps.

Cheers :wink:

Paul

 

[normanW]

there is daylight evenly showing across the entire middle its the extreme ends that are high.

 

[newt]

Seeing daylight under a straight edge could be anything from half a thou to several thou, you need to measure the gap with a feeler gauge, failing that try some slips of paper then measure the thickness. Pauls advice is sound he has done a lot of this. The only reason it is a good idea to measure how much is it will give you some idea how long it will take. This will then test your boredom threshold ( it can result in incredible quantities of good old elbow grease), and in the worse case it may not be worth the effort. You also need to assess any errors across the sole, and also to see if there is any twist / wind in the sole.

 

[normanW]

Haven't got anything to measure that fine,but if I slip a piece of inkjet paper between sole and straight edge it is difficult to pull it back out.

 

[Paul Chapman]

Also remember that the sole doesn't have to be flat all over. As long as it's flat at the front and back and around the mouth a few hollows elsewhere won't matter. I'd give it a go - it's quite satisfying gradually seeing your plane performing better and better as the sole becomes flatter. It might take a while but it's something you can have a few goes at when you have a few moments to spare.

Cheers :wink:

Paul

 

[Newbie_Neil]

Hi Norman

Welcome to the forum.

Cheers
Neil

 

[ike]

Haven't got anything to measure that fine,but if I slip a piece of inkjet paper between sole and straight edge it is difficult to pull it back out.

Approximately .004" then. Not too difficult to flatten that amount.

cheers,

Ike

 

[bugbear]

I have just bought a Stanley 4 1\2 smoother secondhand,the sole is concave in the centre highest points heel and toe,what equipment do I need to flatten the sole please.

Other people have pointed out my site, so I won't repeat that.

But...

The most important question is does it NEED flattening?

I would advise working on an overall cleanup, and lots of attention on the blade and cap-iron before expending sweat on the sole.

The question that never gets a confident answer is "how flat is flat enough"

My site merely tells you how to achieve flatness (fairly extreme flatness, if you spend enough time and care) <i><b>having decided that you need flatness.</b></i>

For smaller planes, a piece of thick float glass works well, although it's not so easy to coat with the blue as a slightly textured surface plate.

In the process I advocate, there's not too much pressure involved when using the flat reference surface, so absolute stiffness is not required.

BugBear

 

[normanW]

Cheers guys think I might give it a go with the plate glass.and especial thanks Bugbear.