Lapping a plane sole

[halken]

how much is enough? i have tried to smooth the sole of a plane and its quite hard work, i have spray glued some 120 wet and dry to a piece of marble and worked away and obviously the base isnt flat as you can see the low spots. Now is it worth me trying to flatten the base or is near enough good enough. I found this site and i thought i would try to refubish my planes
http://www.majorpanic.com/handplane_restor1.htm
its seems quite straight forward just time hungry but i dont mind that so whats the verdict on the plane sole
thanks in advance for any help you can give

 

[Racers]

Hi,

It needs to be flat at the toe infront and behind the mouth and at the heel, so just lap it untill thoes places are in line, probbaly easer to do the whole thing.
120 is a bit fine try 80 or 60 if it quite far out or a turnip file, here is my set up its over a meter long and the paper is stretched tight and vacumed often.
This is my setup

Pete

 

[halken]

Hi pete that doesnt look like wet and dry paper can any type be used and if so do you still wet it sorry if it seems like a daft question
cheers

 

[Racers]

Hi,

Its Oakey Liberty Green from Wicks I think, used dry I wouldn't use it wet unless I was doing the last polishing up stage, but these days 120 is the finest I go to (lazy) it seems to be enough.

Pete

 

[halken]

thanks pete i,ll give it a go

 

[woodbloke]

Here's my set up:

...a piece of 10mm float glass on some 18mm mdf with two side pieces, the abrasive material is simply trapped underneath each of the side bits and screwed down tight - Rob

 

[halken]

Another good setup i will have to make something like that for my self do you see any problems using marble instead of glass

 

[Dave S]

If you find a glass place and ask for a piece of 10mm float glass, there's a good chance they will be able to give you an offcut which fits the bill. That's what I did, and they wouldn't take anything for it.

cheers
Dave

 

[Jake]

...a piece of 10mm float glass on some 18mm mdf with two side pieces, the abrasive material is simply trapped underneath each of the side bits and screwed down tight - Rob

If it is screwed down tight, isn't the glass just going to bend to match any non-flatness in the mdf sub-base?

 

[Ironballs]

When I flattened the sole on a plane at the weekend I double side taped a sheet of 180 grit to the outfeed table on the planer, lapped it, took the paper off and was done.

 

[white_sw]

I use valve grinding paste on a piece of granite for sorting out my planes. Well, the ones I inherited that were rusty and badly pitted.
Takes a lot of elbow grease mind you. I've never tried the wet n dry on a piece of glass.

http://www.pvrdirect.co.uk/productinfo. ... Ref=ANG362

http://www.pvrdirect.co.uk/productinfo. ... Ref=ANG360

I was advised to do it this way by a friend who has been restoring and making his own planes for the last 30 years.

Cheers,
Sam

 

[woodbloke]

...a piece of 10mm float glass on some 18mm mdf with two side pieces, the abrasive material is simply trapped underneath each of the side bits and screwed down tight - Rob

If it is screwed down tight, isn't the glass just going to bend to match any non-flatness in the mdf sub-base?

Jake - it might do I 'spose but really just enough to hold the paper in position and stop it ruckling up is what I meant. The mdf is flat anyway so it's not really an issue for all practical purposes - Rob

 

[bugbear]

how much is enough? i have tried to smooth the sole of a plane and its quite hard work, i have spray glued some 120 wet and dry to a piece of marble and worked away and obviously the base isnt flat as you can see the low spots. Now is it worth me trying to flatten the base or is near enough good enough. I found this site and i thought i would try to refubish my planes
http://www.majorpanic.com/handplane_restor1.htm
its seems quite straight forward just time hungry but i dont mind that so whats the verdict on the plane sole
thanks in advance for any help you can give

Ah, the old, old question.

While Yahoo deign to continue running Geocities, here's my old, old answer:

http://www.geocities.com/plybench/flatten.html
http://www.geocities.com/plybench/flatten_theory.html
http://www.geocities.com/plybench/flatten_practice.html

Two words on the "lapping" technique: "beware convexity".

BugBear

 

[Jake]

The mdf is flat anyway so it's not really an issue for all practical purposes - Rob

Yes, I agree with that bit, just that I wasn't sure how much the glass added to the set up given your description, but if it is actually light tension then it probably wouldn't distort that much.

 

[ivan]

Just a thought - how do you know your marble is flat? Generally you need the flat surface about 10x flatter that your desired plane flatness. Thus to get plane to about 1 thou flat, your ref surface must be better than O.1 thou. One of the cheaper granite surface plates is about this flat, and float glass very much more so. Glass is surprisingly bendy, so you must take account of this too!

 

[yetloh]

Bugbear is dead right about convexity; if this is your plane's problem you are better off flogging it on Ebay and getting another. This is why you should always have a good straightedge with you when buying planes. It is almost impossible to lap flat a convex plane as it will rock.

It is also worth bearing in mind that the ordinary Record and Stanley castings are not stress relieved so removing material by lapping a plane (especially if it is significantly out) can release stresses and result in further distortion; another reason to get a good one in the first place.

Jim

 

[bugbear]

Bugbear is dead right about convexity; if this is your plane's problem you are better off flogging it on Ebay and getting another. This is why you should always have a good straightedge with you when buying planes. It is almost impossible to lap flat a convex plane as it will rock.

What's worse - unless you're careful, it's easy to INTRODUCE convexity when lapping, which is subsequently close to impossible to remove.

BugBear

 

[Benchwayze]

Checked with a true straight edge, I found 18mm, melamine-veneered MDF to be flatter than float glass. Backed up with some 25mm MDF, on a stable bench, the MDF doesn't bend at all. It doesn't crack with pressure either.

:lol:

Regards

 

[newt]

John, I agree, I find MDF fine.

 

[Mikey R]

John, I agree, I find MDF fine.

If you use some kind of lubricant, do you seal the MDF with paint or varnish before lapping so that it doesnt get soggy?