Abrasive for lapping...

[LancsRick]

Yup, I'm opening this can of worms!!

I'm starting to get into restoring hand planes, and recently was given a batch of 13 which I'm working through.

Currently I'm using some flat glass and waterstones. Two issues with that - firstly I'm chomping through waterstones when lapping the blades, and secondly I seem to get some slip in paper at times so things deviate from being flat.

My next step would be to invest in a set of diamond stones, or at the very least an Extra-Extra Coarse diamond stone to flatten the backs and also flatten the waterstones. I'd still chomp through stones, but at least everything would be easy to keep flat.

Are there any other thoughts to what I've suggested please?

Thanks.

 

[Ttrees]

I have a long plate about 5 or 6" wide (at least wide as the paper)and say 40" long for the job.
I go into my local small hardware store, thats the only place I can find it sold by the meter,
less than a pound a meter, and dont put any creases on it when rolling it up....
(or whatever the contrary fellas system is :roll: )
I then clamp the paper to the bench with a flat bit of a door stile, bump up the lapping plate and crease the
paper with plenty of pressure over the plate and repeat on the other side, dont cut the paper as you will be wasting
a good few inches.

You can get a really good stretch on the paper by loosening the clamp a bit, and giving the block a tap.

Keep it clean very often (every few strokes) as the particles on this abrasive paper tends to wear off quicker than the good stuff.

Good luck
Tom

 

[Phil Pascoe]

How much are you flattening? You don't need much of the blade to be flat.

 

[LancsRick]

I tend to do the usable portion of the blade, so less than an inch normally.

 

[Jacob]

Yup, I'm opening this can of worms!!

I'm starting to get into restoring hand planes, and recently was given a batch of 13 which I'm working through.

Currently I'm using some flat glass and waterstones. Two issues with that - firstly I'm chomping through waterstones when lapping the blades, and secondly I seem to get some slip in paper at times so things deviate from being flat.

My next step would be to invest in a set of diamond stones, or at the very least an Extra-Extra Coarse diamond stone to flatten the backs and also flatten the waterstones. I'd still chomp through stones, but at least everything would be easy to keep flat.

Are there any other thoughts to what I've suggested please?

Thanks.

Don't use waterstones - you have to flatten them - kinda defeats the object! If you've already bought diamond stones use them for your tools and just bin the water stones.

It's really easy to flatten plane soles with thin cheap A4 size wet n dry say 80 grit. Plonk it into a pool of white spirit on your flat surface (I use a machine planer bed but anything flat and impervious will do). Wet it with more white spirit and off you go. For a long plane just use two sheets next to each other. You can do it against a scrap of wood as a fence and get all your scratches perfectly to and fro along the length, looking like precision machining
Having flattened on 80 grit then go straight to 150 ish. This won't remove the scratches but it will remove the sharpness of the 80 grit surface and make it low friction. All you need to do. Or miss out the 150 and just start using the plane - the sole will soon loose it's surface sharpness and become low friction.

Having followed this debate for what seems like 100s of years :roll: - I'm pretty sure that by hand there is no more accurate way than the above. Also cheap easy and fast.

PS the wet n dry has to be cheapest thin paper backed. Cloth backed no good as won't stick down flat enough

 

[Harbo]

Another method, as I had the materials to hand, is to use valve grinding paste on an acrylic sheet - flat glass would work too.

Rod

 

[Jacob]

Another method, as I had the materials to hand, is to use valve grinding paste on an acrylic sheet - flat glass would work too.

Rod

Wouldn't the acrylic/glass sheet get ground away faster than the metal?
The advantage of paper is that the flat base, whatever made of, is untouched, the paper and the white spirit being the only consumables. Could use water - but not on my planer table.

 

[ED65]

My next step would be to invest in a set of diamond stones, or at the very least an Extra-Extra Coarse diamond stone to flatten the backs and also flatten the waterstones.

I am a big fan of diamond plates, not least because I've never managed to wear one out personally, but you really don't need one to deal with old plane irons in need of restoration and edge prep. Notice how I carefully avoided saying lapping the backs flat there

Standard coarser diamond plates are aggressive enough for standard duties but they are not particularly coarse in most cases and if the task is lapping out significant pitting then you might want/need something a step up from them. A short length of 80# abrasive roll, paper or cloth, stuck down to a piece of chipboard or plywood should do everything you need .

If you do want to go the route of diamonds avoid the name brands and get something on Aliexpress for under a fiver. I believe there are one of the ebay sellers selling similar who don't charge shipping so prices are similar. 150 is probably coarse enough for most people but 120 and 80 grit are available if you wanted.

 

[custard]

This is the set up I use for flattening off plane soles and the backs of irons.

Couple of things to note,

-stick a little block of wood to the plane iron with double sided tape, it saves your fingers and allows you to get pressure in the right place. If there's any pitting this is a long job starting at 80 grit or coarser, so it makes sense to give yourself every assistance.

-use a 1 metre belt of sand paper (Axi sell a very good cloth backed Hermes version in small quantities), the job goes much faster if you have a reasonably long stroke and you're not changing direction every foot

-you could just cramp the sandpaper down to the machine tables, but I don't like the thought of getting steel fillings into the machine's bearings or electrical components, so I use MDF/Glass on top of the machine table and hoover up the swarf at regular intervals

-I go from 80 grit through to 240 grit, then finish the sole with Autosol and wire wool. Most of the effort is at the 80 grit stage, never change up a grit until all you're doing is scratch removal

-the sandpaper isn't glued to the glass, the glass plate is just shy of 1 metre so the ends are tightly secured under screwed down battens

 

[LancsRick]

Thanks for all the replies guys, really useful. Going to try a longer setup with something on the blade for grip.

The comment about getting diamond players from aliexpress/ebay - is that not a false economy? I had some faithful ones once and they were knackered in short order with the diamonds coming away from the substrate.

Lots of ideas for approaches I've not tried, so thank you.

 

[TFrench]

The ultex ones from ITS are good - I've been using mine for ages with no delaminating. The do they for about £10 each occasionally.

Custard, definitely setting up like that next time I have to lap a sole!

 

[Harbo]

Another method, as I had the materials to hand, is to use valve grinding paste on an acrylic sheet - flat glass would work too.

Rod

Wouldn't the acrylic/glass sheet get ground away faster than the metal?
The advantage of paper is that the flat base, whatever made of, is untouched, the paper and the white spirit being the only consumables. Could use water - but not on my planer table.

The grit embeds itself into the plastic or glass to form an abrasive layer.

Rod

 

[Phil Pascoe]

I did a badly twisted Marples 5 1/2 on a 12" disc of 80 grit AlOx clad MDF on my lathe. It took less than two minutes.

 

[Jacob]

I did a badly twisted Marples 5 1/2 on a 12" disc of 80 grit AlOx clad MDF on my lathe. It took less than two minutes.

2 minutes on a 12 " disc - is that a record? :lol:
Takes a bit longer with the wet hand process I've described above, which is still faster, cheaper, more precise and more efficient than all the other hand processes discussed so far.

Fascinating to read about these slow, tedious, pointless and expensive set ups. Presumably they are getting some pleasure from endless fruitless discussions, the shopping and fiddling about in the shed, but it's not for me!
I wonder which would get the prize for slowest, most expensive, least efficient? Some combination of water stones, diamond plates, diamond paste, granite and plate glass slabs, jewellers rouge, long rolls of sand paper, a magic spell or two, a dash of honerite (the most expensive fluid on the planet :roll: ), followed by lashings of Camellia oil?
"First flatten your paving slab" :lol:

 

[Jacob]

......Most of the effort is at the 80 grit stage, never change up a grit until all you're doing is scratch removal....

You can stick at 80 grit, but a plane sole will get "run in" a bit faster if you go straight to 150 grit for a minute or so but it's hardly necessary.
Helps to work to a fence and keep your scratches tidily in line - then your plane will scoot along in a straight line too, until it's lost the sharpness of the scratches
No need to remove the scratches or work your way through the grits, if you just want to use the plane for woodwork.

 

[bugbear]

The grit embeds itself into the plastic or glass to form an abrasive layer.
Rod

Sometimes called the lapping paradox. You'd naively expect the softer material to wear more than the harder material, but in practise the abrasive embeds into the softer material (and therefore doesn't move relative to the softer material) and abrades the harder material.

Thus, a cast iron lap is used by engineers to work hardened steel. They are careful (sometime using a roller) to ensure that the abrasive embeds properly.

Since the embedding is never 100%, the lap does wear - eventually.

BugBear

 

[Jacob]

The grit embeds itself into the plastic or glass to form an abrasive layer.
Rod

Sometimes called the lapping paradox. You'd naively expect the softer material to wear more than the harder material, but in practise the abrasive embeds into the softer material (and therefore doesn't move relative to the softer material) and abrades the harder material.

Thus, a cast iron lap is used by engineers to work hardened steel. They are careful (sometime using a roller) to ensure that the abrasive embeds properly.

Since the embedding is never 100%, the lap does wear - eventually.

BugBear

So you have to flatten your flat thing - eventually?

The thing about paper wet n dry is that it's made for the job and you don't have to flatten anything - other than the thing you want to flatten. Saves hours of flattening time and it comes A4 size in a flat pack. Helps to store it flat between boards (flat!) - but don't get carried away and start worrying about flattening the boards. :roll: