Tuesday, February 2, 2021

The mighty plough plane


Or plow plane in the US.

Here is a tool that doesn't get much love anymore.  True, some where rather showy and expensive, often used as presentation piece.  But for the usual working man, they may not sport all the bells and whistles, be a tad cankerous to adjust the fence straight and parallel to the body and stay there !

Nonetheless, they are still useful in your modern tool kit.  Especially if you ever try to cut a groove with a dado set on a table saw on smaller pieces and would like to keep all your fingers intact.

My wooden Plows.  From L-R
Okines, London 1740-1770 (one of my oldest tools)
G. Davis, Birmingham England 1821-1876
Greenfield Tool Co , Greenfield USA 1851-1883
All of them are shown with their irons removed.  
They are also shown in the order I acquired them

They are quiet, efficient and yes, do not takes much time to cut your grooves.  Because they are set rank. Hint, the cutting end is rather stout.

So lets have a look at common ailments and how to address them.

Disclosure, this blog is the result of a back and forth conversation via Messenger with a friend who just acquired one.  

My friend in question.  Did not realized until he mentioned it
 that he was on the latest Lee Valley catalog cover..  It's a small world after all (sing along :-)

With his permission, here are the pics of his new acquisition.  These next 4 pics from Sylvain, Bazz, Bazinet.  We met years ago in Ottawa.  We were both members of The Ottawa Woodworker Association and the Outaouais Valley Wood carvers .  If you have such clubs were you live, highly recommend joining one.  If you want to see what a sharp tool looks like, ask a carver, we are fanatics about our cutting edges.  Fun fact, we look at the cut surfaces left by the tool when critiquing carvings :-)

Auburn Tool Co NY 1864-1893.  
Model No 90 Handled plow plane.
Yes it is missing its irons.

Notice the fence is skewed a bit

Yes, it is a tad grimy and would benefit from a light wash.
The plane body and fence are Beechwood, the arms Apple wood and the locking nuts Boxwood

For comparison, here is a "new" one from Jim Bode site

And here is a rarely seen plow plane :-) (same Auburn model).
Yes the fence is mounted up side down... Why, oh why?
If you do not know how a tool work, please do not take it apart :-( 
From Rubylane antique

What I normally used to cleaned the wooden parts of my tools.
Not shown is the first thing I use to clean them Murphy oil soap

And the stuff I used to clean the metal parts.
Missing is AUTOSOL which I used last to clean and protect.
Krud Kutter I used first before dunking parts in Evaporust, making it last longer.
The two sizes containers of Evaporust, I used in the past, 
now I only buy it by the jug having a "few" tools to clean :-)
I keep the empty containers to re-used the stuff many times and 
not putting the dirty stuff back in my clean jugs.
BTW being loaded with iron particles once used up, it does wonder to kill some weeds and keep your grass greener :-) Yes, very safe

There are wood and metal plow planes, for this entry we will be focusing on the traditional wooden plows.

They originally came with a graduated set of 8 tapered cutters. Most often, they will be found in the wild with either one single blade already installed and the set long separated and MIA, or none at all.

My Harlequin set of plow cutters.
Some are sneck irons, some are straight.
The sneck feature is at the top, enabling you to tap the iron backward to reduce the cut. 
Not all irons have it and his Auburn does not.

 Can we get replacement blades?  YES, singles or sets often shows up in tool mongers inventory. Expect to pay about US $100 for a complete match set.  Expensive?  As with all antique tools, supply is limited and spare parts will cost you more than what you pay for the tool.  And if you are lucky you can sometimes spot them in misc. box of hardware at flea markets sales.  Often mixed in with chisels and screwdrivers.  I always rummage thru those and found the occasional good chisels without a handle for peanuts (pocket changes)  And yes the odd plow cutter.  Hint look for a groove in the back.

HOWEVER not all irons will fit your plows.  First they are tapered.  That meant that unless you have the right taper in conjunction with the tapered wedge and the ensemble fit nice and tight in the tool body, we have a problem.  You may not be able to chinch the blade down securely or be able to adjust out enough blade to cut.  Remember we want to set it up for a rank cut (thick shavings)

Look how thick the tapered iron is at the cutting edge.
I measured mine, most are 5/16 in thick and tapered down to 1/8 in.
I have what seems to be an oddball that is only 1/4 in thick at the cutting edge

Three solutions: 1- Make a new wedge (easier) or 2- Replace the iron. Easiest, if you have another, or 

3 - Modify the iron to suit (not recommended).

Another issue, is the centering slot in the back of the iron.  These were hand cuts and it shows.

Common issues: The slot is not straight up and down, the slot does not match the plane sole (metal plate on side, call the skate) or is offset enough to cause problems.  Iron should fit the skate and be centered

More often than not the slot is too narrow to fit on the sole plate.  That last part is crucial to ensure a good solid fit that will not be deflected in use.  I repeat, for proper operation the slot must engage the sole piece.  That is actually easy to correct, more latter.

Poor centering caused by a thick plate unable to
 sit inside the V groove in the back of iron

If your plane did not came with a set of matching 8 graduated cutters (as they are most often found) you can get by with an Harlequin set.  Meaning the set is made up of various makers, which may or may not fit correctly.  Don't panic...yet :-) 

A complete match set of plow planes irons from 1/8 to 5/8.
1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 5/8
Notice how the cutting end is cut narrower, 
the top of the blade cinch down by the wedge remain constant width.
That is done to keep the cutting edge centered on the skate   
Pic from Jim Bode tools

An easy way to address the centering problem with the iron slot not engaging the skate, is to simply file the skate in a small V shape.  CAUTION, go easy, keep it centered by using the same amount of filing on both sides. It DOES NOT NEED to be wide nor coming to a point (sharp) and you DO NOT want to shorten the skate.  We just want to taper it down to engage the V slot in the cutter. Stop often to check your progress.  The skate does not need to fully seat inside the groove, it just need to register. You can also widen the groove in the back of the cutter with a saw file (triangular) In both case remove just enough to make it register.

Of course its would be easier to remove the skate first, but caution, the screws may be really rusted in place and they may snap on you.  A bad thing :-(  Shoot them with a penetrant liquid, let it sit for a while, scratch the slots clean  and make sure to use a proper fit in screwdriver.  If it does not budge STOP leave it alone and regroup.

Notice how the iron slot is not really engaging the skate.
Skate edge is way thicker than the narrow slot.
That could cause the iron to be skewed under pressure during the cut, ruining your groove.
Remember we are taking a thick shaving.

Other issues to look at are the body.  Is it flat or curved?  It must be flat.  Similar for the metal sole plate (skate) and the fence.  Note that the body sides are not too critical, they can have a small hump or hollow, but we want to spot the bowed ones.

I'm using my LV winding stick to check it.
Plenty straight, we do not need machinist precision.
The long shallow U shape piece of metal is the Depth "suggester". 
Yes, I know, its called the depth stop, but as in most planes, wood or metal, they offer more a suggestion than definite depth stops :-) Some like on his Auburn have a screw on the side to lock the setting.  Remember to loosen it before attempting to reset it 
Check its operation.  While the sole of it is steel the screw mechanism has a brass knob 
on top and they sometimes froze solid.  
DO NOT force it, try lubrication, WD 40 or liquid wrench should do the trick. 

and the other side.  Good to go

Next check the skates alignments.  
In this pic, the front plate is not quite in line with the back one
There is a slight bend toward the cutter.  Either remove and fix or simply file it straight, gently.
In my case it so small as to not cause me any problems. So I left it alone.
Only catch is, as you get down to the smallest sized iron, it could cause you some grief.
But being an old military man, I tend to pick my battles wisely. 

Similarly check the fence surface bearing on your work edge.
They get wear and are sometimes damaged.

My almost 300 years old Okines has a damaged tip on one side of its fence

Which someone long ago try to fixed with two nails.
That poor thing need a lot of tender loving care, but because of its age and rarity,
 I must be very conservative in my attempts to fix it.
Not a plane in my user stable.

How is the fence adjusted and locked in place? There are no shortage of patented ideas to solve the vexing problem of getting the fence to move straight with out skewing and to lock it down once set.

Once unlocked, the fence should move smoothly without much wobble.  Often times, the arm get lodged solidly inside the plane body since they are a tight fit to start with in a bid to minimized the play.  Years and years of improper storage and the wood swell and shrink causing it to jam.

My Okines had its arms pretty well stuck for years, managed to take it out yesterday.  Its been acclimated to my shop for years by now and I run a dehumidifier near my plane till in the summer. 


Its arms are secured in place by a small wedge, one on each sides.
Notice the round finial at the end of the wedge, same shape as the blade wedge.
That is one clue about its old age, they long changed to a more elliptical shape 

Next take a look at the arms that hold the fence.  Often times they are wobbly and can twist.

The G Davis has loose rivets securing the arms to the fence.
Notice the one on the left is slightly twisted out of true.
With the fence removed, there is a lot of play in the arms

The method most often encountered is a single screw from the bottom.
This is the Greenfield one, my woody user.

You can see a small gap, but the screws are tight and so are the arms.  
Its been working fine, not touching it.

Must make them secured.  But I will caution you about wanting to glue down the arms to the fence.

I never seen them glued, just secured by either a rivet or a screw.  You want them tight, but guessing without being glued down and secured via a single fastener allows them to flex a bit as needed without cracking as the body and arms swell and shrink.  You also have a cross grain situation if gluing.

How do you adjust it without being skewed?  Simply place a piece of wood or what have you of the correct width against the plane body and snug up the fence to it. Easy Peasy.  I usually used a piece of wood since it very easy to trim to the correct width.

Then there is the often damaged means of locking the fence down. 

Damaged thread on spindle and or wood nuts, missing or improper replacement wedges 

(as in the G Davis above) etc,

Typical small damages on the threaded arms.
Notice the small chips on the threads.
Nothing serious.  
Missing or heavily chipped (big chunks) threads however are a non starter.
Cannot be fixed :-(

This is how another friend of mine, Matt, solved a problem with a stripped thread portion.  Cut if off and reassembled.  Yes shorter arms but at least useable

There is not much we can do about damaged threads, but as long as the nut can move in and out without binding, we should be good.

Next looks at the locking nuts.

See that darker coloured vertical line on the nut.
When I first saw it I thought it was a drip of paint.
Nope, its a filler to stabilized the crack.
Not my repair

From the top

and the bottom.
Crack ran right thru

Of course that extra space that has been filled has enlarged the inside diameter
 of the threaded nut, but it still work great, and yes it has a bit of play, but chinch tight..
How about trying to clamp the split portion tight while gluing?  
Danger, Danger Mr Robinson, you will more than likely break it

If left alone nut would had cracked apart and probably would had been long discarded, rendering the plane useless.  If you want to try this type of repair caution do not force whatever material too tight, you run the risk of making it worse, or break it apart. Smaller checked cracks can be secured with glue, either crazy glue or epoxy depending on crack width, but be careful not to get glues on the threads and take the nut out first, you do not want to glue it to the arms.

Thinking of making your own or repairing damages threads with a wood threader kit?
3/4 in is just about the right size...

... but the thread pitch is different.
That is the Woodstock threader kit sold at various woodworking tools supplies house.

Don't forget to also inspects the two flat locking nut

That one has a crack also (Boxwood) but still strong and work fine.
Notice the flat side goes against the plane body

While the face with some decorations, goes on the outside.
I often see them installed backward.
But I never saw a plow plane with its fence installed upside down
 before this morning while researching them :-)

Missing wedge or wrong replacement.  You are going to have to make a new one.  Don't sweat it, its not that complicated.  If you want to be period correct for the plane, take a look at the original finial at the end of the wedge, or if too damaged or missing, simply look it up on line, chances are you will find pictures of your plane.  The wedge shape at the end often helps denote a particular maker and period.

The actual angle of the wedge are typically between 5ish and 7 degrees ( in my humble experiments).  But remember that the wedge AND the blade make up the final taper.  

Hard to measured.  Tried various tools, this one was the easier to read.
about 6 ish  degrees for the Greenfield

The two others I could not measure because the finials are sticking up from the incline.
So I lined them up on a flat surface and trying to see if they were close to each other

As you can see, with the Greenfield in the middle,
The one in back G Davis, is steeper than 6.
The one in front, Okines is about the same as the Greenfield , 6 ish

Armed with this knowledge, make a graduated set of taper shaped in thin plywood .  Says something like 5.5, 6. 6.5, 7 degrees, that would help you get the angle of the tapered mortise.  But remember that space is occupied by BOTH the wedge AND the blade.

Another way to guesstimate it close, is to shove in a wad of aluminum foil.  Carefully remove and you get the shape.  That is what I use to figured out the taper of socket chisels.  And writing this I think I`m overdue to make myself a set of graduated templates.  I have a few planes in the cue awaiting new wedges :-) 

Be prepared to make a few adjustments, but remember to keep the surfaces straight and level.  On moulding planes you have to sometimes account for a titled mortise, but on the Plows, these are rather straight forward (pun intended).  If you never tried making wedges, try on a Plow first, lot simpler.  

The other critical part of the wedge is at the end.  When shaped correctly it help curve out and expel the shavings on the side.   Look at the pics above by the angle levels, they are all shaped different.  Since it is sitting much higher than say a molding plane, it would not be too fuzzy and trap shavings under.   

These 3 following pictures are the wedge from the G.Davis plane.  It was originally broken in two, long ago, someone attempt a repair by nailing it back together and using hide glue...and made a mess.  Not sure about the wood species, but it is rather hard and brittle.  The end is polished to a glassy shine.

So when I got it, I try to excavated most of the nail, but I had to leave a piece of it.  I made sure nothing interfered and glue the pieces back (3 and a bit) with epoxy. Its working fine.  I retained the original.

On this side you can see the one glue line.  Does not look too bad...

Until you flipped it over. That nail made quite a mess resulting in a few compound cracks.
Nearly destroyed it but the other end of the nail being clinch over, kept it together long enough 
for me to salvaged it.  I have no idea when that ham-fisted repair was made.
That is the surface that lock the blade down.  I made no attempts to disguised the repair.

On the other side, I was not able to completely remove the nail, so to avoid more damages, I simply left a piece of it then filed it down flat later.  Oh, that rusty nail shine inside :-)

On the other side, you can se two glue lines.
Its been to war and back, and still work

Once you have assessed its condition, look up the maker's marks on it and do some research to get some idea of its rarity or not, BEFORE attempting any corrective actions.  If its a common one (Auburn and Greenfield models shown), I will not hesitate to do some more drastic repairs.   Some are really, worth a lot of money, I would then temper my enthusiasm for repairs and preserved as much as I can.  Even if that mean, I cannot fix it without...  Lots of plow planes were presentation pieces.  Congrats you just made your own :-)

Good news is next time you will know what to look for before purchasing and know how to address common issues.

Bob, getting his BP under control with help from Dr Rudy.

Who then carry on with Diva, either she needs it or not :-)

Bob, who really appreciate that little diversion from Sylvain and the one my friend Chris send me chasing down the ID of an old Canadian military ammo can from 1944.  Very cool, I'm now firing on 5 cylinders, one more to go in this old V6 and just like my former Lincoln engine, my water pump is inside :-)