An Inexpensive 50 Degree Smoothing Plane
by Bob Smalser
This article first appeared as a thread on theWoodNet woodworking forum. It was compiled and reproduced here for easier public consumption. All Text and Images are the property of Bob Smalser.
When finishing highly figured wood, I generally prefer panel surfaces to be planed and not sanded. There's a crispness to a planed and scraped surface that brings out the best in the wood. My power jointer and thickness planer are indispensable, but they are risky when used to surface wood with swirled and twisted grain because even with sharp blades and slow feeds, they like to take a chunk occasionally..usually on my most important piece. Well-entrenched in woodworking lore are the heavy Norris and Spiers smoothers of a generation ago.the thick blades, hand-lapped soles and some with 50-degree blade beds are said to be far superior to their less expensive Stanley competitors with thin, cap-ironed blades and 45-degree frogs.especially when used on highly figured wood.
Next winter I have a job that involves 30 or so cabinet panels of Birdseye maple currently stacked in the bolle in my drying yard, and this renews my interest in trying a 50-degree plane. The old British smoothers are coveted collector items, many worth more than my work truck. Lie Nielsen makes a lovely Bedrock-style 4 ½ in 50 degrees, but they are very expensive, and are still basically a Stanley design. As I have some experience tuning old Stanley planes for comparable performance, I decide to convert a Stanley to 50 degrees and tune it for my purpose.
As in most of my articles, I'll purposely use only tools readily accessible to beginners, foregoing milling machines and the like.and all the work done in a crude, temporary 12' by 12' shop. My intent is to provide a model for you newcomers to the craft who will benefit greatly from acquiring older but high-quality tools in need of a hug for very little money.and putting them back into service without a lot of machines and fancy gizmos you don't have yet. Moreover, with enough practice rehabbing old tools, making new ones like in other articles I've written, and practicing traditional joinery for your workbenches and other shop necessities.by the time you create for yourself a nice workshop and are ready for furniture, you may find you no longer feel a need for all the trendy doodads being marketed at you weekly. I'm not saying that all those expensive tools and jigs aren't useful or don't have a place, I'm merely trying to provide you something to help set your acquisition priorities and encourage the practice of time-tested traditional joinery.
I've had a Stanley 4 ½C Type 11 parts plane for some time..with missing tote and knob, a chipped lever cap and a hairline crack in one corner of its mouth. I don't remember what I paid for it, but it wasn't much, and similar defective 4 ½'s can be had today for less than 40 dollars. The crack turns out to be of no consequence, so I leave it, and turn my attention to how I will change the iron's bed from 45 to 50 degrees.
Laying out the desired 50-degree blade angle against the 45-degree angle on the frog's bed, I have three choices. I could build up and remachine the entire blade-side face of the frog, I can remachine the frog's bed as shown by my drawn line, or I can make and install shims for both the frog's bed and also the screw washers so as to keep the screws plumb when mounted. A large shim the size of the frog's face would preclude the use of the blade adjustments without a lot of additional work. Cast iron is soft and easily worked, but it also cracks easily and filing the frog's bed to 50 degrees would encourage that by making the remaining web to the screw cutouts too thin. I decide to make shims, which have the additional advantage of being reversible should I find I don't like the 50-degree blade.
I measure the shim thickness I need with dividers, select a piece of mild steel strapping scrap to match in thickness and width.
.square one rolled edge, and scribe it in place for cutting. I leave the stock over long because I will also take the screw washer shims from it. I could have also used brass, but this was on hand and the thickness is perfect.
I cut it to width outside my scribed lines.
.and square and flatten all surfaces. Now I have to firmly mount it to something in order to file the sharp wedge shape I need for my shim stock. Doing hand and machine work on small, sharp pieces of metal requires firm mounting, as losing control of the piece in a spinning machine can be dangerous. Engravers mount delicate pieces by placing them in the melted surface of a tub of pitch, which would be my preference but isn't something readily available to the average woodworker, so I'll solder my shim stock to a sacrificial piece of thick steel scrap.
I clean and degrease all my mating surfaces to surgical cleanliness. I'm using a large 8" pedestal buffer for these tasks, but your basic 6" bench-mounted grinder will work just as well.
Then I tin the surface of both my sacrificial piece and my shim stock by heating them from beneath to around 450 degrees.then brushing on flux.then touching the plumber's tin solder wire to the surface, brushing it out to a thin layer as it melts. The sacrificial piece and the shim stock are done separately, their tinned surfaces cleaned, then brushed with flux and placed together. The entire assembly is reheated.again from beneath so as to not burn the flux.and the two tinned surfaces will meld without additional solder. It is always best to tin each surface first.soldering in two steps.to insure thorough coverage. For this job, clamping is not required and the weight of the shim stock pressing downward is sufficient for a secure bond.
When cool, I rough out my wedge shape by removing excess steel on the grinder and sanding disk, taking care not to reduce the thick edge..
.and finish the wedge shape by drawfiling with single cut files. You can see from the filing marks on the surface at the top of the picture that filing a perfectly flat surface is relatively fast and easy as the marks left guide your way through the process. I clean the file with a file brush often as I go to prevent deep scratches caused by loose particles and chalk the file with blackboard chalk to keep the teeth from clogging with shavings.
I test fit the frog and measure the angle as I near completion for any final adjustments required, and scribe for the screw slots required.
I drill the necessary holes on the drill press.I could easily have also done them with a handheld drill after clamping down the work piece.
.and finish roughing out the slots using a cutting wheel in the Dremel tool. In all machine operations, I cut all the way through the shim and into the sacrificial piece it is mounted on. Later, I will clean these slots up with files.
After the slots are cut for the bed shim and two screw shims, I cut them to length with the hacksaw while still mounted, then heat the assembly to the temperature of the 450-degree solder to free them.
I shape and fit my screw shims by trial and error.
.and my three shims are now ready for soldering to the frog.
All mating surfaces are cleaned thoroughly with file and sanding disk to expose fresh metal.
.the mating surfaces tinned.
.and assembled on a leveled stand so that when heated, the pieces will meld without any slippage. Note that in all my soldering, I hold the work pieces with clamps instead of a vise. This makes heating faster, as a large vise acts as a heat sink, dramatically slowing down the process. I use MAPP gas instead of propane because it is hotter and quicker.
The result when cleaned is a neat and accurate shim assembly. All slots and edges are cleaned with round and flat files to insure perfect alignment of shims and frog.
While waiting for work pieces to cool at various stages, I flattened the sole of the plane on my jointer table. First I degrease and blue the sole using cold blue to act as an indicator, and rub the plane on 180-grit aluminum oxide wet-or-dry paper to find any low spots. This trial shows that the sole badly needs flattening, so I switch to fresh, uncreased 80-grit paper lubricated with WD-40 and begin flattening.
I can see from the indicated hollow down the center that this plane had been used extensively to plane board edges instead of as a smoother. I continue from 80 grit through all the grits to 600 grit, each lubed with WD-40 and flattened until all the coarser marks from the previous grit of abrasive paper are removed. I find if I degrease my jointer table before each grit, simple friction holds the paper adequately without the need for messy contact cement.
When done, I still have a tiny bit of hollow at each end of the plane, but these aren't sufficient to matter and attempts at absolute perfection will merely serve to widen the plane's mouth.
You'll notice that the lower tips of the frog are cast at 45 degrees, but a trial fit shows they bear adequately and changing them to 50 degrees may shorten them too much for solid frog fit. I do, however, gently ease the 45-degree rear edge of the sole's mouth to 50 degrees, using the mounted and masked frog face as an index.
As the rear of the frog's bed is now elevated, I deepen the mounting hole for the frog adjustment screw's yoke so it can be adjusted for adequate engagement.
The original frog mounting screws will be too short, so I acquire some Allen head cap screws in 1/4 -20 thread. The thread matches the original Stanley screws at the top of the picture but Stanley used an odd root size between #10 and ¼, so I'll have to chase the holes with a ¼-20 tap.
Using a tapered starting tap and cutting oil, I slowly chase the threads to enlarge the root, swinging the tap handle no more than 30 degrees at a time with each cutting stroke before backing to clean the chips and forcing them into the tap's flutes. I also remove the tap with every complete revolution to clean out the chips.the tap is a tight fit and I don't want to risk cracking the brittle casting.
When the tapered tap has cut a few full-width threads, I switch to a flat bottoming tap and cut to the depth I need. Notice the depth gage.I purposely don't thread any deeper than I need to so as not to risk the casting.
A final trial fitting demonstrates any more filing or finishing needed and I am ready to finish the metal surfaces.
I buff all metal surfaces to a shine with mild green rouge designed for steel (Knifemaker's Green) on a stitched muslin wheel.
I then degrease all parts with trichloroethylene (a strong commercial solvent - wear rubber gloves) and finish with a phosphate cold bluing solution that inhibits rust. The bluing solution is liberally swabbed into all recesses and japanning chips.. allowed to dry..and additional coats are applied with degreased 0000 steel wool rubbing hard to work the phosphate deep into the iron surfaces. This is followed by cleaning with WD-40 followed by a thorough wipe of 30-weight oil and allowed to sit overnight. The oil is essential.. WD-40 alone will cause immediate rust. Later, I will degrease the sole and apply paste wax.
My last task with metal is to hone the blade and chipbreaker iron. It doesn't matter whether you use sandpaper/glass, waterstones, Arkansas stones or carborundum stones.... all can be made to work well and easily.... I see more need to practice rather than to spend big bucks on "systems".
I use the set of 4 Arkansas stones because I have them...but were I starting from scratch, I'd merely have my glass shop make up a half dozen thick glass plates and I'd use plain old alum oxide wet-or-dry paper mounted with spray adhesive (cleaned with razor-blade scraper) and lubed with WD-40.
You can buy a honing guide or simply memorize your angles using a child's plastic protractor to set them. Clamping your sharpening media to a bench set at belt height or just below will facilitate maintaining your bevels without putting some rocker in them when freehanding.although a little rocker in your bevels is no big deal and you will undo it in future sharpenings as you gain practice.
I begin by flattening the lower inch of the iron's back rather thoroughly through all four of my stones.then I hone the main bevel using my coarse stones, followed by tipping the iron up by 5 degrees to put in a small secondary bevel using all four stones. I apply more pressure toward the edges one at a time to ease those corners a bit for the last dozen or so strokes on the fine stones. This rounds the corners, preventing me from plowing sharp furrows at the corner of my blade when smoothing a wide board.
As the original plane iron was well worn, I bought a thicker Hock iron, which should also help prevent chattering as the cutting edge dulls on those last few strokes before its time to resharpen.
The chipbreaker iron is also honed dead flat on the coarse and medium stones to fit our newly flattened blade back.
I finish the blade with a light stropping on the 8" wheel with Knifemaker's Green Rouge.
All that matters is that you get that edge dead straight and this sharp...note the hair above the bevel and piled beyond the bare spot.a painless dry shave is the standard for "sharp". I usually discourage replacing plane irons with any life left in them, but I have to say.this is [I]one fine iron[/I].
I assemble the plane with replacement handles and adjust the blade. I'll test it against my usual smoother, a Stanley 4C Type 11 on a board of Pacific Madrone (Arbutus sp). Madrone is a slow-growing under story tree, than when grown in the deep forests here, twists as it reaches up for sunlight. The pith and grain is generally a spiral twist and the wood is incredibly hard and brittle.it has the appearance of beech but is harder.I mill it for use as stair treads, thresholds, and in other high-wear applications..a good test for any hand plane. As a bonus to the flint hardness and spiral grain, this board has a few tight knots and some corkscrewing pith.
And the new 50-degree, Hock-ironed plane takes clean shavings as if the board were made of hard wax. But so does the old 45-degree, stock-ironed plane, also well-tuned. In fact, I don't feel or see much difference at all..the 50-degree plane is a bit harder to push, but it is also considerably wider.
The Madrone's finish is as good as it gets in woodworking.from either plane.
Hmmmm.. no conclusions at all, let alone dramatic ones.. so I fetch a piece of my figured maple from the stack yard.but alas, it's been bathed in some of our Olympic sunshine and I'll have to wait for it to dry out some before continuing the test.
To Be Continued.
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