Introduction: New Sole for a Wooden Plane - Complete Restoration
I am rather a hobby bowyer than a woodworker although I love to work with wood traditionally in general. Many people around me know this and so I often get free offers from generous people. This may be a good piece of wood, old furniture or tools.
This time I was offered a set of wooden planes from eastern Germany. The maker marks on body and irons show that they are at least 70 years old. Their owner passed away since years when the iron curtain was still existing and nobody really felt responsible for maintaining them since then. They basically were (ab)used by anybody who had access to the workshop of a company that wasn't about woodworking at all. So blade and body were in pretty bad shape when I received them. A different person might have just turned the offer down as wooden planes need a bit more effort to maintain and experience to set up than iron planes. They do their job well though and it was a generous offer and so I decided to put some love into them to honour the gift.
I will show you how how you can restore iron and body of a wooden plane in the following.
Step 1: Tear It Apart
First I removed the iron from the body by tapping on the sides of the locking wedge with a mallet. The old varnish smelled like gasoline which came from a common mixture that was used in the GDR. This was rather annoying for me and so I started to strip it off with 80 grit sanding paper.
The handle was pretty loose and easily came off when I pulled on it. At a tighter fit I would have used wood glue but it required epoxy to fill the gaps here and get the handle mounted firmly again. A clamp that wasn't tightened too much held it in place for drying until the next day. In general the narrower the mouth of a plane is the finer work you can do with it. This one was either widened to more than a centimetre (1/2") to do very rough work or opened due to setting the sole many many times. One option was to fix it with a patch but as the existing sole was pretty much worn out I decided to give the plane a new one.
At first I needed to flatten the bottom to have it levelled. A good way to achieve this is to glue sanding paper to a trued surface like a glass plate or a piece of counter top. I attached it with double sided tape but spray adhesive works just as well if not even better. You need to hold the plane as straight as possible when you push it over the sanding paper or you will get a tilted bottom. I used 80 grit for this step. Afterwards you can see where you still have low spots. The surface needs to look the same everywhere.
Step 2: The New Sole
A plane's sole should be made from hard wood that doesn't wear out easily. I decided to use hornbeam as it would give a nice contrast to the beech body. Luckily I had a log laying around from which I could just cut a piece of the size I needed.
To get it levelled I used a poor man's router that I built from a chisel. It's basically a piece of wood where you drill a hole that is slightly tighter than the chisel's through which you than tap the chisel. As my iron angle was at 45° the board needed to be as thick as the existing size of the mouth minus the preferred size. Before I glue both flat surfaces together I use some soap water to get rid of oils on the wood. Otherwise the adhesive may not stick well.
In the following I attach the new sole with some epoxy. Clamps help to get a good fit. I only tightened them so much that the epoxy wasn't squeezed out again. After a night of hardening I removed the excess wood around the plane's body. To get it flush all around I ground the rest down on my counter top with 80 grit sanding paper. I also used it to level the new sole. Checking the heights on all sides with a calliper made sure top and bottom were parallel to each other. Usually you would true the sole with another plane but as I didn't have one that already was levelled I needed to come up with this solution.
Now that the new sole closed the old mouth I needed to create a new one with a chisel. Using the chisel with the bottom side pointing to the body would compress the wood that is going to be removed and thus letting it work against you. So it's necessary to first create some space. This is done by having the chisel's bottom face to the hole while you tap it along the inner mouth faces. As soon as I created a slot in the middle I could turn the chisel around to let it exactly slide along the old mouth opening. With the new mouth I could start to level the sole. Scribing marks on the bottom helped me to identify low spots after a pass with 80 grit sanding paper. You need to continue sanding until all marks are gone. Afterwards I made additional passes with 120 and 250 grit. The sides of the plane were smoothed alongside. All edges are pretty sharp after such treatment and will leave marks if you use the plane like this. The edge in front of the mouth needs to be kept as sharp as possible to hold the processed wood down as close to the blade as possible. As it faces away from the typical plane moving direction it won't leave any scratches on the surface. The opposite edge was slightly rounded with a fine file. Passes on sanding paper rounded the outer edges.
Step 3: Step 3: Finish the Wood
Wiping the surface with a soaking wet cloth got me rid of the sanding dust. This furthermore makes loose fibre ends stand up after some drying time. A final sanding with 400 grit then created a really smooth surface.
I like to have kettle boiled linseed oil as finish which smells so much better than the old gasoline varnish. It's different from pure oil as it hardens a lot faster. That's also why you should but used cloths into water because otherwise the hardening process and the big surface area of cloth may create so high temperatures that it self-ignites. That's not a problem on the treated wood itself though. As a simple tool this is in principle already too much work put into it but I gave this piece full of memories another sanding with 600 grit and two more coatings with kettle boiled linseed oil.
Step 4: Step 4: Restoring the Blade
To get the rust off the blade I wanted to use a method I had seen in a video. So I ground it on a 80 grit sanding paper and then on 250, 1000 and 3000 grit water stones. Experience shows that using a copper brush bit with a drill machine works a lot better - at least for me. Don't forget to wear safety glasses with the latter method as pieces can fly off.
It was now time to get a sharp edge on the iron. Put the stoned completely into water for about 15 minutes before you begin. If you already used them a bit you also need to flatten them. I recommend to use a stone holder to keep the stones in place during the sharpening process put putting them on an anti slip mat or wet dish towel also works okay. Every time the stone gets dry add some drops of water and don't wash away the slurry. It's what actually sharpens the blade.
Similar to using a pencil on the sole using a sharpy to mark the grinding area helps you to identify low spots after grinding. Start the main grinding process by placing the iron flat side up on the stone at about 25°. You can feel the correct angle when you tilt the blade up and down as long as it has been sharpened properly before. Make a few passes at 30° to create a secondary phase when you are done. My experience is that you don't need to create an absolute flat grind. Having a bevelled grind seems to be just as sharp. I started on 250 grit and went over 1000 to 3000 grit.
When you are done with the main surface tilt the blade sideways to round the edges. This prevents the plane from leaving marks on the processed wood. Also grind the back of the blade absolutely flat with each stone. Your blade only gets the sharpness that the back allows. The problem is that grinding the complete back would wear out your stones a lot. So you put down a piece of e.g. aluminium on the side of the stone, put the blade back down on it sideways and grind a micro phase on each stone.
To get the blade really sharp I glued a piece of old leather to a wooden board. Afterwards I rubbed some polish paste on to it. Now I put the blade's angled phase on the board with some good pressure and pulled it back. This should create a burr. Place the back flat on the leather and pull it back under pressure as well to get rid of it.
The chip breaker need to sit absolutely flat to lift the chip away from the cutting area properly. So I also refined its edges on the water stones. Blade and chip breaker got a nice coating with Ballistol oil to prevent them from rusting. Fasten the chip breaker about 1mm (1/25") from the blade's tip on the blade's back. Don't hold the blade in your hand or you may ram the screw driver into your hand when you slip off. Better place it flat on a table.
Step 5: Step 5: Getting Things Together
Some people like to put their finger under the mouth when they insert the blade. I simply place the plane's body flat on a piece of straight soft wood. Slide the blade in on the mouth's bottom with the chip breaker facing up. Then get the wedge in for a tight fit. Some few gentle hits with a mallet are absolutely sufficient.
Control the blade position by looking along the sole. If you need to correct something take the plane so that one of your finger touches the blade and can feel the adjustments. A tilted blade needs to be hit on the side at the top. Hitting it straight lets it stick out a bit more. When it sticks out too much hit the plane's body on the back. The inertia will keep the heavy iron in place while the light body slips down. As the wedge also slides out a bit you need to give it a gently hit afterwards to fasten it again. Adjust it in a way that you can see through the shavings you create.