How to prevent second kerf when resawing board by hand
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Hi,
Hoping that someone can offer some suggestions to address the following problem.
Last weekend I resawed a 1 1/8″ thick 2 1/4″ wide walnut board down to two 1/2″ pieces with absolutely no problems. Well, it was a bit of a workout 🙂
Today I resawed a 1 1/8 thick 6 inch wide walnut board around 16″ long with a goal of getting two 3/8″ thick boards at 6″ x 16″. I noticed problems on the back edge when I got about half way down. I could tell it was going off track, but could also feel that the saw was hitting an edge inside the cut where I could tell I was actually through. Realizing that things were going wrong I started again on the opposite end and met in the middle. Having completed the cut and taking the two pieces apart it was obvious that I’d gone off track and created 2 saw kerfs on the inside of the cut. Fortunately the second kerf did not go too far in and I was able to plane the two boards down to 7/16″, more than I need, but very close.
My current technique involves 4 squaring the board to start off to take out any twist and flatten to give parallel faces to the board. Then marking a cut line in the center on the edges and ends of the boards with a marking gauge, darkened with a sharp pencil. Then in the vise, end up, and making a starting cut with a rip tenon saw to get a nice straight line. Then with a 20″ 7ppi rip panel saw splitting the line. Going slightly deeper on one edge, then flipping the board around go deeper on the opposite edge. 20 strokes of the saw each time and making slow but definite progress.
Could it be that once into the end I should keep a more constant angle of attack with the saw? I think that I may have been altering that angle. Other than that I really don’t have any ideas on what I am doing wrong.
If anyone has any recommendations I’d love to hear them. My next project will involve resawing a 10″ wide 1 3/4 cherry board down its length (Over 3′). Hoping to get 11/16″ or greater and I really don’t want to mess up this board as it’s quite a nice one.
I wish that I’d taken a photo of the second kerf 🙁
Many thanks in advance!
PaulI think, the best hand-tool for resawing is a frame saw with a fairly wide blade under high tension. It should actually be quite large for 6″ or 10″ wide boards. A wider blade will provide a straighter cut, but of course, you have to aim better at the beginning. another advantage of the wide blade is, that even if you push down a bit too hard, it won’t flex so much (and change direction). Of course, you need a frame saw, where the frame can be rotated out of the way.
Anyway, you have to allow a certain margin of error. Sawing onto a thin line is almost impossible for us human beings. But we can saw along a line and make sure to never cross it. We can also saw in between two lines (that are reasonably far apart from each other), if we want to keep the wood on both sides of the cut. There is always a plane for the required accuracy.
I wonder, if your cut was clogged with saw-dust, when you had the trouble on the walnut board – easily happens, when the saw is too short or if you don’t use the full length of the blade; the dust needs to be “raked” out. But it could also have been the grain playing tricks on you.
If you don’t insist on hand-tools, a large band-saw with a wide blade might be the easiest option – not necessarily the best though, and quite expensive. Making a frame saw with a tilted blade might be the cheapest good option.
Dieter
Thank you Hugo,
I did some research and it looks like building a frame saw is probably the best option. The walnut project is for a box to contain the disassembled bow saw that I just completed, so building a frame saw is certainly possible. Unfortunately the band saw is not an option. I work in a shared basement in an apartment building so, whilst there’s space, the noise would be an issue. I cringe when sawing and chiseling mortises even now, but the neighbors are pretty cool with it.
I may try another pass with a stiffer saw in the mean time. The saw I was using was a Lie Nielsen 20″ panel saw and it’s very thin and flexible. I have a 26″ 5 PPI Pax rip saw, so it could be that the Lie Nielsen is too short for the job, or too flexible. I was definitely using the full length. I still have plenty of the walnut left and on seeing the photo of the box so far my mother would like one to hold her watercolor brushes.
Anyway, thanks so much for the help. You have me thinking!
kind regards,
Paul
Hej Paul,
Tom Fidgen (‘The Unplugged Workshop’) has a YouTube series on what he calls a kerfing-plane, which in one version is like a plough plane with a saw blade. It is used to create an initial saw kerf all around the stuff that is to be resawn. The associated frame saw will follow along the kerf created, as that is associated with the lowest resistance.
Albeit an extensive project, once made resawing becomes a lot easier. Saw blades to the plane and frame saw can probably be ordered from Thomas Flinn-Garlick. They also have the nuts necessary.
For $275 a complete kit for both the kerfing plane and saw can be ordered from Bad Axe Toolworks (a bit rich perhaps).
http://www.badaxetoolworks.com/kpfs
Kind regards
/sojThe kerfing plane looks nice. I was about to suggest making your own, then I watched part of the video. Of course, you could use plywood instead of plain wood, saving you a lot of squaring etc. It might have a shorter life, but for the wide cuts you are planning, precision might be more important. I consider making one for myself, because I want to cut a lot of planks for a model sailing boat, about 1/8″ or 3/16″ thick. If I make a long enough blade, I might even be able to cut the planks with the kerfing plane alone – or perhaps make the blade adjustable. It can serve to cut various small strips for model building from wood that is harder than balsa (usually pine and beech).
Thanks for the video, it was very inspiring!
Dieter
Many thanks Dieter and Sven-Olof,
The kerfing saw looks like a very good idea, although you would really need an adjustable fence. The frame saw sounds does like the long term way to go. I’ve not watched all the Tom Fidgen videos, but I shall. I think they did mention an adjustable fence version of the kerfing saw.
At a pinch do you think that a plow plane with an 1/8 (3mm) blade would put me in the ballpark? Go in say 1/4 inch (6mm) deep and have that provide the path of least resistance for the saw?
I will consider the Bad Axe kit. $275 is a little up there, however it’s a cool project, would save me the sourcing of all the components and if it prevents messing up on some nice boards it might just pay for itself.
In the short term I’m going to experiment on more of my walnut. I’ll use the plow as a poor man’s kerfing plane, use the longer, stiffer courser PPI toothed saw and focus on technique. I do suspect that lowering in the cut too far and correcting to stay on the line at the same time might have caused the drift towards the back of the saw. Also correcting the direction may be an issue, perhaps better to go back up an inch or two and correct the cut that way.
I understand the need to leave enough stock for a margin of error. Fortunately with the walnut board I left enough to get the pieces thick enough despite the double kerf problem.
I’ll keep you guys posted on my progress!
Many thanks for your time.
Best regards,
PaulLot of good advice above. Ripping little sticks is easy, ripping boards of more normal dimensions is non-trivial to very difficult depending on the details, that’s why Paul uses a bandsaw even in some of his videos, and why the hand-tool-only crowd has rediscovered the big frame saws of the past.
For the OP, if it’s a really special board I’d just take it to a shop and have them put it through their bandsaw if you can. Don’t want to ruin a special board, and there could be surprises, such as hidden knots or areas of tension in the board which make ripping very demanding. If that’s not an option, practice a lot first, and let us know how it went!
Just another thought – after Paul uses the poor man’s beading tool, he crisps up the bead with a saw kerf. A slightly sturdier version, used from both edges and followed up with a tenon saw might achieve something similar to the kerfing plane, at lower cost.
Paul
One thing that is not clear to me is whether the set Bad Axe Toolworks offer is with an adjustable fence or not. Mr Fidgen initially made for a fixed with, and then later added an adjustable fence
http://www.theunpluggedwoodshop.com/the-kerfing-plane-part-three.html
My memory is like a semi-domesticated black hole. Some engrams just disappears, but I think there has been a post here on the use of a router plane, equipped with a fence and inlay cutters, to start the kerf, which was then deepened with the use of a backsaw supported by a fence.
/soj
Instead of the kerfing plane, you can use a tenon saw or any other saw with a blade with free ends.
If you make your own kerfing plane, you can make one block as the fence, an extra block to set the distance to the blade, then a last block with a slot to hold the blade. All blocks are screwed together. See attachment for a simple drawing. This can be made by plywood. You have to use the blade to cut the groove into the holding block (orange). Add handles as you like…
Dieter
Thanks Ed and Paul,
I’m going to practice more on my walnut boards and try to perfect there before touching my nice cherry board. I could find a shop with a bandsaw, but I would rather improve my skills at this point. If I find it’s not working out then the shop is another option.
I will use a tenon saw to get a kerf around the board, then use my larger stiffer, 5 PPI rip saw and try to relax into it and let the saw do it’s work.
I’ll post pictures and feedback to all. Hopefully this all works.
Many thanks for everyone who has provided advise,
PaulFinally, I can talk a bit about saw set from my own experience. I have to cut a 2×4″ wide, 23″ long piece of pine into two 2×4″ pieces. My saw is an old panel saw with completely new teeth, which was easier to to than I thought – however, no set at all. It bound after a few inches and it was almost impossible to move it any further. Now, with a hardly visible set, it still requires some strength, but it cuts really well and doesn’t bind. In this context, I also found, that oiling makes a huge difference. A bit more set might help too, but I will finish this cut with the current set.
I saw at an angle of about 45°. When I get away from my line, I go back a bit and saw down to the last depth with a higher angle, perhaps 60° (closer to horizontal). This worked fine so far, I got 10″ done and I am on my line.
Dieter
PS: My method on this cut has a flaw: I only marked one side and I am not sawing from both sides, so the other side could be way off already. In fact, it isn’t, but I cannot control it while sawing. Doesn’t matter, I can live with as little as 3/4″ thickness, if I have to plane down that much.
Here’s a picture of the end product with the walnut. It’s a box for the hickory bow saw that I recently made. All pieces were resawn from the same board.
So next it’s onto the cherry board. I had planned to rip the whole board in one shot, but after reading the replies to my original post decided that would be a bad idea. Much better to rip the individual pieces and resaw those.
The next two pictures show my progress on those components. I marked two lines about 1/8″ apart to saw between. The first piece 12″ long x 5″ went pretty smoothly, but I do still get some quite deep gouges from the saw inside the cut. I’m using a 28″ 5ppi hand saw.
The next board was more tricky 18″ x 5″. Cutting from both sides, one side went off and was very difficult to get back on line. You can see this is the side where the cuts appear shorter. Learning from this, the next time I will pre-kerf the cut on both sides using the same hand saw, but clamping a straight piece of wood to the plate to create a very long ‘back saw’.
One thing that I did find useful was to cut 15 strokes from each side at an angle of around 60 degrees, then go horizontal to clean out the middle. Plenty of oil on the plate helps and you can see the oil can in the photo and the oil on the inside of the cut.
I only need 5/8″ thickness and I have way more thickness than I need, so it will be a planing workout in the next couple of days.
Regards,
Paul-
This reply was modified 7 years, 6 months ago by
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I usually use a backsaw as a kerfing plane and go al way around the board about an 1/8″ deep. Then start resawing flipping the board about every 15 strokes. I do notice that when I start getting tired, my saw is mote likely to drift because I loose focus and my form gets sloppy.
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