Archive for the ‘Woodworking’ Category

Resawing – Dueling Saws

Wednesday, April 8th, 2015

Yet two more poor choices to learn from.

a comparison of 2 cutsWhen starting this batch of resawing, I reasoned that using the plain ole rip saw would be OK because it was lighter and easier to handle than the 24″ frame saw. At one point I did show the frame saw to a cut in process but quit because the frame saw had decidedly stronger set and I didn’t want to resaw a resawing cut. Then, along came comments from others about frame saws. So, out it came for the second half of a board.

The saws:

The plain saw is a Stanley rip saw of 1970’s vintage, 26″ long, filed at 5 ppi, sharpened just before starting this recent work. Plate thickness is 0.034 inch. Weight: 1 and 1/2 pounds.

The frame saw is one I built from a Disston 1897 saw cut down to 24″ It is filed 4 ppi and I’m not sure when last sharpened. It has an identical plate thickness of 0.034 inch, and something like 50% more set than the plain saw. (I remembered it as 5 ppi, but it really measures 4 ppi.) Weight: 5 pounds.

The lumber for this comparison is an 8/4 piece of mahogany, 7 and 1/4 inches wide and 32 inches long. The resawing line is right down the middle of its thickness.

shallow angle cut - bad ideaI sawed the first half with the plain saw (marked with blue chalk in one of the pictures). I added something different to the routine … cutting in from the end at a shallow angle. It was not easy cutting from that direction and I broke the “manhandling” rule. Bad idea! I knew from the feel of the saw that the cut had gone a little wrong, but couldn’t see inside to know how it had gone wrong.

When it came time to cut from the other end, I switched to the frame saw. I kept to the routine prescribed in the previous post, without the shallow cut from the end: the saw didn’t fit well in that position.

The difference is remarkable! While heavier, the weight of the saw makes a bigger difference than I imagined it would. The combination of its weight and slightly stronger set made for both smoother sawing and faster sawing. It was almost twice as fast as the plain saw! Better yet, it has far less tendency to wander. The blade, being held taut from both ends has much less opportunity to go its own way.

my 24 inch frame sawTwo more points to add to the learning:

  • Given the choice, use the frame saw. Even though heavier, the weight of the frame saw is an advantage and the blade under tension adds to accuracy.
  • Avoid that shallow cut that has too little guidance and too easily goes astray. Oh yeah, don’t manhandle it.

Resawing again! How to go wrong…

Monday, April 6th, 2015

Learning to resaw well has been a long journey. With all the resawing I’ve done, I’ve found it’s very easy to end up with something like this: photo of dished cuta dished out area in one board and an matching hump on the other board. That kind of result is rather minor on small boards, or with stock where there’s ample room for error. But as board sizes increase, so do the probabilities and the scale of the mishaps. How do these things happen and how can they be avoided? I picked up some useful suggestions at the School of Hard Knocks.

Long ago, I built  a couple of wonderful small boats. For one of those boats, I made a frame saw and resawed a LOT of cedar into very long planks. (4/4 live edge white cedar, up to 10.5 inches wide and 16 feet long). Minor mishaps there were no problem because the raw boards had more than enough material to produce two 5/16 inch thick boards.  More recently, I’ve resawn cherry and walnut, but on a much smaller scale for desk boxes. Smaller pieces mean less opportunity to go astray.

Now, I’m working on something larger than desk boxes and smaller than boats. My lumber for this project is 8/4 African mahogany that varies from 6 inches wide to 10 inches wide. I bought this lumber from Steve Wall Lumber in Mayodan, NC. They have 20 board foot bundles that are packaged for delivery by FedEx. I bought two bundles and am delighted with what Wall Lumber delivers. Both bundles contained clear lumber, S2S, in generous widths, and easily 20 bd. ft. No end checks, splits, knots or other defects. None! The only one complaining is the FedEx delivery guy who carries the 62 pound packages up our steep driveway. (Takes too much time to get out the hand cart.)

setting a kerfThe project calls for boards 1 inch thick and 3/4 inch thick. With careful resawing, I can get one of each out of an 8/4 board. OK, scant 1 inch and scant 3/4 inch That’s plenty sturdy enough for a project that is not super critical about board thickness. Scant thicknesses will work. But, there’s not much margin for error. Which also means, no room for going astray. However, the boards are long, up to 4 feet, giving yet more opportunity to go astray.

OK. What goes wrong? What causes the problems? In a single word: inaccuracy. BTW, I used my kerfing plane to establish a 1/2 inch deep kerf around all edges of these boards. That kerf is a lot better at guiding the saw than is a pencil line.

Inaccuracy in resawing can come from a lot of things:

  1. Sawing too long from one position.
  2. Guiding the saw instead of letting the kerf guide the saw.
  3. Being too aggressive with the saw — “manhandling.”
  4. Impatience.

No matter what the cause, here’s what happens. Resawing is always done a little from one side, then a little from the other. Switching back and forth frequently eliminates irregularities before they become bothersome. Imagine the cut becoming off by a mere fraction in one direction or the other. Sawing too long from one side lets the problem grow. Then, when you move to the other side, the saw will take the path of least resistance, through that inaccurate kerf. This results in the saw bowing within the cut, creating a dish on one side of the cut. The longer the sawing goes with a bowed path, the deeper the dish gets. Since you can’t see inside the board, the only external awareness you have about this happening is increased friction. It sneaks up slowly, and if you’re manhandling the saw, or holding it with a death grip, you won’t notice the increased friction until it’s too late.

Once a bowed path gets established inside the board it is almost impossible to correct. So, don’t let it get started.

Frequent direction changes are the most important factor for success. Aligning yourself to the work is equally important. As an aside, unlike the boat lumber that I did with a frame saw, I’m cutting this lumber with a common rip saw. Nicely sharpened, but nothing special. It is lighter than the frame saw and has a broader blade that (one hopes) helps keep it moving straight. No matter which saw, the body and saw both have to line up precisely with the cut line.

Stance: I face the work with my shoulders square to the work piece, so that both arms can move as one. I spread my feet about a shoulder’s width distance apart, but position them in a line with the cut. I’m right handed, and place the left foot forward, with the toe exactly in line with the cut. The right foot is back. Why? So I can use the bigger leg muscles to power the work. Using the legs to rock back and forth is far less tiring than just the arms alone, and leads to better accuracy. In fact, when properly lined up, one could pin their elbows to their side and let the legs do all the work.

BIG problem source: Maintaining this stance from both sides of the cut is essential. Not keeping this stance on both sides of the cut was the biggest cause of my problems for a long time. There’s plenty of room to take this stance from the end of the bench. But walk around to the other side of the board and the bench is in the way. Modifying the stance to accommodate simply didn’t work.  So, that meant turning the work piece so I could always work from the end of the bench. Open the vise, turn, close the vise, saw, open the vise, turn, close the vise, saw. Yeah, it was too much trouble to turn the board as often as I should have. Instead of turning, I was spending too much time sawing from one side. added blocksOften, way too much from one side. Very slight wanderings were not being quickly corrected from the other side. They added up… until…

Fix: I solved that problem by adding blocks to offset the work piece from the bench. I started with one 2-by and added a second one later. (They have pegs fitted into holes in the face of the bench so they can easily be added to the vise space.) Bingo!!! That provided enough space to maintain the correct stance from either side of the board. No more need for turning the work piece. It stays in the vise and gets approached equally well from both sides. Now, it’s much easier to change directions frequently, as frequently as 25-30 saw strokes at a time. The only need to open the vise now is to raise the work piece as the cut progresses.

holding the sawHolding the saw: How to hold the saw is almost as important as stance. The operative word is “loose!” I hold the saw loosely enough that only the webs of my thumbs push forward and the inner parts of my fingers pull back. The saw handle is free to move within my grip. Why? That method provides the least “guidance” to the saw. It let’s those kerfs do their work. Holding the saw too tightly leads one to “manhandling” the saw and diverting it’s path. Holding the saw loosely also makes it easier to feel friction increasing, to know about an oncoming bowed path before it’s too late. Over time, I’ve found a comfortable grip with only 2 fingers of each hand in the handle’s hole. Index fingers and pinkie fingers point toward the blade: same on each side. It is a grip that is very balanced, one that prevents favoring one side over the other and keeps the blade nicely centered in the kerf.

Changing directions: Cutting in “sets” of about 30 strokes from one side and then a set of about 30 from the other side has given me the most accuracy.

Cutting angles: I’ve tried many different approaches. The “cut toward the center from all corners” approach works well for pieces that are almost square. For long pieces, I cut with the saw’s tooth line running at 90° across the board … mostly. The majority of the strokes are straight across the board. But for 10 strokes of each “set,” I drop the handle stroke by stroke until the tooth line is at 45°, then another 10 to 12 at 30°. This deepens the kerf line gradually and accurately.

Keep the cut line high: By keeping the cut line about chest high, the arms are less inclined to do the hard work, and thereby less likely to push the cut astray. Keeping the cut high almost forces using the legs, and when done this way the arms can be kept even and the saw centered on the kerf more easily.

oil-canOil the saw: That’s a small tomato sauce can with a cloth rolled up inside it. It’s soaked with light synthetic oil (3-in-one). A couple of quick swipes on each side of the saw after every few direction changes keeps the saw smoothly gliding along.

Take a break: Sawing too long makes one tired. Tiredness leads to impatience. Impatience leads to manhandling. … and so on. Sawing for the length of an Oscar Peterson album, a Travis Tritt album, or a Beethoven piano concerto is about right. Then, take a break and come back refreshed.

…and what to do when it goes wrong? The easiest answer is to stop as soon as you detect the bowing and go saw from the other end of the board. ~carefully~ You’ll have to saw from the other end at some point anyway. Make it good.

Recapitulation

  1. Make sure your heart is healthy enough for resawing.
  2. Work all the way around the board with a kerfing saw.
  3. Mount the board in a vise in the manner that enables the same stance from both sides of the cut.
  4. Develop and maintain the same stance from both sides of the cut.
  5. Hold the saw loosely enough to allow the kerf to guide the saw, not your arms guiding the saw.
  6. Switch directions frequently. Work in small “sets:” 10 straight across strokes. followed by 10 strokes of increasing angle (about 45°), then 10 strokes at a more acute angle (about 30°).
  7. Let the kerfs guide the saw, not your arms.
  8. Switch directions frequently. (90°, 45°, 30°)
  9. Let the kerfs guide the saw, not your arms.
  10. Switch directions frequently.
  11. Raise the work piece in the vise often enough to keep the cut line about chest high.
  12. Oil the saw every few changes of direction.
  13. Take a break BEFORE you get tired, grumpy, or impatient.
  14. For resawing that lasts longer than 4 hours, seek immediate medical advice.

Carving Sampler – early work

Monday, March 9th, 2015

The shop is still too cold for what I want to do next; finish the “words box.”

So, do something else!  There’s been a pile of little practice carvings stacked on a window sill for a few years. All were carved in February to April 2012. The stack made a nice home for spiders, but even they fled the cold. I could toss those carvings, but holding on to them has won out so far.

Let’s see…, if I rearrange them just right, maybe they can be put together as a “sampler,” a lot like cross-stitch samplers.

photo of wood carving sampler; a collage of 15 pieces

Getting them to similar sizes and nesting together was an exercise of time and precision, but work that could be done in a warmer part of the house. A piece of 1/4 inch plywood forms the backing. A rough dab of hide glue holds each. If there is any movement, they might be free to dance around a bit. And Ralph; no mitered corners.  :)  Overall size about 18″ square.

Design sources:

1 “Complete” is completely inaccurate in the title of Koch’s book. It is a collection of 7 carving exercises. Good, but not “complete” in any sense.
2 One of 3 similar books, Wilbur covers a much broader range of architectural carvings than Koch. Very highly recommended.

Affordable Hide Glue Pot

Thursday, March 5th, 2015

The stuff likes to be kept warm … about 140° warm.

One can get a really really nice glue pot at TFWW. Yet, for as often as I use hide glue, something more affordable suits my needs. (Sorry Joel.)

As I walked down the kitchen accessories aisle at Walmart a couple of days ago, this “Roll-Back Special” caught my eye. I don’t know how much Walmart stores across the country standardize their sale items, but in my neighborhood it was priced at $8.86. A slow-cooker glue pot for less than 10 bucks!

It does exactly what I want for the sorts of occasional glue ups I do. I mix glue from TFWW flakes in a small glass jar (pickle relish). That jar fits nicely inside the pot. Fill with enough water to surround, but not overwhelm the jar and set to HIGH for about 30 minutes. That gets the temperature up to near 140. It will go to 180 if you don’t watch it. Then, set to WARM which holds right at 140°. Perfect!

Oh… Keep the lid on the pot while not using the glue. Otherwise the temperature drops off fast.

Photo of pot and bag of glue flakes  thermometer shows 140°

Best Brooms Ever

Wednesday, March 4th, 2015

The shop was almost warm enough to be bearable today, and it needed a good sweeping.

Decades ago, we lived in the middle of Indianapolis, Indiana. A blind man would show up at our house occasionally carrying a dozen or so brooms over his shoulder. He sold brooms made by “Industries for the Blind.” We enthusiastically bought from him because his were really well made brooms of sturdy, thickly padded, broomcorn. They lasted almost forever, more years than I remember. They were the best brooms ever. We left Indianapolis over 30 years ago and there are no blind men walking around selling good brooms where we live now. In that time, the last of the blind-made brooms have worn out.

The last of the real broomcorn brooms I bought at a big-box store was so flimsy, it wouldn’t support its own weight. I’ve witnessed a steady decline in the quality of store bought brooms, seeing broomcorn get thinner and thinner and finally being replaced by plastic bristles, set in plastic heads, attached to plastic handles. They don’t behave like brooms and break too often. Pure junk!

photo of 2 brooms

So, I went on a hunt. The answer to my search was not “handmade,” “blind-made,” “sturdy” or any of the other “durable” words, but “broomcorn!” Two new brooms from Broomcorn Johnny’s now hold my praise for the best brooms ever. Brian Newton is the artisan who operates the broom shop named Broomcorn Johnny’s in Brown County, Indiana. We’ve had two of his brooms long enough to know they’re the new “best.” The flat one is what he calls a “cabin broom.” The round one has about the same amount of broomcorn but is tighter wound and great for heavier work. The flat one stays in the house / cabin. The round one just cleaned up the shop better than any broom I’ve had in the past 15 years and hangs there now. (Cabin brooms are available in plain or in a range of color schemes.)

These brooms seem expensive at $60 – $70 each. Yet, I know they’ll easily outlast the $12 box-store brooms by a factor of 8 -10. That makes them a real bargain, and very attractive too.  Highly recommended, and I have no financial gain from this recommendation.

Kerfing Plane – Done

Monday, October 27th, 2014

photo of completed planeThere are a lot more pictures this time because I read that a lot of people avoid saw making, rehabilitation and sharpening. I want to show that it’s within easy reach of anyone who wants to try and doesn’t care to wait while saws take long trips to the sharpener and back. We can find many sharpening guides and tutorials online. Nearly all are very useful. For this particular saw plate, I followed Paul Seller’s recent tutorial about cutting saw teeth. The method worked wonderfully!

The plate itself is roughly 10″ by 1.5″, recycled from an old Disston that I cut down to make my frame saw a few years ago. Cutting to this shape was simple hack sawing. The tooth edge was smoothed “flat and straight” with a simple single-cut mill file. I decided to cut it to the same pattern I use for other resawing work, 5 TPI, zero rake, no fleam … just a dead simple aggressive rip pattern.

My ever handy Stanley No. 36 1/2 R rule has multiple scales in  8, 10, 12, 16 parts to the inch. The 10 scale made easy work of laying out a guide. The slideshow walks through a number of steps, with notes about each.

The 10 to the inch scale of a Stanley rule is used for marking out 5 TPI.
The little no-name saw was OK for cutting the guide but gave up when it came to the plate.
After making the tooth spacing cuts
Which to use, the one with 6 moving parts and adjustments that can sometimes loosen, or... ?
Saw filing setup. The adjustable lamp is the most important part.
When looking from the edge doesn't show what you expect, look from the side and seek those glints of light from unsharp teeth.
Coarse tool, set for a gentle #8.
Finished plane - toe end
Finished plane - business side - What big teeth you have.
Finished plane - fence side
First cut. The angle is off a bit.
Kerfed all around. The slight angle is noticeable at the corners.
First resawn board. Close enough for government work, but not for me.

 

photo of first test resultEnd result? A small piece of pine became the test victim. I set the fence to produce a kerf 3/32″ from the edge and went at it with only casual concern. What will this thing do without a lot of fussy attention? Cutting was easy once the initial grabbing was overcome. Hint: start from the far end as one does when planing a molding. You can see in one of the pictures that the kerf is not absolutely square. It’s tilted slightly. Despite that, I ended up with two boards that have less than 1/32″ of roughness left from the cut.

It will be perfect after I make an adjustment to either the face of the fence or to my right elbow.

UPDATE: It was my right elbow that needed adjustment. The plane is perfect when the monkey pushing it holds it correctly.