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March 27, 2006

How to sharpen with Japanese Waterstones

I already wrote about some of the history behind Japanese water stones, but how to use them is perhaps a more common question. The answer is a bit tricky. It depends...

The first thing it depends on is the type of stone. Natural stones should be soaked in water for quite a while - at least to the point where the surface does not dry quickly when removed from the water. Some people store their stones in water. I don't think that would be a big problem unless you live somewhere where the temperature gets to a point where the water in the pores of the stone would freeze and cause it to spall or crack.

Ceramic stones can either require soaking or not. Read the box they come in. Shapton stones for example just need a bit of water on the surface.

Once the stone is wet, you use it just about like any other sharpening stone. The usual advice is to keep one hand low on the blade to apply pressure and use the other to guide. Use long strokes. Stand in a well-balanced stance so you can move freely. But since waterstones are softer than many oilstones you also need to take care of how you use the stone. Try to use the entire surface so that you don't make a hollow in the center. Sometimes if there is something I'm working on which would definitely create a scratch down the middle I use the side of the stone instead. Of course you can always flatten the stone (they sell a variety of plates and the like for this) but it is better if you can just use the surface evenly if you can.

From this point it is as simple as sliding the metal across the stone. Work up from coarse grits to finer. When in doubt about whether to use a coarser grit to start, just use it. The finer the grit, the longer it takes to remove the same amount of metal, and if you have nicks to remove it can take a long time if the stone you are working on is too fine.

Keep enough water so that the water is still visible on the surface. If you haven't soaked the stone long enough you will get a sticky muddy surface instead of the fine slurry that you should have. For really fine stones, use a nagura stone to create the slurry before you start.

A couple other tips. You can take some of the slurry on a paper towel or rag and use it to polish the areas you are not sharpening. Clean up the black stuff as soon as you are finished. It has a lot of iron in it and will stain things. I'd consider rubbing your fingernails over a bar of soap before hand, or using some lotion, but since I never remember t try anything like that before I start, I can't really say how it would work out.

April 25, 2006

How to use Visegrip pliers

A couple people have shown up here searching wondering how to use vise grips. So here you go:
  • Close the pliers
  • Loosen the knob at the back to the point where the jaws are open approximately as large as the item you intend to grip. If the knob is too tight, then open the pliers first to get it started. You squeeze the little lever next to the handle to open the pliers if they are locked.
  • Open the pliers.
  • Grab the item you want to grab.
  • Try and close the pliers. If you can't close them, then open and back the knob off a half turn or so until they can close with a firm grip. If they don't lock on, then open them and tighten the knob a bit then close again.
That is all there is to it. All the vise grip pliers work on the same principle so you learn one and you know them all.

May 10, 2006

How to use the Swanson Speed Square as a Framing Square

swanson-speed-square-how-to-use.jpg

Since I published the first review of the Swanson Speed Square, many people have been wondering how to use it. There are actually a large number of things you can do with it, but the most common is probably to use it the same way a framing square is used - to determine the correct angle to cut rafters.I'll show you how to determine the angle you need to use.

But before we get there, a couple words on how the pitch or slope of rafters is stated. In the US, rafter slope is typically given in terms like "4 in 12" or "12 in 12". The first would be close to the minimum slope for a shingled roof and refers to a vertical rise of 4 inches for every horizontal run of 12 inches. The reason that 12 is used as the denominator is that by doing so it is easy to do the math. If you have a 10 foot run, and a pitch of 4 in 12, you simply multiply the 10 by 4 and arrive at a vertical rise of 40 inches.

Now, calculating the correct angle for a common rafter is simple with a little trigonometry, but the speed square takes away the need to drag out a calculator. Just set the pivot at the edge of the board and then rotate the square around that point until the edge of the board aligns with the correct mark on the "Common" scale - marked in red in the picture. Then draw a line along the ruled side of the square (the one parallel with the yellow mark). You can see that at "12 in 12" the edge will make a 45% line.

For hips and valley rafters, the angle is slightly different because the ridge itself is at an angle. This is a bit more difficult to do the math for, but once again, the speed square takes away the need to do math. Just do the same procedure as for common rafters, but instead use the "Hip-Val" scale. You will see that because the boards meet at an angle the cut is not as steep.

One thing the speed square won't do for you is determine rafter lengths. However, simple geometry will tell you that the square root of (rise-squared + run-squared) will give you the length of the other side of the triangle. For this you may need a calculator.

One other feature which I've found useful at times is the scribe feature. In the area marked in yellow in the picture you see a number of notches a quarter of an inch apart. You can set a pencil in the notch and slide the square along the board and have a mark parallel to the edge.

As you can see, the speedsquare is rather coarse in its markings. That isn't to say it is not accurate, but rather, the fineness of the markings is better suited to wood framing rather than fine woodworking. So buy one of these and throw it in your toolbags. It should last a long time.

Continue reading "How to use the Swanson Speed Square as a Framing Square" »

May 19, 2006

How do ViseGrip pliers work?

vice-grip-pliers-working.jpg

I've seen some people ending up here while searching for "How ViseGrip Pliers Work" so I've decided to put up a short explanation. The principles are pretty simple, and while I could walk through the math and the free body diagram I'm going to try and do it with words and pictures.

It all starts when you squeeze the handle (see the dark blue arrow). The handle is just a long lever which pivots around the lower point on the jaw (the dark blue circle).

When it does this, it expands the distance between the jaw and the adjusting point (light blue circle). This causes the jaw to pivot around the top pivot point (green circle) which forces the jaws to close (green arrow).

Each of these interactions multiplies the force so that a large movement of the handle results in a small movement in the jaws. The ratio between the movements is the inverse of the ratio of the forces. That is, if the handle moves 1 inch for 1/10 of an inch movement of the jaws, a force of 10 pounds on the handle results in a 100 pound force at the jaws.

Now, the locking part. See the light blue arrows? When the angle between the light blue lines is less than 180 then they will tend to re-open by themselves. Once they reach 180 degrees (a straight line) or slightly more, they will lock. The same principle is true of things like your elbow or knee. The problem with this is that with a rigid mechanical thing, getting them out of the locked state is not easy. With your arm you can just ease off on the pressure so it is not typically a problem. To get out of this situation, the visegrips use a small lever on the handle. If you can look closely you will see it and a small bump it presses against. It does just the opposite of pressing on the handles and has the pivot even closer so that it can pry the lever back to an open state.

The final thing to consider is the adjustment. This is done through the screw on the back of the handle. Twisting it moves the light blue pivot point closer or further to the green pivot point and sets the locking point for a specific position of the jaws.

July 11, 2006

Using the Rafter Table on a Framing Square

Steel Square Rafter Table

At first glance the rafter table stamped into the side of a framing square can be a bit tricky to understand. But it is not so difficult once you get the hang of it. The first thing to understand is that it is based on roof pitches expressed in amount of rise (vertical) over a 12 inch run (horizontal). The table is constructed with values underneath the inch markings on the top of the square. In the picture above I have highlighted in green the rafter length for a 16/12 roof pitch. Because the rafter forms the long side of the the right triangle it needs to be 20 inches for every foot of run, or 20 feet for every 12 feet of run.

The math behind this is pretty simple. Using the pythagorean theorem we know that the square root of the hypotenuse (long side) of a right triangle is equal to the sum of the square of the sides. There a few right triangles where the math works out smoothly. a right triangle with sides of 3 and 4 will have a hypotenuse of 5. (3x3)+(4x4)=5x5. In the case of a 16/12 slope you can see that it follows the same ratio but is just 4 times bigger so the long side will be 5x4or 20.

It gets a bit more complicated when you get to hip or valley rafters. Because they are at a 45 degree angle to regular rafters they have to be longer. You can use the second line of the table to determine their length, or you could also use the pythagorean theorem again, but lengthen the horizontal dimension by 1.414 times since it is now the hypotenuse of a right triangle with even sides (look down at the roof from above to see this).

The next thing the rafter table shows is the difference in length for jack rafters. Jack rafters are those that meet either a hip or a valley rafter. They start out being the same length as regular rafters - so you use the common rafter table to determine this length - but as they work their way along the hip or valley they get shorter and shorter. The "difference in length of jacks" row shows how much shorter each one will be than the previous one based on either a 16 or 20 inch spacing.

The final thing the rafter table shows is how to cut the bevel on the ends of the angled rafters (hip, valley, jack). This is the bevel looking from above. To do this set the square along the top of the rafter with the 12 inch mark on one leg at the end point of the rafter and the "length" given by the rafter table on the other leg the edge of the rafter. Drawing a line from the end point of the rafter will give you the angle you need to cut.

In measuring rafters you need to keep a few things in mind. First is the thickness of the ridge rafter and the top plate. Neither should be included in your calculation of run. In other words, measure run from the inside of the wall and the outside of the ridge rafter. The second thing is that you don't want to have to measure and layout each rafter individually. Make one which fits and then use it as a pattern for all the others. Check the fit first at a few different places as your measurements may be a bit out or you may have a wall which is not quite square to the ridge.

July 20, 2006

How to Paint a Room

painting-roller-screen.jpg

Painting a room is one thing which professionals definitely do differently than home-owners. One of the simplest improvements to your painting you can make is also one of the best. Just throw out that paint pan you have. You know, the rectangular one with a slope to the bottom.

Once you do that get a 5 gallon plastic bucket - any old one will do. A top which fits it is a bonus. Then get a metal roller screen like the one shown in the picture. They cost a couple of dollars at most paint stores. Mine is probably 15 years old and is covered with multiple layers of different colored paints. Along with this get an extension pole. For most residential interiors a 4 foot pole is most convenient. They make some short ones, but they are designed more for working in confined spaces like bathrooms and don't give you the length you want to paint a ceiling or a big wall. In tight spaces you can usually do without a pole so just forget about the ultra-short ones. Get a longer one if you are going to work outside or have really high ceilings. Long poles start to get awkward inside if you don't have high ceilings. Most of these poles are extendable so a 4 foot pole usually extends to something like 7 feet.

Once you have these then screw your roller frame on the end of the pole, pour a gallon of paint in the bucket and get to work. There are numerous advantages to this method over the flat paint pan.:

  • It holds more paint. No stopping to refill.
  • It is twice as fast to load the roller with paint.
  • It is easier on your wrist and arms - you use two arms to hold the pole.
  • The bucket is not as messy.
  • You can dump the screen and the roller into the bucket and close the top if you want to stop for lunch or until the next day.
  • You can mix multiple cans of paint (called "boxing") in the big bucket.
  • The screen just needs a quick wipe when you are done and is easier to clean than a pan.
  • More stable/Less likely to tip over.
  • Pole allows you to cover larger areas more quickly.
  • No stooping required.
  • With a long brush to cut in with you can almost completely avoid using a ladder.
  • I could go on, but you are probably tired by now....

There really is no good reason to use the old "traditional" flat paint pan unless you are using it for sponging or other decorative techniques and need a flat "palate" to work with. While you are at it pick up the best roller frame you can. One which flexes or has the socket break on you is not going to save you anything in the long run.

November 8, 2006

How to Check and Adjust a Framing Square

Framing or carpenters squares last a long time and are big enough that they can get stepped on or dropped or have something put them out of square sometime over their life. Fortunately it is easy to check and adjust them. To do this simply find a flat surface that you can draw lines on. This may rule out the dining room table.

First draw a straight line twice as long as the leg of the square. With the heel of the framing square in the middle of the line, draw a line up along the edge of the framing square (perpendicular to your base line). Then flip the square over with the heel in the same place and draw a similar line.

Framing Square
The two lines should match. If they don't then the square is not square.

To correct it is simple, but go slowly. If the square is at an angle of less than 90 degrees (bent towards itself) then take a punch and a hammer and make some small dimples near the inside corner of the square. This will expand the metal and make the legs of the square bend further apart.

If the square is wider than it should be, make the dimples near the point of the square. This will bring the legs closer together. Keep checking while you are doing this. If you don't have a punch you can get away with placing the square on a hard surface and whacking it with the corner of the hammer face. Repeat until you get a square square.

December 15, 2006

How to Use a Framing Square to Draw an Ellipse

drawing_an_ellipse_with_a_framing_square.jpg

Most people use a square to make things straight or square, but it doesn't have to be that way. It can be used to make graceful curves as well. Here is how to draw an ellipse with a framing square. Use it to lay out a gentle arch over a window or doorway.

Take a straight piece of wood and put two brads into it. The first goes at a distance equal to the height of the ellipse (shown as distance "A" in red). The second is at half the width of the ellipse (shown as distance "B" in Blue. Place the square with the inside corner at the center of where you want the ellipse. Tape or hotglue a pencil or piece of pencil lead at the end of you stick. Run the brads along the inside edges of the square. Flip the square and then do the other side.

January 6, 2007

Using the Swanson Speed Square for Plumb and Seat Cuts

The speed square has a couple advantages over a normal steel framing square for marking and cutting rafters. Because of the pivot point at the corner of the square, you only need to line up one number rather than two. For example, to make a plumb cut on a rafter for a 6 in 12 roof, you just put the pivot at the corner of the rafter and line up the 6. Here is how it looks for a common rafter:

Swanson_speed_Square_plumb_cut.jpg

A second advantage is that the diamond hole in the square can be used to easily mark off seat cuts. The seat cut is where the rafter sits on the top plate. To do this, just line up the diamond with the plumb line you have just drawn and move the square towards the board until the pivot rests against the edge of the rafter. Becasue the distance from the diamond to the pivot is 3 1/2 inches (the same as the width of the top plate) the cut line will be 3 1/2 inches long and will be at a right angle to the plumb line. If this doesn't make sense in words, take a look at a picture or two. Line it up like this:

swanson_speed_square_seat_cut_1.jpg

Then remove the area here:

swanson_speed_square_seat_cut_2.jpg

Of course, the speed square is an old design. Where I am, the building code increasingly calls for the use of 2x6 framing instead of 2x4. This means that the diamond does not work anymore. But with a file and a black sharpie, you can modify your speed square to make seat cuts for 2x6 framing as well. To make aligning with a plumb line easy, I scribed a line entirely across the square. It looks like this now:

swanson_speed_square_2x6_framing_seat_cut.jpg

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May 3, 2007

Squaring Walls and Foundations using diagonals and the 3 4 5 Right Triangle

I've written about framing squares but they are generally too small to ensure that something like an entire wall or foundation line is square. So there are a couple of other methods that can be used which only require a tape measure.

The first of these is very simple. For any rectangle, the diagonal lines from one corner to the opposite corner are equal. Assuming you have a rectangular or square shape, you can just measure both diagonals and if they are equal, then the corners will be square. If one is longer than the other, then the shape is more like a diamond than a rectangle and you need to push in one of the corners on the longest diagonal until both are equal. One thing to be very careful about here especially on framing is that the sides are the same length. If the sides don't match (top is not the same length as bottom or left side is not the same as right) then the diagonal rule does not apply.

The second way is to use simple geometry. You can do this without using a calculator if you use a 3-4-5 right triangle. If you have a right triangle with sides of 3 units and 4 units, the diagonal side will be 5 units long. So start at the corner you want to check, make a mark along one side which is 3 units out (use feet or even yards or meters as the units) on the other side make a mark 4 units out from the corner and then measure the diagonal distance between the two marks. If it is 5 units, then the corner is square. If it is less, then the angle is sharper than 90 degrees. If it is more than the corner is more than 90 degrees.

Once you have the corner square, it is a good idea to lock it into place using a diagonal brace. Triangles are much more rigid than squares. If you bump the corner of a triangle it won't shift into another shape, but if you bump a square it easily turns into a diamond shape.

June 6, 2009

Making a new strap for an old Rolleiflex camera

rolleiflex-strap-lug

Rolleiflexes often came with a leather "EverReady" case - often dubbed "NeverReady" because they are hard to put on and take off to do something as simple as put in a new roll of film. Mine is old and cracked and useless, so I needed a new strap and this is the one I made.

Get a strip of latigo leather - this is the type of leather that belts and straps are typically made of and is stronger than some of the other types.

With a skivver (a sort of leather shaver) or a knife or a plane (what I used), thin the leather down at the ends until it fits through the guides on the side of the camera.

Punch a hole the size of the post and then make a slit above the hole to make room to fit it over the head of the post.

Then slip the leather through the guide and work the post through the hole and slit you made.

I made two short pieces which fit on each side and joined them with a buckle to make a short hand strap. I also made a longer piece which can buckle onto the ends of the short pieces to extend it and convert to a neck strap.

January 5, 2010

Bosch SHU43 Dishwasher Repair - Dishwasher keeps running

My Bosch dishwasher was broken recently. It kept running for hours. Here is how I fixed it:

First, the symptoms: The dishwasher would run for a long time... hours. It didn't really get things clean. When the door opened the inside was not warm.

The first step was running the built-in diagnostics. To do this press the Power Scrub and Regular Wash buttons at the same time, then press the power button. One of the lights will show up.

If the WASH light shows, that indicates a heating fault
If the RINSE/DRY light shows, that indicates a filling fault
If the CLEAN light shows, that indicates a NTC (Temperature Sensor) fault.

Mine showed WASH so there was a heating fault. When this shows it can be a problem with the heating element or the electronics.

One of the common problems with this dishwasher is that the solder joint for the heating circuit can burn out. It is pretty simple to fix if you have a soldering iron and a torx screwdriver (#20 size). The circuit board should be checked before replacing the heating element because it is faster and easier to check and repair.

Step 1 is to unplug the dishwasher. Even though the wires to the power switch are insulated, it is always a good idea to make sure there is no power going to the dishwasher.

Step 2 is to remove the Fascia - the front part of the dishwasher with the buttons on it. To do this you use a torx #20 screwdriver. Open the door and remove the screws from along the top edge of the door. Remove the two screws from the side which hold the control panel in place. I also remove the two screws at the top of the front panel to make it easier to get the control panel in and out.

Removing-Control-Module-01.jpg

Once the screws are removed, the control panel can be pulled up and forward to free it from the door.

Once this is done, disconnect the wires holding it in place. First the connectors to the control module:

Bosch-SHU43-Control-Panel.jpg

Then the connectors to the Power Switch and the Ground Wire:

Disconnect-Power-Switch-And-Ground-Wire.jpg

When these are disconnected, you can remove the panel entirely and set it on a soft surface. It is possible to skip disconnecting the wires, but it requires juggling a half-open door and a wobbly control panel while you try to unclip the control module.

The next step is to unclip the control module. There are plastic clips at both sides that need to be opened and then the module rotates free with a hinge at the upper side:

Unclip by sliding a flat screwdriver or other tool under. Do not bend too far or you risk breaking off the clip.

Remove-Bosch-SHU43-Control-Module-Clip.jpg

Remove-Second-Clip.jpg

Swing the top up so you can get to the next set of clips which hold the circuit board in position. These are similar to the first set, but smaller. You can use your fingers to release them.

remove-Bosch-Dishwasher-SHU43-Circuit-board.jpg

remove-circuit-board-second-clip.jpg

Once those clips are open, you can pull the circuit board up to see the back side.

repair-heater-circuit-solder-joint-bosch-shu43-dishwasher.jpg

Once it is visible, look for a burned solder joint near the middle of the board as shown in the photos. It will look something like this:

bosch-heater-circuit-board-repair-shu43016.jpg

Clean the joint with an x-acto knife or whatever else you can use. Then get out the soldering iron and resolder the joint. Put it back together in the reverse order you took it apart. Don't forget to plug it back in!

Test by running a wash cycle. If the heater comes on and the wash cycle is back to normal times (about 90 minutes) then you have fixed it.

If you can't succeed in repairing it, the whole module is typically available for about $150

About How Do I...?

This page contains an archive of all entries posted to Stuff in the How Do I...? category. They are listed from oldest to newest.

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