Category: How To (How I Did)

You could call this a How To – but people often tell me I did it wrong – now to be fair you can’t really tell me I can’t do it that way, when the video shows I actually DID do it that way – so to cool down the hateraide – lets just call this HOW I DID

How to Cut Circles on a Table Saw (Dangerous)

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This post might not be best called how to cut circles on a table saw, but rather, how not to. This is a dangerous method and I don’t recommend it, but sometimes you may need this method and if you choose to use it be well aware of how dangerous it is.

I am by no means a skilled woodworker. I wish I was as both my Grandfathers were highly skilled in the construction trade, but as a kid I was more interested in goofing off. If you watch my video below, you can tell that some of my safety procedures are lacking, so please don’t imitate me, cutting off a finger constitutes a bad day.

Dangerous, But Useful When Needed

HOWEVER, the technique I show is useful, and if you have your safety guards in place on your table saw, and use a better sliding table you can accomplish the same thing much safer.

I needed to cut some circles so I could build my Gingery forge, and my shop is very limited with tools so I needed to find a work around. After a little internet research and looking into my old Audel’s books I discovered a solution. You can cut circles from squares using a table saw. All you need is a sliding table with a pivot point for a square of wood sized for your circle.

Make a Slide Table

My table saw is old and very inexpensive, so I had to make a sliding table by cutting down two pieces of 1×2 to act as runners. I nailed a piece of wood across the runners as they sat in the slots along side my blade. I then turned on the saw and cut about a third of the way through the center board. Now I have a very cheap sliding table.

Once that is done to cut a circle you need a square of wood the size you want for the finished circle. If you want a 12 inch diameter circle you need a 12 inch square block of wood. Insert a pivot pin in your sliding table the same distance away from your blade as the radius of the circle. So for a 12 inch circle, drive a nail 6 inches away from the cut in your sliding table. This pivot point should be on one side of the blade (imagine a line from your pivot point to the cut you made in the table – the line should intersect perpendicular to the cut.)

Cut Corners (Literally)

Pound the center of your wood square onto your pivot point and ensure that it rotates freely.

Line up your square so that you will cut off one corner of the square. Turn on the saw and slide the table to the blade and cut off each corner of your square.

Once you have cut those corners, cut off the 8 new corners, then the 16 after that. With each cut you will have a more rounded shape. Depending on the size of the wood, and your blade, soon you will be able to rotate the piece into the blade and actually trim it round. Just make sure you keep your fingers well away from the blade and don’t rush.

You will be amazed at how easy this is to do. If you have any other cool shop tricks, please feel free to make a comment. My next trick will most likely involve turning a drill press into a lathe.

October 13, 2011
How to Make Green Sand for Casting Aluminum
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I needed learn how to make Green Sand for metal casting. If you watched the furnace video you saw me making refractory, and making green sand is about the same process. Simply put, it is a mixture of sand, bentonite clay, and a bit of water. Using this kind of sand is called green sand casting.

Since I had some fireclay left over I was going to use it, but after some research I realized that since fireclay vitrifies (fuses) with heat, I probably could not reuse it after I molded something. So I figured I would go with Bentonite (as everyone else does)

Where to Get Bentonite Clay Cheaply

If you cannot buy bentonite clay in bulk (luckily my ceramics supply store has it), you can grind up clumping kitty litter (cheap without additives) and reclaim the bentonite. It must be ground up VERY FINE and you will need a dust mask.

Bentonite now gets added to a 5-gallon bucket of “fine” masonry sand (I used play sand, but the finer the sand the better quality your castings will be). You need a 1 part clay to 9 parts sand. Mix this dry, and then add water in small increments (like coffee mug sized). Mix between additions over several hours. You want the clay to coat the sand evenly, so the more you mix and the slower you work the happier you will be.

Test if your Greensand is Packable

The next thing you need to do is check to make sure the sand is “packable” You can read about this in the Gingery book, or watch my video. Basically you just grab up a handful of sand and squish it in your fist. It should mold to your hand. Then break it in two. If the lump of sand holds its shape and breaks cleanly when you snap it then it’s good to go.

Store your greensand in a covered container (I use 5 Gallon buckets with lids) and the longer you store it (unless it dries out) the better it will be

More Resources:

You can read many good books and articles on green sand casting, or just the process of casing metal. I have several reviews on this site.
August 10, 2011
How to Build a DIY Foundry For Backyard Metal Casting

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July 28, 2011
How to Build a Solar Dehydrator
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I like dehydrating food, sometimes because it makes food storage easier, and sometimes (like in the cases of apples or meat) I like eating dehydrated food.

The devils of food storage are:
- Heat
- Light
- Oxygen
- Moisture.
Dehydrating helps increase shelf life because many organisms (like Botulism) cannot thrive in dry spaces. If you vacuum seal moist food and botulism is present,the bacteria grow and create enough toxin to kill.

However, if you vacuum seal food with less than a 10% moisture level the bacteria stays dormant. So it does not produce toxins. This works well for things that you don’t want to super heat using a pressure cooker.

I have a pretty good electric dehydrator that I use to make jerky and other dried foods. However, it is small and takes up valuable kitchen space when it’s working. Besides that, my wife doesn’t sleep very well if I try to leave it running overnight. She worries about the catching the house on fire.

Research

Build it Solar was first resource I found online, and I went there quite a bit. The idea of the J R Whipple solar dehydrator is really cool, but I wanted it in wood. Root Simple also provided some ideas.

A large wooden shipping crate came from the trash and I decided to get to work.

*I later found a PDF entitled How to Build a Solar Crop Dryer that I believe this research was based on, I linked to it in my download section.

Building the Solar Dehydrator

Basically all I did was to cut a shipping crate to a manageable size, add a door, some legs and a few tray supports on the inside to make the drying cabinet. I will probably add some ventilation later once I know how much I need. I don’t want to cut a bunch of holes on the front end of the experiment as I don’t want to cut too many.

The next stage was to build the solar collector. My original idea was to use some glass scrounged from a storm door. Unfortunately, it was a couple inches too wide. (BTW you cannot cut storm door glass; it’s tempered and will shatter into thousands of pieces). But for an unnamed reason I ended up going with a large 24 x 60 piece of Plexiglass as the top of the collector. The sides and bottom end are 1×6 boards, and the underside is a piece of plywood I had left from my chicken coop shipping box project.

I cut the top end of the 1x6s at an angle (I did not measure the angle, just marked it as the angle it would take to lay flush against the drying cabinet with the bottom end of the collector sitting on the ground. This allows me to hinge the two pieces together so that the solar collector rests on the ground when in use, but folds up for storage. The inside of the collector is painted black to help absorb heat. I painted the outside white because I had white paint. I also cut some ventilation holes in the bottom end of the solar collector, as there will need to be airflow to remove the moisture out of the drying box.

The drying trays and screens for the air vents are aluminum screen. I simply made some frames out of strips of molding and stapled the screen tightly to the frames.

I still need to experiment with the correct drying times and amount of airflow needed, but the plan is to set this on the sunny side of my house, fill with vegetables and see how long it takes to turn them nice and dry.

Stay tuned, and I will add to this post as I learn more about my Solar Dehydrator….
July 25, 2011
DIY Solar Cooker

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From doing research into solar applications I have come to the personal conclusion that solar energy is misapplied in many instances. Our sun is an awesome source of energy, but all too often we use it to create electricity we store to make heat or light later. While this has some really useful applications, each conversion looses some of the original energy. If we focus some attention on directly using the solar energy we get more “bang for our buck.”

There is a really good book called Sunshine To Dollars that has some really cool projects that give you an immediate return on you investment of time and energy.

So after reading this book and others like it, I decided to make a DIY Solar Cooker. I resisted the urge to make a huge solar oven out of a new fiberglass tub my old tenants inexplicably left in my basement. What I decided to do was to build a small wooden solar box cooker. It would have been easier and faster to build one of the many cardboard cookers that places like Build it Solar shows, but I figured that since the technology was pretty well developed this was not an experiment, and I should probably invest the energy into making a more robust and permanent cooker that I could use rather than a throwaway model for a proof of concept.

I decided on building one modeled after a cooker I saw on youtube. The user supergokuel had a really cool 2 part video, so I basically just modified his idea.

I could not find any replacement glass sheets at the local hardware store, but I did find a sheet of Optix brand clear plastic that would fit very nicely on the box I was trying to make.

The bigger your cooker the more efficient it will be, and the larger the pots you can use, so my 1×2 sheet of plastic will work well. I also bought some screws, hinges, and a 4×8 sheet of exterior grade plywood. The black paint and caulking I already had.

Basically I just cut two side pieces in a rectangle, and then cut a 45° angle down one side. I made the rectangle wide enough so that the angled end would be as long as the shorter side of the plastic. (I know this is confusing, this video helps).

The ends and bottom of the oven are cut to match the side pieces and are screwed together to make a box. The top is simply the clear plastic sheet of Optic attached to the box by hinges.

I painted the box black to absorb heat, and when I get more reflective film I plan on mirroring the inside of the box to help generate more heat. Larger box type collectors can get hot enough to bake or roast meat – upwards of 220°

This is a pretty simple project using hand tools and a power saw, but will allow you to cook many types of foods without electricity. For us disaster conscious types, the ability to bake and cook foods outdoors on something other than a grill or campfire has some serious advantages. For those that choose to reduce the use of resources – whether for ecological or self-reliant reasons, this is also a very useful project.

This is a project that I would highly recommend you duplicate of modify for your own usage.

July 18, 2011