V4.8 - Introducing: The Jointer

Here’s a new one for you. There is this woodworking machine that is one of the ‘Top Five’ in any serious woodshop. It makes wavy boards flat, and squares up the fat side with the skinny side and lets you make dimensioned lumber out of goofy wood. What machine is this? The Jointer.

At its most basic, a jointer is two flat tables, with a rotating cutterhead between them. The cutterhead has 3 or 4 very sharp knives in it and they do an excellent job of cutting/shaving whatever is passed over them…hardwood, softwood, plastics, flesh- whatEVER. Those blades will not stop for anything.

That is one way of saying- BE CAREFUL when using your jointer.

Jointers come in a wide variety of sizes. I have seen everything from a 4-inch up to 16-inch. The size is related to the maximum width of wood that can be surfaced on the machine. (“Surfaced” simply means laying the board flat on the table and passing it over the cutterhead as many times as it takes to make that wide side smooth and flat.) Many 4-inch, and some 6-inch, jointers are called “motorized jointers” or table-top jointers. This is because they are very small and their motor has brushes inside it. Once the size gets to an 8-inch, the motor is an induction motor, which is better suited for heavy-duty use.

Jointers are essential for performing most of the operations that are required to ‘square-up’ a piece of wood. Here’s what I mean: Let’s say that you have an old piece of wood and you now want to use it in a project. For our example, let’s say it’s a 2 by 4. Doesn’t matter how long. Step 1 is to lay the board with the 4” side on the infeed table of the jointer and proceed to pass the board over the cutterhead as many times as it takes to make that side flat and smooth. Step 2 is to place that ‘surfaced face’ against the jointer’s fence, over the infeed table, and pass it over the cutterhead as many times as it takes to make one edge of the board flat and smooth. Once these two operations have been done, the board will have a flat ‘face’ (the wide side) and a flat edge…AND they will be ‘square’ (90 degrees) to each other.

A that point, the board can be sent thru the planer and planed to the desired thickness, ripped on the table saw to the proper width and then crosscut sawn to the correct length. All because the jointer was available to give it a flat surface and a squared-up edge.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

V4.7 - Small Gas Engines hate Ethanol

This week’s column came to life back in 2009. I had been dealing with some lawnmower repairs and came to be friends with the gang at Riley’s Small Engine repair. While in his shop I kept seeing warnings against using gas/Ethanol in small gas engines. So, one day I asked what was his reasoning? He said it ‘builds too much heat in the engines and burns then up’.

Now, I’ve had some experience in running Methanol in my race car engines and they are both based on alcohol. But the one thing that alcohol does is make an engine run cooler- not hotter. At times, after a race, the intake would be iced over because of the coldness. So I asked myself “Self- how can something that makes an engine run cooler be ‘burning them up” ESPECIALLY when people run a gas/Ethanol blend in their car engines without any problems?

So, after much thought- here we go. First off, contrary to my first thought- cars DO have problems using blended (the technical name for a gasoline/Ethanol mix) fuel. Think not? Here’s a test. Find some straight gasoline and run it for two tankfulls and track the mileage. Then run some blended fuel for two tankfulls and track the mileage. You will not get the same mileage. The blended fuel gets worse mileage… and that is at the heart of the matter. Ethanol only delivers 62% of the equivalent Gasoline energy - therefore more ethanol (more as in quantity, not a higher percentage of the blend); must be used to deliver the same amount of energy.

In other words, when Gasoline delivers 100% energy, Ethanol can only deliver 62% of that, so more ethanol must be added to the engine.

In Automobiles, electronic fuel injection systems can make on-the-fly adjustments to the air/fuel ratio because of a closed loop in the computer that constantly takes a measure of the oxygen levels in the exhaust gas and if there is oxygen then knows the system is running lean and increases the fuel amount injected. Small gas engines have no such system, therefore, the engine runs ‘lean’ all the time.

THAT is the root cause of the small engines running too hot. Believe it or not, fuel also cools your engine, but if the air/fuel ratio is too heavy on the air part, the engine will run ‘lean’ and get waaay hotter than it should.

So, the bottom line is that you need to run straight gas in your weedeaters, lawnmowers, yard tractors or leaf blowers. Gasahol is somewhat OK for cars, but your small engines don’t have the electronic systems that are a must if your gas engine is to survive it. HINT, if you have an old car without the latest computers – don’t use blended fuel in it either.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you

V4.6 - Tracking your Bandsaw blade

Let’s talk a little more about the bandsaw this week.

Bandsaws can do things that table saws can only dream of, which makes them pretty much a necessity in a shop; however, they need to be set up properly and to do that one needs to keep a few things in mind.

Just to start with a proper definition, bandsaw “wheels” are the spoked or solid items/wheels that are mounted on the axles. Bandsaw “tires” are the rubber, or urethane, coatings on the rim of the wheels, on which the blade actually rides on. Typically, the tires can be removed from the wheels.

Most good bandsaws use a wheel/tire combination that is ‘crowned’. In other words, where the blade rides, the surface has a distinct ‘hump’ in it. This hump/crown allows the blade to be tracked (definition: - centered on the tire) with much more precision than if the tire/wheel were simply flat. On the Delta 14” bandsaws that I am most familiar with, the wheel itself had the crown machined into it and the rubber tire was just flat rubber. When the tire was installed, it conformed to the crown of the wheel.

There are some ‘bandsaw guys’ that say the crown gives the operator the ability to adjust the blade to compensate for blade drift (our last week’s discussion), but in over 25 years, I never saw that as a workable option.

Setting up the blade tracking is not really a difficult thing, but like most adjustable items, one can wind up chasing their tail if they aren’t careful.

Tracking the blade first requires that you center the blade on the bottom tire and the top tire. Once you have the blade centered, blade tension should be applied. I like to start out with only ½ to ¾ of full tension, until the tracking gets fully set. Ok, the blade is on, the tension is set at ½ and the blade is centered on the tires. At this point, roll the wheels and see if the blade stays centered on the tires. If it does, go ahead and apply full tension and roll the wheels again. If the blade stays on and centered, you are probably good to go.

If the initial testing shows the blade trying to creep towards the edge of the wheel, you will need to use the saw’s tracking adjustment to coax the blade back towards the center of the tire. When the blade stays close to the center of the tires, the saw should do its job just fine.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

V4.5 - Teach your bandsaw to cut straight

Let’s go back and visit our old friend the bandsaw, this week. One of the most common problems with a bandsaw is getting it to cut straight. You start out with a nice straight line and start the cut and before you know it, the blade has decided that it wants to shoot off at an angle and destroy the part you did not want cut. Some of the ‘old pros’ call this ‘blade drift’- I call it ‘don’t cut straight’.

Most often, here is what happens. Looking directly at the blade teeth, one notices that each tooth on the blade is bent out at a precise distance. This is called the ‘set’ of the blade. Having the teeth set outward provides clearance for the back of the blade to move through the work. It also provides some clearance for the blade to cut around a curve. However, if (for example) the teeth that are bent to the right stick out further than the teeth that are bent to the left, the blade will cut towards the right. The best solution to this problem is to purchase a high-quality blade, but I have even seen those drift sideways - right out of the box.

Another solution is to make the ‘set’ more equal - more balanced, if you will.

One way to do that would be to increase the bend of the teeth that are not sticking out as far; however, that is a very difficult thing to do if you don’t have the machinery or skill to do so. The more practical solution would be to slightly file the tips of the teeth that are sticking out too far- actually you would be ‘dulling’ them ever so little.

A method I have used is to hold a whetstone against the running blade and let the blade teeth lightly skim across the surface of the stone. A fine touch is a must, but with some practice, it isn’t hard to manage. Take your time and test the blade often by taking a test cut, so that you don’t dull them down too far.

Another thing that causes blade drift is when the number of blade teeth per inch is too high and the wood chips cannot escape from in between them. This typically shows up when doing resawing – sawing very thick wood – because the blade spends a lot of time inside the wood and can actually heat up and bow inside the wood, thereby causing a warped cut. The solution is simple: Use a blade with fewer teeth per inch.

Send your questions or comments to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.

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