The issue is that the data tags on many electrical tools contain misleading information.  Not false, just not exactly the information a savvy consumer needs.  A knowledgeable consumer may look at such factors as voltage required the current draw of the device and the horse power developed by the device.  Most manufacturers report the voltage and current draw of their devices correctly; some however play games with the horsepower developed by the device.

The math for an electrical device is really simple. The conventional outlet in our homes and shops will output 120 Volts AC.  These outlets typically will have a current rating of either 15 or 20 Amps.  For the sake of our discussion, let’s assume that we are using a 15 Amp line.   If we multiple the voltage (E) by the Current (I) we have the maximum watts of power available at the outlet.  So we have 120 volts X 15 amps equals 1800 watts of power available. Now the fun part, each horsepower of work is equal to 746 watts.  Converting the 1800 watts to horsepower, one would simply divide 1800 watts by 746, or 1800/746 = 2.41 Horsepower maximum available at the outlet.

Makes sense, right? So how can a manufacturer of a shop vacuum, that connects to a standard 120 Volt supply, rated at 15 amps, claim that his vacuum is rated at 6.5 Horsepower? Or consider a plunge router that connects to the same power source, the data tag says that it is rated at 3.5 horsepower. During the first few milliseconds of a universal motor starting period, the current draw for the motor raises up to 3 to 3.5 times the normal current.  This higher than normal level of current draw is known as either peak, starting or in rush current. Some manufacturers choose to use this peak current instead of normal or operating current when making calculations for peak horsepower. It’s important to remember that this increased starting current level only lasts for a very short amount of time, so it will not cause an overload of the circuit which would in turn cause the circuit breaker that protects the circuit to trip.

If we go back to the calculations where 746 Watts is equal to 1 HP, the 6.5 Horsepower that the device claims to be developing would require 4849 Watts of power (6.5 HP * 746 watts per hp).  From this you could calculate that the in rush current would be 40.40 Amps.  (4849 Watts/120 VAC)= 40.48 Amps of current. Not possible from an outlet that is rated at 15 Amps. The circuit breaker or fuse that protects the circuit would definitely trip.

Another consideration is that these calculated values are based on a motor operating at 100% efficiency.  The sad truth is that most universal motors operate more in the range of 65% to 70% efficiency.  The remaining 30% to 35% is normally lost to heat generated by the motor. The real numbers on your shop vacuum that has a rating of 6.5 HP (Peak), will in reality only produce around 1.65 HP.  (70% of the 2.41 HP available at the outlet)

To complicate matters even more, the voltage coming into our homes and shops is not always at 120 VAC.  It can drop to as low as 105 to 110 VAC during peak usage hours of the day.  A drop even in a couple of volts can change the maximum wattage available at the outlet. So say you are operating at 105 Volts instead of 120, your 6.5 HP shop vacuum now has a degraded output of 1.47 HP.

The long and short of all of this is simple. No matter how the manufacturer chooses to rate their tools, you simply cannot get 6.5 Hp performance out of a shop vacuum when the power supply to the unit only has  2.4 HP coming out of the outlet. The same would hold true for that router that is rated at 3.5 HP.  Yeah for the very short start up period, it may develop 3.5 HP, but this is not usable power.

So as I said at the beginning, let the buyer beware.  And the best way to do that is by understanding what is and isn’t possible when you are considering the purchase of that new power tool.

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If you recall late last year I wrote about visiting the shop of fellow woodworker, Lee Jesberger.  I went to his shop to investigate his invention, the Ezee-Feed system of in feed and out feed systems for the table saw. In case you missed the posting, the Ezee-Feed system is a set of tables that can be added to all most any table saw that enables a single woodworker to safely and accurately cut sheet goods.  As an added benefit, these tables are easily removed from the saw when not needed.  And re-installation takes only a few seconds.  I have both the Ezee-Feed infeed and outfeed tables attached to my tablesaw, and you would have a real fight on your hands if you tried to remove them from my shop. This is a product that actually does what it claims to d; what a unique concept!

As with most other woodworkers that I have had the privilege to meet, Lee and I soon were deep into discussions about our individual styles of woodworking.   While mine was traditional solid wood work, a lot of Lee’s work involved the application of veneers. I will freely admit that I was impressed not only with the beauty and artistry of his work, but also the beauty of the veneers.  And that was the beginning of the change in my opinions about laminates and veneers.

Over this past year, Lee and I have worked together on several projects.  He was with me from the beginning to the end of the trials and tribulations of adding a bathroom to the basement of my daughter’s home.  And I truly thank him for his contributions to that effort. This project is detailed in earlier posts in the Home Improvement category on this site.  As we worked on these projects, the conversations would occasionally fall back to his passion for veneering. He would often show me pictures of these absolutely beautiful veneers and then explain how he had used them on some of his projects.  The more we talked about veneering the more I became interested.

And that got me to thinking about learning more about this interesting facet of woodworking.  So I approached Lee with a proposition that I hope will benifit not only Lee and myself, but hopefully you as well.  I asked Lee to teach me the art of veneering, starting at the basics and working up to building a couple of projects that will feature the art of veneering.  And while he is teaching me, I plan to document the lessons and put them into an E Book that I hope to soon publish. 

So instead of spending my weekends in my shop, the last several have been spent at Lee’s shop, where he has very patiently explained to me, the ins and outs of veneering.  I have come to understand and appreciate his passion for this form of woodworking.  As the lessons have progressed, I have started to try to equip my shop with the tools needed to do veneering, and to practice the lessons learned on my own.  This is still a work in progress for me.

I have also come to understand that the only thing veneering and laminating have in common are the fact that you glue a material over a substrate.   Veneering is a facet of woodworking that can produce a very fine piece of furniture, Laminating is the stuff that the “chip board mechanics” mass produce. 

So that’s why I haven’t been here as often as I have been in the past.  I want to get to the point that I can add this skill to my own woodworking skill set, it may take a while for that to happen. I promise to let you know how that is progressing.  As for what’s in the future for me besides the veneering lessons, I have about thirteen windows to change in my daughter’s home. I wish that I could tell you that this should go smoothly, but remember that this is the house that shares the love/hate relationship with me.  I promise to tell you about all of the exciting “fun” that project entails as it happens.

So please excuse me, I have to go to Lee’s shop and see what new he has to teach me.

Related posts:

1. Woodworking Techniques – Mortise and Tenon Joints
2. Woodworking Techniques: Scribing Stair Treads and Risers

We all wish that the walls or staircases in our homes were perfectly flat, straight and even.  But unless your home builder went to unusual steps when he constructed the home, your walls will be anything but flat, straight and even.  Wall studs, all have bows, or crowns in them, nothing we can do about that.  If your walls are plastered, as most are here in North America, then the thickness of the plaster used to seal joints, will vary, giving us unevenness in the wall surfaces.  Or if your sheet rocking skills are less then professional, then you will have uneven surfaces to deal with.

Yet we as woodworkers and home handymen want to install stair treads, risers or cabinets against these uneven, not flat and sometimes not straight walls without any gaps showing between the ends of the piece and the wall.  Problem is that we made the pieces (risers, treads and cabinets) flat and straight.  One option that a lot of people employ is to simply cover the gap with trim work, and this may work out ok on some cabinet installs, but it is not the correct method for all applications.  A better method is to simply scribe the piece to meet the contours of the wall.

Let’s talk about a stair riser as our example piece.   And for the sake of our discussion, I am assuming that the tread already has been cut to its final width.  Let’s also assume that the stair stringers or frame work are already in place. So our only task is to fit the riser to the wall.  And let’s make one more assumption that the wall we are working against is on our right hand side.  Yeah, I know that I am always preaching about not making assumptions, but in this case it is only for clarification. 

The first step to getting a good fit is to take your riser back to the shop and cut a 45º bevel or miter along the back side of your riser.  We want this miter on the right end of the board, the end where it meets the wall. Now take the riser back to the stair stringers.  Securely hold the riser in place, and check the fit along the right hand edge.  If your wall were perfect, there would be no gap, and you could continue making up the riser.  But there probably is a gap.

What we want to do is transfer the shape of the gap to the end of the stock.  The best tool to transfer the shape is a drafting compass. This simple tool is the same compass we all remember from our school days.   Take the compass and open it to the widest opening in the gap.  Lock the compass at this width. Before we scribe the shape of the gap, we need to move the stock back to your left, the amount of the compass opening.  If for example, the widest spot on the gap equaled ½”, then you would move the stock, ½” to the left, away from the wall.  Now starting at the top edge of the board, with the fixed leg of the compass along the wall and the pencil leg on your stock, slowly move the compass down the entire face of the riser.  The pencil line scribed by the pencil will be a duplicate of the shape of the gap.

Depending on the amount or size of the gap the next step is to remove the wood the right side of the pencil line. Some tools of choice would be a file, block plain or power sander.  Work slowly, and check the fit as you proceed.  When you can fit the riser completely against the wall with no gap showing, you can then proceed to work the left end of the riser.

The only problem with this method would be if you were fitting a riser between two walls. Then you would have to determine the angle, slope, shape of the walls independently.  The method I use is use two dummy or scrap pieces of stock as trail risers.  I would determine the shape of each ends, and work the trial pieces to fit that end.  When I had a good fit, I would copy that shape onto the actual riser.

Going back to the first step of this process, back cutting the ends of the stock at 45º was actually a step to save me work.  The thickness of the bevel gets smaller as it approaches the edge of the stock.  If I have to file, plane or sand stock from this area, I would rather just have to remove the smaller thickness of the bevel than to have to work through the entire thickness.

Now this process will work the same if you were installing the treads of the stair case instead of the risers.  The only difference would be on the bottom riser.  Then not only would you want to scribe the sides of the riser, but also the bottom edge of the riser where it meets the floor. 

Scribing a cabinet to a wall uses basically the same process, only with a small variation. This is a trick I learned from my late Father in law. Again, for the sake of discussion only, let’s assume that the width of the opening is 24” and once again we are going to scribe this cabinet to a wall on the right hand edge of the cabinet. The trick is to make the cabinet itself only 23 ¾” wide. However, the outside width of the stiles for the face fame would be 24” wide. The stile for the left side would fit flush against the left side of the cabinet; the right hand stile would overhang the cabinet by ¼” along the right hand side of the cabinet.

Making the cabinet a ¼” narrow gives us a little wiggle room when we install the cabinet, just in case the corner is a little out of square. The ¼” over hang along the front is where we will scribe the cabinet to fit the contours of the wall. One additional trick is to back cut the right hand edge of the right hand stile to the 45º bevel, just as we did for the stair riser.

While this method will ensure a great fit of the cabinet along the wall, it does require a little extra work when you are installing the cabinet (Beyond scribing the edge).  Logically, this end cabinet may not be the first cabinet you install in a room, but you want to temporarily install it to determine the scribe line of this cabinet.  Remember that we have to move the cabinet or riser back to the left the width of the widest gap before we transfer the wall contour to the edge of the cabinet.  If the cabinet to the left were already installed and bolted in place, you couldn’t do that, so a little extra work may be involved.  But the fit of the scribed edge is really worth the extra work.

Related posts:

1. Woodworking Techniques – Mortise and Tenon Joints
2. Woodworking Tips and Techniques – An Alternative to Sanding

Here is the first part of the problem.  Wood is basically a series of fibers stuck together.  These fibers run in the direction of the grain of the wood.   When you rip a piece of wood, you are slicing these fibers along their length and tear out is not a problem. However when you cross cut a piece of stock, you are cutting the ends of these fibers. These fibers have very little strength on their own, they rely on the next set fibers for support. For example imagine cross cutting a 2″ wide piece of 4/4 oak. As the blade cuts the first fiber, it is held in place by the next fiber.  This mutual support continues until you have cut almost through the stock.  As the last fibers are cut, there is nothing to support them.  These fibers will normally tear rather than be cut.  This produces tear out.  The sad part is that there is very little we can do about this, wood is simply wood.  And we can’t change the makeup of it no matter how hard we try.

The second part of the issue involves some good old trigonometry. At all points of the blade other than when it’s at true 90°, the height and angle of the blade will form a triangle, the base of this triangle is the top of the tablesaw or miter saw.  The length of this base changes, depending on the height and angle of the blade.  To accommodate this fact, the manufacturers of our tablesaw saw and miter saws have shipped the saws with inserts wide enough to allow the blade to be tilted to its limits and the blade at full height.  This wide open insert is the second part of the tear out issue. This wide opening in stock inserts does not provide adequate support for the end fibers, creating a breeding ground for tear out.

Rather than complain to the manufacturers of our tablesaws and miters saws, a better solution would be to simply replace the stock insert with a zero clearance insert.  These Phenolic Resin inserts are offered for many different brands of tablesaws.  The idea is to remove the stock insert, don’t discard it, you will need it when you do any work not at 90°, and replace it with an insert that is sized for the blade you are using.  If you typically use blades with different kerfs, then it is recommended that you have inserts for each blade. 

To install, first raise the blade to its highest position.  Verify that the blade is really at 90°.  I would recommend that you use a good digital protractor for this task.  If the blade is not at 90°, refer to your tablesaw manual to adjust the zero stops of your particular saw.  Once you are satisfied that you are really at 90°. then completely lower the blade. Now remove and store away the original insert, and replace it with the Zero Clearance insert.  When you get the Zero Clearance insert, it will not have any opening for your blade. We take care of that next. 

The next step is for you to SLOWLY raise the spinning blade, so that it cuts a clearance channel in the Zero Clearance insert.   I have found that using the rip fence to hold one edge of the insert, and push sticks for the other edge works quite well.  Just be patient, don’t rush to get the blade to its final height.   Some woodworkers, who feel that the Zero Clearance insert is important enough, and that they cannot tolerate any tear out, will have inserts for not only different kerfs but for difference ranges of blade height.

It’s important that you only use this insert for work at 90°, as soon as you try to use it for a beveled cut, you will either bind the blade or deform the Zero Clearance insert.  Use the stock insert for all of these cases.

If your tablesaw is one of the major brands, or you like to do it yourself, there is a Zero Clearance insert  kit available that contains parts and tools needed to make your own inserts.  Simply use your original insert as the template for the outer shape of the insert. Use a 2 flute flush trim bit in your router or shaper to create a perfectly matched insert.  

The same problem occurs on our compound miter saws. The wide mouthed insert on most compound miter saws, just doesn’t provide the needed support for those wood fibers as we cut through the stock.  I haven’t located any aftermarket inserts for the compound miter saw yet.  But trust that I am looking.  In the mean time, when I absolutely have to prevent tear out, I will normally place a sacrificial piece beneath the stock piece I want to cut. 

So to the manufacturers, thanks for all of the options that your tools provide.  I just wished you could read the minds of all of the woodworkers, craftsperson’s and trades people who use your tools and provide us with that perfect tool that meets ALL of our needs at the same time.  Oh yeah, keep the price down at the same time.  Is that too much to ask for?

Related posts:

1. Woodworking Techniques – Installing Door Molding

OK, in retrospective I guess I could understand why a massive furniture manufacturer may want to change the time it takes for a piece of furniture made from cherry to achieve the desired aged cherry appearance.  For them time is money, and unfortunately in today’s economic environment, money or the bottom line is the Holy Grail.  But for the everyday non commercial woodworker, I  personally don’t see the reason.  But that is strictly my opinion.

One of the interesting things I gained from the article is exactly how dangerous it is to try to accelerate this normal aging process.  The most commonly used chemicals for this age acceleration processes are “Potassium Dichromate”, “Sodium Hydroxide” and “Potassium Permanganates”.  All three chemicals are known as corrosives, and according to their MSDS sheets are poisonous, and the use of gloves and goggles are mandatory.  Potassium Dichromate in particular is also listed as a known Carcinogenic. Carcinogenics are suspected as being a major cause of cancer.   In an industrial environment, maybe the use of these products could be done safely, but in the average shop the use of these chemical products could cause severe medical problems for you and your family.  This potential problem could be exacerbated if your shop happens to be in an attached garage or in your basement.   You may have on an approved respirator and goggles and other safety equipment on, but unless you also equip the rest of the family with the same equipment, they can be affected by the chemical fumes that can travel through the duct work in your home.

Another interesting fact that came out of the article was that the benefits of these chemicals are short lived. In fact over time, remember time is what we were trying to shorten, there can be significant color loss with the use of any of these three chemicals. Again, I don’t understand why anyone would want to take a chance using these dangerous chemicals for a short lived benefit.dark wood glue

In my shop, time is a fact of life.  It takes time for things to happen, and most of these things I cannot change no matter how hard I try.  The time it takes for wood to age is one of those items.  When I make a project using cherry, there are things I do different then when I make a project out of oak.   I will use rather than the convention white or yellow glues. Any glue squeeze out that is not cleaned up, will not show as badly.  When I work with oak, I normally will switch back to white or yellow glue.

My choice of finish for cherry is a combination of Linseed oil, Tung oil and Polyurethane.  This finish is applied in at least three steps.  After a finish sanding a 50/50 mixture of Linseed oil and Tung oil is applied to the finish. After being allowed to dry for several days, the finish is then sanded with wet/dry sand paper.  Linseed oil is used as a sanding medium.

The second coat is another mixture, this time the combination is a 50/50 mixture of Tung oil and Polyurethane.   This combination is applied to the project, allowed to dry for about 30 minutes before any excess that has not soaked into the wood is wiped off.  Just as with the first application, this coat is allowed to dry for several days. Then I sand this finish with more wet/dry sandpaper, linseed oil is again used as a sanding medium.

The third and often final coat is a coat of quality Polyurethane. I don’t use wet/dry sand paper at this stage.  Instead just a good sanding with a fine grit (300-400) paper is used.  Depending on how or where the project will be used, an additional layer of polyurethane maybe applied. 

And then, the project is moved into its final location and allowed to age naturally. Sure, I admit that my method doesn’t accelerate the aging process, in fact the only thing it has to do with time, is that it takes time. To me woodworking is a pleasurable thing to do, I’m not sure that I want to speed things up, just to make them look older. But if you want to use the any of these chemicals, please be sure that you take all of the proper safety precautions.

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