Woodworking Tools

The Radial Arm Saw

Sometimes the best deals in tools can be made by looking to the past. In the decade when "sliding compound" and "chop" saws are the norm, why would anyone even want to consider a Radial Arm Saw ? I must admit I haven't had much to do with Radial Arm Saws for years, and like many others, had purchased a sliding compound saw. I never was in love with the sliding compound. I found it a bit light-weight and ... well, a bit finictity to use, if you know what I mean.

Recently I inherited at barely operational Radial Arm Saw . It hadn't been used in years and needed a real big clean-up. I decided rather than throw it out, I would re-build this saw from the past and try putting it to work. Lucky for me the motor worked, and pretty much everything else on the saw except the power switch, which was the first repair. All saws movements were either seized or very stiff ... so after a few hours of dis-assemble and re-assembly with bit of new grease and oil ... everything worked like new again.

One of the problems with these ole Radial Arm Saws is that they can be more dangerous than some other saws. Most of the reason for this is because they seldom are fitted with the right blade, which makes all the difference to this saw .... click below to read more

Often these saws came from the manufacturer with horrible old combination blades with teeth in them that looked like they could rip through two inches of solid steel. These old blades are part of the "safety" problem with Radial Arm Saws. If you have one of these blades, I suggest you make an nice shop clock from it or send it to metal scrap, do not use these blades on anything, unless you are cutting fire wood. Their cut is rough and they are far too aggressive for most woodworking applications.

I have found the one of the best blades is the 72 tooth Freud Sliding Coupound cross cut blade , and if you want to add another element of safety, you could pick up the one with the anti-kickback teeth. These 72 tooth blades give excellent cuts and are far less dangerous and aggressive than the old "combo blades" that came with these saws. This particular blade was designed for chop and sliding chop saws and is manufactured with a NEGATIVE tooth hook angle. This means that the blade is biting more into the wood surface and using the table for resistance than postive hook angle teeth that would be biting into the back of the wood being cut where the resistance is more the person holding the wood (and subsequently more dangerous).

Most of the Radial Arm Saws are pretty easy to figure out, even if you have never operated one before. They also do some hand things that a Sliding Compound could never do, like rip wood or use a Dado blade in for certain applications. I particularly like the ease with which 45 degree cuts can be made, and they are accurate, at least on my saw they are ... which is more that I could say for the sliding compound which could never seem to make a decent 45 degree cut.

The disadvantage of these saw is that they are not portable ... at all, despite that in the past they were used on construction sites and were even advertised as construction site saws, these things are big and heavy, and I would venture a guess to say if saw safety were an issue, moving these saws is far more dangerous than actually operating them.

In terms of saw guards and saw dust collection, Radial Arms Saws also have draw backs. The dust collection, although not usually a big issue with cross cutting, is often not well handled by most of these saws although many do at least come with at shute to attach a hose to. These saw never did experience good quality saw guards. That is one area the more recent Sliding Compound and Chop saws have it over the old Radial Arm Saws. But - With careful and deliberate operation and the proper blades these old gems from the past can still be very useful tools.

If you really want to dress up your saw and make VERY usefull, adding a Flip Top fence stop is a HUGE time saver. I have discovered that after a few weeks of use I have fallen back in love with this "vintage saw". I like how sturdy and secure it feels and how it handles cutting. The tool is far more versatile than any Sliding Compound, and the best part is ... you can pick up these tools right now for next to nothing. Just check out your local auction, newspaper or classified ad section. Compared to the price of a decent Sliding Compound, and "vintage" Radial Arm Saw, with a bit of TLC and new Freud blade might just the thing you are looking for!

Copyright Colin Knecht


Shop Made Sander - That Really WORKS

"If you HATE SANDING, and all the dust that goes along with it as much as I do, this article will interest you. I think I have every "sander" ever conceived of just to try to cut down on my "sanding time". A few years ago at one of the Wood Shows, I happened to stop at a booth that was demonstrating what looked like a little home-made sanding device". It looked intriguing but I wondered how well it would work. On the trip home from the show a friend mentioned he had purchased one of those little "V" Drum Sander kits.
Hmmm ... I thought maybe there was something to those little sanders. A few weeks later I went over to his workshop to see how his little home-made sander was working ...

Read more: Shop Made Sander - That Really WORKS

The Agony of Setting Jointer Knives

 "I often wish I was one of those dedicated woodworkers who loved to spend hours of their time "fine tuning" their equipment and sharpening tools to a razor edge. Sadly, I love to spend more time cutting wood than fine tuning the machinery. This shortcoming has disadvantages. Some time ago (I embarrassed to tell you how long ago) I purchased a very nice, brand new 6" Delta jointer. A fine machine, factory set up and "ready to go", or so the salesman told me.

When I got this machine home, I used it for many months (many, many months) and became more and more dissatisfied with it's performance. Oh it ran fine, but for some reason it would not joint a straight edge. I purchased a very expensive straight edge to check the infeed and outfeed tables and they were well within tolerance.

I became more and more frustrated and even considered selling the jointer -  click below to read what happened next

I often wish I was one of those dedicated woodworkers who loved to spend hours of their time "fine tuning" their equipment and sharpening tools to a razor edge. Sadly, I love to spend more time cutting wood than fine tuning the machinery. This shortcoming has disadvantages. Some time ago (I embarrassed to tell you how long ago) I purchased a very nice, brand new 6" Delta jointer . A fine machine by all counts, factory set up and "ready to go" or so the salesman told me.

When I got this machine home, I used it for many months (many, many months) and became more and more dissatisfied with it's performance. Oh it ran fine, but for some reason it would not joint a strait edge. I purchased a very expensive straight edge to check the infeed and outfeed tables and they were well within tolerance. I became more and more frustrated and even considered selling the jointer .

I read two or three articles on "how to use your jointer" properly and still it was delivering cuts that my tablesaw could easily beat (especially with Freud's Glue Line Rip blade that I love so much). I even made a fancy holding device like one article suggested still I got rounded results.

Finally I found an article somewhere, and I don't even remember where, that explained that if the jointer knives are not set properly, unsatisfactory results will be obtained. The article went on to say that if the knives are too high above the outfeed table the wood will have a "snipe" at the end (a place near the back of the board that has extra wood removed by the cutter). The article also said that if the cutters are too low the resultant cuts will be bowed  which is exactly the problem I was having.

Now I was in a conundrum - do I sell the jointer as is and get a bigger 8" that I want anyway, or do I try and fix the problem? I looked for article on how to set jointer knives and found them somewhat conflicting, so decided to talk to some woodwork buddies. The first one I talked to told me he set them up, as level with the out feed table as he could using a strait edge, then rewired his jointer motor to run in reverse and ran a fine, flat sharpening stone over the knives to get them perfect. Since I am not an electrician, and I felt this was making something much harder than it should be - I called another buddy. My second contact told me he now had also been struggling with setting knives and now had the perfect solution and he showed me a pair of very sophisticated setting jigs. He went on to say that these now made his settings perfect. Since I was in the neighborhood, I decided to talk with yet a third buddy. He just chuckled, shrugged and shook his head,  "I don't worry too much about it" he told me, and with that I thought the best advice was the two little jigs, and off I went to the tool store.

At the tool store I asked one of the salesmen where their fine adjustment measuring tools were? He asked me what I was looking for and told him, Jointer knive setup device. He immediately walked to the end of one isle and handed me a small flat wooden box, "there ya go" he said, just what you need. I opened the box to see two long black square bars. "These weren't what I was looking for" I told him  then I pointed behind him to the pair of jig holders one of my friends was using. "Those are for planers" he told me, what you are holding are for jointers". He went on to explain that when you are setting up a planer, the knives all need to be the same height to one another, with a jointer all the knives need to be the same height as the outfeed table and that the tool I was holding, with two back, square rods, which had magnets in the bottom would do what I want.

I was beginning to think that selling the jointer would have been easier, but I struggled on and purchased the recommended tool ... with the two long black square arms. Since there were no instructions in the box, I surmised either this was really meant of woodworkers (who hate reading instructions) .. or, setting up the blades was not going to be that difficult.

The instruction book for the Delta Jointer was helpful. I suggested that each blade needed to be in top-dead-centre when setting the knives. Now my eyesight isn't the best it once was, so I decided that as long as each blade was set in exactly the same place, they would all be the same height, so I etched a line in the front of the table where each blade would be aligned to, and set about setting up each knife. See the white arrow that shows how the square aligns each knife for setup.

After setting all three knives, I decided it was time to test the jointer. As I ran the first piece of wood through, I could feel it was finally working. When I looked at the edge I had just created I noticed a slight "sniping" at the very end. On closer examination, I could see the blades were all a few thousands of an inch high.

To solve this I purchased two inexpensive flat feeler gauges and used them between the knife setting tool and the blades. I found that 6 thousandth was perfect, so re-set the knives. This time the wood ran through perfectly. I ran several other pieces and type of wood all perfect.

There is a strange feeling that comes over oneself when you finally accomplish something that has been bothering you for many, months. I had a new excitement about this tool. Lucky for me, it had not been used much so my blades were in great shape. I will now purchase a spare set of blades so that when these are dull I can put sharp one in as I am taking the dull ones out and save a bit of time and be able to use the machine while the other blades are being sharpened.

I wonder ... maybe I should change my ways and become one of those dedicated woodworkers who spends the time fine tuning and sharpening  what a pleasure working with tools that are sharp and set up properly.

Copyright - Colin Knecht 


Rockwell Hardness Scale for Sharp Woodworking Tools

 "Make Your Own Tools" the article said. I love the idea woodworkers making their own tools, so I decided to make use of some plans in an old woodworking magazine, and make myself three nice marking tools that will leave a crisp fine line on wood I am marking for cutting. The article said it was easy, and I liked the idea of using hardened steel and my own woodworking skills to make some of my own tools. Of course the first thing to do is obtain the materials, so off I went to the "metal supply store" to purchase the steel material for the blades. I asked for a piece of steel, according to the instructions. The grumpy salesman then asked "what hardness do you need?". I was totally lost ... what hardness of steel did I need? the article didn't say anything about that.

I tried to explain what I needed the steel for, but both of us had lost patience with my lack of knowledge, it was time for me learn a bit about steel, and here's what I found ...

Back in the early 1920's (the exact date is a bit fuzzy) a metallurgist by the name of Stanley Rockwell (wow, what a great name), needed to devise some way of determining the hardness of ball bearings. As the story goes, his simple idea was to place a penetrating tip on the steel to be tested, and with careful measurement of pressure, see how far the tip penetrated into the steel. The depth of the dent left would determine the hardness of the steel.

Today we use the same idea, but in a more sophisticated tool with precise measuring accuracy. As a rule, most of the steel you find in woodworking tools, like chisel and plane blades are measured in the Rockwell "C" scale, hence th expression "Rc". The number that follows the Rc code is used to denote how deep the tip penetrated into the steel, the deeper the penetration, the lower the number and the softer the material, so an Rc90 would be harder than an Rc60 for example.
In real tests, today they use diamond indentors and apply a fixed amount of pressure to the diamond tip, then measure how far that diamond tip penetrates the steel. So with 150kg amount of weight, the diamond indentor might penetrate a piece of steel to a depth of .038" - this means that this particular piece of steel would have an Rc harndness amount of 28. By contrast, still using 150kg amount of weight on a harder piece of steel, the diamond indentor this time only penetrates the steel to a depth of .022" - in this case, this piece of steel would be recorded as having and Rc of 69.

The reason there are so many different degrees of hardness is because different tools are required for different jobs. If steel is very hard it is more difficult to sharpen (often requiring special sharpening tools) and it is more brittle. For example a quality turning chisel like a Robert Sorby that are hit with a hammer will have a slightly different hardness than caving knives that are drawn by hand and sharpened frequently. If it is too soft, it won't hold an edge long, which means it needs re-sharpening often or it bends. Such is the case with a hammer. Carpenters expect to hammer nails all day without the hammer's head chipping away or bending. This is "balance" of creating the right hardness. There is also a trade-off in the flexibility of the steel. Softer steel will flex, hard steel will not, in fact if steel is too hard it chips, because it is brittle, which makes it even harder to sharpen.

Sawblades are a great example of combining various degrees of hardness. A saw blade might have a hardness of say Rc50 but the tungsten carbide tips might have a hardness of Rc90. This is so the blade can still flex somewhat (without breaking because it is too brittle) as it moves through the wood, but the tungsten carbide tips which do the actual cutting will last longer as they are harder than the steel. Freud Tools have made a real art out of combining different degrees of carbide to their different saw blades to achieve a wide range of saw blade uses. For example the carbide used in their Laminate/Melamine blades will be slightly  harder than the carbide used in their famous Glue Line Rip  woodworking blades because the  hardness and content of the laminate compared to wood is much different.  But there is also a limit to hardness as it compares with brittlenss.  Freud  actually use a slightly softer carbide in their metal cutting blades because a softer carbide is less brittle, which is what you need for cutting hard metals so all the teeth in the blade don't shatter. (Editors note: carbide is NOT metal, it is only used as a comarison element in this article because most woodworkers are familiar with both hardened steel and carbide)

Most highspeed steel such as what you would find in bench chisels and woodturning chisels are around Rc60. This is because they hold a good edge, but are still reasonably easy to sharpen. Robert Sorby , arguably the finest manufacture of wood turning and carving chisels, is well aware of how important hardness is tool making.

If you had a bench chisel with an Rc90, any time it fell off the bench onto the floor it would chip or fracture, then and you would have to send it somewhere to get sharpened because it is too hard for most conventional sharpening methods. The same thing that happens when you drop a carbide tipped router bit on the floor or bang a carbide tipped saw blade ... the carbide often chips. You now have a very expensive fishing weight, because ANY chipped carbide blade should NEVER be used in a power tool again ... at least if you value your eyesight, as flying pieces of carbide from a highspeed tool can cause serious (and often permanent) physical damage.

And so, back to my tool. I finally decided that the best hardness was that similar to a bench chisel where there would be some flex but that the maker blades would hold their edge longer, and that is exactly what I purchased. Now all I need to do is find the time to make them.

Copyright - Colin Knecht