From the Boatshop
by Ron Magen 

"That FREE Lunch I mentioned . . ."

A few months ago I was fortunate enough to be one of a small number of people from across the country selected to do some ‘real life’ testing of a special type of table saw blade. Anyone who also ‘follows’ the rec.woodworking newsgroup has seen the frequent threads of Blade vs Blade. It’s like the MAD Magazine ‘Spy vs Spy’ segment. The usual propagandists are the Forrest vs the Freud line of blades. Both are high quality with Carbide-tipped teeth. It has been amusing, to me, reading how heated these discussions become. Why? - because in almost the same sentence as the justification that ‘their’ blade cuts to a 0.000 degree of accuracy - ‘they’ talk about allowing for continual ‘wood movement’, or expansion & contraction, due to the normal changes in the environment & seasons!! Also, any boatbuilder KNOWS that NOTHING of wood is ever built ‘exactly to the plan’. There will ALWAYS be some little ‘hitch’ or adjustment necessary to get a ‘fair’ curve to a sheer or chine. That’s why the ‘Art’ of Lofting. It is also the nature, and joy, of working with wood.

What makes this blade ‘special’ it the material on the teeth. Instead of Carbide it is a CERAMIC. Before I even put my name into contention, there was a lot of heated messages about this being a scam, etc. In my past I gained an Associates degree in Mechanical Engineering. The ‘Lab’ was a very large and varied machine shop. All the equipment was ‘experienced’ . . . donated by numerous local manufacturing concerns. One of the things we had to do was grind our own toolbits for the metal lathe work. We started with ‘tool steel’ blanks just like the ‘real’ machinists. Later, with the much greater use of automation and high speed production, the ‘bit holders’ used pre-formed replaceable ceramic inserts. Therefore I knew the material & concept was correct.

I received notification that my name had been selected, and would I call a certain person at the company that was manufacturing the blade; the testing was being arranged by the company that produced the Ceramic Inserts for the blades. I called the toll-free number and discussed MY specific requirements. For ME there is no ‘long runs’ of any one-type of cutting. In one day I can be cutting sheet goods, ripping a 1/16th off a Mahogany plank for a precise fit, cross-cutting pieces of Oak or another hardwood for frames or a stem, then cutting 2x6 Pressure Treated planks for keel supports, or maybe ‘nibbling out’ a wide dado or half-lap in Cedar for a Rose Arbor for Joanne. All with ONE BLADE.

What I NEEDED, and I suspect it is the same for any number of you, was a "Jack-of-all-Trades". Would it be a compromise? . . . OF COURSE. Would it be better than a ‘standard’ 36-tooth Carbide Combo blade that was on the saw now and that had done all these things admirably ? THAT was what they wanted to know. What I WANTED was a blade that would give me an accurate and clean cut in plywood sheet goods . . . the ubiquitous building material of TODAY. It is also one of the top materials when it comes to dulling blades; the blade has to rip & cross-cut simultaneously through layers of wood & glue lines. I also wanted a clean exact rip cut to trim that last 1/32 for a friction fit, then cross-cut that same piece of Mahogany (another naturally abrasive wood) for a tight corner. Don’t forget that I wanted the same clean cut in the softer Cedar which has a tendency to leave a ‘frayed edge’ when cut. There was also the clean angle cuts on the Pressure Treated ‘2x’ stock - I make my own tool stands & saw horses.

What we decided on was a 48-tooth, ATB grind, 10-inch, CERMET blade. This would give me a finer cut than a 36-tooth Combo blade, a good ‘glue line’ rip cut, and a clean shearing cross-cut.

Reading the accompanying literature, and ‘listening’ to the rec.woodworking newsgroup, it seems these types of blade tips are not new; they have been used in the commercial wood product manufacturing industry for several years. However, Tom Walz’s company {Carbide Processors, Inc., of Tacoma, WA} has developed a ". . .superior tip and brazing technology". Their claim is that "(all) Ceramic Tipped Saw blades cut cleaner, faster, longer and quieter with less effort". From what I can gather, this series of ‘real life’ tests (as opposed to the in-depth commercial test-to-destruction already concluded) is focused on extending the market to, ". . . skilled artists and serious amateurs"

While I have no measurable way to test the actual DbA {sound level} of the blade, and a ‘life test’ as to how often and how many sharpening’s would take more than a year, I can attest to the apparent cleanness of cut and the ‘intangibles’ of how materials feel when being cut.

In the most simplistic sense . . . it has done everything I have asked it to. It has cleanly cut everything I have ‘fed’ it, including some ‘freehand’ work on full sheets of ply and some angle cuts. [NOTE: a REAL NO-NO on a tablesaw, especially with the guard removed !! NOT, repeat, NOT a recommendation] While I can’t comment on Corian or Melamine, the most troublesome & abrasive material I use is ‘3/4 inch’ OSB - clean cuts, no problem.

My ‘tablesaw history’ has had five stages, so far. As a teen I used an ‘accessory table’ that held a circular saw upside down. Years later, when we bought our house, I got a B&D 8 inch ‘benchtop’ {probably made out of old tin cans} with their punched out steel blades. Then I ‘discovered’ Carbide blades, and figured a way to ‘shoehorn in’ a ‘good’ 9 inch Oldham blade {couldn’t lower it or raise it all the way without hitting something, but it worked . . . and I was lucky !!}. Finally I decided to get a ‘real’ tablesaw, and decided on the 10 inch Ryobi BT3000 with the Cast Aluminum top. It came with their 36-tooth Carbide ‘combo’ blade. The first time I used it, it was both a revelation and an epiphany. I assembled it per the instructions. I checked all the ‘tuning measurements’ with my basic tools (square, tape, etc); nothing exotic like feeler or dial gauges, or micrometers. Then I grabbed a chunk of that ‘old standard’ - a ‘2x4', Pressure Treated I remember. Raised the blade, under the guard, aligned the ‘miter slider’ & wood for a 1/4 inch ‘slice’, turned on the saw and smoothly ran it through. Nothing - no resistance, no vibration, no sound other than the ‘air noise’ of the blade. O.K. - I’m not used to the adjustments on the saw. Raised the blade about 5 turns more, and slid the wood over about 3 inches. Eased the wood through - the same result . . . almost. This time a piece of the ‘2x’ was left behind !! I simply couldn’t believe it - it was literally like cutting butter. I called Joanne and had her run a piece through . . . just to be sure it wasn’t only me. After getting a bit more familiar with both the saw & 10 inch Carbide blades, I developed the ‘touch’ for this ‘system’. When I first used this CERMET blade, it was re-living that moment all over again.

There has been some negative comments about the blades from some people. Often it turns out to be a person who simply tried it on someone else’s machine; using their usual cutting technique. The comments typically center around cleanliness of cut, tooth marks, or burning. I believe there are a couple of answers to these problems. [NOTE: I’m speaking from MY point of view and experience, I can’t speak for the other ‘testers’. 5 got blades by lottery, 2 of us were selected as ‘Professionals’]

1) Define YOUR requirements -

I knew the particular tasks that are done on a regular basis. There are simply no long runs of any specific type of cutting task, i.e. ripping or cross-cutting. The ‘most used & most useful’ blade style had to be a General Purpose or Combo blade. Agreed, I wanted it ‘skewed’ toward the finer & cleaner cut parameter.

2) Read, TEST, & Learn the idiosyncrasies of YOUR blade -

Each blade, tool, & person is different. Each has it’s own ‘feel’ and range at which they work most efficiently and produce the best results.

We all do many things unconsciously; like driving or walking. {No jokes, please, about some people having trouble walking and chewing gum at the same time}. In the same manner we also get & use ‘cues’ without really thinking about them. My old 4-banger pick-up is a manual 5-speed, and I drive ‘by ear’. Using ‘feel’ and sound while feeding a board through the tablesaw blade, is another example. You just ‘know’ when the engine is lugging, and when to shift up or down. You just ‘know’ when the motor is being overloaded, and to ease off on the hand pressure.

Something that seemed naturally intuitive to me, and the entire concept of ‘power tools’, is to let the tool do the work. The experience of several well-known woodworkers agrees. In any number of their books, a ‘Troubleshooting Chart’ is usually included.. Where the ‘Problem’ is listed as "Blade Stalls", "Burn Marks", or "Tooth Marks / Rough Cuts" the correction is typically - - - "Allow the blade to cut at its own pace". One of ‘operating hints’ about the CERMET from the company is to: "Run them hard, move the material through the blade FAST. For me, this was the most difficult adjustment to my technique. {The effect seems to be analogous to cutting your lawn with either a bagging mower, or one that keeps re-cutting the debris into mulch. An example would be the impacted clippings on the bottom of your mower - they’re surprisingly hot! } I was getting some burning, especially with some thin trimming cuts. I was using my usual style, easing the work through, the Shop Vac making more noise that the saw. For an experiment, I turned off the vac, got a long piece of 2x ‘scrap’ and started making cuts. Faster and faster feed cuts. I really had to move fast to hear a change in the tone of the blade, and NO BURNING.

I’ve now used the blade for a couple of months; it was even exchanged for another because someone else had a complaint about their blade, so the company exchanged all the test blades. A real ‘life test’ will take a year or more - - for MY situation. However, for Tom Walz to wait that long would be unfair. So far it has ripped, cross-cut, made angled & ‘free-hand’ cuts, and ‘nibbled’ half-lap joints in 2x6 Pressure Treated material. I can’t say that it, ‘cuts paper like a Ginsu knife’ simply because I haven’t tried it !! {Hummmm?}. By the same token, although I have used blades from ‘stamped out’ steel, strange 4 & 6-tooth carbide, ‘Pirana’ blades, and various sized B&D, DeWalt, & Oldham ones, I only considered my 3 - 10" blades as QUALITY ones. [a Freud Fine Cross-Cut, Freud Thin-Kerf Rip, {my 15-amp saw is considered ‘underpowered'} and the 36-tooth Ryobi] I have never tried the much-raved about Forrest Woodworkers, nor Dave Carnell’s Matsushita’s.

Before the testing started, I checked all the alignments, cleaned all the sawdust and debris from the mechanisms, and lubricated the appropriate points. Nothing looked other than dusty after two + years of use. ‘Underpowered’ or not, my saw and the CERMET blade hasn’t had any problems doing anything I have asked it to. I’m still learning; every time I try an operation I haven’t done before there is a learning curve. I also tend to make jigs & templates for almost anything I think I’ll make more that one of. The blade cleanly cuts multi-ply ‘Baltic birch’ and 1/8 inch Tileboard with equal ease.

Before I changed out the Ryobi combo blade I made a few ‘test cuts’ and put them aside. [I had the blade professionally inspected . . . it was only about 10% off from the ‘sharpness’ of a new blade; not numerically significant in a test of this sort] The CERMET blade cuts were slightly cleaner & smoother.

From their website {}, the cost of the CERMET blades is not cheap. In my case, although the 10 inch CERMET blade is $88.oo more, Forrest does not even have a 48 tooth ‘All Purpose’ blade. Additionally, the website recommends using a blade with 2/3rds as many teeth as the equivalent carbide blade; therefore my ceramic teeth gives a cut equal to 72 carbide teeth. The cost of having a Carbide blade sharpened locally {suburban Philadelphia, PA} or sending a CERMET back to Universal Saw Company was about the same. HOWEVER, if the ‘life per sharpening’ is even on the low side of what’s claimed, {"Stays sharp 5 to 10 times as long {as Carbide}"}, than the total ‘cost to use’ would be at least 80% LESS than Carbide tipped. If the numbers hold true, the CERMET comes out ahead.

Should YOU buy this blade? I can’t say that my results came from technique, or the specific saw. From all the discussions, comments, and adverts about ‘Super Quality’ blades, a lot of people have them and have spent $130 and up per blade. If you have the ‘Basic 3' blades for your 10 inch tablesaw {NOT counting that Chop or Miter Saw} that’s a LOT of money. That total is the cost of my saw. Of course, if you have a $1200.oo + Cabinet Saw it’s another story. IF I had just bought a saw, had NO blades, YES, I would buy this blade {and this configuration} as my ‘basic, do everything good’ choice. As I grew in skill, or specific type of work, I would then buy blades specific to the job. By the same token, If I was advanced and 90% engaged in specific tasks, I would get a CERMET blade designed for that task. If I could afford it, I would get another CERMET designed for ‘general purpose work’. If not, then a less expensive Carbide one.

While I haven’t seen any advertising in the usual periodicals, the blade lives up to the claims on the brochures included with it. Your money, your choice . . . I’ve made mine !!