Replies

1. 
   MikeHennessy | Dec 18, 2008 05:18pm | #1

   Not so much more teeth, but more a function of how they're ground and set.

   Mike Hennessy
   Pittsburgh, PA

2. 
   Knotscott | Dec 18, 2008 08:34pm | #2

   You don't need a special "glue line" blade to get a glue ready edge. Most decent 24 tooth blades will leave a decently glueable edge if the cut goes well. Nearly all decent 30, 40, 50, & 60 tooth blades will also leave a glue line cut right off the saw. As Mike says, tooth count is part of the equation, but the side grind also comes into play. Some blades leave a smoother edge than others but for edge glue ups, it doesn't have to be glass smooth, just "smooth enough"....it's more important that the surfaces mate well, which doesn't require a lot from the blade other than to not deviate from 90° from the face.

   The real key to a good glue up is for the board to have a flat face, so the 90° edge is consistently reference to the flat face along the entire length....if the board's face wanders, so will the 90° edge, then it gets tricky to mate the boards together without gaps unless you know some nifty tricks. No saw blade will replace the ability of a jointer to flatten an initial reference face....with the help of a sled, a planer can flatten a face too, as can a hand plane with a skiller operator.

   
   

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   Edited 12/18/2008 12:37 pm ET by Knotscott

3. 
   stantheman | Dec 19, 2008 04:06am | #3

   habilis  for what its worth, I have the Freud gl rip on my Ryobi and like it just fine.  I suggest the thin kerf version due to low power but note the need to adjust the splitter (or riving knife if you have the bt3000/3100)

4. 
   tomwalz | Dec 19, 2008 08:45pm | #4

   A flat top or square top grind is good for ripping.   An ATB (Alternate Top Bevel) grind has one tooth with a point on the left, the next has a point on the right and so on.   This gives a smoother cut and is generally used for cross cutting.  Next is an ATAF (Alternate Top and Alternate Face) grind where the tops of the tips slant left then right and the faces of the tips slant in alternating directions as well. 

    

   There are more as well. See

   http://www.carbideprocessors.com/Tech_saw_blade_common_blades.htm  

5. 
   DwayneRichelieu | Dec 25, 2008 04:25am | #5

   A glue line rip is usually a flat top grind on all teeth. It leaves a good cut but the pores of the wood are open and accept glue well. Commercial woodworkers seem to be more concerned about this. An ATB, alternate top bevel, will tend to slightly close the pores. There is an appearance difference of slightly fuzzy on the first, and on the second slightly smoother. An ATB is designed with sharp pointy tips to cross cut the grain of the wood cleanly. Most 10" rip blades will be 24 teeth and nearly always ATB. This makes it more "utilitarian", and is very satisfactory.

   A Forrest blade such as the Woodworker 10"x 40tooth ATB, is a tremendous blade for cross cutting. They manufacture to higher standards than most industrial companies, and do one other thing different. If I understand correctly they grind the side of the carbide teeth closer to the steel plate than most, and this allows the plate to rub and it burnishes the wood, ie closing the pores even more so there is a really nice smooth edge. At the wood shows, this is impressive. To give Forrest their due, they grind the tips with 800grit diamond wheels, and others do 400 grit; and the run out tolerance is tighter than most others.

1. 
   Knotscott | Dec 25, 2008 05:59pm | #6

   AFAIK, most 10" glue line rippers (GLR) are a 30T triple chip grind (TCG), and use a low side clearance for the polished look you noted on the Forrest. The Freud LM74, CMT, Amana, and Systimatic are just some of the examples available. Many of the premium blades use a low clearance side grind technique on various blades depending on the intended application, Ridge Carbide, Infinity, Tenryu, Freud to name a few....Infinity and Freud both offer a dual side grind on some blades so there's even more contact with the side of teeth, thus a higher degree of polish on the edge. Many bulk rippers are 24T flat top grind (FTG)...Freud LM72, LU87, Infinity 010-024/010-124, CMT 201.024.10/202.024.10, DeWalt DW7124/DW7642, Leitz, Kempston, etc., though there are also several 24T ATB rippers from a few other names....Hitachi, Oshlun, Kempston, Freud Avanti, and Bosch come to mind.

1. 
   DwayneRichelieu | Dec 26, 2008 08:03am | #7

   Wow, you certainly know about a lot of saw blades! What does AFAIK mean? I really am new to this forum, but find it very interesting. Your comments are very interesting. I have hardly ever found customers using 10" x 30 TC blades in Western Washington. I had serviced a few hundred commercial accounts for 8 years. The one customer I remember, was not ripping solid wood, but cutting out parts in MDF!

1. 
   BillBrennen | Dec 26, 2008 09:46am | #8

   AFAIK = As Far As I Know