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Bandsaw blades, which one for ripping?

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  • Bandsaw blades, which one for ripping?

    Hello everyone!

    So I am making a trellis for the Jasmine flower plants to crawl up...i need to rip a 2x4 redwood into 8 1x1...nominal dims of course...basically 8 equal pieces.

    Here are the bandsaw blades that i have....which one do I use...

    the one on the right side burned out trying to shave a 8x4 by 6ft long...8" dim tall.

    Here are the blades

    Sent from my SM-N920T using Tapatalk

    _________________________
    omar

  • #2
    General rules of thumb for choosing bandsaw blades:
    1: typically you want at least 3 or 4 teeth in the material when cutting especially when cutting thinner stock but not more than 6 teeth or so. For resawing tall material, say a six in high piece, that would mean a blade with less than one tooth per inch which is a bit unreasonable for home bandsaws... 2 TPI is probably about right combined with a slower feed rate; it's the lowest TPI I ever use on my bandsaw. Deeper gullets are needed when cutting taller material so the waste has somewhere to "hide" while being carried by the blade. When the gullets fill, friction and heat rise dramatically. Slowing down the feed rate compensates.

    2: the deeper the blade (distance from teeth to rear edge of blade, when the blade is marked "1/2 inch blade" that is the dimension being called out) the better it typically cuts a straight line IF the wheels + tires on your bandsaw can handle it. If the bandsaw's wheels + tires are too narrow for the blade then much of the blade ends up unsupported and/or the natural crown of the bandsaw wheel will be too curved for the blade. Deep blades also put a lot more stress on the bandsaw structure as it takes a lot of force to create proper blade tension (the force gets distributed through the cross-sectional area of the blade) and many bandsaw frames may flex under the load. As the blade makes the cut, and the resistance during the cut varies, the forces acting on the bandsaw frame vary too and now you've got a constantly-flexing frame not doing you or the cut quality any favors. Thus a not-so-deep blade may work better than the deepest/largest blade your saw is rated for. I find a 1/2" 2 to 3 TPI blade works quite well for most resaw operations on my 14" bandsaw even though it's rated for up to 3/4 inch blades.

    3: pitch build-up on the blade sides: just adds a LOT of friction. A clean blade works so much better. Crud collected on the sides of the blade is rarely perfectly smooth too so, as the blade rides over the tires and through the guide assemblies these lumps introduce varying lateral upsets into the blade... leads to a fatter kerf and possibly excessive "wander" in the cut direction. Crud buildup on a blade is just like having an uneven crown on the tire - the blade tracking is going to suffer. A clean blade that has also had a thin layer of lubricant wiped onto it (saw unplugged, just turn the wheels by hand while holding a lubricated rag to the back and sides of the blade) helps reduce friction and reduces crud accumulation.

    With all of that in mind, and given the size of the material you described, the left-most blade looks like a good candidate to me. The second-from-left blade would be for thin stock and for making fine curves; it's almost a scroll-saw blade for the bandsaw. For resaw work the gullets would load up too much and create a lot of heat. Also, in a tall workpiece it's likely it'd bow (as viewed from the front of the saw) giving you ugly workpieces. Skinny blades have a harder time resisting grain/density changes in the material. The particular example in your pic also looks pretty worn out/dull. The 3rd blade looks to have a high TPI count even though it's a 3/8ths to 1/2 inch blade... probably good for straight cuts in material up to half an inch tall or so. Of the blades shown, it looks the least useful overall to me. It also doesn't look particular sharp either. I think that 4th blade needs a bath. Cleaned up, it might work for the thickest cuts in your workpiece but would probably have too few TPI for most of the cuts. It'll strut its stuff when resawing tall boards. The burnt-out right-most blade? It looks like it tried to cut through something much tougher than wood - like it hit a nail or rubbed against a rock or something. Or it really overheated and the teeth lost all strength. The teeth are so worn I can't even tell which direction they used to point.

    The last thing: a dull or worn-out blade with the right TPI and depth for the cut is still worse than a fully-sharp blade that has a bit higher TPI and/or less depth. Sharpness rules. How sharp is that left-most blade? It may be past it's prime.

    mpc

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    • #3
      I'm no expert, but for ripping I'd use a wide gullet, few teeth per inch blade, like the one between the 3- and 5-inch marks on your measuring tape. The wider blade would be less susceptible to twist, and the wide gullet would clear the chips faster as the larger teeth would more aggressive.

      The really fine teeth saw blade looks like it's more suitable to cutting metal than wood, perhaps the reason you burned one up trying to "shave" your stock. The blade on the left looks to be about 1/4-inch and I would use them for general work, cutting gradual curves, etc. The blade in the middle left looks quite fine and about 1/8 -inch wide... not sure if that's for metal or perhaps cutting thin stock, like veneer or 1/4-inch ply. The blade between the 2- and 3-inch tape marks, again looks too fine for most wood stock... perhaps for aluminum, brass, or plastic.

      Again, I'm no expert; but blade/tooth design (in my mind anyway) is similar in some respects to any other cutting blade (circular, recip, etc.) in that a fine tooth blade is generally for metal, or some plastics, veneer, etc. Wider tooth arrangements are for ripping, where you want to remove stock quickly.

      Hope this is helpful,

      CWS
      Think it Through Before You Do!

      Comment


      • #4
        Blade #4 to rip the 2x4 into a 1x4, change to blade #1 to slice the 1x4 into 1x1

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        • #5
          Remember that the cuts will be rougher than the piece you bought. It may be just fine for a trellis but if you want it smooth be sure to allow thicker cuts for planing and sanding.

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          • #6
            The one (I;m assuming the bands are all doubled for storage) under the "4" of the tape.
            It looks to be a 1/2 wide blade (good for straight line ripping) and 3 TPI with deep gullets.
            Loring in Katy, TX USA
            If your only tool is a hammer, you tend to treat all problems as if they were nails.
            BT3 FAQ - http://www.sawdustzone.org/forum/dis...sked-questions

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            • #7
              thank you everyone for replying back! that was very helpful in understanding what i need to use. i really need to learn about bandsaws

              i blade on the right most is burned...melted the teeth while cutting an 8" tall x 6ft long (2 cuts) redwood that was quite dry...so that is garbage.

              the blades are folded for storage....the blades are for a gizzly 17" bandsaw...these blades came with the band saw when i bought it used but i have no idea what material the blades are supposed to be for.

              so the blades 2 and 3 from the left are not for wood?

              how do i tell if the blades are sharp?

              what do i use to clean and remove the stuff on the blades?
              _________________________
              omar

              Comment


              • #8
                2 and 3 are wood blades. 2 looks to be a 1/4 x 8 tpi, 3 looks to be a 1/2 x 10 tpi. I clean my blades with simple green or simular degreaser. #4 should have been used for cutting that thick of material. Donít force anything on a bandsaw. All forcing does is burn up blades.

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                • #9
                  Got it! Thx! I got the wood ripped...followed the suggestions. Will post pics once done

                  If i recall, I was having to force it. Makes sense.

                  How do I know if a blade is sharp?

                  .

                  Sent from my SM-N920T using Tapatalk

                  _________________________
                  omar

                  Comment


                  • #10
                    Blade cleaning: any of the blade cleaner chemicals sold for table saw blades, circular saw blades, router bits, etc. will work fine. No matter the blade type it's the wood's pitch and resin that builds up so any pitch/resin cleaner will work. Simple green works well too. A soft brass bristle brush helps with the more stubborn build-ups. Brush away from the teeth leading edge (brush from the blade back to front) to minimize the brush snagging on the teeth and to minimize unnecessary wear on the blade teeth.

                    Is it sharp or not: just like a table saw blade... you have to know how a blade performed when new so you can mentally compare "then" to "now." Dull bandsaw blades tend to:
                    a: wander or zig-zag more in a cut. Dull blades tend to follow the wood grain more rather than slicing through it. Too-low blade tension causes similar zig-zags unfortunately.

                    b: you'll have to push harder on the workpiece during the cut... though knowing the difference between "this is a tough chunk of wood" versus "this blade sucks" takes experience. Especially when trying to cut a thick workpiece... the more meat being cut the harder the blade and saw work and thus the slower your feed rate has to be. Too many teeth in the workpiece (too many TPI on the blade) and/or not deep enough gullets in the teeth make the problem even worse.

                    c: dull blades create a LOT more heat. Find a workpiece that'll take a minute or two to cut through... cut it. Turn the saw off and let it coast to a stop. Quickly test the blade temp - along the side of the blade, don't touch the teeth themselves. If it feels hot at all it's probably dull. On my saw I rarely feel any temperature in the blade. Unless you are cutting a really big workpiece (say resawing something 5 or more inches tall) it should not take a "shove" from you to feed the work. You should never have to "lean into" the workpiece to push it nor should it take two hands to push hard enough - you should be able to feed the work with one hand and use the other hand to help control/guide it.

                    Any blade that was over-worked - e.g. too many teeth in a thick workpiece, too fast a feed rate on the workpiece, no dust collection so sawdust clogged the blade gullets - probably was over-heated which dulls the blade quickly.

                    mpc
                    Last edited by mpc; 05-21-2018, 11:02 PM.

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