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  • forstner in end grain?

    MY daughter asked me to cut some candle stands from some birch logs she bought. THey're fairly dry, about 3" in diameter.
    I cut them down and they're maybe 6" long on my bandsaw.
    She needs 1-7/8" diameter holes about an inch deep for the little glass holders into the end grain of these logs.

    I thought it would be easy. But it was quite hard going. The end grain of the birch is quite hard to sheer off with the Forstner. The first clue was I could not tighten the shank hard enough to keep it from slipping when I applied enough pressure to cut it, not just burnish it. The bit kept rotating but slipped up intot he chuck when I applied down pressure. Eventually the 3/8" shank stepped up in diameter a bit and it stopped sinking into the chuck when that step hit the chuck.
    I had to hand hold it, the log being not perfectly shaped and having bark on the outside, was not conducive to clamping in a DP vise.
    After that it took forever to cut - got very fine dust, not the shavings one is used to when using a forstner. Looked like the bottom of the hole was near burning and looked burnished. I gave up after about 1/2" of this in 10 minutes.

    I thought about a hole template and a plunge router and spiral upcut bit, but I'm not real comfortable with being 6" up in the air with the router and how to clamp the template to the log and how to clamp the log to the table.

    Then I thought about router in the table with a bushing, a 2" template on the end of the log and routing cut side down... still not sure how to cleverly clamp the template to the log and worried about holding the log that near the router bit.


    Apparently this is not the proper application for Forstner. A hole saw won't work, I need the inside cleared out. Haven't seen an spade auger bit that large (1.875" D)

    Any great ideas?
    Last edited by LCHIEN; 04-19-2010, 08:47 AM.
    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 - https://www.sawdustzone.org/forum/di...sked-questions

  • #2
    If you've got a woodworking vise, you could make some v-Blocks that hang over the jaws making a more or less flat top. You can then tack/screw a router template over that and clear out the hole. Depending on how deep the hole needs to be you may need multiple passes in end grain.

    Mike D

    Originally posted by LCHIEN View Post
    MY daughter asked me to cut some candle stands from some birch logs she bought. THey're fairly dry, about 3" in diameter.
    I cut them down and they're maybe 6" long on my bandsaw.
    She needs 1-7/8" diameter holes about an inch deep for the little glass holders into the end grain of these logs.

    I thought it would be easy. But it was quite hard going. The end grain of the birch is quite hard to sheer off with the Forstner. The first clue was I could not tighten the shank hard enough to keep it from slipping when I applied enough pressure to cut it, not just burnish it. The bit kept rotating but slipped up intot he chuck when I applied down pressure. Eventually the 3/8" shank stepped up in diameter a bit and it stopped sinking into the chuck when that step hit the chuck.
    I had to hand hold it, the log being not perfectly shaped and having bark on the outside, was not conducive to clamping in a DP vise.
    After that it took forever to cut - got very fine dust, not the shavings one is used to when using a forstner. Looked like the bottom of the hole was near burning and looked burnished. I gave up after about 1/2" of this in 10 minutes.

    I thought about a hole template and a plunge router and spiral upcut bit, but I'm not real comfortable with being 6" up in the air with the router and how to clamp the template to the log and how to clamp the log to the table.

    Then I thought about router in the table with a bushing, a 2" template on the end of the log and routing cut side down... still not sure how to cleverly clamp the template to the log and worried about holding the log that near the router bit.


    Apparently this is not the proper application for Forstner. A hole saw won't work, I need the inside cleared out. Haven't seen an spade auger bit that large (1.875" D)

    Any great ideas?

    Comment


    • #3
      Why couldn't you use an adjustable expansive bit and a hand brace?
      .

      Comment


      • #4
        Originally posted by LCHIEN View Post

        I thought it would be easy. But it was quite hard going. The end grain of the birch is quite hard to sheer off with the Forstner. The first clue was I could not tighten the shank hard enough to keep it from slipping when I applied enough pressure to cut it, not just burnish it. The bit kept rotating but slipped up intot he chuck when I applied down pressure. Eventually the 3/8" shank stepped up in diameter a bit and it stopped sinking into the chuck when that step hit the chuck.
        I had to hand hold it, the log being not perfectly shaped and having bark on the outside, was not conducive to clamping in a DP vise.
        After that it took forever to cut - got very fine dust, not the shavings one is used to when using a forstner. Looked like the bottom of the hole was near burning and looked burnished. I gave up after about 1/2" of this in 10 minutes.

        I thought about a hole template and a plunge router and spiral upcut bit, but I'm not real comfortable with being 6" up in the air with the router and how to clamp the template to the log and how to clamp the log to the table.

        Then I thought about router in the table with a bushing, a 2" template on the end of the log and routing cut side down... still not sure how to cleverly clamp the template to the log and worried about holding the log that near the router bit.


        Apparently this is not the proper application for Forstner. A hole saw won't work, I need the inside cleared out. Haven't seen an spade auger bit that large (1.875" D)

        Any great ideas?

        You should first address the slippage of the bit shank. If you have cross cut the log so it will sit flat, you could do it on the DP. As for clamping the log to the DP table, use a Jorgie hand screw clamp on the log, and then clamp that to a substrate and the DP table. A sharp forstner should cut a nice hole. A sharp holesaw will also cut the hole, and clear out the wood with a chisel.

        With a lot of fiddling around you could likely clamp a router template to the log, by first applying a Jorgie hand screw clamp to the log, and then clamp the template to the Jorgie. This would be my last method.
        .

        Comment


        • #5
          "With a lot of fiddling around you could likely clamp a router template to the log, by first applying a Jorgie hand screw clamp to the log, and then clamp the template to the Jorgie. This would be my last method."

          Maybe just glue on a router template, then saw it off when finished. He'd probably need to make a template for each piece, though. But he wouldn't have to worry about it moving around on him while routing.

          Comment


          • #6
            My first thought is that your forstner bit is dull. I have never encountered any problems drilling end grain as long as the bit was sharp.
            Dick

            http://www.picasaweb.google.com/rgpete2/

            Comment


            • #7
              Originally posted by LCHIEN View Post
              MY daughter asked me to cut some candle stands from some birch logs she bought. THey're fairly dry, about 3" in diameter.
              I cut them down and they're maybe 6" long on my bandsaw.
              She needs 1-7/8" diameter holes about an inch deep for the little glass holders into the end grain of these logs.

              I thought it would be easy. But it was quite hard going. The end grain of the birch is quite hard to sheer off with the Forstner. The first clue was I could not tighten the shank hard enough to keep it from slipping when I applied enough pressure to cut it, not just burnish it. The bit kept rotating but slipped up intot he chuck when I applied down pressure. Eventually the 3/8" shank stepped up in diameter a bit and it stopped sinking into the chuck when that step hit the chuck.
              I had to hand hold it, the log being not perfectly shaped and having bark on the outside, was not conducive to clamping in a DP vise.
              After that it took forever to cut - got very fine dust, not the shavings one is used to when using a forstner. Looked like the bottom of the hole was near burning and looked burnished. I gave up after about 1/2" of this in 10 minutes.

              I thought about a hole template and a plunge router and spiral upcut bit, but I'm not real comfortable with being 6" up in the air with the router and how to clamp the template to the log and how to clamp the log to the table.

              Then I thought about router in the table with a bushing, a 2" template on the end of the log and routing cut side down... still not sure how to cleverly clamp the template to the log and worried about holding the log that near the router bit.


              Apparently this is not the proper application for Forstner. A hole saw won't work, I need the inside cleared out. Haven't seen an spade auger bit that large (1.875" D)

              Any great ideas?
              I would indeed use the router in your case. To avoid going 6" up.. I would bring the face to be routed down. Drop it in your front face vise (a twin screw in this case shines) so the surface is level with the top of vise and work-bench top. You're now working bench-top level with the bench top as additional support. Cut two pieces of scrap with V's in the faces to fit on each side of the log before clamping as clamping round is difficult.

              After drilling a 1 7/8" hole in a piece of 1/2" MDF I would carpet tape the template over the log face surface clamped in the vise taping both to the log and the bench table to ensure adhesion. At that point I would remove the majority of inner waste with the up-cut spiral.. use a round rasp and get it even closer (1 MM preferably) and then smooth the edges using an over-head bearing pattern bit in con-junction with the exact 1 7/8" hole you cut with the forstner on the DP.

              Good luck however you tackle it...
              Last edited by SARGE..g-47; 04-19-2010, 11:08 AM.

              Comment


              • #8
                I prefer to use a holesaw on end grain. Use a small rod or phillips head screwdriver to break out the center plug and finish the bottom of the hole with the forestner.

                Comment


                • #9
                  Originally posted by capncarl View Post
                  I prefer to use a holesaw on end grain. Use a small rod or phillips head screwdriver to break out the center plug and finish the bottom of the hole with the forestner.
                  That works? I'd think that would be about as easy as breaking-off the end of a dowel rod. The direction of the grain isn't going to make it very easy.

                  Comment


                  • #10
                    Originally posted by Whaler View Post
                    My first thought is that your forstner bit is dull. I have never encountered any problems drilling end grain as long as the bit was sharp.
                    +1 That was my first though too. While there are other ways to do this job, using a sharp forstner bit is certainly the easiest and fastest. I would also suggest you double check the drill press speed setting.
                    _________________________
                    "Have a Great Day, unless you've made other plans"

                    Comment


                    • #11
                      Originally posted by sweensdv View Post
                      +1 That was my first though too. While there are other ways to do this job, using a sharp forstner bit is certainly the easiest and fastest. I would also suggest you double check the drill press speed setting.
                      ~300 RPM, per some chart I have hanging on the wall, for hardwood & Forstner > 1". I'm usually conscientious about changing DP speeds for the job, esp. if I'm going to a large Forstner.

                      re Sharpness: It's a Forstner from an HF set I've had for many years but I doubt I have used the 1-7/8" much... of course, it could be unsharp from the get-go.
                      maybe i'll touch it up with a diamond file.


                      ANd yeah, I don't think breaking an almost 2" wide plug off across the grain is going to work well, esp. if the leverage is only an inch long!
                      Last edited by LCHIEN; 04-19-2010, 12:29 PM.
                      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 - https://www.sawdustzone.org/forum/di...sked-questions

                      Comment


                      • #12
                        Might chuck in a smaller forstner bit you know that cuts well.
                        Erik

                        Comment


                        • #13
                          Originally posted by LCHIEN View Post
                          ~300 RPM, per some chart I have hanging on the wall, for hardwood & Forstner > 1"

                          Forstner from an HF set I've had for many years but I doubt I have used the 1-7/8" much... of course, it could be unsharp forom the get-go.
                          maybe i'll touch it up with a diamond file.

                          I think I mentioned a sharp forstner bit. Lightning might have struck me if I suggested that YOURS was dull.
                          .

                          Comment


                          • #14
                            Originally posted by capncarl View Post
                            I prefer to use a holesaw on end grain. Use a small rod or phillips head screwdriver to break out the center plug and finish the bottom of the hole with the forestner.
                            Ditto on the hole saw. Then at the very end the Forstner if you need a flatter bottom to the hole.

                            I have found that large parallel clamps work well in holding odd shaped things, two clamps tight at different spots and then clamped together against the table should do it.

                            Bill

                            Comment


                            • #15
                              Have to agree with WHALER on the forstner bit. I have made a few of the "square in a circle in a cube" items which entail drilling into end grain on two sides. Usually dress up the bit with a diamond file before starting and sometimes part way thru the drilling. Also as someone stated, as slow a speed as your DP will go.
                              RuffSawn
                              Nothin' smells better than fresh sawdust!

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