Jointing woes

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  • woodynoob
    Forum Newbie
    • Apr 2013
    • 42

    Jointing woes

    I've started to use a large jointer at the woodworking class I'm in. I brought in some rough cut poplar, but have been having trouble. I seem to be creating "wedges" and am losing a lot of wood.

    So, I pass the wood through over and over again until every part has been smoothed, but the end result is a wedge.

    Here is a gallery that shows different views. http://www.icloud.com/photostream/#A8G4TcsmGybcIX Each end of the piece is shown and I placed pennies on the corners to show scale. Thin, light colored wedgey edge is what entered the jointer first and the thick black edge is the trailing edge. I also included other views to show the whole situation.

    Now, the piece was somewhat bowed, but it really looks like I'm going to end up with 1/4 inch thick stock out of an 1 1/2 rough.

    Is this normal? I had the instructor check the table and he said it was ok. If it's not normal, any theories?
    Last edited by woodynoob; 01-29-2014, 08:29 PM. Reason: Fixing URL. Thanks phrog!
  • leehljp
    Just me
    • Dec 2002
    • 8429
    • Tunica, MS
    • BT3000/3100

    #2
    You should be using a thickness planer instead of a jointer for that. You are probably starting out with non-squared (out of parallel) faces, and a jointer won't help much at that point - unless one has very skilled experience.

    BTW, a jointer is for putting a flat edge on one side - for joining two pieces together. It does not make it parallel to the opposing side.

    Edit in: I didn't have but a couple of minutes to type the above, but do have an additional comment or two. In addition to what Jim says below, this is a good reason to properly stack wood until dried, and even after. A board that just sits for a while without being stacked can twist, cup, bow or warp in some way. It doesn't have to be much and often un-noticeable until planed. A board twisted/warped by 1/16" to 1/8" from end to end may not be very noticeable to the eye but upon planing with mild to moderate pressure, can eat off one side and not the other.
    Last edited by leehljp; 01-29-2014, 09:21 AM.
    Hank Lee

    Experience is what you get when you don't get what you wanted!

    Comment

    • JimD
      Veteran Member
      • Feb 2003
      • 4187
      • Lexington, SC.

      #3
      I have a 8 5/8 wide jointer and a Ryobi thickness planer (the original, a AP-10). I usually use the planner on both faces and often use the table saw or track saw to square an edge. I often totally skip the jointer, in other words. But this process only works well for boards that don't have to be flat. For instance, the top of a table or cabinet. Several boards will be glued together which helps to flatten the resulting slab and in the end, it will be fastened to the cabinet removing any remaining lack of flatness - or enough of it for it to look right and do it's function.

      The "really right" way to prepare stock, however, is to flatten one face on the jointer and then an edge. If I am making a door, I may do this. In that case, if the board is not flat, it will show. After a face and edge are straight and flat, the planner can do the other side and the table saw the other edge. When I prepare stock this way, I loose significant wood as you have. When you can work from both ends, without tearout, it may help. Keeping even pressure also helps. But the biggest thing is to cut to rough size first. If you need a three inch wide piece 3 feet long, don't plane an 8 inch wide board 8 feet long this way to get it. If you do, you will loose more wood and spend more time at the planner. A smaller piece will be straighter to start with. The other reason to do it this way is pieces will move when you cut them off the bigger board. So you might need to further plane it after cutting to rough size if you cut it out of a "big board".

      Comment

      • Daryl
        Senior Member
        • May 2004
        • 831
        • .

        #4
        I think one of the biggest mistakes of jointing is to put too much pressure on the wood, especially over the knives. The pressure should be applied on the out-feed table, and then just enough to hold the wood steady and provide a consistant feed. Maybe you can find some cheap off cuts to practice on.
        Sometimes the old man passed out and left the am radio on so I got to hear the oldie songs and current event kind of things

        Comment

        • JSUPreston
          Veteran Member
          • Dec 2005
          • 1189
          • Montgomery, AL.
          • Delta 36-979 w/Biesemyere fence kit making it a 36-982. Previous saw was BT3100-1.

          #5
          Based on my experience, and what I've seen others do, I do the following:

          1. Joint one face of the board.
          2. Place jointed side of board against the fence and then joint an edge.
          3. Surface plane the opposite face of the board.
          4. Place jointed edge against rip fence on table saw. Rip to slightly over width.
          5. If ripped edge is a little rough, either sand or run through jointer.

          Steps 3 and 4 can be swapped, depending upon preference. Just make sure that the jointed side of the board is on the surface of the TS if ripping to width before planing the opposite side.

          Also, if the board is too wide to run through your jointer, there are plans on the web for making a jig to allow you to surface plane twisted wood using a 12" planer. In the past, when I've run into that problem, I've ripped the board on the TS and re-glued the panel together when done.
          "It's a dog eat dog world out there, and I'm wearing Milk-Bone underwear."- Norm (from Cheers)

          Eat beef-because the west wasn't won on salad.

          Comment

          • phrog
            Veteran Member
            • Jul 2005
            • 1796
            • Chattanooga, TN, USA.

            #6
            I think your link has a typo. Is this it?:

            Last edited by phrog; 01-29-2014, 03:30 PM.
            Richard

            Comment

            • cork58
              Established Member
              • Jan 2006
              • 365
              • Wasilla, AK, USA.
              • BT3000

              #7
              Did your instructor have any idea why its doing what its doing. For one thing a jointer is not a planer, it simply makes the surface flat, not square. Ask him why it is doing this and how to avoid it, it is a class right!
              Cork,

              Dare to dream and dare to fail.

              Comment

              • woodynoob
                Forum Newbie
                • Apr 2013
                • 42

                #8
                Lee— This piece definitely had some bow to it, but it lay pretty flat along the floor. However, I’m a beginner, so I may have missed some subtleties there.

                JimD— The steps you describe: joint two sides, then plane and table saw for the other two is what I was taught. For the work I want to do (prettily jointed boxes for example), I really need well dimensioned wood.

                Daryl—When you say that the pressure should be applied on the out-feed table, this is not what I’m doing. For this piece of wood, I’m placing firm pressure toward the rear of the wood (is that the “in-feed table”?) and light pressure on the “out-feed table”. That was what I was told to do…

                JSUPreston—I’ll have to look up at that jig for doing wider wood than the jointer. Not a problem while I have access to the school shop, but in the future, would be useful.

                Cork— From what I understand, a jointer will make your piece square on two sides if you run them both through it.

                ——

                It seems from the responses so far that I understand jointing and planing pretty well—thank goodness. Most likely, there is something wrong with my technique that is forcing the jointer to take a lot off the front part of the piece, but very little off the rear. So, after a number of runs, I end up with a nice hardwood wedge.

                When I received instruction on the machine, there was some mention of sometimes you could turn it around. I understood the issue with tearout, depending on the grain flow, but didn’t understand why you would need to do this. Maybe I know why now?

                BTW, my class is really an open workshop. I do get as much individualized help as I can take. I’m really enjoying it. When I spoke to the instructors after I produced my wedge, they couldn’t really tell me why it was happening and would need to watch me do it.

                I like the idea of getting some junk stock and just practicing. Now I know what to watch out for.

                Great responses! Thanks all!

                Comment

                • LCHIEN
                  Internet Fact Checker
                  • Dec 2002
                  • 20913
                  • Katy, TX, USA.
                  • BT3000 vintage 1999

                  #9
                  i have gotten the wedges.
                  THere's no guarantee of parallel faces using a jointer, only a flat face (and square, flat edge).

                  my suggestions:
                  try and limit the number of passes. obviosuly the more warped the board is then the flattening will require more passes and get more wedge shaped.

                  Going the wrong way will cause tearout to some extent, But, if the board is not too bad on tearout then alternate directions to try and balance the wedging, then make the last few passes in the lowest tearout direction.

                  Good luck
                  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

                  • woodynoob
                    Forum Newbie
                    • Apr 2013
                    • 42

                    #10
                    Originally posted by LCHIEN
                    i have gotten the wedges.
                    THere's no guarantee of parallel faces using a jointer, only a flat face (and square, flat edge).
                    Just to clarify, I don't expect to have parallel faces with using a jointer. However, I do expect to have parallel faces by correct usage of a jointer followed by a surface planer. My problem with the "wedge" at the pre-planer stage is what seems to be an unnecessary loss of thickness on one end. If the thick end of the wedge is 3/4" and the thin end is 1/4", then I certainly won't get more than a 1/4" piece out of the surface planer when I'm finished.

                    I might not understand completely how a jointer works in terms of the geometry of the wood, the infeed and outfeed tables and the cutter itself...

                    Comment

                    • rcplaneguy
                      Forum Newbie
                      • Nov 2012
                      • 37

                      #11
                      Have you checked that the infeed table is absolutely parallel to the outfeed table, both close to the fence, and then far away from the fence? I have seen several jointers that had issues in this regard. Secondly, are the knives adjusted correctly?

                      Comment

                      • rcplaneguy
                        Forum Newbie
                        • Nov 2012
                        • 37

                        #12
                        A tapered cut is usually a sign that the jointer knives are set too low. If you place a board on the outfeed table and rotate the cutterhead by hand, each knife should catch the board and drag it 1/8". If this is not the case, readjust your knives until the board is moving 1/8" for each knife -- test at each end and the center. If it still cuts a taper, adjust the knives so the board drags 1/32" to 1/16" more (5/32" to 3/16", total). If the jointer suddenly begins to make a concave cut, the knives are too high and you need to back them off so the board is dragged 1/32" less.

                        Comment

                        • mpc
                          Senior Member
                          • Feb 2005
                          • 979
                          • Cypress, CA, USA.
                          • BT3000 orig 13amp model

                          #13
                          Also, how long is the workpiece relative to the jointer table lengths? If the workpiece is too long for the jointer it'll be almost impossible to get a consistently flat/straight surface. About twice as long as the total jointer table length is the typically recommended limit. For a beginner, I'd first practice on pieces that are shorter than the total jointer length.

                          My understanding (I don't do a lot with jointers; the one I have is a small benchtop model and I rarely dig it out) is:
                          a: do not apply a lot of force to the workpiece. If the piece is bowed in cross section, or twisted along its length, applying a lot of force will just squash it into a flatter shape so the blades end up removing material from the whole width of the board... then when the force is released the board flexes back to its natural shape and the original bow/twist is restored. With low downward pressure the blades only cut the high spots. The pressure used should be enough to keep the board in contact with the tables, especially the outfeed table.

                          b: the blades must match the outfeed table. Quick/easy test: get a flat board about a foot long or a little longer. Set it on the outfeed table with one end hanging over the blades. With the jointer unplugged, rotate the blade head by hand. The blades should just nick/scrape along the board. If they dig in or try to take a bite, they're too high relative to the outfeed table and the jointer won't work correctly. You can use a metal ruler, blade from a square, etc. to do this test as well. You'll have to test at several positions across the blades though: blade end nearest the fence, mid-way away from the fence, and at the far end of blades. The "ting" you hear when the blades hit the rule should be consistent at all 3 positions; if not the blades are mounted cockeyed, cutting deeper on one end compared to the other end. Or they're worn and don't have a straight cutting edge. (edit: what rcplaneguy posted while I was busy typing)

                          c: boards with a lot of twist, or twist+cup, are hard to joint because it's difficult to keep the board at a constant attitude as it moves across the blades. Especially if the board is longer than the infeed table; then the "high spot" may start off the infeed table and will thus lift that edge of the board during cutting when the high spot finally reaches the infeed table.

                          mpc

                          Comment

                          • leehljp
                            Just me
                            • Dec 2002
                            • 8429
                            • Tunica, MS
                            • BT3000/3100

                            #14
                            Originally posted by woodynoob
                            I might not understand completely how a jointer works in terms of the geometry of the wood, the infeed and outfeed tables and the cutter itself...
                            I personally think that this is the crux of your problem, and to me, there is one step missing for your situation. Look up "winding sticks," and give that a try. Repeating what I said in my first post, to me, you probably have boards that are twisted or bowed just enough to cause the problem without it being seen by the naked eye before it begins.

                            Winding sticks will show the minute' twist, or bow that the naked eye misses. With the winding sticks, you can see before hand what area and approximately how much is going to get planed on the jointer before it gets level on a specific side.


                            To be honest, even a thickness planer will not get some warps out, but will generally leave the board with even thickness.
                            Hank Lee

                            Experience is what you get when you don't get what you wanted!

                            Comment

                            • Brian G
                              Senior Member
                              • Jun 2003
                              • 993
                              • Bloomington, Minnesota.
                              • G0899

                              #15
                              I think this is being overthought. All you want is a flat face on one side. When you achieve that, stop face jointing. Use a straight edge across the face to figure out if the face is flat.

                              If your board has substantial bow, you're not likely going to out-joint and out-plane with power tools nature's desire to make your board do what it wants to do on its own. You can probably defeat nature with hand planes, though.

                              Practicing with rough boards is a good idea. Use a pencil and draw cross-hatches across the entire length. This will give you an idea of flaws in technique or problems (cup, bow, twist) with your stock.

                              I don't bother with edge jointing until after I thickness plane. This lets me "correct" grain alignment by bandsawing my own reasonably straight edge, joint it straight and square to a face, and then rip to dimension. You don't have to accept the sawyers idea of what the straight edge should be.
                              Brian

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