Jointer (User) problem

[Mark Hoeting]

Good evening.

I am in the midst of jointing some 3/4" x 44" cherry stock in order to glue up a couple of panels for two blanket chests.

When jointing the stock, the edges seem to been either concave or convex, as per the picture below. Each of the boards have this to some extent. I have attempted to identify two of the more obvious ones for the purpose of this message.

Can anyone lend advice on what I am doing wrong? I have check the jointer and everything seems square....blade to the outfeed table, etc....
I am taking off about 1/32" - 1/16" per pass over the blade.

Thanks in advance.

Mark

http://www.astate.edu/executive/cio/6881.jpg

[John Michaels]

I'm new to woodworking and had similar problems using my jointer. I found using board straighter clamps (available from Grizzly) on the table saw to straighten the edges works for me. If the the boards are for a glue-up application I can use my router table to get a real sharp edge. I also make a planer sled for face jointing instead of using a jointer. A large (usually means expensive) jointer makes the task much easier, but there ultimately seems to be a lot of practice involved with using a jointer.

[Gary Breckenridge]

:) I think your outfeed table is out of adjustment. Lay a steel straight edge on the outfeed table and it should just barely touch the knives as you slowly spin them.:)

[Tom Hintz]

Mark,
You can do lots of strange things to wood with pressure in the wrong place (or too much of it) even with the machine set up right. I think learning to use the jointer is one of those rights of passage in woodworking we all have to work through....
I have a tutorial (with photos and video) at the link below that might contain a few answers for you.

http://www.newwoodworker.com/basic/usejntr.html

[Eddie Darby]

Do you own a very straight edge?

http://www.leevalley.com/wood/page.aspx?c=2&p=50074&cat=1,240,45313

I would use these straightedges to check each piece of woods edge. If you place one piece of wood up against another, you are checking only how close they match each other.

The straightedges along with a feeler gauge can also be used to check if the two tables on your jointer are in plane with each other.

[Don Henthorn Smithville, TX]

if you get both concave and convex edges then either your wood is very wild or it is incorrect technique. Remember the infeed table is the board's reference for only the first 6 to 8 inches of the board and then the outfeed table must become the reference. The procedure I was taught many years ago was to start the board along the infeed table by keeping the leading edge flat against the infeed table and the fence. Then as soon as there is enough board past the blades to be able to transfer your hands to a position just behind the cutters, transfer your hold to over the outfeed table and hold the board flat against the outfeed table and the fence . Keep pushing the board through and keep transferring your hold to the position just behind the blades. The idea is that you hold the board so it is registered against the infeed table until the board goes through the cutters. Then the newly cut edge will be in registration against the outfeed table so you need to transfer your hold so that the rest of the board is registered against the outfeed table. This should give you a good straight edge on the board.

Hope this is clear and is of some help.