Jointner technique help

[Brian Runau]

I am learning to use my first jointer. My technique needs help. I have read and watched a couple videos to get some instruction.

In planing a board I put the concave side down, milling with the grain. One corner is higher than the other. I put consistent pressure on the front end to keep from tilting the board as I joint it. I feed the board into the knives with pressure on the infeed table until I have sufficient board on the outfeed table to switch my pressure and then I switch all my pressure to the outfeed table; while trying to maintain consistent speed through the cutter head. The wood at the twist is being consistently removed. You can see that portion of the lumber moving down the piece as it is milled flat.

Results I get are that the board, after a few passes, comes out wedge shaped. I have taken suffient meat off the front end without removing as much from the rear end. Although it does seem that it is almost flat on one side at this point.

Is this normal look for cupped wood that is twisted as you mill it flat?

Thanks.

Brian

[Mike Goetzke]

Sounds normal to me.

One thing I learned quickly milling my own lumber - mill as short a piece as possible for the project (well in most cases - don't get ridiculous). Think about it - half the length and you 1/2 the cup.

[Faust M. Ruggiero]

Brian,
Make sure you are not pushing down on the work piece too hard. Even if you put your pressure on the outfeed table, you can still force a twisted board flatter than it really is. Then you just keep removing stock without really changing the shape. Next time, keep very light pressure the first couple passes.
fmr

[Darnell Hagen]

Are you splitting the difference in the twist, or are you pushing the leading edge flat to the table?

Is your lumber coming out straight? Does your jointer make every board a wedge, including those without twist?

[Tom Hintz]

The jointer does not have a mechanism to keep the opposing sides parallel to each other so the more cuts you take, the more it can taper the piece. That tapering effect can be increased depending on the kind of defect in the wood. Some encourage it to start tilting the board as the wood is removed.
The jointer is more technique dependent than just about any other machine in the shop. Practice will certainly help but you have to get in the habit of "doing it right" also.
I ahve a few stories on using the jointer (one specifically on tapering at the jointer) at the link below, scroll down to the Jointer section.

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

[Myk Rian]

I get wedges at times also. Nature of the beast.

Make sure the knives are on the same plane with the outfeed table.
Take small cuts. 1/16" or less.

Cut the board shorter if the project will let you.
What I have done is joint the leading edge a bit, then the trailing edge, instead of running the entire board over the blades.

[glenn bradley]

All good info here but, Tom hits it on the head; jointers just make a surface flat. They have no way of maintaining a parallel relationship with an opposing side; that's what your planer is for.

[John Coloccia]

If I have a bad board, I use a jack or fore plane to knock down the bad spots before putting it through the jointer. This minimizes the number of passes, makes the initial passes straighter, and thus minimizes the wedging. This is one of those cases where it's good to have a little neander in you.

[Van Huskey]

First, as others have mentioned with this type of board you will probably get taper no matter what.

Given you mention it is your first jointer how well is it setup? Are the infeed and outfeed tables parallel? If they are not you will get taper on all your boards. For example if the outfeed slopes down from the cutterhead you will take more of the first part of the board and less of the back, even with good technique.

[Robert Reece]

Here is a technique I use when I have a board with a twist. The problem if you push the leading edge onto the infeed table all the way across the face of the board is that you will have to remove a lot of material before you get one side reasonably flat. Ideally you would like to "split the twist". So I rock the board until the gap at the two high corners is about the same, then I put a small shim under the trailing edge. Now I have three points which I can keep stable and three points makes a plane, which is what you are after. As I push the board through I usually get enough of a flat part on the outfeed that I can slip the trailing shim out just before it hits the cutterhead. If I don't have enough of a flat, then I stop and restart from the leading edge before the shim hits the cutterhead. I never run the shim into the cutterhead.

This has worked pretty well for me and keeps me from burning up too much material. Also keep in mind that you don't have to get the entire face of the material flat. You only need enough of a flat surface so that the board won't change shape as it goes through the planer.

[Brian Runau]

Thank you for all the input. Big culprit here was to much pressure taking twist out of the board.

Oh well, I learn by doing.

Thanks.

Brian