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Never used a jointer/planer much but know that I have one I'm sure that will change. I know that you should plane with the grain and that you change the pressure to the out-feed table. I also know that you can get kickback on a jointer so...
which side of the blade is most dangerous? The in-feed or the out-feed?
I know that both should be treated as dangerous but when thinking about the dynamics involved I started wonder which table was the most dangerous.
Relative to the first part...grain direction...you'll start to get a feel for what works best and will be able to read the boards. Honestly, most of the time it doesn't matter too much, but some boards and some level of figure can make things interesting. One of the benefits of a wider jointer capability is one can also skew the material relative to the cutter head to work around figure a little better when necessary since it creates a shearing cut relative to the movement direction of the material.
Safety when jointing means your hands are vulnerable anytime they are in the vicinity of the cutter head, regardless of infeed or outfeed position. Always work slowly and carefully as you move the material through each pass. When jointing, one should not be exerting "pressure" on the boards at all, other than what's necessary to keep the board from flipping up and that's just on the outfeed side. If you put pressure on the board, you'll be distorting it and therefore, not shaving off the high spots. This is something you learn with practice...keep the board moving through the pass and let the machine flatten it. And again, what little pressure is needed to control the board will pretty much be on the outfeed side.
Marshall
It takes a little bit of time to "read" a board. It's not rocket science or anything, but sometimes the board just doesn't want to cooperate. If your grain is always running downhill, toward the back end of the jointer, you can expect to get a nicer surface.
For edge jointing start out by marking a straight line along the visible face. This will let you see the progress. I have found it is easier to keep track if the concave part of the board is on the table. It won't matter if you start with concave, or convex, down, once you get the hang of it, but in the beginning it's easier with the concave side down.
Set your jointer to take a very light cut, and have the tables as close as possible to minimize the cutterhead throat opening. My Jointer is set to only take about a 32nd or less, of material for each pass.
Start the board with just enough pressure on the infeed table to keep it on the table and flat against the fence. After a hands length has passed over the cutter head, transfer pressure from your lefthand, just enough again to keep it on the table and fence, to the outfeed table side. Continue to keep the pressure on the outfeed, while simultaneously feeding with your righthand. Your right hand is only guiding and pushing. If you apply downward pressure with you left hand on the inFeed table, you will end up with a banana. It is the outfeed table and cutter head that are your reference points.
Face jointing is a little more involved, but the principles are the same. The problem is that face has no reference, so you basically have to choose the reference.
Read the wood and find out which ends are not flat. Read across the diagonal. I myself prefer to have the High point corner enter the cutterhead closest to the fence. This means that that the trailing edge highpoint corner will be opposite the fence. Mark these opposite corners with diagonal lines so that you can gauge your progress.
Once again start the board off with pressure applied to the leading edge, and bias that pressure toward the corner you want to flatten first. Once the material has passed over the cutter head, a hands width, apply the down ward pressure on the newly jointed section. The board is "gliding" over the cutter head, you're not bearing down on it with gorilla force.
In the middle of the board, the cutter head may not make contact at all, but once you get to the end, that opposite high corner will engage the cutter head . It here that you are just trying to "skim" the board over the cutter head. You will need a push block for this that engages the end of the board so that you can continue to feed the board. Don't use your thumb! though you will want to. Make a purpose specific block.
Edge jointing follows face jointing. Apologies for writing it backwards.
I have a small 6" Jet jointer that I've put some pretty good sized material through. I also have 100 + year old, 16" , that can whack off a 1/2" per pass easily, that I have slowly been restoring. The technique is the same, although that 16" is still a little bit intimidating.
Go slow, use a pencil to mark the wood so you can see what is happening, and set that jointer for very light cuts. Better to make 3 or 4 controlled passes, and do it right than do one pass and have it come out wrong. ;)
Marshall, you've had some good advice above.
Jointer kickback is very dangerous due to the possibility of dropping your hand or finger into the cutter. Never have your hand over the cutter, as soon as possible transition both hands to the outfeed table.
The risk of injury from the stock ejection is very low since we stand to the side due to jointer construction. This isn't true of planers by the way, never stand in the infeed or outfeed path of a planer.
Regards, Rod.
When ever I use a jointer with a porkchop guard, I lean into the guard with my hip so that if things go awry, the guard will snap shut. As stated above, never apply pressure above the cutter. Never.
Mike's advise is one of the best I've seen on this subject. Emphasis on the amount and points of pressure. Many people use too much pressure both against the table and against the fence. It's not necessary and distorts the end result.
One addendum is for severely twisted face jointing - put the pressure on the center of the board and keep it there, taking a more-than-usual bite.
Back in the old days, when somebody fell into the chipper, there wasn't much you could do for them, they'd bleed out before you could cut them free, not that there was much left to save. This was called an "industrial accident" and there would be an inquiry. At the small-shop level, there was the radial arm saw, and the worst that would typically happen is that an arm would be sliced down its length, but the emergency crew could do an on-site amputation, often quite high up towards the shoulder. Not so bad. Nobody uses the radial arm saw much anymore. The constant between then and now is when the feed hand gets caught in the jointer, and that's a bit more tricky, because half the arm is okay and the lower half is burger meat. Extraction is difficult, because sometimes the operator is still conscious. That's why people say to never get your hand anywhere near the cutterhead.Quote:
Originally Posted by Marshall Harrison
Using a jointer is like skating, but you never want to be on the business side of the net.