# Jointer--what am I doing wrong?



## DaDeO (Dec 1, 2010)

I've never had a problem planing boards before, but planing the edge of some of that multi-laminated 8mm plywood is giving me a problem! Every time I run some through, the edge comes out curved. What's with that?


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## woodnthings (Jan 24, 2009)

*Either of 2 things or both*

Machine set-up or technique.

See post 11 below.

If you start with a curved board, more than 1/8" hollow on edge, chances are you'll end up the same way. So, joint in a little from each end then sight the board. Keep at it until your sighting tells you it's straight. Then run a few light passes and you should be OK.

If not then the set-up is off. Assuming both your tables are adjustable, make certain the outfeed table is just at the highest peak of the blade rotation, no more, no less. Then raise the infeed to the same height and check across both tables with known straight edge, or a 48" aluminum level. It should all level out and be in one plane.. If not more problems .....I gotta feed the dog now. Good luck, Best Wishes, Merry Christmas! :laughing: bill

BTW this is post number 4,444 maybe no one will notice...


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## GeorgeC (Jul 30, 2008)

woodnthings said:


> Machine set-up or technique.
> If you start with a curved board, more than 1/8" hollow on edge, chances are you'll end up the same way. So, joint in a little from each end then sight the board. Keep at it until your sighting tells you it's straight. Then run a few light passes and you should be OK.
> 
> If not then the set-up is off. Assuming both your tables are adjustable, make certain the outfeed table is just at the highest peak of the blade rotation, no less. Then raise the infeed to the same height and check across both tables with known straight edge, or a 48" aluminum level. It should all level out and be in one plane.. If not more problems .....I gotta feed the dog now. Good luck, Best Wishes, Merry Christmas! :laughing: bill
> ...


Why does the post counter to the left say 4,448?

George


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## GeorgeC (Jul 30, 2008)

woodnthings said:


> Machine set-up or technique.
> If you start with a curved board, more than 1/8" hollow on edge, chances are you'll end up the same way. So, joint in a little from each end then sight the board. Keep at it until your sighting tells you it's straight. Then run a few light passes and you should be OK.
> 
> If not then the set-up is off. Assuming both your tables are adjustable, make certain the outfeed table is just at the highest peak of the blade rotation, no less. Then raise the infeed to the same height and check across both tables with known straight edge, or a 48" aluminum level. It should all level out and be in one plane.. If not more problems .....I gotta feed the dog now. Good luck, Best Wishes, Merry Christmas! :laughing: bill
> ...


Is it only this specific plywood? Or do you have a problem with all ply wood?

Personally I find plywood difficult to run through a jointer.

George


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## woodnthings (Jan 24, 2009)

*because I made 4 posts after that one*



GeorgeC said:


> Why does the post counter to the left say 4,448? George


:smile:


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## jack warner (Oct 15, 2010)

why would one want to run ply through a planer.


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## Rick C. (Dec 17, 2008)

He's running the plywood through a jointer, to square an edge.
Woodnthings, I've never heard of taking a little off at each end to get it closer. Now I've learned another trick.


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## cabinetman (Jul 5, 2007)

Plywood doesn't joint too well. Taking off some from each end may work, but it's one of those "got lucky" things. There's no degree of predictability.

I would just attach a straightedge on the ply and make a pass on the table saw.












 









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## GeorgeC (Jul 30, 2008)

woodnthings said:


> :smile:


Ah so!!

George


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## jack warner (Oct 15, 2010)

oh i get . i was thinking thickness plainer.


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## woodnthings (Jan 24, 2009)

Rick C. said:


> He's running the plywood through a jointer, to square an edge.
> Woodnthings, I've never heard of taking a little off at each end to get it closer. Now I've learned another trick.


Rick if it may help to think of a jointer like a giant hand plane rather than a one step, one shot, one pass wonder machine.
Your sighting abilities come into play right from the start...cup? bow?...twist?....Then use the jointer to remove all the stock that is offensive, especially if flipping end for end will reduce the number of passes, and it will once you get the hang of it. Keep planing/jointing part way in then lifting the work piece off, until you get as close by eye then use firm down pressure on the outfeed table to flatten (surface) or straighten (edge) the stock.

I've never gotten used to calling a Jointer a "planer" since you really are referring to a "thickness planer" you've got every one confused. This happens a lot here and the terms do make a difference when asking a question. 
They have different meanings in the UK for example, where 
a jointer/planer means a jointer over here.

Having said all that the jointer can indeed be used as a planer, but a planer can't be used as a jointer . :no::yes: bill






And why they cut CURVES:


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## jack warner (Oct 15, 2010)

i too never use the joiner as a planer, but i will use the planer as a joiner. you just have to make sure you start of with a true 90 on the planer table


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## woodnthings (Jan 24, 2009)

*Jack did you watch the videos?*

The jointer makes one straight and flat surface or edge, if all goes well.:smile: Then you can make one or both edges square to that surface. 
The planer makes that flat and straight surface, which now is resting on the bed of the planer, a* uniform thickness,* since the cutters are above and will remove anything in their way. 
You can't make 2 opposite surfaces parallel, or a *uniform* *thickness* on a jointer. They can only be made straight and flat and "square" to one another and with no reference to the opposite surface. If you've flattened one surface, then you can edge joint both edges. But the remaining surface will not be a *uniform thickness* to the original. It might be square to it, but not uniform thickness. 

You can use a jointer as a planer but not conversely. The videos show and explain why much better than I did above.  bill


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## jack warner (Oct 15, 2010)

after your post i watched it, and agree for the most part. i dont own a joiner they take up too much room in the shop and there are other tools that can be used. i always do my large surface first, via the surface planer, then i use an electric hand planer for one edge, then table saw to square ( cut a hair over what i need the cleaned up with a pass or two again with the electric hand plane. thats always worked for me.

or after using my thickness planer, if the board is less than 6" wide, ill cut on the table saw to square one edge, put that edge one the table side of the planer, and run it, flip it do the other side and done. normaly i dont do this if the board is thiner than 1/2 in.


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## DaDeO (Dec 1, 2010)

Thanks for all the comments, guys! I already had a straight and parallel (?) edge after cutting on the TS, but just wanted to clean the edge to joint it at 90 degrees with another board for a fence. Every time I would run this stuff through, I end up with a board that looks like a bow, as in bow & arrow. The more I would run it through, the more it would curve! I just went to the TS and made a fine cut and left it at that! Just can't figure out why that particular piece won't come out straight. Everything is set up right, as any other board I've ever run through came out ok.


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## woodnthings (Jan 24, 2009)

*Now come on!*

You're gonna tell us that one piece of plywood is smart enough all by itself to come out curved? That makes no sense. I'd look for jointer knives that aren't parallel to the cutterhead, one side of the bed that is twisted, or a bed that is higher on one side than the other WRT to knives....somethin' ain't right. :thumbdown:
So, if you take a relatively straight 1 x 6 about 4' long and joint it,using the same location on the cutterhead, it will come out as straight as you can measure it, but not the same size plywood? 
Beats me. bill


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## MastersHand (Nov 28, 2010)

If your blades are dull even a little especially with plywood. The plywood likes to jump up or ride up on the knives instead of sitting flat on the off feed side it will ride up on the knives. The way the plywood grains are it has a hard density like a knot. Try a little extra pressure than normal on the off feed side.


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## DaDeO (Dec 1, 2010)

Yeh, ok, I have a problem! Have to check everything out! Ran a poplar board through last night and had the same thing! Ends measure the same, but the middle came out about a 1/16 wider! So the plywood isn't the only smart one out there! :laughing:


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## WirelessG (Dec 30, 2010)

jack warner said:


> i too never use the joiner as a planer, but i will use the planer as a joiner. you just have to make sure you start of with a true 90 on the planer table


Really you should run a rough-cut board through a jointer to get a flat face, which you later use as a ref in the planer. I believe a lot of people skip this step as they think the rough-cut lumber is flat enough. However on crappy-cut lumber you would have to run it through the jointer first.


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## WirelessG (Dec 30, 2010)

DaDeO said:


> Yeh, ok, I have a problem! Have to check everything out! Ran a poplar board through last night and had the same thing! Ends measure the same, but the middle came out about a 1/16 wider! So the plywood isn't the only smart one out there! :laughing:


How much of each end is okay? Just the first inch or so?


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## woodnthings (Jan 24, 2009)

DaDeO said:


> Yeh, ok, I have a problem! Have to check everything out! Ran a poplar board through last night and had the same thing! Ends measure the same, but the *middle came out about a 1/16 wider!* So the plywood isn't the only smart one out there! :laughing:
> Thanks for all the comments, guys! I already had a straight and parallel (?) edge after cutting on the TS, but just wanted to clean the edge to joint it at 90 degrees with another board for a fence. Every time I would run this stuff through, I end up with a board that looks like a bow, *as in bow & arrow*. The more I would run it through, the more it would curve! I just went to the TS and made a fine cut and left it at that! Just can't figure out why that particular piece won't come out straight. Everything is set up right, as any other board I've ever run through came out ok.


So, are you makin' sad faces or smiley faces :sadr:smile:?
Are your knives freshly sharpened?
Are they set even with the outfeed table and parallel with it.
Does your jointer have an adjustable outfeed table?
Are the in and out feed tables straight across when set to the same height at the cutterhead? (co-planer)
Are they parallel front to back when checked with winding stick or an accurate level? (not twisted?)
If all the answers are "yes" then it's that smart piece of plywood goin' off on it's own......beats me bill


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## cabinetman (Jul 5, 2007)

DaDeO said:


> Thanks for all the comments, guys! I already had a straight and parallel (?) edge after cutting on the TS, but just wanted to clean the edge to joint it at 90 degrees with another board for a fence. Every time I would run this stuff through, I end up with a board that looks like a bow, as in bow & arrow. The more I would run it through, the more it would curve! I just went to the TS and made a fine cut and left it at that! Just can't figure out why that particular piece won't come out straight. Everything is set up right, as any other board I've ever run through came out ok.


The answer is don't joint plywood on a jointer. You said you *already had a straight and parallel edge after cutting on the TS*. That's where you should stop. 

It's entirely possible that your jointer is set up perfectly, but operator error could have caused your problem. Where and how much pressure you applied on the piece as you ran it through could have caused it.












 









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## Billy De (Jul 19, 2009)

Just something to think about have you changed the blades recently? Most people think by setting the two tables level placing a straight over the tables and setting the blades to this, is the way to go.
I know this defies logic but its not correct. 
When setting mine I have a small jig that came with the machine it`s just a small piece of metal with two marks on it, placed on the out feed table with one mark on the edge of the table.

When the blade is set correctly it contacts the jig and drags it till the second mark rests on the edge of the table an the lets it go you then know the blades are set correctly.

I know that Bill(Woodnthings) had a post recently showing this procedure maybe he`ll post a link to it.

I saw this some time ago but cant recall if it produced a bowed or a splayed piece of timber,I`m not saying this is the answer just my shot at it. billy.


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## Billy De (Jul 19, 2009)

Just found it,as I said before I`m not saying this is your problem its just an idea.http://www.woodworkingtalk.com/f2/jointer-knife-set-tool-10977/


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## woodnthings (Jan 24, 2009)

*Maybe it's the knives*

No problems prior to jointing the plywood, tell me it's not the knife setting, that was OK.
I'm, thinking the knives were borderline "dull" and by running the plywood repeatedly over the same spot on the knives, that finished them off as dull.
Having just sharpened/replaced the knives on my fixed outfeed Craftsman 6" jointer, it made a big difference in the cut. So I would try that first. On a fixed outfeed table there is no height adjustment. There are no ways or gibs either so a condition of the table and cutterhead being out of parallel is not likely. I would not suspect that issue, if the jointer was working OK before. Knives set "higher" than the outfeed table will result in concave boards. They should be set as close to level/even as possible on a jointer with no height adjustment.
I use a flat aluminum bar, because of the extra weight, it won't tip over and because it's pretty darn flat. The more often you do this, the better you get and learn when it's just kissing the knife.
Not to say a knife setting tool isn't more precise, just saying "very close" is close enough for most folks. (like me)  bill


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## DaDeO (Dec 1, 2010)

The board's edge comes out smooth all along the edge, but it's curved, not straight! I believe I've found the problem; it appears the edges of the knives by the fence are worn down, putting them lower than the outfeed table, thereby making the board's edge curve up on cutting. Haven't adjusted the knives yet, so we'll see if that's the problem.


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## DaDeO (Dec 1, 2010)

Sorry, bill, read your post after I posted. Duh!


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## Kirkus (Dec 19, 2010)

Boy do I feel stupid. This is kind of off-topic, but... I've always had trouble jointing an edge of a board that's longer than my jointer bed. I never thought of (or heard of) running one end over the blade then the opposite end until you have a flat surface on enough of the ends to run it in one pass. This has been one of those "thank you thank you thank you" threads for me.


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## cabinetman (Jul 5, 2007)

Kirkus said:


> Boy do I feel stupid. This is kind of off-topic, but... I've always had trouble jointing an edge of a board that's longer than my jointer bed. I never thought of (or heard of) running one end over the blade then the opposite end until you have a flat surface on enough of the ends to run it in one pass. This has been one of those "thank you thank you thank you" threads for me.


Jointing boards longer than the beds is a common practice. If you're jointer is set up correctly, that's how you do it. I would not recommend doing one end, and then the other end.












 









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## woodnthings (Jan 24, 2009)

*How you do it?*



cabinetman said:


> Jointing boards longer than the beds is a common practice. If you're jointer is set up correctly, *that's how you do it. I would not recommend doing one end, and then the other end. *
> .


Confused :blink:
I joint one end then the other all the time on boards that have more than 1/16" curve, the board doesn't care it it's coming or going, just the offending material gets removed. Joint-sight-joint, some more. If you don't do it this way the hollow falls onto the leading edge bed on the infeed table,then raises up as it runs over the leading edge of the table tilting the board. That's how I joint a board longer than the tables with substantial curve, bow or twist. Just get rid of the offending material first, then use proper joining technique to flatten and true.  bill


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## cabinetman (Jul 5, 2007)

woodnthings said:


> Confused :blink:
> I joint one end then the other all the time on boards that have more than 1/16" curve, the board doesn't care it it's coming or going, just the offending material gets removed. bill



IMO, a straightedge and a pass on the table saw is more predictable, faster, and less likely to screw up one or both ends. I'm kind of in favor of making suggestions that might minimize having a problem. For this type of problem, jointing ends could be hit or miss.












 









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