Jointer Knives

[Bob Haskett]

For those of you that were not following my last thread, I was having problems with snipe, and dull/nicked knives on my used jointer I recently purchased. I had a ridge running the length of the board.

Ok so my new Jointer knives came in today for my G1182HW. I had my tables all calibrated and ready to go. I dropped the knives in, checked the height in reference to the outfeed table, and was ready to start face jointing a scrap piece of wood.

1st pass: WOW it was doing much better than before but I had a SMALL amount of snipe on the end...Made a small adjustment to the outfeed table and gave it a second pass...Second pass: looking good! snipe gone and the board was just about perfect. Third pass: I feel heavy vibration in the wood as the wood passes over the blades, I finish the pass, check the piece, no snipe, but it looked like someone had chewed my board up and had a ridge in the wood much like I did before the new blades. So I Checked the belt, checked the knives to make sure they were all seated properly still, checked everything. Everything was as it should be. Gave it another pass, same story.

What on earth is going on? Are knives that easy to dull/nick? Did I just get a bad set of knives? Am I doing something wrong? I am just taking off a VERY small amount on each pass. I just dont get it.

[Keith Westfall]

Is there something stuck down/below around the cutter head that the knives might hit?

That has to be a frustrating thing to say the least... :(

[Tom Hintz]

I also would be looking below the head (after checking just to be sure there is nothing in the wood itself...hidden piece of screw or something). Even cheap knives dont go away that quickly without something spurring that on.
I have seen outfeed chutes get clogged on one side when a long chip gets wedged and starts holding up smaller debris. The result can be bad things at the cut. Unplug it and check the chut and everything below the cutterhead carefully. I hope this is sometning as simple as a clog or piece of debris in the wrong place for you.

[Myk Rian]

I've had freshly sharpened, and new knives develop a nick after a couple boards. It happens.

[Paul Ryan]

Pictures of the cut may help the diagnosis better. I have been on the same sharpend kives for about 1 1/2 years. I don't face joint very often but run almost every cut long grain end over the jointer before assembling or gluing. The knives will get nicked but if that happens and the ridge they leave caused problems. You can off set the knives a little slide on in and the following out slightly so they cut out the ridge. But I would like to see your cut, to verify it is a blade nick causing the issue.

[Bob Haskett]

I will post pictures when I get home tonight, however, there is what appears to be a nick, along with it looks like a dog chewed up my wood when it comes out.

I checked under the cutterhead, and in the chute and did not see any debris. I also checked the wood to see if there were any foreign objects. Nothing.

I called grizzly tech support about the issue and they told me to ship the knives back, after they check the knives out, they will send me a new set if they are defective.

[glenn bradley]

The chewed part has me concerned that the cutterhead is not being controlled. I would be super careful running that machine till you get this figured out. What do the Grizzly tech support guys have to say about all this other that sending you new knives?

[Bob Haskett]

I have 2 sets of knives, I put the other set back in and they have a nick but otherwise leaves a glue ready face. Because of that fact, they think it is the knives.

[Paul Ryan]

I have 2 sets of knives, I put the other set back in and they have a nick but otherwise leaves a glue ready face. Because of that fact, they think it is the knives.

That sounds more like it to me Bob, it isn't hard to nick a knife but it has to be deep nick to cause a major problem. I once ran a board though on edge that had a staple in it, that caused a problem, I changed the alignment of the knives and that got me buy for a while. But normal operation knives will last a long time unless abused. Face jointing is tought with rough lumber because there can be dirt, dust, and other debris caught in the rough of the lumber. But again I rarely face joint usually it goes through the planer and I check it then. The mill I buy most of my lumber is real good about making sure their material is as flat and straight as possible.

[Bob Haskett]

That sounds more like it to me Bob, it isn't hard to nick a knife but it has to be deep nick to cause a major problem. I once ran a board though on edge that had a staple in it, that caused a problem, I changed the alignment of the knives and that got me buy for a while. But normal operation knives will last a long time unless abused. Face jointing is tought with rough lumber because there can be dirt, dust, and other debris caught in the rough of the lumber. But again I rarely face joint usually it goes through the planer and I check it then. The mill I buy most of my lumber is real good about making sure their material is as flat and straight as possible.

So now I just have to wait on them to inspect the knives, then send me the new ones, hopefully then I will be good to go.

[Bruce Wrenn]

Brian over at Holbern sells a better knife, for less. He sells same knives (Titan) as Global Tooling. On one of my 1182's (the newer one) if knives are set too high, they strike castings of machine. Knives, even cheap ones, should last quite a while. When I bought my first 1182 (used) it still had the original knives on it. They were only 20 years old. Previous owner had one of those "touch up stones" that he used on them.

[Bob Haskett]

Not sure what is going on then. The knives that were on the jointer when I purchased were sharp, but nicked. I figures I needed a replacement set anyway, so ordered a set. After a few passes they were chewing up my boards. I swapped back to my old knives and all is well except the nick. I have tried shifting the knives back and forth, but there are just too many nicks. No matter how I shift them at least one ridge running the length of the board shows up.

I called Grizzly, and they said if you want them this week to buy a new set and have them shipped to you and send the old ones back. When they get them and inspect them they would refund me.

[Dan Schocke]

One thing you might want to check is that the knives are ground properly -- make sure that the sharepened edge is straight. I recently bought one of the Ridgid jointers that have been on clearance, and as I was setting it up I was having fits setting one of the knives. I could set it level with the outfeed table on both ends, but it seemed way off in the center. After adjusting the jack screws 3-4 times, it gradually dawned on me that there was no way that the knife edge was ground straight. I pulled the knife, checked it with a straightedge, and found that it was aout 1/32" high in the middle. Amazing that thing made it through quality control... I'm not sure what would have happened if I had tried to use the machine with that knife installed, but I can't imagine that it would be pretty.

Fortunately I had a spare set of knives and was able to get up and running quickly, but I still learned my lesson. I don't think I'll ever install a jointer knife again without first checking that it is ground straight.

[george wilson]

Chinese steel is famous for poor quality control,brittle HSS,half melted ball bearings in mild steel,and who knows what other defects. Your nick could have been in a place where the HSS knife had some kind of defect.

On other forums where mostly professional machinists post,these defects have been discussed. Look what has been found in Chinese plywood in this forum-pieces of soccer balls!

[Bob Haskett]

Well hopefully I will get it all working soon.

[Kyle Iwamoto]

No offense intended here, but how did you adjust the knives? The reason I ask, is if 1 is set too high, it does all the work, and can get dull really fast, since it's the only 1 working.
Second, what kind of wood? Some hardwoods are just that, hard, and if there is a knot, I can see it damaging your blade really quick. Which then brings the grain direction and highly figured woods question. I found out the hard way that you cannot joint curly koa...... IF you're jointing curly maple, it may just be the wood that's giving you some percieved trouble.

Just my $.02.

[Bob Haskett]

No offense intended here, but how did you adjust the knives? The reason I ask, is if 1 is set too high, it does all the work, and can get dull really fast, since it's the only 1 working.
Second, what kind of wood? Some hardwoods are just that, hard, and if there is a knot, I can see it damaging your blade really quick. Which then brings the grain direction and highly figured woods question. I found out the hard way that you cannot joint curly koa...... IF you're jointing curly maple, it may just be the wood that's giving you some percieved trouble.

Just my $.02.

Used the A-LINE-IT system that has a setup for adjusting jointer knives. I had them dialed in to within .001 of eachother.

Was just testing cuts on regular construction grade 2x4s. I checked the wood for foreign objects and found nothing.

[Andrew Hughes]

Dont forget to clean the oil off new knives.Good luck getting your machine running again.

[Brian Runau]

I cut some 5/4 stock in half on my bandsaw and wanted to joint the faces for smaller stock. When I cut it there was a knot on both side that did not show on the outside of the stock. How do you joint this face?

Thanks

[michael case]

Hey Bob,

Sorry to to hear this. I have two sets of grizzly jointer knives having purchased a back up set with my Griz jointer. I wish I only had one set. I don't want to bog down this thread with my opinions on sharpening, but I'm pretty stringent and grind all my own knives and chisels and finish them on high quality Arkansas stones. So when I saw the ridiculous over-honed and untrue edges on the knives I received I re-ground and honed them properly before using them. I found them to be thin. The backs were impossibly dipped and could not be properly flattened. And their performance has been sub-standard. It has not been anything like your disaster but they do nick up really really fast. So I have to get some new sets of four. I've had lots of nice things to say about my Grizzly jointer and would recommend it to anyone, but the knives IMO are crap. Good luck with your new knives

[Kyle Iwamoto]

Used the A-LINE-IT system that has a setup for adjusting jointer knives. I had them dialed in to within .001 of eachother.

Was just testing cuts on regular construction grade 2x4s. I checked the wood for foreign objects and found nothing.

I dunno, seems like you got everything covered. must be cheap/junk blades, like many others said. Perhaps learn to sharpen? I've sharpened nicked blades using wet/dry sandpaper and the infeed or outfeed table as a plate. Make a wood jig for the blade angle. Takes a little while to grind down a nick, but it works. Remember to flatten the back too.