# Rapidly dulling knives on 6" bench top jointer



## Woodworkingnewbie (Oct 10, 2014)

I'm trying to plane 5" rough cut reclaimed red oak boards on a bench-top jointer to remove warps and bends before sticking it through a thickness planer. However, I can only do about three to five boards before the blades are dull. I have already gone through three sets of blades. I'm trying to take off 1/64th at a time, it usually takes about four to five passes to clean the board up but by the time I'm on the third board it will start to smoke. And when I examine the knives they're dull. I've tried a slow feed rate, then a slightly faster feed rate...I've tried prepping the boards by pre-sanding and power washing with the same results. Is it possible that the wood is too hard for the blades or should I look at getting a larger jointer with carbide blades?


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## epicfail48 (Mar 27, 2014)

Either your blades are complete crap or the wood is harder than the blades. I'd get new blades


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## BigJim (Sep 2, 2008)

If the wood is really dusty/dirty it can dull the blades quickly also.


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## jacko9 (Dec 29, 2012)

*jointer blades*

Dirty boards will dull your blades real fast. Red Oak is not that hard and I never have problems jointing or planing it but, I never use reclaimed wood.

Carbide blades will help but only for so long before you dull them. If you do sand the boards to bare clean wood, red oak should cut easy with sharp blades unless you lost the temper in the blades by heating them too much.

I would sand and then get new blades. If your going to keep cutting reclaimed wood I would not waste money on carbide blades.

Jack


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## woodnthings (Jan 24, 2009)

*it's the dirt*

Go over the boards with an angle grinder and a wire brush first to remove most of the dirt. Something like this or if you can, a larger version:
http://www.ebay.com/itm/Sears-Craft...086?pt=LH_DefaultDomain_0&hash=item2342128036

Carbide tipped jointer knives here:
http://www.ebay.com/sch/i.html?_nkw=6"+carbide+jointer+knives


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## Steve Neul (Sep 2, 2011)

I believe it would be more thorough to wash the wood with a power washer and allow it to dry before surfacing it. It would dry overnight.


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## verdesardog (Apr 2, 2011)

Get a helilical cutter head for your jointer....


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## wericha (Apr 29, 2012)

We do a lot of work with reclaimed wood, and it can be challenging. Whenever we begin a project we first check all the material with a metal detector. We then go over all surfaces with either a wire brush or wire wheel on a grinder to remove as much embedded grit and grime as possible. I *NEVER* recommend the use of a power washer. Even after all that, we still run into problems with quickly dulled knives.

Depending on the history of the wood, it could indeed have become "hardened" somewhat and that may be part of the problem. We had some oak in the shop a while back from a barn built in the late 1800's. That was some of the densest and hard oak I've ever seen.

Tell us a little more about what jointer you have and where the oak came from.


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## Steve Neul (Sep 2, 2011)

wericha said:


> We do a lot of work with reclaimed wood, and it can be challenging. Whenever we begin a project we first check all the material with a metal detector. We then go over all surfaces with either a wire brush or wire wheel on a grinder to remove as much embedded grit and grime as possible. I *NEVER* recommend the use of a power washer. Even after all that, we still run into problems with quickly dulled knives.
> 
> Depending on the history of the wood, it could indeed have become "hardened" somewhat and that may be part of the problem. We had some oak in the shop a while back from a barn built in the late 1800's. That was some of the densest and hard oak I've ever seen.
> 
> Tell us a little more about what jointer you have and where the oak came from.


Why don't you like a power washer? I'm a furniture refinisher and routinely wash furniture with one. The water doesn't soak into it very deep so I can't see the harm in washing the wood prior to planing it.


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## wericha (Apr 29, 2012)

You're probably right, the amount of water coming out of a pressure washer is relatively small and really shouldn't soak into the wood.

For our purposes, the wire wheels and brushes really work best, I can quickly remove a lot of grime and debris and begin to see the character of the wood. It also lessens the impact on planer knives and saw blades.


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## Woodworkingnewbie (Oct 10, 2014)

wericha said:


> We do a lot of work with reclaimed wood, and it can be challenging. Whenever we begin a project we first check all the material with a metal detector. We then go over all surfaces with either a wire brush or wire wheel on a grinder to remove as much embedded grit and grime as possible. I *NEVER* recommend the use of a power washer. Even after all that, we still run into problems with quickly dulled knives.
> 
> Depending on the history of the wood, it could indeed have become "hardened" somewhat and that may be part of the problem. We had some oak in the shop a while back from a barn built in the late 1800's. That was some of the densest and hard oak I've ever seen.
> 
> Tell us a little more about what jointer you have and where the oak came from.



The Jointer is a Porter Cable PC160JT, It only has 2 knives that are HSS. 

http://www.lowes.com/pd_80877-70-PC160JT_0__?productId=3059865&Ntt=porter+cable+jointer&pl=1&currentURL=%3FNtt%3Dporter%2Bcable%2Bjointer&facetInfo=

I think I need to go for a better jointer that has more knives, and that are carbide. I wanted something small as my garage is also my workshop. I have considered the Steel City Benchtop model

http://steelcitytoolworks.com/index.php/specials/6-granite-bench-jointer-w-helical-cutterhead.html

But it does not come with Carbide knives..

Any recommendations on a better jointer?

The wood is from a house in Missouri that was built around early 1900's. The guy that built it owned an oak mill and the entire house is made from oak. Most of the boards I have come from interior walls, that were never painted, but were full of _Mud dauber nest, the reason for the power wash. _This seems to help with the knives staying sharper but not for long. I can run a 2x4 pine though the jointer with little or no issues. But the Oak boards is another story.


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## wericha (Apr 29, 2012)

If you have space available, I'd highly recommend against benchtop jointers and look for a stand type model. Keep an eye on CL, good deals can be had and you can likely find a really nice 6" jointer for close to what you're looking at for a bench model.

I haven't looked at the bench models in a long time, so I don't know about the knives. Generally speaking, HSS comes in different grades and the better quality knives are quite durable. A good 6" jointer with HSS should stand up to the kind of work you're doing.

The wood you're getting is a great find. It is true old growth which means it has a tighter grain pattern and is far denser than anything available today. Given that density and hardness, your best bet is to take very light passes with the jointer. It will take a lot longer, but the results will be worth the effort.


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## fareastern (Sep 19, 2014)

Your post doesn't say what the boards were used for in their previous life.If you are really unlucky they will have been used for flooring and may have all sorts of grit embedded in them.Just as you should always store new boards off a concrete floor to keep the grit off,old floors will have been walked on by boots that have grit on their soles and maybe traversed by trolleys that have been used on all surfaces.A power washer is as likely to push grit in as to push it out unless the flow can get under the edges and apply more force than was used to push the grit in.A wire brush may reduce the problem but maybe won't eliminate it.Even carbide knives become dull quite soon in these circumstances but they will outlast HSS.If I had to make a choice it would be a set of carbide knives unless a batch of clean wood cost less.


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## Woodworkingnewbie (Oct 10, 2014)

*Thank you!!! Moral of the Story don't buy a benchtop jointer...*



wericha said:


> If you have space available, I'd highly recommend against benchtop jointers and look for a stand type model. Keep an eye on CL, good deals can be had and you can likely find a really nice 6" jointer for close to what you're looking at for a bench model.
> 
> I haven't looked at the bench models in a long time, so I don't know about the knives. Generally speaking, HSS comes in different grades and the better quality knives are quite durable. A good 6" jointer with HSS should stand up to the kind of work you're doing.
> 
> The wood you're getting is a great find. It is true old growth which means it has a tighter grain pattern and is far denser than anything available today. Given that density and hardness, your best bet is to take very light passes with the jointer. It will take a lot longer, but the results will be worth the effort.




Funny thing, I found a Delta 37-190 on CL for $250.00. It was in great shape with a little surface rust. I took some 220 grit sand paper and a sanding block and cleaned it right up. Then went to work on oiling all the parts that should move and tightening all that shouldn't. I then reset the co-plane on the tables and now they are with in .003 of each other. I was unable to get them any closer. I checked the knives and they were within .00005 of each other with a dial indicator. 

Let me tell you what a world of difference this makes. I was able to go through my lot of board for my first project with very little effort and the edges are very straight and true. I am very excited!!:gunsmilie:


Thank you everyone for all of your replies I will post a picture of our final project when its finished.


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## Woodenhorse (May 24, 2011)

Get a couple of sets of carbide blades. One set to send out for sharpening while the fresh set is on the jointer. I joint and plane wood that's much harder and denser than red oak quite frequently and HSS does not hold up as well. 

Brian


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