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I just installed the second set of factory supplied blades in my Dewalt 735. I am relatively new to planing so I don’t have a feel for the average life expectancy of the cutting edge. The first replacement (swapped edges) came after planning enough red oak for 14 stairs – I quess I was ok with that lifespan (or maybe it was just the 60gal of chips )

What is the general consensus / experience / success with re-honing these blades? If you have experience this, is it something that you could do manually with fixturing the blade or does it need to be professionally done (surface grinder, etc)? I understand that if they are re-sharpened, all bets are probably off with the height gage accuracy but I can’t tell if there is enough exposed blade to even entertain the idea. Also, if there is a better alternative (longer lasting) replacement blade, I’d be interested in hearing about it.
 

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That seems like an awfully short life on those knives. I probably planed 400-500 bf of 4/4 to 3/4 stock before flipping to the second edge. Mostly white oak, cherry and poplar with some ash mixed in. (and some pine twice a year for a guy that makes about 1,000 toys/year for some charitable groups). I take light passes, about 0.02" (1/3 rotation of the crank)--which may help. After a few hundred feet i can tell the knives are no longer new, but the cut is still much better than the planer i had before.

earl
 

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O.K., this suggests a question, if generally shallow cuts of about 1/32" are made, would the blades last longer or wear faster than if one makdes deeper cuts.

Also, in regard tot he depth of cut gauge on the 735, I never use it. After cleaning up one face of a board I start and continue with shallow cuts until the second face is clean up. Then measure with the dial caliper. If my project requires material that is thicker than what the board will clean up to, that material is not satisfactory for the project. So, obviously the workpiece for the project has to be less that what the board first cleans up to. From there I start planning and measuring with the caliper until I reached the desired thinckness.

If however, the needed thickness is quite a bit less that that of the board be chosen may re-saw it and to save what would other wise be just wasted. I suppose that what I do is probably differenct than the average used of a planer.

Just wondering.

Jerry
 

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There are better quality steel blades than most planers come with. The ones I am familiar with have more cobalt alloy in them. Carbide can last a long time but are brittle and if you hit a hard knot they may chip. Here is a link to a home made sharpening jig that is almost free to make. Doug Abbott' Planer Knife Sharpening Jig
 

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This is a common complaint for planers that have the reversible, non resharpenable, knives on them. The issue almost always is a result of taking too much off each pass. I have the DW 734, and I am still on the first set knives, and have had the machine for 3-4 years now. I have flipped the knives already, and I did that the first summer I had the machine. That was a result of the process of learning how to use the machine, resulting on the first side of the knives getting pretty messed up. For most of my passes, I am taking off 1/64"-1/32" for each pass. While this does result in more passes through the planer (which really goes quicker than you think), their are a few benefits I have noticed. First, the knives stay sharper MUCH longer. Next, since less material is being removed for each pass, it leaves a nice surface, with less potential for tear out. In fact any tear out I do get is easily sanded out. Finally, it is less wear on the machine.
 

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O.K., this suggests a question, if generally shallow cuts of about 1/32" are made, would the blades last longer or wear faster than if one makdes deeper cuts.

Also, in regard tot he depth of cut gauge on the 735, I never use it. After cleaning up one face of a board I start and continue with shallow cuts until the second face is clean up. Then measure with the dial caliper. If my project requires material that is thicker than what the board will clean up to, that material is not satisfactory for the project. So, obviously the workpiece for the project has to be less that what the board first cleans up to. From there I start planning and measuring with the caliper until I reached the desired thinckness.

If however, the needed thickness is quite a bit less that that of the board be chosen may re-saw it and to save what would other wise be just wasted. I suppose that what I do is probably differenct than the average used of a planer.

Just wondering.

Jerry
Every time i plane lumber i wonder the same thing!! One side of my brain says that the 1/3 revolution (about 1/48") on the dial is kinder and gentler. The other side of my brain thinks it might be easier to get punched hard 10 times instead of slapped 30 times!! I don't know the answer but it's all i think about while i'm planing.

My depth pre-sets are pretty much spot on, so i use those to some degree. Like you Jerry, the caliper is the final judge.

Another thing that likely helps the knives, and definitely helps the finished stock, is to pay attention to grain direction and work with it as much as possible. Much lower risk of chip out also. The old guy i plane toy wood for thinks i'm half crazy for feeling every board before every pass--but he gets a kick out of it. When i work alone i don't need to do that--everything comes off in a specific placement!!

earl
 

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Discussion Starter #8
I also generally take real shallow passes and don’t rely on the height gage for final thickness but I had the same thoughts as Earl … a cut is a cut. If I have to take 5 passes vs. 2 passes – the blade would seem to see more wood in the first case. Regarding the short blade life – I’m not sure what the bdf was on the stair tread project was – probably nowhere near the 400bdf mark, it was all 6/4 stock but technically I would think there would be another metric (like square surface ft). But this leads me to wonder how to tell if the blade is done – maybe I was turning the blades over too quick. I “decided” the blades needed replacement when the feed was having a hard time pulling the stock through on a thin cut and it wasn't due to any cupping / warping issues.
 

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Most planer blades can be resharpened if they are not too badly damaged. Cut a slot in a board to hold the blade at the proper angle, and secure the blade into it with a little bit of the blade edge protruding. Mount some fine sandpaper to a plate of glass or a flat plate of steel. [Masking tape works well.] The blade can then be passed back and forth over the sandpaper to resharpen the edge. Run the blade so you are sharpening across the egde, not longitudinally. Maintain the correct angle to the sandpaper, and use a little water or light oil to lubricate the sandpaper. You can use finer and finer sandpaper until you get the blade as sharp as you want it. Repeat the procedure with both or all three blades until you have them where you want them. As you will reinstall the blades and reset them with your setting gauge it shouldn't affect your height setting.
If one or more of the blades has a nick you can offset the blades slightly so the what one blade doesn't cut the other will get.

My experience with my planers is that the finer the cut you take the better will be your results.

Gerry
 

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I also generally take real shallow passes and don’t rely on the height gage for final thickness but I had the same thoughts as Earl … a cut is a cut. If I have to take 5 passes vs. 2 passes – the blade would seem to see more wood in the first case.
Yes and no. A planer knives really do work in a similar manner as a hand plane by taking shavings. A smoothing plane can be setup to take whisper thin shavings or very heavy shavings. Pushing the smoother over a piece of wood to take whisper thin shavings takes very little effort compared to the heavy shavings. There are a lot of factors as to why this, but it really comes down to that there is a lot more friction when taking the heavier shaving. This friction translates into heat. For a hand plane, that heat is nominal. But take it to a planer where the knives are spinning at a very high rate of speed, that heat is going to build up MUCH more quickly, where high speed steel is more prone to go dull due to the heat. Also the size and thinness of a lunch box planer knives there isn't much mass to dissipate that heat like there would be on a larger knive, so they tend to dull even faster.

In the end, for lunch box planers, your best bet to knive longevity is to take light passes.
 

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Most planer blades can be resharpened if they are not too badly damaged.
One thing to point out with planers like the 735 and the 734 there isn't much of the knife exposed. The knives on these planers fit pretty snug on posts so that there is minimal effort require to line them up, which is necessary for double sided knives. I could see getting by with one good honing on each side, but I think after that there just wouldn't be enough there to sharpen. Unfortunately these knives are pretty much considered disposable.
 

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Regardless of which blades you use on a thickness planer they will need to be sharpened. When you notice a reduction in cut quality is the time to touch them up. There are lots of plans for jigs to hold your blades (as well as plane irons, chisels, etc..) while sharpening them.

Let me suggest that there is a much easier way to touch them up. Three light passes over the Trend diamond credit card sharpener's coarse side followed by three light passes over the fine side will restore your blades with minimal metal removal. This requires virtually no pressure and the diamond cuts very quickly. Be sure to use the lapping fluid for this and not water as some companies suggest since that will cause rust and waste your sharpener. Cleaning the card with the white cleaning pad will remove any metal shavings left behind.

I use the cheap dollar store shelving pad (like a router pad only thinner) draped over a saw horse. I set the card on this and it doesn't move. Holding your blades at an angle is very easy since the flat rides nicely on the card surface. Again, this requires almost no pressure. This is also how I touch up my router bits.

Making small cuts reduces the heat as mentioned and will extend your life span.
 

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Regardless of which blades you use on a thickness planer they will need to be sharpened. When you notice a reduction in cut quality is the time to touch them up. There are lots of plans for jigs to hold your blades (as well as plane irons, chisels, etc..) while sharpening them.

Let me suggest that there is a much easier way to touch them up. Three light passes over the Trend diamond credit card sharpener's coarse side followed by three light passes over the fine side will restore your blades with minimal metal removal. This requires virtually no pressure and the diamond cuts very quickly. Be sure to use the lapping fluid for this and not water as some companies suggest since that will cause rust and waste your sharpener. Cleaning the card with the white cleaning pad will remove any metal shavings left behind.

I use the cheap dollar store shelving pad (like a router pad only thinner) draped over a saw horse. I set the card on this and it doesn't move. Holding your blades at an angle is very easy since the flat rides nicely on the card surface. Again, this requires almost no pressure. This is also how I touch up my router bits.

Making small cuts reduces the heat as mentioned and will extend your life span.
Mike; how about just lapping the back flat side (the disposable blade type)? Obviously you'd need to flip the blade to do the other back edge(?). Wouldn't that be just as effective as it is for carbide router bits? Essentially, leave the factory ground edge alone?
 

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O.K., this suggests a question, if generally shallow cuts of about 1/32" are made, would the blades last longer or wear faster than if one makdes deeper cuts.

Also, in regard tot he depth of cut gauge on the 735, I never use it. After cleaning up one face of a board I start and continue with shallow cuts until the second face is clean up. Then measure with the dial caliper. If my project requires material that is thicker than what the board will clean up to, that material is not satisfactory for the project. So, obviously the workpiece for the project has to be less that what the board first cleans up to. From there I start planning and measuring with the caliper until I reached the desired thinckness.


Jerry
I haven't benchmarked this, nor intend to, but I'd say with a much confidence that if you plane less thickness, the blades will last a little longer due to reduced heat/stress being put on the blades. Would seem logical that if we run these 735s at the slower speed when wood species allow or the particular finishing step the project is on allows, that it'd also reduce wear. I also plane about a 1/32" or so and run all of my like pieces through prior reducing the next level of thickness, which results in a matched thickness which I also gauge as I'm going and when complete.

I'm considering the carbide blades for my 735 after the next set of HSS blades are worn both sides. I too was curious about honing them. I've planed at least 200' of everything from red oak, western red cedar, white oak, peach, mahagony, dark walnut & of course pine without blade issues. The $150 price tag on carbide blades while not really needing them hasn't warranted the purchase just yet. I've also considered the Byrd Helix setup, great reviews, a few have reported unequal planing and more snipe than standard HSS blades, but it's generally a 4 out of 5 rated upgrade for a whopping $450. That's more than 2/3 this planers cost, or nearly 1/2 the cost of a Helix bladed jointer which I would like one day.
 

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Dan, the small ground edge is where you can make the easiest difference. This is how all sharpening I have seen is done.
 

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I went through this with my DW735. The blades wouldn't last through one small job.
I solved it by buying a Byrd head for it. Might be pricey, but in the long run it beats buying knives for $50 a set. The price of the head equaled 8 sets of knives.
I never considered sharpening them, because when you get a nick in them, they're trash. And nicks happen too easily with those thin knives.
 

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Discussion Starter #17
I went through this with my DW735. The blades wouldn't last through one small job.
I solved it by buying a Byrd head for it. Might be pricey, but in the long run it beats buying knives for $50 a set. The price of the head equaled 8 sets of knives.
I never considered sharpening them, because when you get a nick in them, they're trash. And nicks happen too easily with those thin knives.
Thanks for the input. They are pricey - I'm not sure I do enough planing to justify them but its worth a consideration. I've read somewhere about minor scalloping that may need to be sanded smooth. What has been your experience with this - is the planed surface finish ready?
 

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I haven't benchmarked this, nor intend to, but I'd say with a much confidence that if you plane less thickness, the blades will last a little longer due to reduced heat/stress being put on the blades.
I am not so sure. Instead of making one pass you are now making 2 passes. Also, the blades keep cool by cutting wood same as a router bit stays cool. If you are feeding a router bit too slow it will burn wood. The same is true of drilling metal. If the bit isn't cutting it will turn blue very quickly.
 

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I'm coming to the conclusion that there are at least two categories of uses of the Dewalt planer. The reason for saying this is obvious. It comes from my personal experience and the reading of this thread along with it's posts. I started with a 734 and upgraded to the 735. I have used the planers in my shop for about four years now with complete satisfaction using the blades that came with the machines. I flipped the blades on the 734 but only after nicking one of them. The point being, I am only a hobbist and the use that I have asked of the tools is nominal compared to a working professional shop that is so much more demanding than the type of use that I ask of my tools.

My conclusion is that the standard or supplied blades work just fine for the average hobbist and I am pretty sure that is why Dewalt sells their machines with the grade of blade that they do. They know that the users thar are going to really push the planers will not depend on the standard blades. All of what I just wrote is pretty much, as I said, just plain commen knowledge to all that read this, but maybe for a person that is shopping and wondering, it will have some value.

Jerry
 

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Well said Jerry, I completely agree with the lunch box planers, they are meant for the hobbyist. Most of the lunch box planers are actually well made and can handle most of what is asked of them. I have even seen guys run large Roubo work bench slabs through them! But as any bench top machine, there are limitations when compared to the large floor model version. With the planers, you hit on the head in regards to the knives, and I believe their are some trade offs. For planers with a single sided set of knives, I believe they tend to be a little thicker and as a result tend to hold their cutting edge long. With the flippable knives, they tend to be a little thinner, so each edge will dull quicker than the single sided version. The trade off is that you have two edges to work through. While you won't get 2x the life out of the double sided knives, I would guess you are getting somewhere between 1.5x-1.75 times the life, as long as you don't take too deep of passes.
 
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