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I can’t see the forest for the trees
Sometimes I can't see the forest for the trees.
This is true whether I’m in the shop or out roaming around the rest of the world. The other day I was in the shop, dressing a bunch of stock for a project. My 13″ Ridgid benchtop thickness planer was fighting against me the whole time. It’s generally a great machine, but that day was another story. It wouldn’t remove more than 1/32″ per pass, even less on wider boards. It was also pausing feeding boards from time to time, leaving burn marks on the boards where the blades came into contact with the wood. This meant I had to do my best to push or pull many of the boards through the planer. Not only was it slow going, but it was also hard work, frustrating and the burn marks were causing me more problems.
Admittedly, I wasn’t paying a ton of attention to the details. I was focused on the project as a whole and making the customer happy. After all, I had a deadline I promised the client, so the clock was ticking. Then it occurred to me what the problem was; it was time to change the planer blades. I should have realized that earlier. And once I paused and thought for even a few seconds, I realized it was also about time I cleaned the infeed and outfeed tables so there would be less friction while the hard maple and black cherry planks were being dressed.
Time to regroup
The knives in the planer are double-sided, though I wasn’t sure whether I was currently on the first side or the second. Fingers crossed, I opened up the housing on the back end of the planer, locked the cutterhead in position, then loosened all the bolts securing the first blade in place. The visible edge was far from sharp, but thankfully, once I removed the blade and checked its other side, I was in luck; I was only half way done with these blades. This saved me a trip to the local supplier, as well as about $80 for a new set of three replacement blades.
I installed the first one, and rotated the cutterhead to switch the next blade around before flipping the final blade around and reinstalling the housing. Next, with the cutterhead fairly high above the table, I cleaned the infeed and outfeed tables. Finally, I moved the planer back into position, flicked the ON switch and fed the next board through. It was like a dream come true. No forcing the stock through the planer, no burn marks and a much smoother surface once the board came out the back end of the planer.
Next time
While I was rotating the new knives, I noticed a set of old, dull knives under the outfeed table. I also knew I would eventually need to replace the knives I just rotated and wanted to be ready for action when the time came. I could simply purchase a new set, but it seemed like a bit of a waste to me. Sharpening the old blades is something I should consider.
I made a quick call to my local sharpener to see what his thoughts were. Turns out he charges 85 cents per inch. Some quick math (13″ x two sides per blade x three blades in total) tells me that each set of blades includes 78″ of edge and would cost $66.30 to sharpen. Not cheap, but slightly cheaper than the new set I could purchase.
DIY sharpening
Then another revelation; I could try my hand at sharpening these blades myself. Honing the undersides would be easy, but the long bevel edge would pose some problems. It’s not an overly thick blade, so the blade isn’t that wide, meaning it will not be easy to maintain a correct and consistent angle when honing the bevel. It doesn’t need to be perfect. I’d at least like to give it a shot. It won’t make any sense if it’s going to take me a few hours to complete, especially if the final results aren’t great, but it’s at least worth 15 minutes of my time to see how it goes. If I fail, I’ll take the set of three blades in, along with about a half dozen 10″ saw blades I have, over the next week or so.
Have you ever tried to sharpen a set of lunchbox planer blades? Any tips for me? Should I just take them right to my sharpening service? Or maybe just head to the local retailer to grab a new set of reversible knives? The last option seems like the least fun, but might be the smartest in the long run. I always hate spending money if I don’t have to, but if it’s simply the right decision, I’m happy to pull out my credit card and get on with things. The plan is to continue with the shop project over the next week or so, as the deadline still looms. I’m looking forward to hearing your thoughts, though, as I’ll be getting the sharpening equipment out sometime next week. I guess this means I have no excuse not to sharpen a few kitchen knives while I’m at it.
Looking Good
The freshly planed board, with a much smoother surface than I'd been getting in the past.
Rob Brown - rbrown@canadianwoodworking.com
Rob is the editor at Canadian Woodworking & Home Improvement and a studio furniture maker.
Another trick is to offset your blades alternately to the side. Usually there’s a 1/8″ play . That way if you get a nick you can go in and slide each blade 1/8″ the other way. Admittedly this won’t help a dull blade but might help get a bit more use from your blades before they need a serious sharpening.
Dewalt 735 planer blades can’t be sharpened because the screws contact the workpiece after one sharpening..
I bit the bullet and installed a segmented cutter head.
Cost me more than the planer but have not even had to rotate a single cutter since and they have 4 sides.
I’ve been sending my planer blades out for sharpening for years now. So far works out fine. Don’t do it more than twice per set as they wind up too narrow and won’t register as well. In my case I have the older two blade model so cost is less.
Rob, check out the youtube link below which will direct you to a video posted by William Ng that shows you a brilliant low cost method of sharpening planer knives yourself. https://youtu.be/pUoEPgcqUFc?si=DqWtvj5eero7xvVi
It’s always nice to replace the blades and get a smooth outcome. I find I do that too, leaving them in longer than I should, on the bandsaw.
Steve
Would love to see a post on how you get on with sharpening the blades. Mine need doing, though also have picked up the odd knick so not sure how helpful sharpening will be in the end. Though if your planer makes you money might be worthwhile considering swapping to a carbide insert cutterhead?