Is this Kobalt block plane worthless??

For many years now, Kobalt has been offering a 6.5” block plane that is essentially a Stanley No 9½ clone. Most budget store brand planes on the market today are criticized for being made too cheaply. Some can be redeemed and made to work. But I had no intention on figuring out if the Kobalt was one of them.

That is, until today. This Kobalt plane came to me included in a bundle of block planes that I recently bought. My first thought was “is this Kobalt even worth cleaning up?” My second thought was how many others have wondered the same? So, I decided to document my investigation. Could I toss it in my travel toolbox and trust it when I need it? Pull it out for riskier tasks? Is it worth spending the time to clean it up and sharpen it? Or will it live out it's days holding doors open and making sure that papers don't blow away? Let's find out!

So what is the value of a 9½ block as a woodworking tool anyway?… 

Well then, the 9½ block plane’s key features are a 6.5" sole, a standard 25 degree bed, a 1 ⅝” wide blade and and an adjustable mouth. Depending on how you sharpen the blade, you get an effective 50-60 degree cutting angle. It's perfect for cleaning up figured or difficult grained wood. Now, you “could” set up a 60½ block plane to do the same by putting a steeper angle blade on it. But then you have to remember which blade is in what plane. And honestly, who has time for that?

Time to measure this plane up...

Luckily for this investigation, I have a couple Stanley 9½ block planes to line the Kobalt up against for comparison. A 1930’s Made In USA and a newer Stanley Sweetheart. I would not expect the Kobalt to match them in earnest. I am using them as reference points to highlight design choices in the Kobalt's construction. But could this Kobalt really be their stunt double when needed?

Looking at these three 9½ block planes side-by-side, the 1930’s Stanley is by far the lightest and most compact.  It was made out of pre-war steel and was built to last and endure.  Whereas the Stanley Sweetheart is certainly the heaviest and most robust, as it was built to impress and try to reclaim the Stanley brand name. The Kobalt comes in the middle as it was built to meet cost and retail price targets.

Stanley 1930s -- 1lb 7.1oz

Kobalt -- 2lbs 0.0z

Stanley Sweetheart -- 2lbs 4.3oz

The first functional part to assess is the lever cap. With most lever caps, there's a balancing act between its ability to hold the blade locked in place and the ability to adjust the blade. Ideally, the lever cap can be backed off slightly so that adjustments can be made, and then again locked in place by fully tightening the lever cap. After all, a 9½ is a finishing smoother to clean up small defects. You need to be about to make micro adjustments. If the blade cannot be set precisely and held on place, all is lost. The Kobalt was definitely the most finicky of the three, with the lever cap popping loose several times when trying to make adjustments, but it is essentially functional 

The design of the Kobalt's lateral adjustment lever leaves a lot to be desired. It can only make slight adjustments because it makes contact with the blade too far from the screw. Even worse, using the lateral lever can lead to the lever cap coming completely loose all too easily when the lever tries to fit between the frog and blade.

To be fair, I would not expect a fine Norris adjuster like is on the newer Stanley Sweetheart, or the machining artistry of the 1930s Stanley’s lateral lever. However, in the picture below I included a Stanley No 65 that has the adjuster from which the Kobalt’s is loosely based on. This 65 has no lateral lever. Half of the block planes that I use lack lateral levers and even when they have them, I rarely use them. The choice to even include it on this plane seems a waste of a limited production budget. Undoubtedly, some product manager wanted the feature, but I think no lateral lever would have been a better decision.

Now, what really irks me about the Kobalt even more than lateral lever is the adjustable mouth. On most adjustable mouths, when the mouth is about midway open, the front sits flush with the body. On the Kobalt, the mouth perpetually has it's tongue sticking out. What is worse, it cannot be closed as tightly. Maybe the screw on mine is mounted 1/16” further back than it is supposed to be, but every picture I ever see of this plane has it's throat plate protruding. To add to this the groove and throat adjustment lever seems very restricted on movement almost to the point of uselessness.

In the pic below, the Kobalt in the middle looks like the throat is almost good with “almost” being the operative word there. The Kobalt mouth is actually closed as tight as it will go. Meanwhile, both Stanley's are at the middle of their range of motion and could both close down another 1/16”. So why does this matter? As I stated earlier, the value in a 9 ½ is in its ability to avoid tear out on difficult wood. A tight mouth is essential to avoiding tear out 

I should also point out that I'm disappointed about how far the back of the mouth goes behind the blade. The Kobalt’s blade is not extended deeper than either of the Stanley’s. Instead, the bed that the blade rests on stops further back.

This is not a mistake. On older Stanley's, cracks and chips behind the mouth are common. The mouth forms both a stress point and a weak spot for the casting where the iron gets thin. Stopping the mouth short reduces the risk of casting failures and defects.

Why does this matter? Well, it brings into question whether the blade is well enough supported to avoid chatter or not. That eighth of an inch of missing steel could allow blade flex if the blade is not rigid enough.

So, let's break this down...

What will it take to get this to be a block plane that I trust to use beyond just cleaning and sharpening? Well, first, the lateral lever just goes. I cannot fix its engagement point or its ability to unset the blade and lever cap. It's a liability that I do not need.

The throat plate screw hole needs to be lengthened at least 1/16” to let the throat go further back and get closer to the blade..

The throat’s range is also limited by the groove in the throat lever. The hook on the right will need to come back to the pin hole another 1/16” or so.

Ideally, I would reduce the bend on this lever and roughen the contact points slightly. This would give me a larger range of motion between fully tightened and fully loosened.

As to the throat plate itself, I could unweld and reweld that screw forward. Certainly, just moving this screw forward 1/16” or so would be a solid improvement. However, this seems risky. Welding could deform the plate.

For me to really use this regularly, I would want to flatten and bevel the back of the throat plate. This will help get clean shavings. And I would want to shorten and bevel the front of the throat plate some.

This last one is not just cosmetic. When I look at the front of most of my planes, I know how the mouth is set by just looking at the throat plate in the front relative to the body. That is not possible to determine quickly with the Kobalt. I would forever be picking it up and checking the mouth closely.

So, is this Kobalt block plane worth the time it takes to get it running?

The initial cost of this plane to me is essentially $0. If I went to grab a new one from the store, it would cost me about $20.

So, if my goal was to make money on this plane, I'd just auction it off as-is and move on with my life. Instead, I decided to write this article and hope that it ends with me having a new reliable loaner.

So, let's go to the shop...

...and see how quickly I can get this plane working smoothly?

I am timing myself to see how long it really takes me to get this plane tuned up. I have less than 2 hours to wrap this up.

12 minutes in and the sole and sides are flat and clean.

Less than 20 minutes in and the blade is sharpened to 8000 and ready to go. Time to start working on the throat plate.

The first trial on a cherry block was not a failure. However, that rippling you see in the curls are a sign of chatter. So, I have a little more work to do 

Finally feeling like an acceptable block plane after over an hour of work! 

I used my plane hammer to dial in the blade until I was continually getting shavings that I liked. I took many strokes to make sure that that blade wouldn't quickly dull or move. Mission accomplished!

It would seem that this plane is not worthless after all! It has certainly proven itself in my books. Bringingv it back to its cousins, it now looks less out of place.

So, what all did I do? I carefully flattened and slightly angled the back of the throat plate to help shavings eject smoothly. Also, having a sharper back to the throat plate helps in breaking the wood fibers. This is part of how a tight mouth helps avoid tear out.

I also smoothed and slightly beveled the front of the throat plate so that it looked nicer and made it easier to eye the mouth adjustments. 

Lengthening the groove for the throat plate was easy enough thanks to a hard smooth riffler. However, the time that I spent deepening the throat lever’s groove was a waste. The pin protrudes above the lever and the front knob hits against it. I recommend just removing the throat lever as it's as useless as the lateral lever. Below you can see the Kobalt sticking that tongue out in farewell.

So, let's recap (TL/DR)…

While parts of the Kobalt block plane are useless, the plane on the whole isn't. If this plane is your only option, then yes, you can make it work.

That said, time is money, and generally, my time is valuable. So, I would not say that this plane costs you only $20. In fact I could say that it cost me as much as the Stanley Sweetheart that it's next to. The time that I spent tuning the Kobalt, and the time l would spend getting it adjusted each time I use it all costs me time. In the end, the Stanley Sweetheart is a far better investment.

So what will become of this particular Kobalt? I have now invested more time into it than I'll ever get back from selling it. So it will join my collection of loaners and beaters. It will serve to protect my other block planes from missed nails and clumsy hands. A better fate than I first feared.