Thursday, February 11, 2016

All about Mitre Box Part 3 Ahh the smell of WD 40 in the evenings

This Wednesday I got a break, I got to do a shift at the Wood Hobby shop on base, while a friend looked after Heather. Thank you Jeannie.

Did not really had any projects on the go, so I decided to bring in my Stanley Mitre box No 60 and tear it down. Inspect its condition and clean it.

Just in case I brought in some Liquid Wrench, but it was not necessary, 
WD40 works fine and that is what I used to scrub it clean.

As received, the front post was installed in the rear position.
The give away is the spring, it is designed to lift the saw off the saw kerf at completion of the cut. Since the saw then clear the board it can then be rotated without harming the saw. That feature does not quite work with the spring in the rear...

Stripped down for initial assessment.

Everything looks fine, nothing is broken. The screws (4) holding both vertical post had damaged slots on them, a little bit of work with a file took care of that. These post were supposed to be removed when breaking down the box for traveling or storage. That is true of all these types of mitre box, it does not affect their precise set up, there is a gib screw on the cast fitting to adjust them just perfectly... That screw does not move so when re-installing the post, their position is not affected, once set.   

In our Day to Day shop environment there is really no need to disassemble the posts,  except if you are thinking of taking it on the road, then I would advise you do take them down in order to protect them and their settings.

The sacrificial board has obviously been sacrificed to the gods :-)
I would need a replacement. That is the result of not taking the time to properly adjust the saw stops to prevent this... Tsk, tsk.

This look like the original board, it has never been removed ( I can tell by the screws, pristine looking Phillips) and two peculiar things. The board has some coating on it (Shellac or varnish?) and it has a small angle on the back side.

Strip further down to clean the casting and inspect.
Nothing broken,but there is a start of rusting under the brackets. 
Removed and cleaned off.

Not sure what kind of grease that was but it is pretty dry and gummy.
Notice the offset hole? That is to tweak the position of the swinging arm just right.

First initial clean up. I spray literally WD 40 on it and scrub it with a brush, wipe it, re-coat it and then lightly sand with 120 grit. I am not trying to make it shinny new looking, just get the grime off and stop the light surface rust. I leave the machining marks, It would be counter productive to sand them all off and I would ruin the precision. 

Base is now fully cleaned, look at the transition between the fence and the bed casting, it has a fillet.

That is why the old board has a taper on the back edge

So it fit closely to the fence without being  raised.
Granted the taper is overkill, but it is sure to fit without a hitch :-)
If you are making a new one don't forget that small detail.

After a bit more selective scrubbing, it is ready for re-assembly.

My friend Dave starting to machine a replacement board out of some ash he had. What kind of wood should you use? You want something that is flat and will remain so, quarter saw would be ideal. Something easy on the saw teeth, that rule out MDF or plywood. We used ash, because that is what we had. 

After dimensioning to size, the thickness is critical . It is about 1/2 in thick. Too thick and you will not be able to used the two grab screws adjustable in and out to grab the piece being cut.  You can see that without the taper it would not sit flush with the fence.

We duplicate the angle on the old board which turns out to be 40 degrees.
There is about a 1/8 of an inch thickness left at the top.

Ready for another life of dutiful service in my shop.
Well almost, still need to let the new board adjust itself in its environment, my shop, to let it do any stupid wood tricks then tweak the adjustments.

After a few days I will re-assess the board condition, making sure it stayed flat.
Then give it a coat of polyurethane to seal it.
I still need to take apart the two posts guides, give them a good cleaning.
There are the odd screws that could uses replacement, and I just happened to have a donor MB No 60, so bonus :-)

Next parts would be cleaning up the saw and tuned it for the box and run thru the adjustments making sure everything is working as expected and finally do some test cuts :-)

I dunno when I will be able to do that,  but sometimes in the near future...

Bob, resurrecting yet one more vintage tool


  1. Hi Bob,
    I was already impressed by part 2 of your series.
    This part is helpful too. Even if I've got only one of the cheap blue models I will see if I can improve it a bit.
    The blade was already changed. And now I will see if I can mount such a board. The problem with my model is that I'm always running out of square while sawing and I guess this is because the sawed boards don't have support from the underside.

  2. Bob,

    Once adjusted, how close to 45* will it cut? Good enough for framing, for base boards and crown molding, or even for case work? Having never used an adjustable Mitre box I guess I'd like to know if one would earn space in my over crowded shop.

    BTW, nice series of posts.


    1. Hi Ken,
      my experience with mine is, that it is good enough for frame work and baseboards. For fine case work I've currently built a donkey ear. So I will touch up the boards after sawing.

  3. Thanks Stefan, glad you got something out of it "-)

    If your mitre box does not have a solid support under the board, as typically the case with these, yes you can run into that kind of problems. But if the blade is drifting sideways it is probably because it is not tensioned enough.
    2 solutions:
    1- put in a thin sacrificial board under your work piece for adequate support. How thin? Just as long as it can be made to fit under your workpiece, could be as thick or thin as needed.

    2- See if you can tension the blade more, failing that you have to take light cut, do not force the saw down, let it cut of his own weight.


  4. Hi Ken

    These "good Mitre Boxes" can cut bang on 90, 45 and etc.
    Mine has preset detents for the most popular angles for making many sides frames (4, 5, 6, 8, 12)
    These are machined into the cast bed, so they are only as good as they made them. But you can also adjust and lock it with a set screw at any angles whatsoever.

    These boxes can be made to be very accurate but remember that they work in combination with a saw. Both have to be tuned foe each other for maximum accuracy. I will get to that in a later post.
    You cannot go wrong with many of the good old MBs made by Langdon/Millers-Falls and Stanley.
    The more I learn and discover about this later model (70s) from Stanley, my No 60 MB, the more I am impressed by the construction and levels of appointments to make it a very good performer.


  5. One last thing Ken
    Take a look at Gerhard cut results after he had his MB saw sharpened by Harrel (Badaxe) and after he tweaked it as per my recommendations.
    It is cutting accurately, bang on, but look at the finish cut. Pretty impressive results right off the saw.
    That is what a well tuned box and saw is capable of.
    If you don't know Gerhard, look for the link I put in my part 1 in miter saws