Building a Treasure Chest. (Lock and all)

I'm on vacation, so since Phlebas and Dent both asked so nicely, I'm gonna use the time to show how I build a basic barrel-top chest with a half-mortise lock.

I'm taking pics as I do this, so what you see is as far as I've gotten today.

Let's start with the lock:

I draw a full-size pattern starting with the pin spacing.

For this box, I think I'll need a good seven inches. (cough)



This is just to make sure the gates fit and to find the placement for the pins.

I used 1/8th inch steel plate:



-and used an edge grinder to get to this point:



Then I finish up by drilling and filing:



And there's your first part, the throw bolt:



Then you cut out the "gates". You can use more for added security(as many as will fit in the case) I usually do just two to avoid problems with the key aligning with them properly:



And use a hacksaw to cut a notch in the gate to fit a length of spring:



The fit should be snug enough that you can use a pin punch to crimp the spring into place:



Check the fit and file where necessary to allow passage of the pins between the notch positions on the gate:



Cut out the case and bend/weld it into shape:



and drill the pin holes.

Check the alignment of the gates to be sure the "locked open" and "locked closed" positions are lined up and nothing jambs when you go between positions:



Next is the ward:



and here's where we need to start on the key.

This is where it gets really difficult, because you have to meet three requirements:

The "sweep" of the key must be enough to move the throw bolt from one position to the other, clearing the ward(s) and lifting the "gates" just enough to pass the bar without catching the top pins.

(Making the key look cool is a bonus, but you'll find you have to make tradeoffs in looks and security to keep the key from being too fragile or fiddley to be practical.)

I started with a simple blank welded from round stock and a couple of steel pieces:



(There's a shload of work with a jewelry file not being shown here)

Cut the key to pass the ward:



And then weld the case halves together:



Then trim the bottom of the gates to "code" the lock:



Then rivet the gates into place, adding washers to keep them flat against the bolt.(It's easier to make your own sometimes) :



I weld nuts to the throw bolt to keep it centered at this point, grinding them down to a good fit:



Insert the throw bolt assembly into the casing and put in the two rivets that act as the bolt guides. Leave the lock bar out for now.

Find the spots on the key where the gates make contact:



And cut away until the gates are lifted just enough to clear the lock bar(The center hole is unobstructed when the key is engaged with the gates and before it begins to move the bolt):



Once you're happy with the fit and the action, install the lock bar(center rivet)

Now cut two strips of 1/8" steel and bend in a "U" shape to act as the catches for the lid.(Once the chest is done, the catch will be built to fit)



Set the lock aside for now and we'll get started on the chest it's self.



I had to resaw and glue up more than usual this time. I think my supplier is either on the mill's meep list, or just hasn't learned yet that he can turn down a meep shipment.

Still, I found a few boards:



And the rest,... well...



So anyway, I started with the front:



A little trick I learned for "stylizing" square objects is to make them a bit narrower on the bottom.

It's subtle, but it makes a difference:



You'll see the full effect a little later.

I routed out the recess for the lock:



And the fit was good:



So I drilled and filed the hole for the key and screwed it together:



The glue's dry, so everything else makes a trip through the planer:



You WILL experience the joy of conformity, you lump of Sh*t.

The dado head is your buddy when you don't want to spend a month on this part:



Here's where the line is drawn between the obsessive compulsives and people that just do this for fun:



I could have just ran the front and back over the dado head, but it would have left a notch in the side. It would be covered by the steel anyway, but I would know it was there.

This is what you want it to look like:



Every once in a while you get lucky and the bottom fits perfectly like this:



(But not this time. I spent an hour or so shaving this meep.)

At this point you're probably thinking"meep that's not too hard."

So bear in mind that I cut the bottom 1/2" smaller than the top. That means I had to cut a 1-1/2 degree angle in the top and bottom of each side so that it would lay flat and also angle the notch that holds the bottom in place and the side cuts on the bottom piece it's self.

I made twice the work for myself just so it would taper a bit.

Now for the sides of the lid:



Here's another tricky part: You need the slats to follow the curve of the lid. There's a few ways to go about this; you can draw it to scale and sketch lines radiating from the bottom center to find the angle, or eyeball it and use scrap pieces to zero in, or if your name is...Oh, let's say Parker, you'd probably want to have a handy equation. Say; Take 180 degrees and divide it by the number of slats you want to use times two. (It's not perfect, but it'll get you in the ballpark.)

In this case, it was 6 degrees:



-And it fits!



Now I glue the box together and clamp it for the night:



I skipped the "in progress" shot on the lid because you really have to haul meep to get a smooth layer of glue into the mortises and between the slats while assembling it, or it'll bond crooked and have a bunch of gaps.

If you look closely, you'll notice that the sides of the lid are mortised in. I saw a western once where a guy robbed a stagecoach or something and got into a pretty tough-looking chest by simply staving in the side of the lid with the meep of his pistol.

There will be no weak points on this box.



You can see how all the staves fit together nice and tight.



Believe it or not, there's a good two cups of Titebond holding that lid together.

Once the lid was dry, I filed the ends of the staves even and ran a 3/8" roundover bit over all the outside edges.

Now we're ready to start binding this sucker in iron:



I'm off vacation now, but I since it was President's Day, I had the place all to myself. I managed to get all of the pieces cut out.

Doesn't look like it, but there's a fair amount of steel in one of these suckers. About a stick and a half, all told. (30')



One of the bigger pains in the meep as far as construction steps is making the lip for the lid's edge. It takes a steady hand with the wirefeed and you can spend forever trying to get it to look seamless:



Here's the layout for welding:



Just a little minor trimming on the bands, and we're all ready to weld it up!

But before we do that we need to sort out the handles. We start with 1/2 inch round stock:



I fix my small torch in a vice so I don't have to worry about what it's getting up to while my back is turned:



It's just a matter of flattening the steel to fit a pin now:



And here's the completed cage.(Notice the plain handles) I've also measured and drilled the rivet holes:



The rivets are actually screws that I've taken a wirefeed to and filled the heads on. I predrill the holes, run an intact screw in and out of each to thread and then twist each modified screw into place with a pair of locking pliers.



The final fit before finish sanding, varnishing and "riveting" it together. (Notice the taper toward the bottom?):



There's still a lot to do.

I installed the lid assist. (This is a great little invention. It stops the lid from opening too far and is spring loaded, so it takes some of the weight off when you open it and keeps it from slamming closed hard enough to seriously hinder your ability to count to ten.)



I drilled the pilot holes for the rivets and screwed in some unaltered screws to thread the holes:



I'll leave the screws in place while I do the finishing touches on the lock.

I cut a piece of angle iron and chisel out a recess for it to fit in:



-And cut a piece of angle iron and weld the tabs into place:



The latch gets welded together and installed in the lid. Here's where you do all the adjustments to get the thing to engage smoothly with the lock:



Now we take the whole thing apart again, sand, stain and varnish:





When the finish is dry I put the box back in the cage, thread the "rivets" in with locking pliers, reinstall the lock, catch and lid spring:



And there you go. A completed chest: