Archive | May, 2013

Cardboard Sword Coffin

22 May

00 sword coffin

My daughter asked me to pack some of her belongings, including some swords. Before I packed the fancy Japanese ones, I thought I would practice by making a protective box for a (cheap) wooden one.

01 sword

The sword – a bit over a metre (40″) long , 250mm (10″) wide.

02 base outline

I drew lines onto a cardboard box, forming a six sided shape. Out from the ‘coffin’ shaped hexagon, I drew parallel lines 50mm, then 10mm (for a fold), and another 50mm.

03 base cut out

Cutting around the outside makes the shape more obvious.

04 base cut and bent

Then scoring all the fold lines and cutting out tabs.

06 pizza wheel

This is my favourite tool for putting folds into corrugated cardboard. It’s a pizza wheel from a $2 shop, but I ran the edge against a grinder for a moment to take the cutting edge off it. Pressing down on that 1mm edge will crush most cardboard quite easily – even the triple thickness stuff. I found it tends to run off the line rather easily unless I prescore the line with a knife.

05 side glued and clamped

Here I’ve folded over a side, glued it (cheap white PVA glue) and clamped it to a piece of wood to keep it straight. Keeping it vertical (i.e. perpendicular to the base) was a problem. I used a bungee cord to put tension on it but I should really have grabbed a right angle brace of some kind.

07 clamping other side

And then gluing and clamping the other sides. You can see the first long side glued up here, looking quite solid.

08 base folded and glued

Gluing sides with PVA glue is a slow process, with time to watch about 1/2 an episode of NCIS before the glue has set enough to remove the clamps.

09 test of sword in base

A quick test to make sure the sword actually fits inside. Did I mention that this was the second box I made?

10 marking lid shape

I found another chunk of cardboard box and drew around the coffin to mark out a lid.

11 pattern of lid

The pattern of the lid is much simpler, as the sides are only one thickness of cardboard, not two folded over. Equally, it’s nowhere near as strong.

12 lid cut and bent

The lid cut out and folded. Unfortunately, since I used a chunk of cardboard from a shipping carton, there was a large slot going most of the way through it. Hence the offcut waiting to be glued in to strengthen it.

13 gluing support for lid

Gluing the support piece onto the lid. I was working in the living room so some flour and a bag of potatoes got drafted as gluing weights. They worked well.

14 lid partially glued

Again, working around the sides to glue the lid. As with the base, I was able to leave sizable tabs to glue to, for four of the joints. However the joints in the sides are at a very shallow angle which means the tabs left over are quite small. I had to add small strips of cardboard to make the joints solid enough.

15c sword with supports

I folded and glued a couple of support brackets out of cardboard, cutting notches to hold the handle and blade. The handle notch had to be cut reasonably accurately. The one for the blade was easier. I just cut it oversize then slid it up the (tapered) blade until it fit nicely, then glued it in place.

15b support bracket closeup

A closeup of one of the support brackets.

16 closed coffin

Result, one closed coffin which should protect the sword quite nicely. Rather a lot of work when I could have just wrapped it in bubble wrap, but a good chance to try out some different techniques.

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