Thursday, July 9, 2015

Treasure chest with curved lid part 6, the lid

The lid is going to be almost semicircular from the front going to the back. Length wise it will be straight.

I started by drawing an arc that would correspond to my plans for the lid. 
On a board I marked a distance of 11" near one edge and a center between those. I then placed one leg of the compass something like 1.5" below the center and adjusted the other leg to touch the points 11" from each other.
Then I scribed the piece of a circle using that setting.

I measured the curved distance ( I know you can calculate it as well, but I don't remember how to since it is only a fraction of a circle).
I got the distance to be 16" (41 cm) more or less, so I made 6 boards with a width of 2.75" (7 cm). Each board was intentionally cut about 4" too long.
Using my scrub iron in the plane, I planed a bevel on each side of all the boards. I just eyeballed the angle.
The boards for the sides of the lid each got a bevel that was twice the angle of the inner ones. In hindsight it would have been smarter to wait with these two bevels, but I know that for the next time I am going to make such a lid.

I flattened what was going to be the inside of each board, and then I laid out all of the boards and numbered them. I had added an arrow showing the direction of the grain, so I didn't make it more difficult for myself than I had to.

Each pair of bevelled edges were then jointed together. Pretty much like how you do with any glue joint. The only difference is that here I had to turn one board the opposite direction, to get the bevels to match up. A few swipes with the smoothing iron in the plane, and the seam seemed tight enough.

When all the joints were completed, I again lined the pieces up. I added some blue masking tape to hold the pieces, and then carefully folded the lid. I placed the assembly on the scribed arc, to see if it looked fine.
It turned out that I had been a little too aggressive on the bevels, so I was about an inch short.
I made a seventh stick about an inch wide to rectify the width of the assembly.
This stick was made with out any bevels (at least that is what I tried to, but I didn't check it with a square).

The now seven pieces were lined up, taped and flipped over.
Now the bevels were open so I could add some hide glue to both sides of each joint. I used a small brush to get a nice layer of glue all over the surface.

Once all the glue was applied, I gently lifted the two sides of the lid and when the shape was obtained, I put the assembly upright on the work table.

I adjusted the individual boards so the inside edges of the joints lined up the best I could. I then added some more masking tape to help close the inside seams by putting some tension on the opening of the lid.

After the glue had started to set, I carried the piece out to a nice and warm spot so the glue can dry.
I then measured the width of the assembly and found that I am still about 1/2" short..

It doesn't matter much, because one of the joints of the centre stick is not very tight on the outside.
The plan for tomorrow is to remove the centre stick, and glue in another one which is maybe 3/4" wider. That would give me a bit of surplus wood that I can plane away to make the lid fit nicely.

The scribed arc that represents the ideal shape of the lid.

Initial testing of the bevels.

Flattened on the inside

Jointing the bevels

Ready for the first test.

Checking the shape of the assembly.

About an inch too narrow.

Now there are seven pieces in the lid.

Glued up, view from the inside.

Glued up, view from the outside.


  1. That look like a fun project I must try that sometimes

    1. It was easier than I anticipated, I just hope that the dovetails will go as smoothly as well.

  2. I wasn't expecting the dome to be so high. What are your thoughts on this expanding and contracting?

    1. It did turn out to be a bit higher that I wanted too, but I can only blame myself and my eyeballed angles for that.
      To tell the truth about the wood movement: I don't know what will happen, except as Bob says that it will get wider and narrower.
      I am going to plane down the thickness of the top to make the round outside surface. The ends will be dovetailed in, with the end boards being the tail boards. That will maybe be strong enough to prevent the lid from breaking anything, but then I'll have to live with some bending in the lid instead.
      The wood is very dry now, so most likely it will expand as it goes of the ship.
      I didn't really try to design my way out of wood movement, so it is possible that it will self destruct. Maybe that is one of the reasons why those dome shaped chests are not "the thing" anymore.

      If someone can learn a bit from one of my failures, I think that it has been a successful build :-)


  3. It will get wider and narrower -)
    Bob, running and ducking while sipping

    1. And hopefully stay together as one unit while doing so :-)

  4. Following your project gives a lot of perspective as to the skills of chest makers throughout the middle ages to the 19th century. That being said, you are doing a fine job of it!! As usual of course.

    Also, here's a question I meant to ask you before. Do you enjoy writing in English? Most of the people I know who speak English as a second language have told me that at first they found writing in English difficult at first, but then enjoyable (I'm told that English is a colorful language) Since my skill in other languages is severely lacking, I have no other frame of reference to whether or not English is actually colorful. I was just wondering your opinion.

    1. Hi Bill.

      Thanks for the nice comment.
      I must say that the curved lid is quite a challenge for me. At first the plan was to just make the ends square, but as usual I decided to stray from the original plan. I figured that making the ends slanted, would be a just a little bit more difficult.
      It turned out that it is way more complicated than I had ever imagined.
      Nothing is straight, finding a reference point is difficult and even marking out the dovetails is a challenge.
      My first attempt was to make the tails first. They looked fine, but I had forgotten to take into account that I had to make them angled.
      Now I have made the pins first, and it is still not easy.
      I have managed to mount one end, but off course the piece cracked just before seating completely.. I will just glue the crack and adjust the dovetails in that section.
      But I am really impressed with the level of difficulty that arises from such a small change.

      Regarding the English writing question:
      I do enjoy writing in English, but I am afraid that my vocabulary is a bit limited, so I can't use the full English language. Therefor I doubt that I can claim to be able to write a colorful English
      I sometimes find myself in a situation where I am in a bit of doubt regarding a phrase or if a word really means what I think it does, and then I normally rephrase or rewrite instead of trying to find out if I was correct in the first place (good old fashioned laziness).

      It is a bit odd, but when I was a child, I actually liked to write. Somehow the school system managed to destroy that.
      Personally I think it is because I am fairly slow when writing by hand, plus I don't have a very pretty hand writing.
      I find it a lot easier to type, but that wasn't allowed in those days. If it had been, I could perhaps have gotten better grades.
      That is also why I have always preferred oral exams to written ones.

      I must be getting old, because I find myself more and more irritated by the way the Danish language is maltreated by youngsters incapable of writing a meaningful sentence. I guess the same is a problem with English.

      If I write in Danish it is usually an email to a friend or some family, so I actually write more in English nowadays than I do in Danish.

      One of the benefits of writing in English is that it is a fine way of reaching out to a broader "audience", and be able to get some feedback from people all over the World.

      I would like to be able to write German more fluently, but I just had 3 years of German in grammar school, and that is 26 years ago. I used to subscribe to a German magazine called Motorrad Classic (Classic motorcycle).
      Reading a language is a great help because you get to see a lot of sentences, and how the structure of a sentence is made. I can still read and speak German pretty well, but writing it would take some serious effort from my side.