catsittingstill (![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
catsittingstill) wrote2014-06-03 07:45 pm
catsittingstill) wrote2014-06-03 07:45 pm
Entry tags:
The Current Project
My current project is an instrument case, made using the same wood strip and fiberglass technique I first learned in order to make canoes. It seemed to me at the time that this technique should be adaptable to lots of things, and I have been craving a better case for my octave mandolin for ages.
Here is where I began the instrument case, gluing the flat top and bottom together.
Here is the next step in the process, making the sides around the jig, or form, that I used to get the right shape.
Here is where I glued the sides to the bottom.
Shaped the top and bottom to match the sides.
What I don't seem to have mentioned is that the bottom and sides were glued together, while the top was held to the jig by 3 screws but not actually attached to the sides. Indeed I ran a strip of tape around the top of the sides, so that the top *could not* become glued to the sides. Then I glued little 1 inch strips of cedar to the top, to form a lip that exactly fit the sides. To hold the cedar strips to each other and the top while the wood glue dried, I hot glued each one to the tape. Then I took out the screws that had been holding the lid on, drilled the holes out with a Forstner bit, and sealed them with a matching white pine plug.
Then I sanded everything off nicely. Then I got into working on _The King's Lute_ and didn't have a lot of time and set this project on the shelf. For about two and a half years.
Mid-May I decided I really wanted to start working on it again.
I fiberglassed the top, (epoxy seal coat, then fiberglassed the top, then used fiberglass cut on the bias to tape the lip and edge of the top together) then undertook to break the hot-glue bond between the lip of the top, and the tape on the sides. This involved using a cedar strip and a mallet to whack *up* on the lower edge of the lip, while securing the project to the workbench. Mostly I clamped one end, and wacked the other, but I had to change ends a lot. I did succeed in getting the top off this way, and I only wrecked the fiberglass in a couple of places, which was easy enough to patch.
The tape had been on there for two and a half years. When it came off, which happened only reluctantly, it left some serious goo behind. I tried scraping (slow), sanding (what a mess!), denatured alcohol (no help), and was making very little progress. However I asked in the hardware store and the people there recommended Goof-Off. Which stinks to high heaven, and I used half the bottle, but I got all the tape goo off in about an hour which is about five hours less than the scraper was going to take, so yay. And if anybody needs Goof-Off I've got half a bottle you can have.
Then I fiberglassed the bottom part of the case. (Same deal; epoxy seal coat, then used two strips cut on the bias to fiberglass the sides and part of the bottom, then fiberglassed the bottom.)
Now originally the jig had little feet on one side, and not on the other. The feet went on the bottom when I was gluing the side strips together on the jig. When I glued the sides to the bottom, I did it with the jig upside down, and the feet sticking up in the air. Then when I attached the lid, I put three screws through the lid into the feet.
Here is the case with the lid off and the jig (and the feet) showing:
So when I got the lid off, the feet were sticking up in the air, and there was a gap of the same size as the thickness of the feet between the bottom of the jig and the bottom of the case. I left this gap on purpose during the design phase, so that I could whack the jig down into the case to break the hot glue bond.
Which I did today. It took some serious whackage, let me tell you. I whacked all the way around the edge of the jig. And all the way around again. And then figured out that the jig was loose, except at the head of the case, where the curve was tightest. I whacked it more. And finally the jig was loose all the way around.
Now in my head I had modeled that the jig would be loose and would just slide out. In reality it was seriously wedged in there. I ended up making a hole at the head and tail ends of the top plate of the jig, unscrewing the screws that held the top plate to the posts, and levering out the top plate (carefully) with the breaker bar. Now I had the bottom plate, firmly wedged into the bottom of the case, with three wooden posts sticking out of it.
This shows the top plate out and kind of displaced, so you can see part of the bottom plate and one of the posts.
I drilled holes parallel to the case bottom through each of the posts, put a handy carriage bolt through each, and made a short loop of rope (square knot: it works) to pass under both ends of a carriage bolt and over the breaker bar. Then I used the top plate with the holes in it to distribute the force on the fulcrum over as much of the edge of the case as possible, and gently levered up with the breaker bar. Change posts, lever again. Change posts, lever again. And so on. It took me--I kid you not--two hours.
It worked; I got the jig out of the case. It might even be possible to use it again, maybe. Though I don't know if I'll ever build another octave mandolin case so maybe it doesn't matter. The case was not damaged, the lid fits nicely, but not too snugly, over the case, as shown here.
Here is where I am as of today; the inside of the case is sanded, but unfinished.
Most of the inside of the case has to be hand sanded because of the size and the angle. I made a lot of progress on that today; I may be ready to seal coat the inside tomorrow.
Here is where I began the instrument case, gluing the flat top and bottom together.
Here is the next step in the process, making the sides around the jig, or form, that I used to get the right shape.
Here is where I glued the sides to the bottom.
Shaped the top and bottom to match the sides.
What I don't seem to have mentioned is that the bottom and sides were glued together, while the top was held to the jig by 3 screws but not actually attached to the sides. Indeed I ran a strip of tape around the top of the sides, so that the top *could not* become glued to the sides. Then I glued little 1 inch strips of cedar to the top, to form a lip that exactly fit the sides. To hold the cedar strips to each other and the top while the wood glue dried, I hot glued each one to the tape. Then I took out the screws that had been holding the lid on, drilled the holes out with a Forstner bit, and sealed them with a matching white pine plug.
Then I sanded everything off nicely. Then I got into working on _The King's Lute_ and didn't have a lot of time and set this project on the shelf. For about two and a half years.
Mid-May I decided I really wanted to start working on it again.
I fiberglassed the top, (epoxy seal coat, then fiberglassed the top, then used fiberglass cut on the bias to tape the lip and edge of the top together) then undertook to break the hot-glue bond between the lip of the top, and the tape on the sides. This involved using a cedar strip and a mallet to whack *up* on the lower edge of the lip, while securing the project to the workbench. Mostly I clamped one end, and wacked the other, but I had to change ends a lot. I did succeed in getting the top off this way, and I only wrecked the fiberglass in a couple of places, which was easy enough to patch.
The tape had been on there for two and a half years. When it came off, which happened only reluctantly, it left some serious goo behind. I tried scraping (slow), sanding (what a mess!), denatured alcohol (no help), and was making very little progress. However I asked in the hardware store and the people there recommended Goof-Off. Which stinks to high heaven, and I used half the bottle, but I got all the tape goo off in about an hour which is about five hours less than the scraper was going to take, so yay. And if anybody needs Goof-Off I've got half a bottle you can have.
Then I fiberglassed the bottom part of the case. (Same deal; epoxy seal coat, then used two strips cut on the bias to fiberglass the sides and part of the bottom, then fiberglassed the bottom.)
Now originally the jig had little feet on one side, and not on the other. The feet went on the bottom when I was gluing the side strips together on the jig. When I glued the sides to the bottom, I did it with the jig upside down, and the feet sticking up in the air. Then when I attached the lid, I put three screws through the lid into the feet.
Here is the case with the lid off and the jig (and the feet) showing:
So when I got the lid off, the feet were sticking up in the air, and there was a gap of the same size as the thickness of the feet between the bottom of the jig and the bottom of the case. I left this gap on purpose during the design phase, so that I could whack the jig down into the case to break the hot glue bond.
Which I did today. It took some serious whackage, let me tell you. I whacked all the way around the edge of the jig. And all the way around again. And then figured out that the jig was loose, except at the head of the case, where the curve was tightest. I whacked it more. And finally the jig was loose all the way around.
Now in my head I had modeled that the jig would be loose and would just slide out. In reality it was seriously wedged in there. I ended up making a hole at the head and tail ends of the top plate of the jig, unscrewing the screws that held the top plate to the posts, and levering out the top plate (carefully) with the breaker bar. Now I had the bottom plate, firmly wedged into the bottom of the case, with three wooden posts sticking out of it.
This shows the top plate out and kind of displaced, so you can see part of the bottom plate and one of the posts.
I drilled holes parallel to the case bottom through each of the posts, put a handy carriage bolt through each, and made a short loop of rope (square knot: it works) to pass under both ends of a carriage bolt and over the breaker bar. Then I used the top plate with the holes in it to distribute the force on the fulcrum over as much of the edge of the case as possible, and gently levered up with the breaker bar. Change posts, lever again. Change posts, lever again. And so on. It took me--I kid you not--two hours.
It worked; I got the jig out of the case. It might even be possible to use it again, maybe. Though I don't know if I'll ever build another octave mandolin case so maybe it doesn't matter. The case was not damaged, the lid fits nicely, but not too snugly, over the case, as shown here.
Here is where I am as of today; the inside of the case is sanded, but unfinished.
Most of the inside of the case has to be hand sanded because of the size and the angle. I made a lot of progress on that today; I may be ready to seal coat the inside tomorrow.