Oseberg Ship by KrisWood - 1:25 - Vibeke Bischoff Plans

[KrisWood]

On this attempt I used a razor saw. I've also got a coping saw but that never cuts straight in any direction. I'm thinking about using an X-acto chisel for the next attempt.

 

Edit: I think I figured out a way to do it. If I mark the line on both top and bottom, and then saw from the end rather than from the top, I can make sure the razor saw follows both lines. If I cut along the outside of the line on the second piece then it should be pretty easy to sand it to fit.

Edited January 2, 2020 by KrisWood

[Cathead]

You could try building your own miter box/jig out of scrap wood, something that would provide a flat, smooth surface that the whole razor saw blade can be held against as it cuts. That would also help with ensuring consistent cuts in different pieces.

[KrisWood]

I have a mini miter box but it only has slots for 45 and 90 degree angles. I can probably build one with the correct angle for the keel scarf out of scrap wood, though. Thanks for the idea!

[KrisWood]

The scrap wood miter box worked flawlessly! 😁

 

 Thank you @Cathead!

 

 The paper is peeling but the center line and stations still line up almost perfectly and the joint feels as strong as the wood.

 

Next step will be figuring out how to cut the T shaped cross section of the keel and the wedge shaped cross sections of the stem and stern. Do I do that shaping before or after scarfing them all together?

[Cathead]

Cool! As for the T-shape, I'd forgotten about that. Would be it easier to start over and manufacture a T-shaped keel using two different pieces of wood, rather than trying to cut the T-shape onto your solid piece? Another option, depending on the tools available to you, could be to carefully use a table saw set very low to "rout" the lower edges of your keel. Whether that's practical or safe depends on the size of the saw and workpiece.

 

How does the T-shape transition to the wedge shape? I can't quite picture this. A wedge sounds like it could be carved/filed/sanded fairly easily, but I'm not sure about the connection.

[KrisWood]

@Cathead, I don't have a table saw, so that's out. I have a full set of X-acto blades (straight, curved, and chisel, large and small), a rotary tool that I could make into a router but building a frame for that would be a project in itself, and various files both full size and needle. The vikings cut theirs with broadaxes, so I think the closest I've got are the X-acto knives. At the moment I'm leaning toward a large file to rough it out, then needle files and sanding blocks to fine tune it. I figured out last night that I can scarf together the pieces while they're square as long as I draw the lines to cut where they'll be AFTER the pieces are beveled into wedges. If I cut the scarfs where they are on the plans at their current widths, the scarfs will end up too short after beveling.

 

As for the transition from T to wedge, the T of the keel transitions into a rabbet shortly before the curve of the stem and stern. The garboard strake follows the rabbet until it gets to the T, at which place it is riveted along the bottom of the T, then follows the transition to the rabbet on the other end.

 

You can see the cross sections before and after the transition between rabbet and T on the left hand side of the plan of the keel drawn of the original ship by Fr. Johannessen in 1933:

 

http://www.unimus.no/felles/bilder/web_hent_bilde.php?id=12384245&type=jpeg

 

Here is a photo from the construction of Saga Oseberg showing the garboard strake being fitted, where the transition is clearly visible toward the forward section of the ship in the right hand side of the photo:

 

[Cathead]

Careful cutting and filing can achieve almost anything from a solid piece of wood, so have at it!

[KrisWood]

The mini plane is my new best friend. After a few minutes of planing and light sanding the keel is now a wedge, and the place where the rabbet will transition to the T is easy to see as a natural result of the curve of the keel's cross section. I'm super happy with how easy that was.

 

I hope to scarf the stem parts together and plane them tonight. 

[KrisWood]

I ran into a critical flaw in my scrap wood miter box method this morning. It only works if the razor saw is perfectly vertical. I cut the scarf for the two parts of the stem this morning and had my saw at a slight angle without realizing it. My top edges lined up perfectly. My bottom edges had about a millimeter too much material left over. "Well", I thought, "better too much than too little." So without thinking much about it I flipped the pieces over and cut the bottoms at the same angle. That's when I realized my mistake. Now the top and bottom match perfectly, but there's a raised triangle /\ ridge shape in the middle. Nothing a little careful filing can't fix but it means a little more work to make it right.

 

On my next scarf I'll draw the lines on my miter box BEFORE I cut, so I can make sure to follow a vertical path with the blade. 😆

[Louie da fly]

Yep. Seems so obvious in hindsight (don't ask me how I know).

 

Steven

[KrisWood]

@Louie da fly, Ok, I won't ask, but I have some guesses.

[KrisWood]

Stem and stern posts are scarfed together. They match the plans almost exactly, so I didn't screw up as bad as I'd thought!

 

Next I'll scarf them to the keel. 🙂

[michael mott]

I have been using my razor saw just like this one for at least 20 years its a bit beat up but still works like a charm one trick to getting the saw to cut vertical when setting up your mitre boxes (you will end up making a few they are really handy) st to use a small square next to the saw as a guide if you don't have a small square a square block of anything to guide the saw works well. 

 

 

Michael

[KrisWood]

@michael mott, I'll try that tomorrow, thanks!

[Louie da fly]

Looks very good, Kris.

 

Steven

 

[KrisWood]

I got the stem and stern scarfed to the keel now, but there's a definite twist in it somewhere. The stem leans sightly to the right and the stern leans slightly to the left. Is this a problem? How do I fix it?

 

[mtaylor]

It's a problem....  Where's the "twist".. in the long keel or at the joints?  

[KrisWood]

Looks like it’s at the two joints connecting the aft piece of the keel to the fore piece and the stern. Each joint tilts a little to the left when viewed from the front. I forget if that's port or starboard.

[mtaylor]

Left is port (hint:  4 letters each).    The tilted joints are probably the problem then.  Hmnm... studying the photo.. looks like the aft one (top of the photo) is the problem.  About the only way to fix it, is take the joints apart and re-work them.  Someone else might have a better idea though.

[Cathead]

When you glued these together, did you weight them down evenly? Pieces may seem to lie flat when dry-fit, but glue can cause the joint to warp a bit during drying. So, as Mark says, one option would be to try again and ensure that everything is weighted and/or clamped down nice and flat so that it dries that way.

 

If this were a "regular" ship and the twist was minor, you might be able to get away with pulling the stem and stern back into line with other planking and framing. But the way these pieces stick out, and with the relative lack of support around them, I don't think that would work.

[KrisWood]

When I glued them the joints were too small for the clamps to hold them straight so I placed thin flat shims of wood on Either side and used multiple clamps to make the shims into a sort of splint holding the joint in place. I suspect the problem on this part is that I didn't cut straight on the base of the stern.
 

Meanwhile, my copy of "Saga Oseberg: rekonstruktion af et vikingeskib" arrived today! It took about a month to get here from Denmark, and it's written entirely in Danish, which I don't speak, but it's got tons of photos, plans, and information on both the original Oseberg ship and the Saga Oseberg reconstruction. This will take me a while to digest, but I think it's the single most valuable resource I've found yet for this project. 🙂

[KrisWood]

Do you have any suggestion for how to keep the parts vertical while gluing them?

[mtaylor]

Don't go vertical.  Lay on the side of the keel and on a piece of glass (if you have it) or a very flat surface.  Then glue everything together.  Lay another flat piece of glass on top or weight it down with bricks, books, heavy objects.  

[KrisWood]

But what if the keel isn't flat? As per the plans, it curves in all three dimensions.

[mtaylor]

When I mentioned laying it flat, on it's side like in the post on Saturday where you show us it's "bent".

[michael mott]

Following along with Mark's suggestion of laying it flat, you have marked the centre line use that as a datum and put shims of thin material Wood, card or plastic to lift up the areas that are thinner until the center line is equal at all points from the glass. Tape those to the glass so they do not move also tape some blocks to the glass that are taller than your keel to keep it in position then when re gluing place sand bags or other weights to hold the re glued keel in position until it is set.

 

Michael

[KrisWood]

Shims in place. I taped down the keel and stern too, just in case, then put the appropriate thickness of shims on top the thinner parts.

[KrisWood]

Then I put plywood on top and covered it with books. Not sure why the forum doesn't pick up the orientation of these photos.

 

Moment of truth to come when I open this up later. 🙂

[michael mott]

7 hours ago, KrisWood said:

Not sure why the forum doesn't pick up the orientation of these photos.

I find the the iPhone pictures are sometimes upside down when I load them up to the computer, I use Ifanview (free photo editing tool) to resize and to orient them.

 

Hope that your fix works well on the keel.

 

Michael

[KrisWood]

The good news is, it's straight as an arrow now.

 

The bad news is, in all the fixing of the scarf, first from bad cuts and then having to take apart the joint, I lost about 2mm from each side of the joint. This puts it well into the curve of the stern. If I'd glued it at the angle that the scarf lined up, my sternpost would have leaned several degrees aft. I decided last night to put it at the correct angle and hope. The attached photos show the result.

 

I also discovered, now that my stern is straight, that the stem leans much farther to starboard than I'd thought so that needs to be taken apart as well.

 

At this point I've decided to call it a learning experience and start over. I've got much better plans to work with now and have a much better understanding of how to cut scarfs.

 

Now to run to the hobby store for more 3/8" basswood.