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

[KrisWood]

Minor update: I roughed out the "T" of the keel last night. Nothing photo-worthy, it looks awful rough-hewn as it is at the moment. Next step will be building the jig. There's no point doing any further work on the keel until it's aligned with the bulkheads and I can see the curve of how the garboard strake aligns with the keel. I'll get started on that tomorrow.

[KrisWood]

Ok I take it back. I couldn’t resist posting a photo. Here's the best section of the keel shaped to the cross section templates. I stopped trying so hard to make the keel fit in the templates when I realized it was moot without having the bulkheads to align the curves.

 

 

[Louie da fly]

Nice work, Kris. It's a pleasure following this build.

 

Steven

[KrisWood]

I looked up the dimensions for my rivets and it looks like I'll need 28 gauge wire (about 0.3mm) but all I have is 18 gauge, so I'm going to have to order some. Does anyone have recommendations for what would be best for making tiny rivets?

[bigpetr]

Kris, can I ask what are dimensions of Oseberg rivets?

[Cathead]

12 hours ago, KrisWood said:

Does anyone have recommendations for what would be best for making tiny rivets?

Out of my experience, sorry.

[Landrotten Highlander]

This is frequently mentioned in the LSP builds (Large Scale Planes) and used to replace eroneous or poor quality rivets on plastic air frames.  They can be painted to look like wood.

http://mikegrantdecals.com/shop/product/rivet-decals/

[KrisWood]

I should have specified, I meant tiny functional rivets. I learned how to make brass and copper rivets by hand in my metalsmithing class in college decades ago. I think I can probably fashion an anvil of sorts out of materials I have on hand, too. I looked it up and my gas stove gets well over the melting point for both copper and brass. I just need to get the wire to make them. Now if only the craft stores in my area weren't all shut down...

 

It also occurred to me last night that I have no idea where I'm going to find a 0.3mm drill bit. Any recommendations for drilling tiny holes? I also have nothing capable of measuring smaller than 1mm, so I'm going to have to trust that the drill bit and the wire are the right size.

 

@bigpetr, the rivets for the planks on the Oseberg Ship have shafts 6mm to 7mm in width, that's ~0.3mm, or 28 gauge at 1:25 scale. I forget the size of the heads, I think it's about 22mm to 25mm for the diamond shaped plates that go between the rivet heads and the plank. I'll look it up again after work.

 

 

[Cathead]

There are model drill sets out there that go down to .3 mm, like this one from Model Expo. It's listed as backorder right now but they have many different sets you could explore and there are likely other sources for such sets.

[KrisWood]

@Cathead, cool, thanks! Since that one was out of stock I just ordered this one instead:

 

https://www.amazon.com/gp/product/B000SKVF8I/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

Turns out all I needed to know was that they're called micro drill bits, then they came right up when I searched for them.

Edited May 15, 2020 by KrisWood

[KrisWood]

I did some more research on making tiny rivets and it doesn't seem possible much below 1mm diameter wire (18ga). That leaves me with a question:

 

If no one is making/using wire rivets in models at this scale, how do you all get your planks to stick together? Is it just glue holding them in place? Is the technique different for lapstrake vs frame first hulls?

 

I'm worried that wooden trenails won't be strong enough to hold this thing together.

[Cathead]

Pretty much all wooden models are held together with glue, even at much finer scales than this. Any treenails/rivets are just for appearances.

[KrisWood]

I started cutting out the planking templates today. 😁

 

The little table mounted jigsaw had no trouble going through 1/4" plywood. It turns out the part I was most afraid of, cutting the stair step lines of the planks, was far easier than I'd thought it would be.

 

I did run into a few problems though.

 

First, I forgot to mark the center line on the templates before cutting them, so aligning them is going to be a chore.

 

Second, my base board for the planking jig is longer than my keel, but my templates are shorter than the height of my stems. I'd forgotten that I had originally intended to do this on a shorter base board with the stems hanging over the edges.

 

Lastly, the scarfs on the stern are just awful. I was pretty proud of them when I first made them, but now that I look at them again for the first time in a week I can clearly see they're nowhere near as good as the scarfs in the keel and bow.

 

I think I may need to cut my keel parts out yet again, but at least I have a power tool to do the cutting this time around. That said, is doing the keel and stems over again as layers of plywood for a model that isn't for display and only needs to hold together long enough to burn a bad idea? I think it might actually be stronger than these scarfs...

 

 

Edit: now that I think of it, I wouldn't need to use plywood, just layers of solid wood, and build up to the thickness for each cross section. I think I might try that!

[KrisWood]

Just for fun I attempted a tiny rivet at scale today. It didn't come out very pretty but it is functional. I'm not sure it's worth it to make hundreds of these...

 

 

My gas stove turned out to be hot enough to anneal the wire but not hot enough to melt it into a ball at the end. Also I did the drilling and cutting of the clink plate in the dark and cut it with wire cutters. If I do this again it'll be in the light with a chisel. 😆

[Cathead]

8 hours ago, KrisWood said:

is doing the keel and stems over again as layers of plywood for a model that isn't for display and only needs to hold together long enough to burn a bad idea

I think you're the only one that can answer that, given the specific personal context of why you're doing this and what the model is intended for.

[KrisWood]

By a bad idea, I meant catastrophically bad, as in would fall apart completely at the first stress.

[KrisWood]

Last night I attempted cutting the keel as one piece of plywood. I right away encountered many many problems with it.

 

1. The table mounted jigsaw has a guard arm that gets in the way of cutting anything larger than the table. The keel is far longer than the table so this means it's near impossible to cut out this way. The process involved dozens of progressively larger arcing cuts, with the first few being very shallow and having to back the work piece off the blade and cutting from the other side whenever I hit the guard arm. I ended up cutting out 2/3 of it before giving up on it completely because I ran out of time for the day / couldn't cut the midship portion at all because it's impossible to cut within a few degrees of 180º. 
2. Once I got the aft stem cut completely cut out, it was apparent why no one builds this way, not even the kit manufacturers. The 1/4 ply was VERY flimsy. It was far lighter and more flexible than my solid basswood parts, and almost as bad as balsa. When I felt it flex I realized that every kit I've seen uses a tall bulkhead-like keel to fit the frames into. I could draw a new keel in this way but really a tat point I may as well build a kit instead of a scratchbuild.
3. A few days ago, when buying the wire for my rivets, I also picked up some more wood glue. As soon as I got home I noticed that the label clearly says not to use it on parts that can get wet. DUH! It's water based glue! I've known that since I was a kid. This should have occurred to me sooner. Even if my current basswood keel didn't have terrible scarfs, it's still held together by wood glue and would come apart eventually in water. That lead me to researching marine plywood. The regular plywood I'd bought from the hardware store would delaminate if submerged for too long. I'd decided to try making a keel out of it anyway since I'm planning on burning it, but problems 1 and 2 above were too much to make it worthwhile.

 

I hereby speak from personal experience: A plywood keel isn't worth the time, effort, or material it takes to cut out the part!

 

I'm going to have to get some more printer ink so I can reprint my keel templates and make a new basswood version. At least I won't have to chisel it out this time, and I learned a lot along the way.

 

Edit/PS: Can anyone recommend an easy-to-use-for-beginners marine epoxy? I imagine the RC boat building folks must have something.

[bigpetr]

I would not worry about water based glue. I would use it and seal the finished hull with varnish. It will prevent plywood from delamination too.

[KrisWood]

I've run into a roadblock on my project. I've cut out all my planking bulkheads and started building the jig. By the time I got a quarter of the way through gluing it together I realized the problem...

 

When I'd cut out my bulkheads I made two assumptions:

 

1. That my table mounted jigsaw would cut straight lines
2. That as long as I glued my templates to the plywood along these straight lines, all I'd have to do is stand my bulkheads up on the baseboard and everything would line up

 

It turns out both of these are false. At various points in cutting my bulkheads out I strayed to either side of the lines, meaning my bulkheads vary in height by up to a millimeter or so (2.5 scale centimeters). This means that many of my bulkheads do not reach the keel, rendering them effectively useless because that means they'll also never touch the planks, or if they do the planks will be out of fair (it'll result in dimples in the hull if I plank it as it is right now).

 

I figured if most of my bulkheads are as close as possible, I could correct it with some careful filing on the ones that stand the highest, to bring them all to the same level, so I kept on gluing bulkheads to the jig.

 

That's when I made my second mistake. I started gluing bulkheads higher up when they didn't reach the keel while standing on the baseboard. This meant I was no longer using the baseboard as a reference. As I approached amidships with my bulkheads they gradually climbed higher and higher, and because I lack depth perception (my left eye cannot focus) I misjudged how the bulkheads lined up with the centerline. The higher the bulkheads got, the further to the port side they crept from the centerline.

 

I need a better way to build a jig....

 

Can anyone please share example images or links to jigs using planking bulkheads for lapstrake hulls? I'm going to need to take this whole thing apart and re-glue it and I'd like to do it right on my second try.

[KrisWood]

 I did some searching on the forums here and this build gave me an idea:

 

 

I'll cut a notch in each bulkhead for a "false keel"  to fit my actual keel on top of. Then there's no way they can get out of alignment.

 

[Cathead]

I'm not sure I can envision what you're describing. Photos might help.

[KrisWood]

I'll post some photos before and after whatever I get done today.

[KrisWood]

Ok here's the before photos. There's an increasing gap between my keel and bulkheads with every bulkhead I add. You can't really see it in the photos but some frames are off of center by as much as a millimeter as well.

 

I'm going to take this thing apart, add a false keel, and put it back together again.

[mtaylor]

If all you have is a jig saw, you could draw your line for the final size, then draw another line away from the first for cutting.  After cuttting, sand to the first line.  I did that in past before I had a few special tools. 

[KrisWood]

I ran out of time to finish all the bulkheads last night, but it's already soooo much better!

 

 

[KrisWood]

@mtaylor, I'll definitely do that from now on.

[KrisWood]

Finally found time to finish the notches in the bulkheads to fit them on to the false keel. 😁

 

All the clamps are because nothing is glued yet, but I'm excited that it's starting to look ship shaped!

[KrisWood]

Next step will be adding filler blocks to keep the bulkheads squared and at the right height. 🙂

[Cathead]

Cool. As you said, it's nice to see the hull taking shape, even as a ghost.

[KrisWood]

As I'm lining up the bulkheads it occurs to me that this would be a lot easier to fair if I had some planks to line it up with. I don't want to glue it in place before fairing it if possible. The Saga Oseberg book by Thomas Finderup has a diagram of the planks drawn flat, but it doesn't have a scale. How would you go about figuring out the correct scale?

 

You can see the diagram in a lecture by the author in this video at 37:51

 

https://webtv.vikingeskibsmuseet.dk/?poditemid=40145&tagsid=121&soegeord=

 

The image in the book is higher resolution and I've aligned my scan of it with the version in his lecture to correct any distortion from the scanning near the binding of the book. Now I just need to figure out the size at which to cut out the planks....