S.M.S. Emden (1910), HMV, 1:250

[MrConk]

This is a mighty build and highly informative. Thank you for sharing with all of us.

[drg]

Originally Posted by PaperLab

This is remarkable approach from somebody who just starting in paper medium. It took me decades to come up with something similar and in my case wasn't happy ending after my model eventually landed in a trash bin....

Don't know whether you are familiar with this specific edge to edge assembly while working on boxy structures. Using chiseling type of blade like Xacto #18 shave off the edge at 45* of each end so after butt join it creates almost seamless edge and basically no edge coloring is required.

Not always possible and more time consuming than usual tabbed edges joint but when done cleanly it really looks head and shoulders above...

Thanks!

There's no way I could do the 45 degree cuts on paper! I realise it should give a perfect join, but I'd have thought it makes the edges very weak and potentially tricky to join?

[drg]

Originally Posted by MrConk

This is a mighty build and highly informative. Thank you for sharing with all of us.

Thanks, no problem.

There's a long way to go, and a lot of potential disasters to avoid...

[PaperLab]

There's no way I could do the 45 degree cuts on paper! I realise it should give a perfect join, but I'd have thought it makes the edges very weak and potentially tricky to join?

Not that difficult when using proper blades. You need chiseling type like #18 or something lighter for thinner papers. Given, heavier card might be easier to work with but even lighter types like the one used by HMV could be adopted just as effectively. It's not for every occasion and if you feel the edge might be weak beef it up from the inside. Just need some practice...

Darius

[brosen1953]

Hi All
In woodworking, this type of edge joint is called a "scarph or Scarf joint" and its very strong when done with epoxy; it's commonly used to join pieces of plywood, especially in boat building where the boat is longer than typical plywood dimensions.

see: https://en.wikipedia.org/wiki/Scarf_joint

However, with plywood, they recommend that the "scarph" be several times the thickness of the pieces being joined. the sloped edges are usually done with a block plane. I don't see how to do this with paper but maybe someone has some pictures of the technique?

Also, to chime in on some earlier posts about rubber cement & PVA for bonding/joining. some suggestions;\

1. The photo earlier shows regular elmers rubber cement. There is a better product: Elmers craft bond acid free rubber cement:

https://www.amazon.com/Elmers-Craft-...70_&dpSrc=srch

If rubber cement is used properly (both sides, adequate amount, thoroughly dry, pressed together hard with a small roller) it should not come apart. My parents were in the leather goods business for 40 years and used it like that to hold pieces of leather together before sewing, so that the alignment would be perfect for the operator with no possibility of slippage. No problems that I recall (except smell). Also, if the parts with the dried glue are first put in contact very lightly (without pressing down) they can be repositioned before pressing down and there's no rush at all since the glue is already dry.

Another idea I use is to use good quality, acid free double sided tape instead of glue to secure the pieces before "welding"(see following)

2. Alvar Hansens excellent "card modelling" book suggests running a tiny bead along the edges as a "weld" line. This would secure (like sewing the edges of the leather) the bond permanently.

3. I don't like elmers regular PVA; too wet. There is an elmers product called "craft bond" which is much drier, like "tacky glue'. That is good stuff.

4. I have also been trying Roket Card glue which is good for "welding" but can get runny so care has to be taken with application using the minimum amount. Because of this I don't like it for joining large flat areas because there is a lot of squeeze out.

One other small problem with Roket glue is that it dries shiny which would make the bead shiny. I later spray with a matte fixative spray that gets rid of the shine and incorporates UV protection.

Best
Barry

[PaperLab]

Good points Barry. I suspect this type of paper edge joint has it's roots in woodworking.

When I do it I usually shave off around 75 to 90% of the paper thickness. It's very hard to be exact when cutting by hand and I'd rather be safe than sorry.
Also from my observation people who adopted this technique tend to coat paper with few layers of dope even before making first cut.

Either Nitrate or Butyrate will do. When properly done with couple of layers to both sides paper takes some properties of styrene sheet. Personally I find it easier to work with. One serious drawback is the odor...

Darius

[brosen1953]

Thanks Darius, just two points in response

1. That odor problem with dope issue is not trivial. I wonder if there's a less toxic product?

2. I've done a number of scarph joints with marine plywood to make an 8' piece into a 16' piece. With woodworking, the finishing is done after the joint is made. With paper models, the joint is made after the printing. What happens to the printing at the join? is there a continuity problem?
Best
Barry

[drg]

Thanks guys.

Barry: The Elmer's glue I got is also "no wrinkle" and "acid free", so I wonder what the difference is? I can only see it being useful for positioning the largest parts like hull sides and decks, but it is definitely a useful tool to have.

Darius: The HMV paper is only about 100 microns thick (0.1mm) according to my vernier, so I can't see me doing a scarff joint on that anytime soon - that's assuming I've understood correctly. I'll stick with butt-joints with the edges painted, backed up with a doubler for large pieces.

[Renaud]

Are you sure about the 0,1 mm you are referring to, regarding HMV paper? I have not my kits here to check it, but I remember having measured, years ago, a stack of 20 sheets at a time, and it resulted in a global thickness of about 3,6mm, that is 0,18mm per sheet.

[Renaud]

I have next to me a stack of usual paper, rated 90 grams per square meter, that is still rather thin, just slightly over what we use usually to write or others common tasks, and the 500 sheets rise up to 50 mm, that is, consequently, 0,1 mm per sheet.
It seems to me that the HMV paper weight 180 grams per square meter, twice the paper I speak about, the thickness coud so be around 0,2 mm, more or less, depending of the stuff it is made of and the manufacturing process.