Curved Top Railings--how to make them

[testazyk]

Hi all, I'm working on the 80's vintage Mantua Sergal Sovereign of the Seas and in those days they gave you no help--not even laser cutting!  I'm about to put top rails on the scalloped bulkheads and wanted to hear anyone's thoughts on the best approach.  In newer kits they give you precut pieces. 

 

Ideally, I'd build them up out of 2x6 walnut strips but because the curves are so extreme I can't envision how to do with with scarfs.  Plan B is to trace them from the actual ship and cut them out of ply and sand them to shape.  Any suggestions or guidance would be most welcome.  Attached are some pics to give you an idea of what I am describing. 

 

Thanks!

 

[Jim Lad]

Tom, one way to do this is to cut a thin piece of paper (like tracing paper) to shape and glue several short pieces of wood down on the paper and then cut and sand to shape.  You can leave the paper fixed to the bottom of the railing pieces as added strength.

 

John

[Dr PR]

Another way to create complex curved railings like this is to build them up with many thin strips bent around a jig and glued together. The strip width is a bit larger than the railing vertical thickness. After the laminated strips are glued the railing can be sanded to the desired thickness. A real advantage of this method is that the railing is really tough and there is no "grain" for it to break along. The downside is that it is more work than just cutting a piece out of thin plywood.

[Jaager]

The timber efficient way on the original ship would probably have used six pieces of timber to make the rail.

It would still require spilling from wider stock and five scarphs.   Three hook scraphs - but for the two "v's"  I can't think of anything but a straight butt.

Given the mfg and the year of origin, the wood species that you are calling walnut is probably actually of African origin.  It is probably in the Mahogany family, open pore and brittle.   It probably does not want to bend thru the thin dimension, never mind bending thru the thick dimension - which also never goes well with any  species.  This one will probably split if you try to bend it in that plane.

Since you are going to need to obtain wider stock, why not use an appropriate species for the rail?   If you like the Walnut color - which would not be the color of the original, a dye can do it.  For a stain, Walnut is probably the most common shade.  You do not want to use a stain though,

 

On your JPEG #1 -  the pattern of the deck butts indicates that the designer of the kit was beyond incompetent.  The deck plank butt patterns in the 17th century may have been less regimented, but a butt on the same beam for every other strake is just wrong and ugly.

Edited April 7, 2022 by Jaager

[allanyed]

Aircraft plywood is available in most hobby stores and on line and is available in thicknesses down to 1/64".   1/32" thick material for example would be the equivalent of a 3" thick rail at scale 1:98.   https://www.aircraftspruce.com/catalog/wppages/finnishbirch.php is one supplier, but I am sure there are more.

 

You can make a copy of the plans and print on label paper then cut this out and stick it on the plywood.  A sharp #11 blade on a scalpel or hobby handle can then be used to cut out the pattern.    You may want to cut the outside first, then make a molding cutter from a piece of old hacksaw blade or stiff back razor and scrap a mold patten.   Once done, cut the inside of the pattern.

 

Alternatively you can make two or three patterns on the thinnest plywood and then glue them up with a little offset to form the molding pattern.

 

Lot of ways to skin this particular cat.

 

Allan