making a brass dome for ship's compass

[brunelrussell]

Brunelrussell here; as some of you know I am working on a large-scale model of the steamship Great Eastern.  The ship had two compasses surmounted by domes around 2 feet in diameter, or one quarter inch scale size.  I tried using hollow brass beads but in compressing them to the slightly oblate shape required, the seams opened.  I then tried making them of brass tubing rings glued together, which had worked on the capstan tops (brass sheet in that case) but the edges of some of the layers exfoliated.  Nobody on line has hollow brass spheres that small.  If anybody knows of another way, please lemme know.  Thanks in advance

[grsjax]

You can use a dapping block to make metal domes.  Here is a link to a set on Amazon  https://www.amazon.com/dp/B00JPLHDR8/ref=asc_df_B00JPLHDR85356372/?tag=hyprod-20&creative=395033&creativeASIN=B00JPLHDR8&linkCode=df0&hvadid=216554815864&hvpos=1o1&hvnetw=g&hvrand=533642903297776801&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1015579&hvtargid=pla-416568837597 .

You can probably find the same thing cheaper on eBay.  You can find these in pretty much any size you need.

[Moxis]

When I was building my model of the Clara May a few years ago I met the same problem. After thinking hard I finally used following method: First I made the form of the compass dome out of plasticine. When ready, I covered it with a jelly mixed of epoxy and milled fibreglass "dust". When the first layer was cured I applied second layer of the same stuff. And finally when everything had cured, I cut an oval hole on the dome where the glass should be situated. Through this hole plasticine was removed and voila, I got a hollow quite strong dome which was then sanded smooth and painted with brass paint. The last thing was to glue a printed compass rose inside the dome and an oval transparent "glass" into the hole and the compass was ready.

[KeithAug]

Hi Brunelrussell - If you look at my Altair Build  - top of page 20, this is an option for making a dome.

 

[brunelrussell]

I just may try that dapping thing, but thank you all for your suggestions!