I thought the following would be interesting for some of you replica builders.
Darkangel and Franzkait brought up a very interesting topic with repect to brass and/or bronce sleeves soldered into steel brackets.
The idea was that because of the difference of materials an electrochemical corrosion will take place that will destroy the steel bracket.
Basically Franzkait and Darkangel are correct with the claim, but to my knowledge the effect is negligible in this context and will not very much effect the structural integrity of a rudder hinge made that way.
The matter is different in the case of plumbery where a complete system of water tubes are conected and are electrically earthed.
However the idea is interesting and I would like to check it out.
The idea of this test is not to proof that brass/bronce sleeves have not been used during WW1, but to examine whether there is a technical reason for using steel sleeves instead of brass/bronce, because of the potential destruction of the sleeve or the holding bracket due to electrochemical corrosion.
My pertsonal opinion is that there will be no such a reason and that the use of steel sleeves was nothing but a neccessity because of the shortage of brass/bronce.
The first image shows the new made late Fokker style strap along with an earlier style Fokker hinge. The erlier one is about 15 years old and showed no sign of severe corrossion where the brass sleeve is brazed to the steel strap. Admittedly this hinge was never exposed to the elements and was stored in our workshop
The other hinge is the new made piece for the experiment. The sleeve is of brass
This image shows the experimental hinge prior to soldering the sleeve in place. The file marks I set as to no one may claim in the end I exchanged the hinge.
This photograph shows the experimental hinge after it was partially soft soldered. I did the soldering only partial to give water the better oportunity to get into the small corners of the connection. Also note how the soldered brass sleeve got almost the same color as the steel strap.
To study the effect I decided to put a dummy rudder spar in place as well.
The experimental hinge will be exposed to the elements whithout oil and whithout paint, just to check the effect the electrochemical corrosion taking place in such a design.
My prognose is that the effect will not be very noticable (whithin a reasonable frame of time).
Just to make things clear: The test is to find out what happens to the soldered connection between sleeve and holding strap.
I will occassionally report about this test.