Common rudder fracture - left to corrode

[skiziks33]

After using a epoxy primer on the porous steel, can I create a flat/smooth surface for the cloth using filler first on the steel to fill in an crevices? Or should I cut layers of cloth to build up an even shape of the steel? Can apply wetted cloth directly to the primed steel?

[maja]

Glass fibre structure in the very central part of the ruddder contributes very little to the bending strength. So my oplinion is that you may certainly smoothen the steel plate surface with some thin layer of epoxi filler.

[skiziks33]

Hi all.
A Rudder update

I decided to have a new rudder built using a mold of the old. To order and transport a new Marieholm rudder from Sweden would have been expensive and unnecessarily complicated. The corrosion of the original is too extensive to bother with a repair. Thank you for all your advice though. If the structural integrity of the original steel wasn't compromised, than a repair would have been possible, but it is too risky the way things are.

The builder is using an aluminium alloy for the internal framework, rather than the steel used originally. The frame will be molded in solid fiberglass, rather than using the foam of the original.

Should be much stronger and possibly lighter

Any thoughts? Generally. These are the materials used by modern rudder/boat builders.

I will post an image when it's completed.

[johan swe-1870]

That seems like a good idea.

Maybe it will not be lighter. Instead of steel there will be aluminium, that will be lighter. Instead of foam there will be GRP, that will be heavier I think. The weight shouldn't be that important, but the strength is.

I think you will be happy with the new rudder. Keep us informed, and please show some pictures if you can.

[skiziks33]

frankly
for trading weights you've suggesting, I'm hoping for a similar weight to the original

Can the gudgeons and pintles be found somewhere new?

[skiziks33]

Thanks for all your help and advice folks, in repairing the old and designing the new. The old was filled and faired to it's pre-break form. Then it was used to make a fiberglass mold. The new rudder was laid up using this mold and a sheet of 1/4 inch aluminum alloy was cut to for the inner blade. FInally the rudder was faired, barrier coated and painted using interlux/international Micron CSC and brightside paint. Turns out to be a bit lighter than the original, and should be stronger. New pintles and bolts were order from Goran in Sweden

rudder.jpg (146.71 KiB) Visad 10897 gånger

[johan swe-1870]

That is well done!

You can now even offer to make new rudders in you area.