Making a moul/template for stainless steel rudder repair

[benlui]

I was horrified the other day when I dried out the boat on the pier wall to see that the bottom of the rudder where it is connect to the skeg had broken away. At least this explains why I was loosing up to 2kts under sail, as the rudder was bending off to the side with the pressure. However I am going to make the repair myself and my question is as follows:
I need to make a "template/moul" of the part that will need to be made up in stainless steel, so that I can hand it to a stainless maker. I will obviously dry out the boat for this, but what is the best "stuff" to make this with? I was thinking a kind of a putty like stiff, but has anyone any ideas? It would need to be fast drying.
I’m thinking a template/moul will be the best way to not screw up measurements and angles.
If i could only manage to put pics up on this post i would, but a degree in computers is needed to do so!

 

[Adamastor]

Look at polyester fairing paste. Sands nicely and can set in something less than 10 min. Are you making a shoe bracket for your rudder tip? If so, you need to make a plate template out of something like rigid cardboard or the likes, because your fabricator will likely also be using plate to build.

 

[lw395]

Hard to visualise what you need. Suggest talking to fabricator to establish exactly what he needs to work from.
It may need a pretty robust mock up of the skeg shape etc, as the forces in fitting a stout bit of springy stainless to it can be large.
Make sure the pivot axis is right, it obviously needs to run through the other rudder hangings but this may not be obvious off the boat.
Might be best to start discussing the design with a lot of photos etc.

 

[Cliveshep]

Post some pics, see here for how to do it:
http://homepage.ntlworld.com/topcatsail/Photo_tutor/Photo_Tutor.html ............the excellent YBW photo-tutor

 

[oldsaltoz]

Are you planning to repair the skeg, the rudder or both?

 

[benlui]

HERE ARE THE PICS OF THE REPAIR IN WHICH I NEED.
Thanks for the simple instructions Clive, lets hope it works.

http://i690.photobucket.com/albums/vv262/vdonnelly/R2S.jpg
http://i690.photobucket.com/albums/vv262/vdonnelly/R1S.jpg

(Pic of repair on aanother boat) http://i690.photobucket.com/albums/vv262/vdonnelly/R3S.jpg

 

[benlui]

I am planning to attach a stainless steel bracket from the skeg to the rudder but filing out some of the fibreglass to bed in the SS bracket, and bold through into the skeg. I don’t plan to fibreglass over the bracket again, as I like to be able to inspect the bolt fittings each season, and this allows easy access to them.
Where would you get polyester fairing paste? This appears to be what I need for the job. The bracket will be a shoe like bracket as shown in the pic with the blue hull boat.

 

[Eygthene]

I'm not familiar with the structure of the skeg on your boat, but often the GRP is only a few millimetres thick, with a core of timber or polyurethane foam. Hopefully as there was a fixing for the lower pintle at this point, the core should be quite strong locally.

I would consider wrapping the new stainless steel part around the outside with a good leg length (fore/aft) on either side and bolting through, rather than cutting into the GRP for a flush fitting. The extra drag will be insignificant and it will be stronger than filing away some of the GRP. The forces on rudder hangings can be very high and you don't want to weaken the skeg in such a critical area.

 

[cliff]

[ QUOTE ]
HERE ARE THE PICS OF THE REPAIR IN WHICH I NEED.
Thanks for the simple instructions Clive, lets hope it works.

(Pic of repair on another boat)

[/ QUOTE ]That's better - now we don't have to follow links and can see the pics directly.

Looks like a piece of stainless steel strap, NOT plate, bent into a "U" shape - not exactly a precision fit - should be easy to form a replacement yourself. Looks like it is only there to restrict fore/aft/side-to-side movement and does not actually support the rudder's weight.
---------------------

Artificial Intelligence is no match for Natural Stupidity.

 

[benlui]

Thanks for putting the pics up like that, double dutch to me. Yes, that repair does not provide vertical support. This is provided at the top where the rudder is hung. This repair, is also very rough indeed, and I will have to be a bit more tasty than this in my repair.