Splitting a rudder

[Malish]

I did a search of the forum but couldn't quite find the answer I was looking for so:

A surveyor has provided me with a report which states that the glass fibre rudder of my Rival 32 shows significant delamination (sorry I have no pictures). He recommends splitting the rudder open, checking the condition of the tangs then working outwards making the rudder good on the way (drying out, drilling holes injecting epoxy etc). There is currently no play in the rudder but I quite like the idea of checking the tangs simply for peace of mind given that the rest of the work has to be done (and I only want to do it once!).
The question I have is how best to split open the rudder? I assumed that one would simply split along the original join but I have seen images where instead a large panel has been cut out of the side to facilitate inspection and work, and then presumably glassed back in afterwards. Views from those with experience would be much appreciated.

 

[ghostlymoron]

Best way is with a fine circular saw Dremel or other. Run it round the seam, the rudder should then split apart and can be epoxied back together. This is still major surgery though.

 

[johnlilley]

Speaking from personal experience only, I repaired a couple of Rival rudders by cutting a large panel from the face opposite the bonded tang face. Remove all the failed foam and inspect the tangs (stainless in both cases & sound) Glass the face back with epoxy resin & glass cloth. Seal the entry point of the stock. Interestingly enough if you go to my web site & click on SITE INDEX on the home page the picture in the middle with the rudder cut open is a Rival rudder if I remember I think I have included some photos of the tang welds and rudder close up on the SHIPWRIGHT page

Regards


John

 

[Quandary]

I rebuilt the rudder for a friends Westerly after it got broken up in a grounding. I think you will find splitting it difficult, particularly at the trailing edge where there will be a lot of solid laminate. Without seeing your rudder I suspect it will be easier to take apart and make good if you go in from one side, A bit of micro surgery may be enough to check the tangs etc. (You can normally see where they are in winter by looking for a condensation pattern, do you know anyone with a cold room?)
You can always make a bigger opening if you need it. I used polyurethane foam, West epoxy and powder bound mat plus some rovings. ( A recent poster says polyurethane is unsuitable but it is probably what is in there, it certainly needs to be closed cell) Use the good side to make fairing templates and then finish with an easy fairing mix of epoxy with glass bubbles.

 

[oldsaltoz]

Splitting a rudder at it's outer perimeter is indeed the hard way, and depending on what manufacturer made the thing, you could wasting a lot of time and materials.

You only need to cut around the perimeter if doing a complete rebuild and perhaps replacing/relocating the tangs.

'Some' rudders are built from one side only, this means the tangs are fixed to the outer skin on side only, so when you split the rudder only the free side will come away, and only then by breaking any foam used in construction.

Cutting a panel in one side will give you the same access and a lot less work and materials needed to repair the thing.

However, you must select the free side or be faced with breaking the joint between tangs and outer shell.

To establish if your rudder has this type of construction you only need to tap the outer casing on both sides and listen, one side will give a more solid sound on the fixed side, though this may be restricted to just a few (perhaps 4) areas, so tap both sides at the same location to confirm.

Once you locate the solid spots, make your cut out outside them, then cut around each of the solid spots and the panel should all but lift out with.

Stainless steel welds on the stock and on the tang frame can and do rust, mostly because the area was not properly pickled after welding.

When repairing rudders I use epoxy resins and cloth designed for epoxy, no CSM.

The cut outs around the original fixing points can be reused by cutting them off close to the skin and leaving the area behind them clean and clear, when you the panel back in place and you can the tangs through the holes, fill them with resin mixed with micro fibres and push your cut sections over this till at the required level and let it cure, then you can sand and fair with micro balloons, just ensure the balloons are the closed cell type.

If you are wondering why I cut the fixed side and not the free side, it's because it ensures a proper fixing on re assembly, coming in from the free side means you have to dig out the fixed side to inspect and possibly repair it. This way we know it's secured.

Hope this helps.

PS. if you find water damage as a result of water entry via the stock to rudder interface at the top of the rudder let me know and I will detail the '0' ring method of fixing this.

 

[Malish]

Folks
Thanks for the prompt responses and the links to some images, most informative.
Oldsaltoz - I have already found your O-ring method but am a bit confused by your response above - early on you say that you should cut into the free side or be faced with breaking the tangs joint and yet at the end you talk about cutting the fixed side - can you clarify?

 

[Poignard]

.... if you go to my web site ....

Very interesting and informative website, if I may so so.

 

[Dipper]

I repaired my rudder after the weld on the tangs failed by cutting an access panel in the side. You can see photos of the repair procedure I used here. The photo below shows the repair just before replacement of the panel. I opted for the panel approach because it maintained the shape of the rudder and also due to the design of my rudder, splitting would have been very difficult.

There are surprising few images of rudder repairs on the internet and most of the pictures I found were of aircraft rudders.

 

[Keith 66]

I just did this job on my Sabre 27 rudder, i split it on the original join, using a 4 1/2" diamond cutter, Could have cut a panel in it but the tangs had failed completely.
Marcon were in the habit of welding mild steel tangs to an awful lot of their rudders & Sabres arent the only ones to have failures, good way to check is run a strong magnet over the rudder blade.

 

[oldsaltoz]

Folks
Thanks for the prompt responses and the links to some images, most informative.
Oldsaltoz - I have already found your O-ring method but am a bit confused by your response above - early on you say that you should cut into the free side or be faced with breaking the tangs joint and yet at the end you talk about cutting the fixed side - can you clarify?

By cutting the fixed side then cutting the fixed points to release the cover you expose the fixings, this is the side that fails, If you cut the free side you have to dig out the fixed side to see if the fixing points are ok.

 

[oldsaltoz]

By cutting the fixed side then cutting the fixed points to release the cover you expose the fixings, this is the side that fails, If you cut the free side you have to dig out the fixed side to see if the fixing points are ok.

This refers to the internal rudder tangs that support the aft end of the rudder that is welded to the rudder shaft.
Hope this helps.

 

[TQA]

West System have an article on repairing a rudder.

http://epoxyworks.com/index.php/rebuilding-a-rudder/

 

[bluerm166]

There are a number of 'surgical' rudder repair videos on you tube which may give some pointers including this :

https://youtu.be/MRXNnFx7DBQ

 

[mel82]

Splitting a rudder at it's outer perimeter is indeed the hard way, and depending on what manufacturer made the thing, you could wasting a lot of time and materials.

You only need to cut around the perimeter if doing a complete rebuild and perhaps replacing/relocating the tangs.

'Some' rudders are built from one side only, this means the tangs are fixed to the outer skin on side only, so when you split the rudder only the free side will come away, and only then by breaking any foam used in construction.

Cutting a panel in one side will give you the same access and a lot less work and materials needed to repair the thing.

However, you must select the free side or be faced with breaking the joint between tangs and outer shell.

To establish if your rudder has this type of construction you only need to tap the outer casing on both sides and listen, one side will give a more solid sound on the fixed side, though this may be restricted to just a few (perhaps 4) areas, so tap both sides at the same location to confirm.

Once you locate the solid spots, make your cut out outside them, then cut around each of the solid spots and the panel should all but lift out with.

Stainless steel welds on the stock and on the tang frame can and do rust, mostly because the area was not properly pickled after welding.

When repairing rudders I use epoxy resins and cloth designed for epoxy, no CSM.

The cut outs around the original fixing points can be reused by cutting them off close to the skin and leaving the area behind them clean and clear, when you the panel back in place and you can the tangs through the holes, fill them with resin mixed with micro fibres and push your cut sections over this till at the required level and let it cure, then you can sand and fair with micro balloons, just ensure the balloons are the closed cell type.

If you are wondering why I cut the fixed side and not the free side, it's because it ensures a proper fixing on re assembly, coming in from the free side means you have to dig out the fixed side to inspect and possibly repair it. This way we know it's secured.

Hope this helps.

PS. if you find water damage as a result of water entry via the stock to rudder interface at the top of the rudder let me know and I will detail the '0' ring method of fixing this.

Hey

Splitting a rudder at it's outer perimeter is indeed the hard way, and depending on what manufacturer made the thing, you could wasting a lot of time and materials.

You only need to cut around the perimeter if doing a complete rebuild and perhaps replacing/relocating the tangs.

'Some' rudders are built from one side only, this means the tangs are fixed to the outer skin on side only, so when you split the rudder only the free side will come away, and only then by breaking any foam used in construction.

Cutting a panel in one side will give you the same access and a lot less work and materials needed to repair the thing.

However, you must select the free side or be faced with breaking the joint between tangs and outer shell.

To establish if your rudder has this type of construction you only need to tap the outer casing on both sides and listen, one side will give a more solid sound on the fixed side, though this may be restricted to just a few (perhaps 4) areas, so tap both sides at the same location to confirm.

Once you locate the solid spots, make your cut out outside them, then cut around each of the solid spots and the panel should all but lift out with.

Stainless steel welds on the stock and on the tang frame can and do rust, mostly because the area was not properly pickled after welding.

When repairing rudders I use epoxy resins and cloth designed for epoxy, no CSM.

The cut outs around the original fixing points can be reused by cutting them off close to the skin and leaving the area behind them clean and clear, when you the panel back in place and you can the tangs through the holes, fill them with resin mixed with micro fibres and push your cut sections over this till at the required level and let it cure, then you can sand and fair with micro balloons, just ensure the balloons are the closed cell type.

If you are wondering why I cut the fixed side and not the free side, it's because it ensures a proper fixing on re assembly, coming in from the free side means you have to dig out the fixed side to inspect and possibly repair it. This way we know it's secured.

Hope this helps.

PS. if you find water damage as a result of water entry via the stock to rudder interface at the top of the rudder let me know and I will detail the '0' ring method of fixing this.

Hey oldsaltoz! Would you mind posting the o ring repair tips? I would very much appreciate that, I am stuck with my repair, corrosion at stock to rudder spot... thanks, Mel

 

[Catalina36]

You can find the location of the tangs by running a moisture meter over the rudder, they make it go off the scale.