Bent Rudder post

[Steph]

Does anyone know if a rudder post can, or should be straightened? My post has been bent as a result of hitting an uncharted submerged object or chain (in 14' water). Actually, we don't know yet if there was any internal damage between the post / fingers and the foam. Foss Foam advised me to replace it as the 304 Stainless steel's structural integrity can not be restored once straightened. Anyone else have experience with something like this? Thanks.

 

[Ross]

To some extent it depends upon the amount of deformation. The 300 series stainless steels have a tendency to work harden And they may be deformed in one direction without harm but may be work hardened in the process bending them straight may result in some cracking. It will be a judgment call depending upon the degree of the bend. I would err on the side of caution. A rudder is a terrible thing to lose.

 

[sailingdog]

I am a bit curious as to why Foss Foam would use 304 Stainless for the rudder post. 304 is not as corrosion resistant as 316, and is far more prone to crevice corrosion and chloride ion stress cracking in a saltwater situation.

 

[Ross]

I am a bit curious as to why Foss Foam would use 304 Stainless for the rudder post. 304 is not as corrosion resistant as 316, and is far more prone to crevice corrosion and chloride ion stress cracking in a saltwater situation.

That answer is pretty easy , 316L costs more than 304. probably 5 bucks for the steel in the rudder. They could use a heavier tubing with a greater wall thickness and not lose any market share or profit. But too many engineering departments are run by accounting in this day.

 

[Allan12210]

Unfortunately the short answer is because it is Cheap (relatively).

 

[Steph]

Yes, it's 304 SS

I double checked my email from Foss and they said it's 2" sch 40 SS Type 304 pipe with wall thickness of 0.154". Other than the bend (I guess where the post enters the hull (bushing), I haven't had any problems. Guess we'll see when they drop the rudder. If insurance is covering the damage, would you insist on a new one? Duh, I think I would...your thoughts? Thanks.

 

[Ross]

Re: Yes, it's 304 SS

I would go for a new replacement if everything else was approximately equal.

They could make the rudder post from schedule 80 pipe but then they would have to build the boat stronger so that the rudder would bend before it torn the bottom out of the boat.

 

[Hermit Scott]

I would make it solid aquamet 22, especially if insurance was paying for it. Maine Sail has the skinny on rudder post and material that is best. We went through this in a post not too long ago.

 

[tommays]

Living with SS everday and doing a whole LOT of repiars on really bent up stuff ?

When metal is bent part of it gets stretched and no matter how you make it straight it is stretched FOREVER

It is allmost alllways cheeper to start with TGP(Turned, Ground,Polished) shaft as SS PIPE generaly has a welded seam which makes it really had to make it into something straight unless you have it centerless ground

And the welded seam is a whole nother issue in saltwater

 

[sailingdog]

HS—

Depends on the diameter of the rudder stock... If it is a larger diameter, going with solid aquamet 22 is probably overkill and way too expensive.

 

[Ross]

In this case straight is a relative thing and thick wall pipe or tubing is no doubt the best choice of material. My rudder stock is solid 1 inch diameter bronze but it is supported on both ends. These spade rudders have to have large diameter stocks because they are just long levers.

 

[Warren Milberg]

Steph: I agree that you should drop your rudder and inspect the rudder post. If it is bent, I suggest replacing the rudder whether insurance pays or not (my sense is that they should). My previous boat was damaged by Hurricane Isabel and was totaled when the insurance surveyor found the rudder post slightly bent. You just don't ever want to be in the position of sailing on a blustery day and keep wondering if today is the day the rudder will fail....

 

[jdhohmann]

We had that happen on another boat before, we dropped the rudder and heated the post on the opposite side of the bend to a nice cherry red, laying clothes on the fiberglass to keep it cool... When the shaft cooled down the shaft returned to almost normal, but good enough to stop the rubbing on the hull.. ACtually our Hunter is just about to go through the same procedure in a week or so. I too hit bottom when bottom wasbn't suppose to be there according to the charts, just by Lubec, Maine!!!!

 

[RichH]

Ive successfully done this.

Boat was 1973 Pearson with a hollow 304SS rudder shaft. The rudder was bent to 30deg when the boat came loose from a mooring during a storm.

I heated the shaft at the bend and restored it back to nearly true.
I then added an internal 'sister' shaft for strength in case the reworked OEM shaft was weakened (or subsequently broke at a later time) by the rebending. I cut many holes into the bottom end of the sister shaft to accept poured filled/strengthened epoxy. I pours the epoxy mix into the bottom of the OEM shaft, inserted the sister shaft, poured more epoxy mix down the sister. I cut the top of the sister even with the top of the OEM shaft and then welded it to the OEM - seal welded just below the rim of the OEM.

This was done in ~1986 and to my knowledge the sister is still employed.

 

[Steph]

thanks everyone

thanks for all the advise. The boat is being inspected today by the insurance company surveyor and we'll see what he says...but I'm inclined to replace it. Thanks again.

 

[Hermit Scott]

Rudders seem to be the first thing to go if you get caught in heavy weather. Has anyone inserted a solid round into a pipe type rudder post to strengthen it? Not as ideal as solid but are there any issues that are negative about this?

 

[RichH]

Solids are inferior (lb./lb. & $/$) to 'tubular shapes' with respect to FLEXURE and BENDING .... see above post #14