Topic: Rudder holding post repair (Read 5984 times)

BlueWotsit · « **on:** April 28, 2019, 05:26:58 pm »

Hi

The bottom rear lip of the hull on my Morecambe Bay Prawner which holds the lower part of the rudder rod in place sheared off as can be seen in the photos.

Wondering what the best way of repairing this might be, I cannot remove the rudder to do the repair as it will be impossible due to the design to fit it back in afterwards.

Being quite a large wooden rudder constructed around the brass rod, its important I guess that the repair is really solid. As can be seen the piece is intact, its really best way of reaffixing it without gumming up the rod

Thanks in hope
Andrew

tonyH · « **Reply #1 on:** April 28, 2019, 05:50:34 pm »

Hi Andrew,
Is it a rod within a tube or a tube within a tube?

tonyH · « **Reply #2 on:** April 28, 2019, 07:13:44 pm »

Think I've sussed it

I assume that its all one shaft end and that it's the pintle, hiding in the blue bit so a new bit of tube, solder onto a strip of brass sheet and sandwich the thin bit of the hull between, rather like a made-up rudder. You can fair it in if you want to by cutting channels out of the sides of the keel for the strap to sit in and then filling as needed.A bit like the straps on this.

BlueWotsit · « **Reply #3 on:** April 28, 2019, 08:01:09 pm »

Hi - had to find my magnifying glass as eyes not so good these days !!

Rod within a tube but when I move the rudder both move together

What I think it must be knowing the chap that made the boat many years gone by, he would have made the wooden rudder from two pieces and bonded the outer tube between them when sealing together, then the other rod would have been dropped in - the key problem I have is there is no access from above deck as its all planked above the rudder from the stern for about 3.5 inches.

So I am restricted to sorting somehow from below

cheers guys

BlueWotsit · « **Reply #4 on:** April 28, 2019, 08:07:26 pm »

This is the rudder showing when the boat is on the stand

The bit that is broken away is probably about an inch long

tonyH · « **Reply #5 on:** April 28, 2019, 08:58:10 pm »

Do the rod and the tube move easily as one when you move the tiller? I.e. As one piece? Because it looks as if the builder has just drilled a hole in the end of the keel as the bottom bearing so all you've got to do is make another bottom bearing out of a short piece of brass tube and, effectively, sellotape it to the end of the keel using a brass strap or similar.

Tony

derekwarner · « **Reply #6 on:** April 28, 2019, 11:14:29 pm »

It would appear that the lower pintle bush a short length of K&S telescopic brass tube over the actual rudder pintal

The K&S tube has corroded onto the pintle creating the fracture out from the wood

As Tony suggests, it is a poor design but not the end of the world.....the replacement could be near identical, however leaving the very bottom end open ....this was, once per season the boat could be inverted & a few drops of WD 40 or the like sprayed into the cavity hole

That way it will be all OK for the next sailing season

Derek

BlueWotsit · « **Reply #7 on:** April 29, 2019, 08:45:33 am »

Thank guys I think I see where you are coming from

Basically put into place a piece of brass tubing similar size to the outer one, over the bit of rod that protrudes as in the photos

Yes the existing rod and tube moves freely as one

For the fix suggested looking at photos A2 and A4 this seems to only be a tiny piece of tube needed.

Then strap it into place in the location as shown in photo A2 and A4

Couple of questions regarding the strapping in

- would it be easier to epoxy in the bit of wood that had previously snapped off just levering out what seems to be the bit of corroded metal (pic A5) so the new tube fits snugly then strap it - or just leave it open as Derek suggests

- what is the best way of connecting the brass strip to the hull

Thanks everyone

BlueWotsit · « **Reply #8 on:** April 29, 2019, 09:04:15 am »

Just a thought - how important is it to fit another piece of tube.

Could I not use fibreglass type filler in the area broken away, just ensuring that the existing tube still moves, and then smooth it to shape just strapping the small bit of tube currently showing

Martin (Admin) · « **Reply #9 on:** April 29, 2019, 11:05:26 am »

"...how important is it to fit another piece of tube"
Not critical but preferable / best solution.
( Doesn't have to be brass, any tube, even plastic, would make a better bearing than nothing! )

"... fibreglass type filler..."
An Epoxy is strongest fix.

"... what is the best way of connecting the brass strip to the hull"
Thin brass / tin strip, epoxied on. Couple of small nails / pins as well.

BlueWotsit · « **Reply #10 on:** April 29, 2019, 01:05:28 pm »

Thanks Martin for this ... and of course all others who responded

Will give this a go

regards
Andrew

BlueWotsit · « **Reply #11 on:** April 29, 2019, 01:32:27 pm »

Had a look in my spares box and not got any tubing which is sufficiently wide enough to fit over the lower protruded bit.

However I wondered if one of the attached image fittings cut to size would be ok

thanks

malcolmfrary · « **Reply #12 on:** April 29, 2019, 02:54:17 pm »

Quote from: Martin [Admin] on April 29, 2019, 11:05:26 am

"...how important is it to fit another piece of tube"
Not critical but preferable / best solution.
( Doesn't have to be brass, any tube, even plastic, would make a better bearing than nothing! )

"... fibreglass type filler..."
An Epoxy is strongest fix.

"... what is the best way of connecting the brass strip to the hull"
Thin brass / tin strip, epoxied on. Couple of small nails / pins as well.

The big plus point of using plastic tube rather than brass is that plastic will not weld itself to the rod.
Its not as though it is a shaft doing thousands of RPM, so a plastic bush will be fine.

BlueWotsit · « **Reply #13 on:** April 29, 2019, 03:02:05 pm »

very good point Malcolm, I will see if I have any fish tank tubing left anywhere

BlueWotsit · « **Reply #14 on:** April 29, 2019, 04:09:53 pm »

This is where I am currently at

I used a bit of fish tank tubing, then reinforced the inside with a bit of brass tubing

On the diagram:

point A - is where the tubing has been pushed over the existing outer tube

point B to C - is the original inner rod now covered by the tubing

point D - is the tubing going over the reinforced new bit of brass tubing which is pushed as fas as the original inner rod location

Firstly do you guys think this will now work - the rudder moves ok

I am going to put a brass strap over the connection - whereabouts do you think the best location will be ? - should I fit 2 straps ?

- I was thinking of putting the strap under the wooden rudder before the tubing starts - then either putting a second strap over the new bit of tubing section or even drilling and nailing the new bit of brass tubing into the hull

Then finally I will epoxy / fill in around the new tube then I can shape it to finish. How far up should I fill do you recommend ?

thanks
Andrew

tonyH · « **Reply #15 on:** April 29, 2019, 04:30:00 pm »

The new tube needs to be able to slide onto the old outer brass tube since the old inner rod AND outer tube have effectively welded together and can be considered as 1 piece. If you use the flexible pipe as you have shown it will grip on the rudder shaft, twist in the new filler and break it again!
What you're aiming for is a bearing that allows the rudder to turn, not a fixture so only the new bit of brass, rigid plastic or whatever needs to connect to the hull. Brass is the easiest because you can pre-solder it to the strap, fix that securely and then use an epoxy filler to tidy it up.Tony

BlueWotsit · « **Reply #16 on:** April 29, 2019, 04:38:34 pm »

Hi Tony I see where you are coming from - what I seem to need then is an outer tubing to fit over everything - measuring it I seem to need something with a hole which is just about 8 to 9mm in diameter

Any recommendations as to a suitable mail order I could get this from

Many thanks

tonyH · « **Reply #17 on:** April 29, 2019, 06:07:59 pm »

Hi Andrew,
Take off the plastic tube then what's the diameter of the brass rod and tube combination? If you can clean off some of the grunge with a bit of wet and dry first it will help the accuracy. Once we know that I'm sure that one of us will have a couple of inches of something that will suit!
Tony

BlueWotsit · « **Reply #18 on:** April 29, 2019, 06:19:05 pm »

Hi Tony

Gunge duly cleaned

appx 7mm is the nearest I can measure the widest part of the rod combination as being

regards and thanks again
Andrew

malcolmfrary · « **Reply #19 on:** April 30, 2019, 08:44:35 am »

The old original brass tube bearing is only corroded on to the rod. A slitting disc on a Dremel will allow it to be peeled off, just leaving the original rod, which can be cleaned. Run that in the plastic bearing which can now be much more compact, should be no further problems.

tonyH · « **Reply #20 on:** April 30, 2019, 11:17:36 am »

Totally agreed Malcolm but has Andrew got a Dremel?

Subculture · « **Reply #21 on:** April 30, 2019, 12:32:57 pm »

Bit of copper sheet, bend it around the shaft- if you have a blowlamp heat it to cherry red and quench in water will make it super malleable. Leave a bit sticking out to glue into the keel and epoxy in place. Bulletproof.

BlueWotsit · « **Reply #22 on:** April 30, 2019, 03:50:48 pm »

I wouldnt trust my eyesight to try cutting out the exposed section of the brass tube, bearing in mind I also dont have much room to work in with being unable to withdraw the rudder from the hull totally.

tonyH · « **Reply #23 on:** April 30, 2019, 05:26:22 pm »

Bit of 7mm (ish) tube, bit of brass strip. If it suits, send me a PM
Tony

malcolmfrary · « **Reply #24 on:** April 30, 2019, 09:28:54 pm »

Quote from: BlueWotsit on April 30, 2019, 03:50:48 pm

I wouldnt trust my eyesight to try cutting out the exposed section of the brass tube, bearing in mind I also dont have much room to work in with being unable to withdraw the rudder from the hull totally.

I know the eyesight feeling. That's why I have a clip-on loupe to enhance the spectacles. A small power tool is pretty much a must for any modeller, a burr will quite gently put a slot the length of the unwanted tube to allow it to be opened out a fraction after which it should pretty much fall off. If it happens to leave a bit of roughness on the shaft, not a real problem, just a bit of surface that will hold lube better.

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Author Topic: Rudder holding post repair (Read 5984 times)