Adding a skeg
- Thread starter Hawgwash
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Not an overly complicated job and something I really like to have to protect my prop. Just don't do it like this guy .....
Somewhere in my files I have close up of the cavitation (caused by proximity of prop & shoe) eating his propeller.
PS what you call a skeg, I call a shoe.
Somewhere in my files I have close up of the cavitation (caused by proximity of prop & shoe) eating his propeller.
PS what you call a skeg, I call a shoe.
Attachments
Last edited:
Nomad Willy
Guru
Yes a shoe.
But to put a shoe on this boat an extended keel must be built on and a new rudder made to be able to carry a vertical load of a considerable portion of the weight of the boat.
Probably the most dificult part will be to get the stern bearing very firmly attached in exactly the right place and aligned perfectly w the existing propeller shaft. Not a small job at all.
What do you expect to gain from the added keel and shoe?
But to put a shoe on this boat an extended keel must be built on and a new rudder made to be able to carry a vertical load of a considerable portion of the weight of the boat.
Probably the most dificult part will be to get the stern bearing very firmly attached in exactly the right place and aligned perfectly w the existing propeller shaft. Not a small job at all.
What do you expect to gain from the added keel and shoe?
RT Firefly
Enigma
Greetings,
Mr. mb. "...new rudder made to be able to carry a vertical load of a considerable portion of the weight of the boat." I don't think so unless when one chocks the boat, a support is placed under the new skeg/shoe portion or one hits something in which case the OP is probably screwed anyway. Otherwise, the rudder is still just hanging there, albeit with a post going into the end of the new skeg.
Mr. mb. "...new rudder made to be able to carry a vertical load of a considerable portion of the weight of the boat." I don't think so unless when one chocks the boat, a support is placed under the new skeg/shoe portion or one hits something in which case the OP is probably screwed anyway. Otherwise, the rudder is still just hanging there, albeit with a post going into the end of the new skeg.
Thanks bp & mb.
Eric, I like it for the reasons bp said, protection.
Plenty of junk the size of a man's arm around here to spoil a good cruise.
Skeg vs shoe; I'll defer to the two of you although it is odd, I cannot find "shoe" but "skeg" as I used it, is frequently defined as such.
Eric, I like it for the reasons bp said, protection.
Plenty of junk the size of a man's arm around here to spoil a good cruise.
Skeg vs shoe; I'll defer to the two of you although it is odd, I cannot find "shoe" but "skeg" as I used it, is frequently defined as such.
Last edited:
Depends on the boat. My boat is a pig to turn in tight quarters and I will be adding fish tails to the rudder at next haulout. Some times a horizontal wing on the rudder helps steering too ..... it depends. You need to consult with someone experienced in this area.
Last edited:
Nomad Willy
Guru
RTF,
IT's all about prop protection. Well that would involve contacting the bottom and frequently that results in the boat being stuck .. as in won't move. Could be mud and could be rock. But when the tide goes out the boat w all it's weight will settle on the bottom. And there's a good chance the bottom of the rudder will come to rest on the bottom where there is not a depression. It's not unlikely that 50% of the boat weight will come to rest on the rudder.
My rudder is 3/8ths" thick and solid bronze. The shoe is also but way over 3/8".
Went to the computer to post this picture. That shoe is cast bronze.
IT's all about prop protection. Well that would involve contacting the bottom and frequently that results in the boat being stuck .. as in won't move. Could be mud and could be rock. But when the tide goes out the boat w all it's weight will settle on the bottom. And there's a good chance the bottom of the rudder will come to rest on the bottom where there is not a depression. It's not unlikely that 50% of the boat weight will come to rest on the rudder.
My rudder is 3/8ths" thick and solid bronze. The shoe is also but way over 3/8".
Went to the computer to post this picture. That shoe is cast bronze.
Attachments
Last edited:
kulas44
Guru
IIRC, Gerr's book goes into detail about this.
Brooksie
Guru
- Joined
- Oct 20, 2007
- Messages
- 1,310
- Location
- USA
- Vessel Name
- Island Seeker
- Vessel Make
- Willard 36 Sedan
I think it would be well worth adding a skeg bar under the propeller. It should be quite easy IF you have access to the inside of the keel to run your bolts up through. You will need a new. full depth rudder. 1-1/4 stock should be plenty and yes make it full height. You want the propeller to clear the bar by 10%D. I made my bar of stainless, drilled the aft end for a piece of cutlass to form the gudgeon. and the forward end for 3 5/8" bolts which go up through the keel. Grind a taper at the front of the bar.
The major question is, based on the length of your bar, is the bottom of your keel strong enough to take the force or do you need to reinforce it and can you reinforce it.
The major question is, based on the length of your bar, is the bottom of your keel strong enough to take the force or do you need to reinforce it and can you reinforce it.
Last edited:
markpierce
Master and Commander
- Joined
- Sep 25, 2010
- Messages
- 12,557
- Location
- USA
- Vessel Name
- Carquinez Coot
- Vessel Make
- penultimate Seahorse Marine Coot hull #6
One of several "must haves."
IMO - Everything takes engineering!
It's said to be fact that somewhere near a billion neutrons fire in the brain with each step taken while running. Now, I call that Engineering!!
You and Mark have opposite rotation. What is your power? Be interesting to know how many different single motor, transmission combos and prop rotations there are. Follow me?
markpierce
Master and Commander
- Joined
- Sep 25, 2010
- Messages
- 12,557
- Location
- USA
- Vessel Name
- Carquinez Coot
- Vessel Make
- penultimate Seahorse Marine Coot hull #6
The Coot has a "left-handed" propeller (goes counter clockwise in forward gear), which means the prop-walk is to starboard. Works great with a starboard helm position. Right-handed prop is just the opposite. The 80-hp JD engine provides plenty of power for the boat's heavy-displacement hull/weight combination while not expecting a speed faster than 7.3 knots.
FF
Guru
- Joined
- Oct 12, 2007
- Messages
- 22,552
Why not consider a basket to keep junk out of the prop?
Have one made where the commercial fish guys do and bolt it on.
KISS
Have one made where the commercial fish guys do and bolt it on.
KISS
Refugio has a Volvo TMD100A (225hp), Twin Disc MG509 (with trolling valve), 3" shaft, and 40x23 RH prop. FWIW my bronze shoe extends all the way forward to above the waterline.
I know it's too much power but what can I say, I'm an acceleration junkie.
I know it's too much power but what can I say, I'm an acceleration junkie.
caltexflanc
Guru
IMO and experience, a deep keel ahead of the props takes care of 80% of the needed protection. A skeg is very nice, no doubt about it , but the cost to properly retrofit one (as noted in a few posts above) is not insignificant.
Nomad Willy
Guru
Two things.
1. Re caltex's post above he may get what he wants just by adding to the keel.
2. Me thinks Hawgwash should just go buy a trawler.
1. Re caltex's post above he may get what he wants just by adding to the keel.
2. Me thinks Hawgwash should just go buy a trawler.
If you only saw that underbody picture of the Monk 36, I don't think anyone would think its from a "trawler". That all around lack of protection would concern me in the PNW. I'd still take it cruising if that's what I had, but I would always be a bit on edge and ready with anchor and diving gear. Maybe an outboard on an OMC transom lift? Probably better to retrofit some underbody protection like he's considering.
Keith
My thoughts as well but when I think about it, how many twins have any protection other than some tunnels?
Eric...I will, I will.
When the stars are aligned and I can get my entire right foot in my left ear hole.
A broker on the weekend said two years for most buyers to "go buy a trawler." I'm only half way there.
Nomad Willy
Guru
Hawgwash,
Then half the fun's ahead!
I've always enjoyed looking to buy. But I'm of a personality type that likes things undecided.
Then half the fun's ahead!
I've always enjoyed looking to buy. But I'm of a personality type that likes things undecided.
Britannia
Wannabe
ARoss
Guru
- Joined
- Nov 17, 2007
- Messages
- 637
- Vessel Name
- My Yuki
- Vessel Make
- 1973 Marine Trader 34
Another solution to adding a skeg
The early Marine Trader 34's did not have a skeg under the rudder post.
First photo (not my boat) shows the original configuration. A PO of my boat extended the keel (glass) and added a channel/bar extension under the prop back to the post. It obviously doesn't provide as much protection, but can reduce the risk of fouling on a line or such. Note the bolts securing the skeg are thru-bolted, vs vertically into the keel.
The early Marine Trader 34's did not have a skeg under the rudder post.
First photo (not my boat) shows the original configuration. A PO of my boat extended the keel (glass) and added a channel/bar extension under the prop back to the post. It obviously doesn't provide as much protection, but can reduce the risk of fouling on a line or such. Note the bolts securing the skeg are thru-bolted, vs vertically into the keel.
Attachments
stubones99
Guru
IMO - Everything takes engineering!
It's said to be fact that somewhere near a billion neutrons fire in the brain with each step taken while running. Now, I call that Engineering!!
Neurons? or are you a nuclear man?
RT Firefly
Enigma
I think it's pronounces new-kler.
stubones99
Guru
Similar threads
