Through holes and prop

[PK123]

Hello to all,
My first post here. I am in the process of buying an old boat and it was hauled out of the water yesterday. Ive attached a couple of photos below of the hull which is going to be pressure washed today for a better view and for the surveyor to look at.
There is a circular patch immediately behind the keel fin that Im curious about? Also the prop has been shattered in the past and Im wondering if something like that might have created an issue elsewhere such as the stuffing box, the prop shaft? Theres a little bit of salty water in the bilge and Id value any observations and thoughts on thru holes, this mid patch and the state of the prop. I hasten to add that the prop is being replaced with a two blade new prop.
Many thanks in advance!

.

 

[Parsons]

Getting a professional surveyor, or DIY?

Very impressive prop damage! Yes, striking something with the prop hard enough to tear the blades off could damage stuff, particularly the cutlass bearing which is in that strut right in front of the prop. It could have also bent the shaft severely aft of the cutlass bearing, but less likely as it is SS. The stuffing box is insulated from this by being between the cutlass bearing and the engine, and if traditional boxes are resilient. Since you are going to do the prop anyhow, it may be worthwhile to either take the shaft to a machine shop to have it checked on a lathe for bend, or even just replace it for a few hundred. Naturally, replace the cutlass bearing as they do wear out every thousand engine hours so it's probably in need of switching anyhow. As you inspect, violently shake the shaft and strut to see if they wiggle around, in case the blow damaged the bonding to the hull. Fixable, but you should know. Removing the shaft means re-alignment, and that is not a DIY job. Must be done with boat sitting and settled in the water, to relieve the stresses.

The circular area may be just a mold mark or a filled-over through-hull. I've not see a through-hull mounted exactly centerline before, but who knows. Examine the matching spot inside for the quality of that work. That should be right under the transmission or engine.

Salt water in the bilge means something below the waterline is leaking. Could just be a stuffing box drip (easily tightened) or a leaky through-hull or inlet hose. Identify every though-hull from the bottom, then find them inside. Touch and wiggle every through-hull / seacock. Cycle every seacock closed and open, a couple times. Make sure all hoses below waterline are double-clamped and still flexible.

 

[rgranger]

from the pic, your prop issue looks more like corrosion than from an impact. That can be addressed with proper zincs on the shaft and a new prop. The big circle "patch" is not something I have seen before but if I had to guess, I would suspect that there had been a grounding plate there at one time and the hole in the middle of the circle is where the grounding wire passed through the hull.

 

[capta]

Your prop hasn't shattered, it has corroded away. I would imagine every piece of bronze on the boat is in similar condition, which means all new through hulls. The damage to the engine could be extensive, as well.
The circle looks to be an old rudder hole, but I couldn't know for sure until I looked inside. I don't think I'd even waste the money on a surveyor, I'd just run, run, run away from that boat.

 

[dlochner]

The prop has been pinked. Which translates to all of zinc in the bronze has been leache out by galvanic corrosion. This is serious. The source of the corrosion needs to be located and repaired. It is likely that poor wiring has contributed and the wiring probably needs a major work. The other bronze through hulls probably need replacing too.

Don’t waste you money on a survey. Walk away now.

 

[fstbttms]

Id value any observations and thoughts on thru holes...

Thru-hulls, not "thru holes"

...and the state of the prop.

The prop is badly corroded and the loss of the blades is due to either an impact or them simply falling off. This is not a death sentence for the rest of your underwater metals as some here would have you believe (although close inspection of all of them is definitely in order) but is almost certainly the result of the prop and shaft going for a long period of time unprotected by anodes. It does however speak to neglected maintenance and should make one worry about what else wasn't properly maintained by the PO.

 

[Scott T-Bird]

That hole behind the keel looks purposeful, and I suspect it is for draining the bilge when hauled for winter. Many northern boats have it. But I am confused about the size of the plugged circle and I didn't see the tiny hole in the center until it was pointed out. I'd agree that nothing should be fatal to this deal without further explanation. If you need to replace a prop, shaft and cutlass bearing, that's no big deal if the price of the boat is right. Nothing else about the bottom would bother me. There's no apparent damage around the area where the shaft exits the hull. The hull actually looks very good. If it was me, I'm no walking away. I can't tell but it looks like only the prop is a (obvious ) problem!

The lines and joint at the keel look fine. There has to be an explanation for that symmetrically round patch. Find out what it is!

 

[Scott T-Bird]

from the pic, your prop issue looks more like corrosion than from an impact. That can be addressed with proper zincs on the shaft and a new prop. The big circle "patch" is not something I have seen before but if I had to guess, I would suspect that there had been a grounding plate there at one time and the hole in the middle of the circle is where the grounding wire passed through the hull.

Very possible, and perhaps an explanation for the condition of the prop. I think I would be using these issues as a reason to negotiate, as they don't appear to be a reason to walk away.

 

[rgranger]

The big circle "patch" is not something I have seen before but if I had to guess, I would suspect that there had been a grounding plate there at one time and the hole in the middle of the circle is where the grounding wire passed through the hull.

So I did a little digging on grounding plates and found this one...

It is the glowmex 2 1/4" grounding plate. It would explain the hole in the middle of the drepression.

 

[dlochner]

Given the position of the "depression" and its shape, it might have been a sail drive at some point. Knowing the model and make of the boat would be helpful as would the dimensions of the depressionn/hole.

A closer look at the strut, further suggests this boat has been repowered. strut bases are typically set in hull, this strut looks to have been bolted to the hull.

There is no evidence of an anode having been attached to the shaft or prop. The lack of an anode strongly suggests the owner didn't know what he was doing.

If the strut is bronze, its condition is also suspect. If it is SS, it may be OK.

Unless there was some remarkable feature that made the boat otherwise highly desirable and the price is deeply discounted, I stand by my original assessment, walk away.

 

[fstbttms]

Given the position of the "depression" and its shape, it might have been a sail drive at some point.

This seems exceedingly unlikely.

There is no evidence of an anode having been attached to the shaft or prop. The lack of an anode strongly suggests the owner didn't know what he was doing.

What it suggests is a lack of maintenance.

If the strut is bronze, its condition is also suspect. If it is SS, it may be OK.

The strut is electrically isolated from the shaft and prop. It is unlikely that whatever caused the prop corrosion also affected the strut.

 

[dlochner]

Unlikely perhaps, however the location is correct and the shape is more or less correct. You've seen a lot more boat bottoms than I have, do you have another viable explanation.

A lack of essential maintenance by an owner and an owner not knowing what he is doing is a distinction without a difference.

Maybe, depends if the strut is bonded to the rest of the underwater metals, it is connected. We don't know.

In the end, there are serious electrical/bonding issues and we don't know enough about the boat otherwise to offer any advice beyond, walk away or spend a lot of money on a survey on a boat with some red flags.

Walk away.

 

[fstbttms]

Unlikely perhaps, however the location is correct and the shape is more or less correct. You've seen a lot more boat bottoms than I have, do you have another viable explanation.

The general size of the depression doesn't seem big enough for a saildrive leg. Also, if you were to remove the saildrive leg, you would glass the hole over flush with the rest of the hull. Presuming that is what happened, why is there a buildup of paint around the patch? There wouldn't be. But let's say I'm wrong. How would you explain the small bolt hole (theoretically plugged)? A grounding plate would explain it.

A lack of essential maintenance by an owner and an owner not knowing what he is doing is a distinction without a difference.

You know what happens when you assume, right?. There are many scenarios by where a knowledgeable boat owner might not replace anodes. A very common one is that the PO became sick or passed away and the boat sat uncared for. That doesn't mean he "didn't know what he was doing."

Maybe, depends if the strut is bonded to the rest of the underwater metals, it is connected. We don't know.

I see no evidence of corrosion in the picture of the strut. It looks fine.

 

[dlochner]

The general size of the depression doesn't seem big enough for a saildrive leg. Also, if you were to remove the saildrive leg, you would glass the hole over flush with the rest of the hull. Presuming that is what happened, why is there a buildup of paint around the patch? There wouldn't be. But let's say I'm wrong. How would you explain the small bolt hole (theoretically plugged)? A grounding plate would explain it.



You know what happens when you assume, right?. There are many scenarios by where a knowledgeable boat owner might not replace anodes. A very common one is that the PO became sick or passed away and the boat sat uncared for. That doesn't mean he "didn't know what he was doing."



I see no evidence of corrosion in the picture of the strut. It looks fine.

The level of pinking in the prop is extreme, all three blades broke off. That in and of itself is a warning sign, something is seriously amiss.

Shaft anodes almost always leave a mark, which is a very clean area on the shaft. that is absent.

The usual distance between the forward end of the prop and the strut is ~1 shaft diameter. The gap on this boat is much more than 1 shaft diameter. I doubt any reputable manufacturer would leave this large a gap.

Whatever the reason, lack of knowledge, old age and infirmity, or carelessness, the absence of the anode and the condition of the prop are indicative of poor maintenance with serious and expensive consequences.

Have you ever seen a strut mounted as this one has been? The struts on the 2 boats I have owned are mounted in depression that is part of the hull mold and faired in so that the base is not visible. This strut appears to be mounted to a piece of something (G10?) which is bolted to the hull. It looks like it was added on.

The depression is in exactly the right place for a sail drive of some sort. The hole in the middle might be an attempt to install a drain plug for the bilge. To my eye, it looks like the hole for sail drive was just glassed over from the interior and not even faired in.

It would be interesting to see a photo of the shaft log from inside the boat. Is it sufficiently reinforced? How is the strut attached to the hull, a photo showing the inside of the hull would be helpful.

And the most important data point missing is the age, builder, and model of the boat. But I may have found some information.

There is a Mirage 27 for sale at Crescent Beach Marina, which matches the OP location and boat description. In the listing it is noted that the boat has been repowered. See link to listing below.

Were Mirage 27s ever built with sail drives? A search for images of Mirage 27s revealed a poor photo of one on the hard that appeared to have a sail drive. More telling is a post on SailNet.com (sorry Phil...)about a Mirage 27 which has a sail drive. See Link below.

Based on this additional information, I'm standing more firmly behind my initial assessment to walk away from this boat.

I'd much rather steer a new sailor away from the boat he thinks he wants than to encourage him to buy a boat full of problems, get discouraged and leave the sport.

Details : Crescent Beach Marina

crescentbeachmarina.com

Mirage 27 - Owners Manual.

I have inherited a Mirage 27 from my father. Enjoying the boat, but having difficulty finding any information/manuals other than for the sail drive. I'm looking to drop my rudder this winter and hoping someone here has a manual/repair book that will make this less of a trial and error repair...

www.sailnet.com

 

[fstbttms]

The usual distance between the forward end of the prop and the strut is ~1 shaft diameter. The gap on this boat is much more than 1 shaft diameter. I doubt any reputable manufacturer would leave this large a gap.

What? Bwahahaha! Puh-leez

And BTW

MIRAGE 27 (PERRY) - sailboatdata

Photo courtesy Adam Hunt.

sailboatdata.com

 

[dlochner]

What? Bwahahaha! Puh-leez

google it.

Measure the distance when you're cleaning bottoms. The distance between the prop hub and the cutlass bearing will be about the same as the shaft diameter.

 

[fstbttms]

google it.

Measure the distance when you're cleaning bottoms. The distance between the prop hub and the cutlass bearing will be about the same as the shaft diameter.

I've been cleaning boat bottoms for 28 years (many tens of thousands of service events) and I can tell you that this statement, "The gap on this boat is much more than 1 shaft diameter. I doubt any reputable manufacturer would leave this large a gap" is simply ridiculous.

 

[dlochner]

I've been cleaning boat bottoms for 28 years (many tens of thousands of service events) and I can tell you that this statement, "The gap on this boat is much more than 1 shaft diameter. I doubt any reputable manufacturer would leave this large a gap" is simply ridiculous.

Not sure what you are saying here. Are you saying the gap between the prop hub and the strut is not more than a shaft diameter? Because if you are, you and I are not looking at the same photo. If you are saying that reputable manufacturers install shafts that allow the prop hub to be a hub's length away from the strut, then you and I have a different definition of reputable.

The boat was repowered. It was originally a sail drive, now a shaft drive and it was poorly installed. That's the story. No one has come up with a more plausible explanation of why there is a depression in the hull, the strut is oddly installed, and the prop pinked. Tell me a better story, and I'll consider it.

 

[fstbttms]

Not sure what you are saying here. Are you saying the gap between the prop hub and the strut is not more than a shaft diameter?

I'm saying that 1 shaft diameter (or less) is not standard in either the sailboat or powerboat sectors. There is no standard and many, MANY manufacturers build with more than 1 diameter between hub and strut. I see it every single day. And your assertion that boat was repowered is simply an assumption. Seems unlikely that somebody would go that effort and expense for a 27-foot production sailboat. Such a modification would almost certainly cost much more than the boat was worth.

 

[FastOlson]

Count to ten, then everyone take a deep breath. Count to ten, again. There really is not enough information available on which to base strong opinions.
I wonder if there is an on line-listing for the boat in question, and this might help us all form better long distance assessments. Maybe. Perhaps.