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SailNoFo 10-19-2017 10:23 PM

Large Blister on Oday 31 Rudder
 
2 Attachment(s)
Bought used 1985 Oday 31 Spring '17. Took boat out for season to discover large blister on rudder (see attached)Attachment 102985

Attachment 102993. There was no blister at time of boat survey in Spring. Any suggestions/references regarding repair options? Thanks.

boatpoker 10-20-2017 08:12 AM

Re: Large Blister on Oday 31 Rudder
 
No way that happened without some obvious indicators that would have been caught by any half decent surveyor. Wavy-ness on lower part of rudder suggests a patch job that should have been caught by your surveyor.

JimsCAL 10-20-2017 08:21 AM

Re: Large Blister on Oday 31 Rudder
 
Assuming this is not just a big bottom paint bubble, I would say you are looking at either rebuilding or replacing the rudder. Start by drilling a hole in the bottom of the rudder and see how much water comes out.

Repair would involve cutting the rudder apart, fixing any corroded internal structure, and putting it back together. A new rudder can be made by Foss Foam. Here's the link.
http://www.newrudders.com/standard-rudders/

eherlihy 10-20-2017 08:46 AM

Re: Large Blister on Oday 31 Rudder
 
From the comfort of my desk, that looks like a water bubble in the antifouling paint. In essence, the bottom paint was applied with inadequate preparation and water got behind it and formed a "bag."

You probably have water in the rudder of your boat. Every time that I have looked for water in the rudder post of an O'day 35 I have found it, including on my boat. I used to siphon the water out every year when the boat was hauled. Two years ago I poured a gallon of automotive antifreeze (concentrate, not the 50/50 stuff) in the rudder post. I made it through last year with no issues.

When the time comes, I'll probably just buy a new rudder from Foss Foam.

SailNoFo 10-21-2017 05:08 PM

Thanks for comments. Going to yard/boat tomorrow. Appears probable that the blister is mostly gas from foam rather than water. does that change anything with respect to treatment?

JimsCAL 10-21-2017 06:32 PM

Re: Large Blister on Oday 31 Rudder
 
As was noted by me and eherlihy, the first question is is this just a bubble in the paint, or is it in the laminate. The second thing to do is drill a hole in the bottom of the rudder to see how much water drains out. You can also tap all over the rudder to see if you have delamination. In delaminated areas you will get a dull hollow sound and may feel some give in the fiberglass skin. If you get a solid sound, then you still have a good bond between the foam and outer skin.

Until you do the above, there's not much we can do except guess wildly about what you are dealing with.

TQA 10-21-2017 10:27 PM

Re: Large Blister on Oday 31 Rudder
 
Drill hole in bottom of rudder - see how much water runs out. An egg cup or two is OK quarts are not.

Grind off blister [ start from top of vent it first.

Lock tiller or wheel and get someone to try to move the rudder [ really hard ]. while you see and feel for any evidence of internal failure.

SailNoFo 10-23-2017 05:48 PM

Re: Large Blister on Oday 31 Rudder
 
Again, thank you all for your comments. I went out to the yard this weekend to discover that the blisters have disappeared (which I gather translates to the blisters were in the paint* rather than the laminate). I will go out again in the next couple of weeks** to drill hole in the bottom of the rudder and measure amount of water that comes out. Is there a proper technique for drilling a hole in the rudder? I'm planning to use 1/4" drill at the lowest part of rudder going in from bottom (rather than side). I don't know the construction of the rudders but presumably I won't hit a water pipe/electrical line (or equivalent) doing that. (?)

The surveyor tapped around the rudder quite a bit during the survey. He told me about a dead spot but I gather he concluded it shouldn't be a deal breaker (or if he did, I wasn't listening).

* I would not have imagined that paint could hold that amount of water. Did this blister exist while the boat was in the water (or does it appear only when the boat is pulled)?
** I planned to drill the rudder when I was out this last weekend but putting the cover on (first time) took a little more time than I expected.

boatpoker 10-23-2017 06:00 PM

Re: Large Blister on Oday 31 Rudder
 
I have a hard time believing that blister is limited to the paint especially considering the unfair are below the blister.
Did you sound the rudder this time?. did you stick a knife in the blister?, Did you try to peel the paint ?

eherlihy 10-24-2017 08:00 AM

Re: Large Blister on Oday 31 Rudder
 
I will say this one last time; I recommend that you do not drill a hole in your rudder. Siphon the liquid out, and pour some antifreeze in.

boatpoker 10-24-2017 08:10 AM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051255777)
I will say this one last time; I recommend that you do not drill a hole in your rudder. Siphon the liquid out, and pour some antifreeze in.

That rudder is foam cored (or was when it left the factory) I think you'll find that filling it with ethylene glycol will dissolve the foam and destroy the rudder

eherlihy 10-24-2017 08:23 AM

Re: Large Blister on Oday 31 Rudder
 
1 Attachment(s)
Quote:

Originally Posted by boatpoker (Post 2051255801)
That rudder is foam cored (or was when it left the factory) I think you'll find that filling it with ethylene glycol will dissolve the foam and destroy the rudder

Then my rudder should have been destroyed by now. Ethylene Glycol has had no discernable effect on the foam in the rudder of my O'day, other than keeping the water from freezing and the rudder from delaminating, after two years.

[EDIT] adding a picture
https://www.sailnet.com/forums/attach...1&d=1508848280

boatpoker 10-24-2017 08:30 AM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051255825)
Then my rudder should have been destroyed by now. Ethylene Glycol has had no discernable effect on the foam in the rudder of my O'day, other than keeping the water from freezing and the rudder from delaminating, after two years.

Don't know how you are getting away with it. No production builder I know of uses epoxy foam which would be resistant to the EG, it's pretty simple chemistry.

Was your rudder rebuilt using epoxy foam ?

eherlihy 10-24-2017 09:23 AM

Re: Large Blister on Oday 31 Rudder
 
Perhaps you could elaborate on the simple chemistry involved... My knowledge is limited to what I have researched at the Foss Foam website, and my experience.

Quoting from the Foss Foam website; Rudder Care | NewRudders.com

Quote:

Tough fiberglass and urethane plastic used in the construction is nearly indestructible. The urethane core is composed of a strong closed cell urethane. Water, gasoline/diesel, solvents or marine borers will not damage your rudder blade, even if the fiberglass coating has been damaged.
Further; Ethylene Glycol - Boiling, Water, Car, and Carbon - JRank Articles
Quote:

In industries, ethylene glycol is used as a solvent (a substance that dissolves other chemicals) and as starting material for the production of Dacron and some types of polyurethane foam.

boatpoker 10-24-2017 09:31 AM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051255913)
Perhaps you could elaborate on the simple chemistry involved... My knowledge is limited to what I have researched at the Foss Foam website, and my experience.

Quoting from the Foss Foam website; Rudder Care | NewRudders.com



Further; Ethylene Glycol - Boiling, Water, Car, and Carbon - JRank Articles

Your first reference is kind of curious in that it says solvents will not harm the "rudder blade". It make no reference to the foam.

Your second reference clearly states that ethylene glycol is a solvent !

Suggest you try another search "polyurethane foam dissolve ethylene glycol"

eherlihy 10-24-2017 10:01 AM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by boatpoker (Post 2051255921)
Your first reference is kind of curious in that it says solvents will not harm the "rudder blade". It make no reference to the foam.

Your second reference clearly states that ethylene glycol is a solvent !

Suggest you try another search "polyurethane foam dissolve ethylene glycol"

I had hoped that with your background as a marine surveyor that you could reply by educating us on the "simple chemistry" - rather than directing us to conduct a fruitless google search. For the benefit of others; here is that search, and I'll save other readers the trouble; it provides nothing that supports @boatpoker 's assertion;

Boatpoker, you need to read ALL the words that I cited from Foss Foam. Here, I'll help make it more obvious for you: "The urethane core is composed of a strong closed cell urethane. Water, gasoline/diesel, solvents or marine borers will not damage [the urethane core of] your rudder blade, even if the fiberglass coating has been damaged." So, Foss is claiming that solvents will not damage the urethane core. Clear enough?

Regarding my second reference, I concede that EG is a solvent (some of us recall from high school that water is frequently called the "universal solvent"), but again reading ALL THE WORDS, it states that EG is "a starting material in the production of urethane foam."

TQA 10-24-2017 10:23 AM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051255777)
I will say this one last time; I recommend that you do not drill a hole in your rudder. Siphon the liquid out, and pour some antifreeze in.

How do you get the siphon tube to the bottom of the rudder?

eherlihy 10-24-2017 10:35 AM

Re: Large Blister on Oday 31 Rudder
 
I have about 10-feet of 3/8" OD clear vinyl tube from the local big box store (about $3). I am not 100% sure of the length, but you could simply measure from the cockpit to the bottom of the rudder, multiply that by 2, and then add the length necessary to go from the rudder post to the cockpit coaming. Add a couple of more feet if unsure.

I feed/drop the tube all the way to the bottom of the rudder post, and over the coaming, and toward the ground. While standing on the ground I apply a vacuum to the end (I have also used the faucet to push water through the hose, and into the rudder) to get the siphon started. Then I wash out my mouth with clear water (not necessary if I used the faucet).

http://www.clipartreview.com/_images...289-118009.jpg

In the past, I have drained over a gallon.

I did not bother to siphon the rudder post out this year (I may still change my mind), as I noticed that the rudder was full of antifreeze.

boatpoker 10-24-2017 10:50 AM

Re: Large Blister on Oday 31 Rudder
 
Guess what they use to clean up Polyurethane guns .......
Produced by:
Professional and Specialized Services
in consultation with the Construction
Health and Safety Program,
Ministry of Labour
Alert #C11/0196
ISSN 1195-5228


HAZARD SUMMARY

BACKGROUND:

Polyurethane foam is being used more and more as an insulation
material in residential construction. Recent experience
indicates that some contractors may not be providing workers who
handle it with adequate respiratory protection or training in
proper work and hygiene practices.

Polyurethane foam is usually prepared on site in a closed system.
The following materials are mixed in a 1:1 ratio:

- base resin, comprising polyols, amines (often tertiary
amines) to act as catalyst and plasticizers; and

- isocyanate (both monomeric and polymeric), usually
methylene bisphenyl isocyanate (MDI).

Normally, two workers are involved in spraying the foam: a
sprayer and a helper who cuts off excess foam and cleans it up.

To clean the spray gun, the workers use an organic solvent such
as glycol ether (ethylene glycol monoethyl ether).

eherlihy 10-24-2017 11:45 AM

Re: Large Blister on Oday 31 Rudder
 
I am still waiting on @boatpoker 's "simple chemistry" explanation... (Do you know? or are you just "googling" to defend a position that you have taken.)

I am open to the fact that it may be inappropriate to recommend pouring EG into a rudder post. I am not a chemist. It is becoming clear that boatpoker is not a chemist either. I suspect that someone reading this thread may be, and hope that they will help settle this. To really answer the question, we would need to know exactly what kind of "urethane foam" (there are several) is used by Foss Foam as core in their rudders, and we would also need to qualify the type of Ethelyene Glycol (there are several of these too) in the antifreeze that I used.

However, these are FACTS:
  • Foss Foam states that their foam is not subject to damage from solvents.
  • I understand that Glycol is used as an ingredient to some urethane foams.
  • In the two years that my rudder has been exposed to it, I have not seen any indication of damage from the Ethelyene Glycol based antifreeze that was poured into my rudder post of my '87 O'day.

I do not recommend drilling a hole in one's rudder to let water out. [this is REALLY the last time I will say this, as I am unsubscribing from this thread] In fact, I advise against doing so because I believe that will assure water intrusion into the rudder, and lead to further delamination. Funny, but if I recall correctly, my surveyor suggested that I drill a hole in my rudder - eight years ago. I ignored him.

Getting back on topic, it seems that I was correct in my suspicion that the "bubble" was, in fact, in the antifouling paint. That said, I suspect that the rudder was improperly prepared for painting.

The next time that I need to clean a Polyurethane Foam Spray Insulation gun, I will heed bp's advice and use glycol ether.

JimsCAL 10-24-2017 12:15 PM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by SailNoFo (Post 2051255089)
Again, thank you all for your comments. I went out to the yard this weekend to discover that the blisters have disappeared (which I gather translates to the blisters were in the paint* rather than the laminate). I will go out again in the next couple of weeks** to drill hole in the bottom of the rudder and measure amount of water that comes out. Is there a proper technique for drilling a hole in the rudder? I'm planning to use 1/4" drill at the lowest part of rudder going in from bottom (rather than side). I don't know the construction of the rudders but presumably I won't hit a water pipe/electrical line (or equivalent) doing that. (?)

So this sounds like it was just a big paint bubble. I would plan on stripping the paint off the rudder and apply new paint properly before launching in the spring.

I am one that sees no problem with drilling a hole in the bottom of the rudder to see how much water is inside. I've done it. Just need to inject epoxy (use the West Products syringes) and you seal the hole. And no, you won't hit any water or electrical lines.

boatpoker 10-24-2017 12:54 PM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051256065)
I am still waiting on @boatpoker 's "simple chemistry" explanation... (Do you know? or are you just "googling" to defend a position that you have taken.)

I am open to the fact that it may be inappropriate to recommend pouring EG into a rudder post. I am not a chemist. It is becoming clear that boatpoker is not a chemist either. I suspect that someone reading this thread may be, and hope that they will help settle this. To really answer the question, we would need to know exactly what kind of "urethane foam" (there are several) is used by Foss Foam as core in their rudders, and we would also need to qualify the type of Ethelyene Glycol (there are several of these too) in the antifreeze that I used.

However, these are FACTS:
  • Foss Foam states that their foam is not subject to damage from solvents.
  • I understand that Glycol is used as an ingredient to some urethane foams.
  • In the two years that my rudder has been exposed to it, I have not seen any indication of damage from the Ethelyene Glycol based antifreeze that was poured into my rudder post of my '87 O'day.

I do not recommend drilling a hole in one's rudder to let water out. [this is REALLY the last time I will say this, as I am unsubscribing from this thread] In fact, I advise against doing so because I believe that will assure water intrusion into the rudder, and lead to further delamination. Funny, but if I recall correctly, my surveyor suggested that I drill a hole in my rudder - eight years ago. I ignored him.

Getting back on topic, it seems that I was correct in my suspicion that the "bubble" was, in fact, in the antifouling paint. That said, I suspect that the rudder was improperly prepared for painting.

The next time that I need to clean a Polyurethane Foam Spray Insulation gun, I will heed bp's advice and use glycol ether.

While I do not have a degree in chemistry, the first 20 years of my working life were spent in the polymer industry. The courses I took over those years and what I learned in the business would probaby qualify for a degree.

Sorry, it is so elementary I didn't think a further explanation was required. Bottom line .... like dissolves like
(Google that phrase :) ) .... ethylene in the foam - ethylene in the glycol.

While I cannot/will not speak for Foss Foam I did just have a chat with Bob Walker (president/owner). When I told him what you were doing his reaction was (I thought ) pretty funny. Suggest you call him and ask him directly.

TQA 10-24-2017 08:42 PM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051256001)
I have about 10-feet of 3/8" OD clear vinyl tube from the local big box store (about $3). I am not 100% sure of the length, but you could simply measure from the cockpit to the bottom of the rudder, multiply that by 2, and then add the length necessary to go from the rudder post to the cockpit coaming. Add a couple of more feet if unsure.

I feed/drop the tube all the way to the bottom of the rudder post, and over the coaming, and toward the ground. While standing on the ground I apply a vacuum to the end (I have also used the faucet to push water through the hose, and into the rudder) to get the siphon started. Then I wash out my mouth with clear water (not necessary if I used the faucet).

http://www.clipartreview.com/_images...289-118009.jpg

In the past, I have drained over a gallon.

I did not bother to siphon the rudder post out this year (I may still change my mind), as I noticed that the rudder was full of antifreeze.

That will work if the rudder is hollow. Rudders are almost never hollow, they are full of foam.

As I said you have to drill a hole in the bottom [ use a battery drill] and see how much comes out. a cup is OK more than a quart and you need to have a look inside.

A little Marine tax will fill the hole.

eherlihy 10-25-2017 03:53 PM

Re: Large Blister on Oday 31 Rudder
 
So I heard back from Bob Walker;
Quote:

I would not recommend pouring antifreeze down the rudder shaft. I believe that over time it will melt the foam. I would love to dissect your old rudder.... We have been filling the shafts with foam since around 2000.
While he is not unequivocally stating that it will dissolve the core of the rudder in my '87 O'day, he is curious enough about the effect that he would like to dissect the rudder. This is not an endorsement of antifreeze. I will, therefore, remove it. I would love for Bob to perform his dissection for free... but I'm guessing that won't be happening.

By the way @boatpoker , I looked at your website and was surprised to find at least one unattributed picture that I took of my boat with the following prequel; "the resolution of some of these photos is not very good as I cut and paste them from my survey reports"
The picture in question is this one: http://www.pcmarinesurveys.com/PHOTO...osion/keel.gif

The image above is hosted from your website and will change to an error when you have removed it.

This is not your picture, you did not take it (and I hope that you have not used it in your surveys) but you are presenting it as your own and using it to generate business. This is not the first time that I have pointed this out to you, although I wasn't aware it was on your website at that time. Please remove it from your website.

Editing to add that I will remove the above when the picture goes away.

boatpoker 10-25-2017 05:16 PM

Re: Large Blister on Oday 31 Rudder
 
Quote:

Originally Posted by eherlihy (Post 2051258217)
So I heard back from Bob Walker;

While he is not unequivocally stating that it will dissolve the core of the rudder in my '87 O'day, he is curious enough about the effect that he would like to dissect the rudder. This is not an endorsement of antifreeze. I will, therefore, remove it. I would love for Bob to perform his dissection for free... but I'm guessing that won't be happening.

By the way @boatpoker , I looked at your website and was surprised to find at least one unattributed picture that I took of my boat with the following prequel; "the resolution of some of these photos is not very good as I cut and paste them from my survey reports"
The picture in question is this one: http://www.pcmarinesurveys.com/PHOTO...osion/keel.gif
This is not your picture, you did not take it (and I hope that you have not used it in your surveys) but you are presenting it as your own and using it to generate business. This is not the first time that I have pointed this out to you, although I wasn't aware it was on your website at that time. Please remove it from your website.

Editing to add that I will remove the above when the picture goes away.

Thank you for pointing that out. There are over 3,000 photos on my website, it gets a little hard to track sometimes. You found 1 of 2 that were not attributed. I have corrected the issue.


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