# Epoxy on the prop?



## newportermike (Nov 23, 2011)

Just bought a nice Pearson 303 and the surveyor has said there is a little corrosion on the prop. He has suggested that I may want to "Epoxy it". What is that? A two part solution? Do I just paint it on?


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## asdf38 (Jul 7, 2010)

In general he's talking about some form of epoxy two part coating. Similar to a paint but probably more robust. I don't know what product exactly he might be referring too but I think people here will be able to help. 

I wanted to note that the use of the word epoxy has also confused the crap out of me for a while. Prior to boating epoxy was a two part adhesive to me. But it's also a paint and a structural filler. I find it disappointing when the word is used by itself without specifying the type of product.

Even the great books like Don Casey say "fill it with epoxy" - well the 5 minute loctite epoxy at the hardware store? What are you talking about? I was aware that west marine sold west systems (not related) products by the (expensive) gallon but didn't know exactly what to make of it. Having learned a lot more and finally having bought some west 105 (general purpose resin) and 205 (hardener) I finally understand that yes, west epoxy is a sort of do it all solution for filling, bonding fairing etc.


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## jfitzgerald (Nov 15, 2007)

Never heard of anyone painting a prop to fix corrosion and not fammiliar with prop corrosion. For what it's worth, I'd fill the voids with J&b epoxy from Home Depot. Scotch tape to hold it from dripping out while curing and sand it smooth. If the $10 pack doesn't more than fill all the voids, I'd buy a new prop. Good sailing


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## sailingfool (Apr 17, 2000)

Use the Petit Zinc barnacle coat spray paint on your prop...its an offical SN endorsed product, well sort of.


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## hellosailor (Apr 11, 2006)

Epoxy the prop....OK, fire up the engine and then run the *tards hand through the prop.

One does not epoxy a prop and any idiot surveyor knows that. There are maybe two specialized prop coatings on the market that some folks say will protect them from corrosion but there's nothing epoxy will do except tear itself off in use. If there are holes to be filled, craters? The prop probably needs to be replaced due to unseen galvanic damage anyway.

Epoxy the prop...Pour the epoxy in his pants, forget his hands, they'd just damage your prop blades further.

Sadly now, you've got to question everything he has said.


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## CalebD (Jan 11, 2008)

I'm with HelloSailor on this topic. I've never heard of anyone using an epoxy product (JB Weld or whatever) for filling voids on a propeller. There is not much that is right about this suggestion. For one thing no epoxy will be equal in weight to the metal so the prop will be 'out of balance'. 
The thing to do is to take the prop to a reliable prop shop and have them 'spin' it and test it for balance. They can tell you if it is out of balance. They can also add new material to your old prop if that is all it needs which will cost a lot less then a new prop. Used props will cost less of course.


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## Lou452 (Mar 2, 2012)

As a welder that gets by working the trade I would look at the post you have seen draw a line down a paper take the vote epoxy yes on one side epoxy no on the other side. I want to go on the no side. If you find the right welder he can add filler metal to SS. Alum. Brass and other metal if he knows the grade and type of alloy. Heat can distort metal the pitch and balance could be effected. A good welder with the skill level you need will fetch $29 -$ 46 and hour the shop that he works for will charge at 2x that to cover cost of the operation. My bet two hours labor? The prop will need to have a grinder before and after the weld. Then you will need a machinest or tradesman that can tell if the prop is balanced and still in pitch. I have know idea what this might cost. When ever you weld a metal you change the grain structure of it. A host of problems can happen SS. can start to have corrosion problems if not treated properly after welding or by the wrong choice of filler metal application SS has many types and grades. The same is true for brass and Aluminum. So when you finish you have a used prop that has been fixed and will need to be inspected from time to time. I do not know what a new prop for this type of boat cost but I would not think of fixing if it is under $500 Jb weld is a good epoxy I use it ! It can be better than welding for many things and may be a good fix for a limited time on your prop but I can not help but think the spots that are pitted will not keep doing this under the epoxy letting it flake off IMHO LOU452 ( X ray quality)


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## Lou452 (Mar 2, 2012)

Question how bad is the prop ? Could it be taken to a shop and just polished and balanced? I stand with hello sailor's opinion of this surveyour. He has you focused on the prop. You may need to be looking at some other issue? Then maybe his mind was not engaged on the prop or it is in better shape than we are thinking


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## SloopJonB (Jun 6, 2011)

asdf38 said:


> In general he's talking about some form of epoxy two part coating. Similar to a paint but probably more robust. I don't know what product exactly he might be referring too but I think people here will be able to help.
> 
> I wanted to note that the use of the word epoxy has also confused the crap out of me for a while. Prior to boating epoxy was a two part adhesive to me. But it's also a paint and a structural filler. I find it disappointing when the word is used by itself without specifying the type of product.
> 
> Even the great books like Don Casey say "fill it with epoxy" - well the 5 minute loctite epoxy at the hardware store? What are you talking about? I was aware that west marine sold west systems (not related) products by the (expensive) gallon but didn't know exactly what to make of it. Having learned a lot more and finally having bought some west 105 (general purpose resin) and 205 (hardener) I finally understand that yes, west epoxy is a sort of do it all solution for filling, bonding fairing etc.


West is just a brand name that is heavily marketed and overpriced. Epoxy is epoxy is epoxy. It can be "tuned" by the selection of hardener for faster or slower curing and you can add damn near anything to it to make thickeners, fillers, fairing compounds etc. Those can also be "tuned" for specific purposes - strength, ease of sanding, waterproofing etc.

There's nothing magical about it, it's just a plastic resin, albeit probably the best and most versatile for boat uses. It's also pretty expensive. Find an industrial supplier and you'll save a bunch over retail type suppliers.


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## Minnewaska (Feb 21, 2010)

I'm surprised no one has suggested the possibility of de-zincification. If metal is flaking off and appearing like corrosion, it could throw a blade. Have a prop shop look at it. If so, get a new one.

A poorly balanced prop can damage your cutlass bearing and possibly the transmission, engine mounts, stuffing box, etc. It wouldn't be a $5 experiment.


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## SloopJonB (Jun 6, 2011)

:worthless:


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## asdf38 (Jul 7, 2010)

SloopJonB said:


> West is just a brand name that is heavily marketed and overpriced. Epoxy is epoxy is epoxy. It can be "tuned" by the selection of hardener for faster or slower curing and you can add damn near anything to it to make thickeners, fillers, fairing compounds etc. Those can also be "tuned" for specific purposes - strength, ease of sanding, waterproofing etc.
> 
> There's nothing magical about it, it's just a plastic resin, albeit probably the best and most versatile for boat uses. It's also pretty expensive. Find an industrial supplier and you'll save a bunch over retail type suppliers.


Are you kidding? This was my entire point. Epoxy is not Epoxy. When Don Casey or someone on this forum says to seal the deck core with epoxy they one type of epoxy. When they say they painted their deck with a two part epoxy they mean another and when they say they coated their iron keel with epoxy they are talking about another use. You can't interchangeably use the 5 minute epoxy at the drug store, or JB Weld, or a two-part epoxy deck paint. It's infinitely confusing and frustrating for someone new to watch someone else say "use epoxy". There are a vast number of different formulas, forms and concoctions of epoxy. Epoxy is not epoxy and when you're talking about it you should be somewhat specific.

If you know of a brand that produces forms of epoxy similar to West Systems at lower prices you should say what they are.


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## hellosailor (Apr 11, 2006)

Yeah, epoxy is all the same.
Wood is all the same.
Metal is all the same.
Canned food is all the same.

And as any zombie can tell you, brains is all the same. (Um,yum.)

West Systems is a premium name not because they are the only folks who can brew epoxy, but because they have an established track record for products that perform and endure, and a similar track record for customer service and technical support.

If I KNEW I could buy the exact same product at half the price, sure I'd vote with my wallet. But if you only want to do the job once and do it right, sometimes yes, you do pay for the reputation and assurance that the product will work. And with epoxy, that can mean "still working after 50 years". That's worth something.


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## SloopJonB (Jun 6, 2011)

asdf38 said:


> Are you kidding? This was my entire point. Epoxy is not Epoxy. When Don Casey or someone on this forum says to seal the deck core with epoxy they one type of epoxy. When they say they painted their deck with a two part epoxy they mean another and when they say they coated their iron keel with epoxy they are talking about another use. You can't interchangeably use the 5 minute epoxy at the drug store, or JB Weld, or a two-part epoxy deck paint. It's infinitely confusing and frustrating for someone new to watch someone else say "use epoxy". There are a vast number of different formulas, forms and concoctions of epoxy. Epoxy is not epoxy and when you're talking about it you should be somewhat specific.
> 
> If you know of a brand that produces forms of epoxy similar to West Systems at lower prices you should say what they are.


Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A, though the latter may be replaced by similar chemicals. The hardener consists of polyamine monomers, for example triethylenetetramine (TETA). West and others like MAS, System 3 and generic bulk epoxy are all just subtle variations on the same base product - some mix their hardeners for a 1 to 1 ratio for simplicity, some make it a 5 to 1 ratio so they can sell you their calibrated pumps and so forth.

The rest is simply modifiers like talc, glass balloons etc. Things like "5 Minute", JB Weld etc are merely pre-made combinations for convenience with specialized, small jobs. You can do the same thing yourself with available additives - mixing in aluminium powder gives a close approximation of JB Weld for example.

Epoxy paint is a whole separate product line from resin. When someone says "epoxy the deck" they are usually referring to filling or laminating or other repairs, not to painting it with 2-part paint. Also, I frequently see 2-part polyurethane paint referred to as "epoxy" and one part paints called such things as "epoxy modified" - that is just marketing. Real epoxy is 2 component - always.

I think you see it as more complicated than it really is - learning about all the different fillers can take some research but using the basic resin is no more difficult than regular polyester resin. I suggest you read the WEST web site - they did a lot of the development work on what has become the standard uses of epoxy. There is a huge amount of info on how it is, and can be used. Way too much to provide here in the sort of detail you seem to be after.


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## SloopJonB (Jun 6, 2011)

hellosailor said:


> Yeah, epoxy is all the same.
> Wood is all the same.
> Metal is all the same.
> Canned food is all the same.
> ...


A little research and experience goes a long way. We used to have a local outfit - Industrial Formulators - that brewed epoxy that in many ways was better than West - Cold Cure was great for working near freezing temperatures, they had mixes for wet environments and so forth. They sold out to System Three who continue to produce those products.

Stone fabricators use large volumes of epoxy and I can tell you that they don't use West, they use industrial brands that are every bit as good. I have used more brands of epoxy than I can count and I have found many to be superior to West in many ways - West hardeners are far too fast IMO, even their "slow" hardeners kick very quickly for example.

I regard System Three to be about the best I have used overall.


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## Lou452 (Mar 2, 2012)

"Sadly now you've got to question everything he has said." is the only part of post quote not a joke. It is what I mean when I stand with hello sailor"s opinon. It is hard to joke an maybe no one should when its in print. I think most folks know hands will not be in props and ex-marines will not show up. It is good to have opinons. Pictures have been suggested. The cost of a new prop. The value of this boat and the rpm of the prop in use. How much will it be used and what type of use. Just to motor into the slip if the wind dies or to make a run out of a river channel with current and tide? What is the base metal of this prop? All of us could have better input if we can have more information


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## dabnis (Jul 29, 2007)

Minnewaska said:


> I'm surprised no one has suggested the possibility of de-zincification. If metal is flaking off and appearing like corrosion, it could throw a blade. Have a prop shop look at it. If so, get a new one.
> 
> A poorly balanced prop can damage your cutlass bearing and possibly the transmission, engine mounts, stuffing box, etc. It wouldn't be a $5 experiment.


Agree, maybe find out why it is being "corroded"? How bad is it? Pictures maybe?


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## Minnewaska (Feb 21, 2010)

Chris12345 said:


> Yeah, sure.
> It will throw a blade.
> There is a pound of metal missing, the vibrations will tear the boat apart.
> Without anyone noticing.
> ...


Do you know what de-zincification is?

Video: Marine Propeller Nightmares | BoatingLocal.com


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## bljones (Oct 13, 2008)

SloopJonB said:


> West hardeners are far too fast IMO, even their "slow" hardeners kick very quickly for example.


Interesting. usually I hear the opposite, that West takes forever to kick and cure.

I only use West for a few reasons. It works, it offers good coverage, the shelf life is decent, the batch consistency is great, and ALL of the chandleries and most of the lumber yards in my area stock it- so if I run out of anything, i can restock 7 days a week. This is important to me, because I don't know about you, but I never run out of hardenerat the end of a project, always in the middle.
And why is it that it's always hardener that comes up short?
Before I started using West, I ran the numbers on MAS, System 3, the loud mouth, EAST and West. When you compare coverage from a MIXED gallon, West is ahead of the pack, but the margin is slim. I'm buying it in gallons, and in volume the cost for most epoxies becomes pretty similar.

Oh, and those "overpriced' pumps are a whopping $15, and they have likely saved me $30 worth of wasted material, cleaning supplies, mixing cups and cursing and swearing.


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## bljones (Oct 13, 2008)

as to the topic at hand, I'm with the no 'poxy on da prop group. Epoxy is wonderful stuff but it doesn't fix everything.


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## Lou452 (Mar 2, 2012)

As a pipe welder let me take a stab at it for Chris First of all the metal alloy must have zink and have less than it started with. Easy to figure out just from the word. Now lets start looking at some real world seen it kind of thing. Brass has zink. Brass valves will get this in two ways one is a plug dezincifcation. just like it sounds a pulg hole eats out you get a weep hole in the valve this is bad worst case. Fix a small hole braze it up and soon out pops a new hole in a new place. Just a poor quailty day. Little can be done hope you can keep going untill you can shut down and make a repair replacing valve asap. Broad surface decay dezincafcation is even pitting over the entire area could be more in high flow turbulent areas. You might polish this out and get more use this is not as bad. Both can have micro cracks but plug type will be deeper. White surface oxide is a big clue this is going on. Some of the new brass alloys have less zink and will stand up much longer. a real enginer might talk about ph levels, ( salt) flow, stagnation, temp, other factors. adjust them and you can extend the life and use valve with broad surface uniform corosion. Lots of salt will lead to plug type more than the other factors! The Kicker here is I speak of a brass valve and opinion. A brass valve is not a prop on a boat and it dose not spin. Still I think I have put some good views in this thread. Butterflys causing tusnmia joke?


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## Lou452 (Mar 2, 2012)

Newporter mike: Nice boat sounds like you are blessed. Prop is small potatoes We will just use hot air to power up. I want to help you with that prop Minnwaska good link to that shop


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## SloopJonB (Jun 6, 2011)

bljones said:


> This is important to me, because I don't know about you, but I never run out of hardenerat the end of a project, always in the middle.
> And why is it that it's always hardener that comes up short?


Do you use graduated Dixie cups to apportion your resin & hardener? I do and I have found the graduations aren't adjusted to account for the taper in the cup. If I put the hardener in the bottom of the cup and then the resin I'll end up with excess hardener. If the hardener goes on top, I run out of it - there is that much difference in the volume top to bottom in those cups. It isn't enough to affect the cure but it does mean you have leftovers of one or the other component at the end of a kit.

Once I discovered this, I just reversed the layering from one batch to the next and I generally don't end up with any significant leftovers.


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## bljones (Oct 13, 2008)

I use pumps. Before I start slathering the project at hand, I grab the can of hardener and/or resin and give it a heft. It always FEELS like I will have enough, but then I go to mix the batch for the second coat, and *splut* *splutter* juuuusssttttt enough, definitely not enough for coat number 3. Off to the store while coat 2 kicks, and I'm back in action. With any other epoxy, I'm waiting at least 5 days for it to show up at the front door.


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## LakeSuperiorGeezer (Oct 8, 2010)

Tap the prop with a wrinch or small hammer. The prop should ring, if a dull thud, you need another prop. The problem is dezincafication

Do not use a fresh water prop in salt water
The problem with brass instead of bronze

http://www.michel-christen.com/2T-H.pdf
Through hull failures with brass


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## Lou452 (Mar 2, 2012)

LakeSuperiorgeezer, The link you have put in is very good also. Lots of good info on that sight. May I guess you are in the no epoxy club?


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## LakeSuperiorGeezer (Oct 8, 2010)

Lou452 said:


> LakeSuperiorgeezer, The link you have put in is very good also. Lots of good info on that sight. May I guess you are in the no epoxy club?


I don't know because not enough troubleshooting has been done on the prop. If there is dezincification, the epoxy, even though it is wonder product for may things, will not be up to fixing the prop. Also, what material is the prop made of because brass will have stress in any welds that are done and has to be heat-treated. Nickel aluminum bronze welds ok without stress relief. Come to think of it the nickel aluminum bronze has no zinc in it so dezincification is not possible and is my choice for a propeller. Is there any pink discoloration from dezincification?

By the way, do not use a slide hammer to remove the propeller or propeller shaft. You can destroy the transmission. There are pullers specifically designed for propeller removal that are rather inexpensive and do a good job of getting the prop off.


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## newportermike (Nov 23, 2011)

Thanks all. It is a max prop...so replacing it is very expensive. There are some corroded areas, they don't look too bad. Perhaps the Petit zinc barnacle paint is a good reccomendation. Or should I just run it for the season, see how it performs and think about getting a fixed prop next year?


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## newportermike (Nov 23, 2011)

I just use it when there is no wind!!! So it does not get a lot of use but I will be going on a three day cruise from Boston to Newport and need to know that it won't let me down.


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## Minnewaska (Feb 21, 2010)

The folks at PYI (MaxProp) are outstanding. Just pack it up and ship it to them and they will weld back whatever it needs. It takes a couple of weeks unless you tell them you're in a hurry. You definitely can't mess with the balance on a feathering prop.


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## hellosailor (Apr 11, 2006)

Minnewaska may have the best idea of all. If PYI takes care of their customers, they can certainly do what any good welding shop can do, and rebuild missing metal. Since there could be an issue per Lou452 of playing whack-a-mole if there are problems in the metal itself...again, PYI would be aware of that and who knows, they might just replace the blades as defective.

Certainly worth giving them a call & sending the prop in.


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## Lou452 (Mar 2, 2012)

newportermike, You need to have some way for all of us gauge how good or bad your prop is. Maybe it is in fair shape? A picture with something for size to compare with like a ball pint pen, a metal rule with a scale. You might find a tire tread gauge. Anyway you can help someone determine how good or bad your prop is. You might try to clean it up with a 4" ss wire brush on 4" grinder. Make sure you wear eye protection!! a face shield long sleeve shirt and leather work gloves. The brush will spin at about 7500 rpm. In 30 min.time one little wire may fly out of the brush they can poke into your skin not bad if you have long sleeves WITH OUT EYE PROTECTION IT IS BAD ! You can find a cheap 4 inch grinder with a 5/8 shaft under 30 dollars. It will work like a champ. You can buy better ones also if you feel you will use it more with the right blades and wheels you can brush, cut, grind metal, stone, concrete. With the brush it will not remove metal. It will help make your prop clean to paint or epoxy. Good luck hope it works out for you !


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## Lou452 (Mar 2, 2012)

Just read the two posting about PYI. I think I like the advice. I can weld any weldable alloy but even with my skill I recognize the men that do it day in and day out should be the best. I would send my prop to them. The balance issue could be the very big.


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## sailguy40 (Feb 6, 2010)

asdf38 said:


> In general he's talking about some form of epoxy two part coating. Similar to a paint but probably more robust. I don't know what product exactly he might be referring too but I think people here will be able to help.
> 
> I wanted to note that the use of the word epoxy has also confused the crap out of me for a while. Prior to boating epoxy was a two part adhesive to me. But it's also a paint and a structural filler. I find it disappointing when the word is used by itself without specifying the type of product.
> 
> Even the great books like Don Casey say "fill it with epoxy" - well the 5 minute loctite epoxy at the hardware store? What are you talking about? I was aware that west marine sold west systems (not related) products by the (expensive) gallon but didn't know exactly what to make of it. Having learned a lot more and finally having bought some west 105 (general purpose resin) and 205 (hardener) I finally understand that yes, west epoxy is a sort of do it all solution for filling, bonding fairing etc.


I certainly agree with this. They say use epoxy but no one ever clarifies which of the many to use for the job at hand.


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