# barnacles on prop, shaft



## pegasus1457 (Apr 14, 2002)

I neglected to protect the prop shaft with antifouling paint and now that the boat is on the hard, I see it is covered with barnacle skeletons.

I have knocked off as much as I can, but would like some advice on the best way to rid the shaft of what is left.

On/Off? Is it safe to use on bronze? How badly does it attack the cutlass bearing if I get a few drops in it?

Sandpaper? 

thanks,
pegasus


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## JimsCAL (May 23, 2007)

Scrape them off. Don't use ON&OFF as its a strong acid.


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## Vasco (Sep 24, 2006)

Scrape and then buff with a wire wheel or one of those 3M wheels.


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## tager (Nov 21, 2008)

Be careful. You don't want to have to get your prop balanced.


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## jjablonowski (Aug 13, 2007)

*Why NOT to paint your prop with bottom paint*

Our friend Maine Sail says it better than I can:
Why Not To Paint Your Prop (with copper based paint) - SailboatOwners.com


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## TaylorC (May 15, 2008)

I never see painted shafts, so I don't think you forgot to do anything. You should also have zinc collars on your shaft. Yeah - I get barnacles on my shaft also, I knock the big parts off with something hard like a scraper, and finish with scotch bright or a wire brush. They come off easier if you get them when they are wet, and don't let them dry out.

I've used Petttit Prop-Koat on my propeller with some success, but its very expensive and application is a two step process (primer and clear coat finish). I might be tempted to try it on my shaft _*but*_ I would be careful to avoid coating where the zincs were going, you want a good electrical contact between the zinc and the shaft.


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## GaryHLucas (Mar 24, 2008)

I must be missing something here. My aluminum rudder shaft was badly damaged by copper bottom paint. I know it because the only place eaten away is right at the bottom paint line, nothing above or below. However I fail to see how copper bottom paint could damage a copper alloy! I'd have to believe it was electrolytic action from stray currents, and no zincs.

Gary H. Lucas


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## KeelHaulin (Mar 7, 2006)

May I ask why it makes a difference to not paint your prop; while most people paint their thru-hull, stanchion and skeg? These items had 30 years of paint on them on my boat; and none had the de-zincification that was shown in the pictures of the props over on that thread.

I don't discount the possibility that the paint causes galvanic corrosion; but I am wondering why it would be different for a prop than a thru-hull.


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## T37Chef (Oct 9, 2006)

After you get it clean, try protecting it with Zinc spray by Pettit. I have used it for years with much success.

See here: http://www.pettitpaint.com/fileshare/product_pds/1179320.pdf


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## pegasus1457 (Apr 14, 2002)

TaylorC said:


> I never see painted shafts, so I don't think you forgot to do anything. You should also have zinc collars on your shaft.
> 
> I've used Petttit Prop-Koat on my propeller with some success, but its very expensive and application is a two step process (primer and clear coat finish). I might be tempted to try it on my shaft _*but*_ I would be careful to avoid coating where the zincs were going, you want a good electrical contact between the zinc and the shaft.


I am not that ignorant  I have zincs on my shaft and I wouldn't dream of putting anything between them and the shaft.

Someone in my boatyard said that he had sprayed his shaft with a product from WM [I do not recall the name] and it kept the marine growth off his shaft and prop. I will have to ask him what he used.

"Expensive" is a polite way of characterizing the Pettit-Koat. But I guess for $175 you get 10 yrs use out of a quart.


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## mitiempo (Sep 19, 2008)

Gary
Props are made with alloys that sometimes include zinc. When copper painted the zinc will dissolve. See this link to an explanation by Maine Sail.
Why Not To Paint Your Prop (with copper based paint) - SailboatOwners.com
Brian


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## KeelHaulin (Mar 7, 2006)

The zinc will dissolve IF it is not protected by another piece of pure zinc. This will happen regardless of if there is copper paint on it or not. If this is true; then again I ask why the same chemical reaction does not take place on non-grounded fittings like thru-hulls and skeg shoes?


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## christyleigh (Dec 17, 2001)

T37Chef said:


> After you get it clean, try protecting it with Zinc spray by Pettit. I have used it for years with much success.
> See here: http://www.pettitpaint.com/fileshare/product_pds/1179320.pdf


Well.... that makes me feel a little better. I tried that stuff for the first time this year and at a fall haul the prop and shaft had hundreds of barnacles. But..... in the N.E. it was a good year for barnacles with the wet June we had and I didn't get out that much. It's all I had so since it was just a short haul I cleaned and re-painted with the same..... we'll see next haul.
And.... another... But..... a couple guys who keep their boat in the same area saw my mess and boasted about the much better protection they got from the 2 part (actually 3 with primer) EP2000 at $67 a quart.
So much of it seems to be where and when.... I'm a bit deeper into the small cove and the few things I've read about barnacles makes me think it's more of a crap shoot than I would like to beleive


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## pegasus1457 (Apr 14, 2002)

*more info on spray-on barnacle prevention for prop shafts*

The product that I was told about is Pettit's Zinc Coat Barnacle Barrier.

Product description from one retailer's web site:

*Pettit Zinc Coat Barnacle Barrier 1792* is specifically designed to be used on bare metals such as steel, stainless steel, cast iron, copper, bronze, galvanized steel and lead, both above or below the waterline. Zinc Coat forms an excellent adhesive bond to underwater metals and running gear and inhibits corrosion on these surfaces. Properly applied, Pettit Zinc Coat Barnacle Barrier yields a smooth, hard surface that self-cleans under way.

Price for a 16-oz spray can is about $22.

Edit: I just saw the previous post reporting negative results for this product. But the guy in my boatyard had a clean shaft at haul out and mine is a mess, and we were both in the same harbor all season.


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## T37Chef (Oct 9, 2006)

Seems these things are subject to a lot of variables...I can only say that for me, the Pettit Zinc Coat Barnacle Barrier Spray works well. That means I found that it reduced the amount of barnacles to an acceptable amount (two dozen or less).


We use the boat often except August and dead of winter.
Kept on the Chesapeake Bay in brackish water in a shallow creek where summer water temps reach 80+


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## mitiempo (Sep 19, 2008)

KeelHaulin
"Why the same chemical reaction does not take place on non-grounded fittings like thru-hulls and skeg shoes?"
I think specifically because they are not grounded (and I don't believe they should be). By not being grounded they are not a connected part of the "electrical mix" underwater, and at least as far as thru-hulls are usually a fair ways from the prop and shaft physically as well.
I received an interesting link in an email that is from a company selling a prop for the Atomic 4 that besides better performance promises to almost eliminate prop fouling (I have no association). Scroll down to "No More Barnacles!"
Boat Seem Underpowered?
Makes for interesting reading.
Brian


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## OasisII (Dec 25, 2007)

*cleaning the prop and shaft*

I am not sure that anyone fully addressed the cleaning of your prop. I have had great success with fine emery(sp?) cloth (waterproof sandpaper) and straight vinegar.

Put the vinegar in a spray bottle. Spray the vinegar on and lightly sand. It takes some time, but the prop and shaft look like new.

Mike


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## T37Chef (Oct 9, 2006)

Good tip OasisII, I have done the same with great results, and yes, it does take some time, but worth it.


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## ChuckA (Dec 28, 2008)

I just had a 33 year old Pearson surveyed. The prop was painted and barnacle covered. The surveyor advised me that a prop should produce an audible "ring" when tapped lightly with a piece of metal. lack of a ring indicates dezincification which can result from copper paint on Bronze. His advice was not to paint the prop, but to polish it to a bright shine, which slows down growth. Here is a photo (from before I got religion) showing the prop on my former inboard powerboat, after refurbishing by Ocean Props in Middletown, RI. 









Note: I since learned that the nuts are on backwards in this picture. The thin nut is supposed to go against the prop with the thicker nut on the end of the shaft. It ran like that for a couple of seasons after which I reversed them. Don't think it made any real difference.


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## BELLATRIX1965 (Jan 2, 2007)

*Prop Anti-fouling / Prop Shaft Nuts*

ChuckA - you had the prop shaft nuts on CORRECTLY in your photo - the thick nut should be next to the prop - its numerous threads take up the axial load of "pushing" the prop onto the shaft taper - the thin nut is only a jam locking device to keep the whole mess from un-screwing (just in case anybody else looks at this thread!).

As far as prop anti-fouling goes, I watched a fellow sailor having his boat pulled after a long (early May to 25 October) season here in Buck's Harbor, Maine - not a barnacle on it! His secret - stove black! You know, the stuff that comes in a tube that you buff onto the surface of your wood stove to make it - well - black! I wouldn't have believed it if I didn't see it myself! Anybody else ever try that?? It will be on my prop next Spring for sure!


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## sailingdog (Mar 19, 2006)

I'd point out that vinegar or acetic acid will remove the barnacle bits...without damaging the metal. 

Polishing the surfaces makes it more difficult for the underwater growth to adhere...but coating it with something like vaseline or such will help prevent growth as well...


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## Bene505 (Jul 31, 2008)

sailingdog said:


> I'd point out that vinegar or acetic acid will remove the barnacle bits...without damaging the metal.
> 
> Polishing the surfaces makes it more difficult for the underwater growth to adhere...but coating it with something like vaseline or such will help prevent growth as well...


Coating your shaft with vaseline -- never hard of that.

I heard something about covering your prop with a sharpie's indellible ink. Didn't try it though.

Anyone want to get 3 products and use a different one on each prop blade? tehn we would really have a very controlled study to see what works.

Regards,
Brad


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## T37Chef (Oct 9, 2006)

The vaseline works, for a while. I use it on my speedo wheel


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## mgmhead (Jan 14, 2007)

The Petit spray has been the best I've found. In the Chesapeake from 
April till November and only cleaned once in August, in the water and scraped by hand. This was the second year I've used it and I found that several coats (3 or 4) gave better results than the two coats applied the previous year. Maybe 2009 was a milder year for barnicles in Rock Hall, but I don't think so. Anyhow, next spring I'll be applying six coats of Petit Zinc Spray.


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## pegasus1457 (Apr 14, 2002)

mgmhead said:


> Anyhow, next spring I'll be applying six coats of Petit Zinc Spray.


The Pettit instructions warn you not to apply more than 2 coats or risk wrinkling and peeling. Don't get carried away


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## ChuckA (Dec 28, 2008)

> ChuckA wrote> I since learned that the nuts are on backwards in this picture. The thin nut is supposed to go against the prop with the thicker nut on the end of the shaft. It ran like that for a couple of seasons after which I reversed them. Don't think it made any real difference.





> BELLATRIX1965 wrote > ChuckA - you had the prop shaft nuts on CORRECTLY in your photo - the thick nut should be next to the prop - its numerous threads take up the axial load of "pushing" the prop onto the shaft taper - the thin nut is only a jam locking device to keep the whole mess from un-screwing (just in case anybody else looks at this thread!).


That's what I used to think too, but I've been told otherwise by people with more knowledge and experience than me. The image below is from the installation instructions on the Michigan Wheel website it clearly shows the thin nut going on the shaft first, followed by the thicker nut. 









Here is a link to installation instructions on the Tacoma propeller website, a dealer of Michigan (and other) props. It specifically states:


> *Correct Nut Instaltation Procedure*: Install Jam Nut (thin) first than the Full nut (thick) goes on second.


my parting comment: on the cruisers & Sailing forum GreatKetch wrote>


> At least you didn't ask which nut goes on first the big one or the little one. That ALWAYS starts a fight.


I'm not sure why. I think it has to do with most of the load is taken up in the first 1.5 threads. The flexibility (thinness) of the nut affects the load distribution as well.

I'm a lover, not a fighter, so I'll let it drop at that.
Cheers,
Chuck


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## T37Chef (Oct 9, 2006)

Chuck...FYI, time for a new thread I think


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## saildog1 (Apr 19, 2007)

I also use the Petit Zinc spray and it works pretty good. Do a couple coats and the prop and shaft should stay clean. Don't spray the zincs.

LUNA
Tartan 3800 #3


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## GaryHLucas (Mar 24, 2008)

The prop nut debate is interesting. A couple months ago I got a copy of Professional BoatBuilder and they had an extensive article on it. It seems there is an ABYC standard on it, and the thin nut goes against the prop! The reason makes sense. When you tighten the outer nut it it unloads the threads on the inner nut. So you want the outer nut thicker to carry the load, and the inner nut locks it by friction.

Gary H. Lucas


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## chef2sail (Nov 27, 2007)

I am in the same creek as t37chef. Like him I use the petit spray and am amazed with the results. When swimming in the summer I put the snorkel on and do a few dives and use a green pad to take of any critters who want to nest..

Dave


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## T37Chef (Oct 9, 2006)

I will be curious how the Pettit Zinc Coat works this year, seems the barnacles are the worst ever!?


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## aa3jy (Jul 23, 2006)

T37Chef said:


> I will be curious how the Pettit Zinc Coat works this year, seems the barnacles are the worst ever!?


I hear nothing is working effectively... I'm using both Prop Speed and Pettit Zink Coat..fowling up on all surfaces that where prepped with both products..

I dive on my bottom weekly..


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## Seaduction (Oct 24, 2011)

T37Chef said:


> I will be curious how the Pettit Zinc Coat works this year, seems the barnacles are the worst ever!?


When I hauled out here in FL in March 2012 the yard personnel couldn't believe the condition of the prop after 21 months in the water. I coated it in Rock Hall, MD in April of 2010 with 3 or so coats of the Petit Zinc Coat. When hauled here last year it was nearly free of barnacles. The bottom paint was also very clean as well. Next haulout, I'll take a picture of the prop.


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## chef2sail (Nov 27, 2007)

I talked to our diver today. He said this year they are seeing a new smaller barnacle in the Chesapeake mid/ north areas. It has really been a crazy year for them evidently. We have slowed to 5.5 under power so he is diving on us next week,


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## Seaduction (Oct 24, 2011)

chef2sail said:


> I talked to our diver today. He said this year they are seeing a new smaller barnacle in the Chesapeake mid/ north areas. It has really been a crazy year for them evidently. We have slowed to 5.5 under power so he is diving on us next week,


Darn arthropods have probably developed an appetite for zinc!


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## 4arch (Jul 7, 2009)

I had a hard time getting decent speed under power this weekend. I already knew the bottom was getting fouled but now it seems to have hit the prop big time too. I used the Pettit spray back in April. With divers not allowed at my marina, I'll just be slow for another few weeks until getting hauled out just before our big trip in August.


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## 4arch (Jul 7, 2009)

Seaduction said:


> Darn arthropods have probably developed an appetite for zinc!


If that's the case, we're running out of alternatives! Everyone will have to go to dry sailing or lifts.


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## JSL3 (Jun 6, 2007)

I've also had luck in the past few years with Pettit Zinc Coat Barnacle Barrier - but not this year.
Had to dive the prop this past weekend and it was pretty well fouled.
Didn't take too long to scrape off the critters (must be a hardy bunch this season).
A few years ago, before using the Pettit Zinc Coat Barnacle Barrier I also tried the vaseline trick which worked fairly well.
Maybe both next year?


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## T37Chef (Oct 9, 2006)

Maybe both is right. Now I am going to have to dive and see whats up this weekend.


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## T37Chef (Oct 9, 2006)

or is it this one? LOL


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## JimsCAL (May 23, 2007)

After being away for 2 weeks, I spent an hour in the water cleaning the prop and bottom yesterday. Bottom only had some slime (I used Pettit Horizons) but prop and shaft had lots of small barnacles (used Pettit Zinc Coat). Pretty much the same as in previous years here in Western Long Island Sound.


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## eherlihy (Jan 2, 2007)

Two years ago (2011) I had the bottom of my O'day 35 soda-blasted, barrier coated, and had three coats of Pettit Horizons applied (initial coat of red, and two of blue). So far, the paint has held up VERY well, and still seems to be doing it's job. I dove on the boat this week, and brushed off heavy slime, but no barnacles.

The prop and shaft, were a different story. I had applied two coats of Pettit Transducer paint (mentioned earlier in this thread) in the spring. The prop and shaft were completely covered with little barnacles. They scraped off easily with a putty knife, but the little buggers seem to have adapted to the zinc based paint.

This was instigated after I noticed diesel smell, and black exhaust (soot) while motoring, and that she would only reach 2100 RPM at WOT. After the brushing and scraping, the motor would run at 2800 RPM at WOT, and speed (motoring) increased from 4.9 to 6.0 KTS.

She's not perfectly clean, but she is a good deal cleaner than she was.


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## blutoyz (Oct 28, 2012)

-1 for the Pettit spray

I had to scrape my prop after 1.5 months in the water, it was covered with barnacles


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## chucklesR (Sep 17, 2007)

After almost 3 years in the water (mid chesapeake) my boat was covered in barnacles and the recent infestation of slime going around on the bay.
I had a diver clean the bottom last week - he said the paid did it's job as the barnacles were not firmly attached (they came off with a light, long stroke of the blade - you could hear him 'whoosh, whosh' scraping away). That's WM's CPP, two coats by the way.

The Max prop and shaft on the other hand were coated. The max prop's blades still rotated, but otherwise they were more paddles than blades. My best speed was 5.0 knts. 
I'm looking forward to streaking across the bay this weekend.


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## T37Chef (Oct 9, 2006)

chucklesR said:


> I'm looking forward to streaking across the bay this weekend.


There's something I don't need to see uke


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## chucklesR (Sep 17, 2007)

T37Chef said:


> There's something I don't need to see uke


Jealously is so ugly.

At least you'll be looking at my stern


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## JonEisberg (Dec 3, 2010)

I've been using Propspeed for the last several years, works better than anything else I've ever tried...

However, perhaps this has already been mentioned before or elsewhere, but by far the best solution I've ever found to inhibit growth on running gear of a boat that is sitting, is enclosing it all in a heavy duty black plastic garbage bag, or something similar...

Not convenient for most, I realize, but whenever I know my boat will be sitting for awhile, I put a bag on it... This growth needs some light to flourish, and simply blocking out the light really does seem to do the trick to a significant extent, in my experience...

It's easy to rig the bag with a tagline at the bottom, so that it can be removed without going back in the water... Of course, it goes without saying that if you make this your routine, you definitely want a foolproof 'reminder' tagged to your ignition key, that there's a bag and some light line wrapped around your running gear...

I'm lucky, my prop is quite accessible, I've even been able to get a bag around it without going in the water, using a large fishing net from my floating dock... Of course, those with a prop in an aperture, or a saildrive well forward of the rudder, there's no other option than to dive on it...

Another solution would be to configure a larger form-fitted 'diaper' from a larger tarp, that could led under the boat without going in the water, and be tied off at deck level from each corner... The key would be to make it truly 'form-fitting' to the hull, however, any light getting inside it will defeat its effectiveness to some degree...


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## chef2sail (Nov 27, 2007)

chucklesR said:


> Jealously is so ugly.
> 
> At least you'll be looking at my stern


This I want to see. A 37 Tartan vs. a 38 Morgan....Both similar PHRF ratings.

I am willing to be the committee boat, since I can sail back and forth between you in our undersized 35 C&C. BTW my money is on Shawn.


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## chef2sail (Nov 27, 2007)

chucklesR said:


> I'm looking forward to streaking across the bay this weekend.


Hoping for 15 knots of wind I see

We are having our bottom done Monday. We have slowed considerably too. Its our third year on Ultima 60 and we coated with the petit stuff on our haul out last summer. I am interested in what the diver finds, as we are still sailing quite fast in the 6+ to 7+ range but under motor barely 5.5


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## chucklesR (Sep 17, 2007)

chef2sail said:


> This I want to see. A 37 Tartan vs. a 38 Morgan....Both similar PHRF ratings.
> 
> I am willing to be the committee boat, since I can sail back and forth between you in our undersized 35 C&C. BTW my money is on Shawn.


Irwin 38 mk II - not Morgan.

So's my money in a straight up race because I have floppy sails and believe in the 'set them and leave them' trimming school. 
Also if he gets there first he can drop anchor and I can raft up to him and save my back/deck from work/mud.

Craigtoo is going to the same place, same time. I actually out PHRF him in his Sabre 34 also. I guarantee I can beat him because he'll be towing a dinghy.

PHRF is for racing, I'm a cruiser. I don't tweak my sail trim every 1.3 seconds on my cruising boat. I relax and enjoy the sail.

Especially, getting back to the original topic - now that the barrier reef has been removed from my hull, prop and shaft.


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## T37Chef (Oct 9, 2006)

I think the rating are similar for the Morgan 38 vs T37? Does not matter though


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## chef2sail (Nov 27, 2007)

T37Chef said:


> I think the rating are similar for the Morgan 38 vs T37? Does not matter though


I think so..you have the 37-2 right. Its phrf is 132 Not sure what keel Chuck has. His is between 138 and 150 depending. Pretty close.

I gave you the edge as he's a reformed multihull sailor 
( all in good fun)

http://offshore.ussailing.org/Assets/Offshore/PHRF/High+Low+Mean+PHRF+Handicaps.pdf


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## jimgo (Sep 12, 2011)

Hmmmm...so maybe it's a good thing my boat isn't in the water?


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## T37Chef (Oct 9, 2006)

37C, although sometimes I even get confused if its the 37-2 or 37C?


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