Rust on Keel of 38 Hunter (2008, bought new in 2010)

[Tom Lampley]

I need some advice on repairing rust on my keel. I have a 38 Hunter that is only 6 years old but seems to be getting a lot of rust bleed thru on the cast iron keel. I received a quote for almost $3K to sandblast this off to bright metal and apply vinyl ester and to prep for bottom paint. This price did not include moving boat in/out of their paint shop.
Questions:
--Do I really need to do this or is there a less expensive alternative to get by on until I need to soda blast the whole bottom (which it doesn’t need for several years yet. It’s a hard paint and not chipping)?
--Any other Hunter owners with similar experience? I heard Hunters seem to be prone to similar rust issues in the keel
-Could this be covered under warranty?
Thanks for any advice on this.

Tom

 

[Justin_NSA]

Welcome to the cast iron keel club! The less expensive alternatives are all DIY. The most popular application is Interlux Interprotect. If you can get it taken care of under warranty, go for it!

 

[Jackdaw]

$3k? That's a good deal.

 

[Warren Milberg]

As a member of the "Cast Iron Keel Club," I would say what you have is no big deal. It is a relatively easy DIY job. Sand the keel down as much as you can. Apply a couple of coats of Interlux Primocon and then bottom paint. Or, if you are up for it, sand and then apply Interlux Interprotect, then bottom paint. Either way, your keel is going to outlive you by many years....

 

[CloudDiver]

Tom,
Typical example of sketchy contractor trying to rip you off assuming you don't know any better.
- $3K is B.S. unless they blast the entire hull below the water-line, barrier coat it, and bottom paint.
- Someone correct me if I'm wrong, but late model Hunter laminate is already made with vinyl ester resin, so the there really isn't a need for a new barrier coat on the hull. If I'm wrong and your hull was laminated w/ polyester resin, you could benefit long-term from the application of a barrier coat (epoxy, not vinyl ester resin). For the blasted keel barrier coat, epoxy. Interlux Interprotect 2000 sticks tenaciously to clean metal.
- There is no need to roll your hull into a paint shop. Both a barrier coat and the new application of bottom paint can be rolled on. Is there some kind of environmental laws in your area that says you can only paint inside an enclosed shop? For spraying there probably is a rule for that, but never have I heard that for rolling.

Find yourself a mobile sand-blaster. Pay them to blast just your keel only. Don't pay more than $800. $100 per hour for a one day job is more than fair and it shouldn't take them a whole day. Wait for fair weather, you want to apply the barrier coat as soon as the blasting is done. Use acetone in a garden sprayer to rinse down, this displaces any residual surface moisture. Roll on two full gallons of Interprotect 2000, hot coating (you should get at least 3 coats with 1/4" nap roller, but I'm guessing 4 and that is a good film thickness). You should be rust free for years after, possibly longer.

 

[kloudie1]

First of all, Welcome to the forum, Tom..
Warren and Cloud Diver are correct.. DIY if you can .. clean the keel up (sanding, wire brushing or blast.. acetone or stove alcohol wipe down), and coat with Interprotect, per their instructions.. then bottom paint on top of that..

 

[Tom Lampley]

Thanks to all that have responded! First time I've used this forum and have been pleasantly surprised at the responses I got.
Couple more questions:
--Do I need to wire brush the entire keel or just those areas where there is rust?
--Will the Interprotect (same as Interprotect 2000?) adhere to the areas that have not been taken down to bare metal?
--After applying Interprotect (several coats) will regular bottom paint adhere to that?

Thanks.

Tom

 

[CloudDiver]

Tom,
Interlux Interprotect 2000E is an epoxy based barrier coat. It comes in a big can and small can that you have to mix together (base plus catalyst, just like you have to mix epoxy resin with hardener). Catch 22 is that you have to use up all the paint you mix within 5 hours or it will cure in the can (don't ask me how I know this). BTW, best online price for this product is right here with our host, the SBO store. I really think 2 gallons is just the right amount to get 4 good coats on your keel with a 1/4 inch nap roller. Foam rollers are too fine and will fall apart, 3/8 nap is too much and will leave a heavy 'orange peel'.
Yes, Interprotect is designed to be painted on clean, bare metal or fiberglass... so you really need to sand blast the entire keel. Many DIY guys will tell you can wire wheel, flap disc, or grind off you keel until clean... yes, you can, BUT - it's a nasty, nasty job and it does take quite a long time to do it that way. The exposed clean metal will be rusted on the port side before you make it around to the starboard side. You really have to ask yourself, what is your time/sweat/frustration tolerance worth in dollars? PLUS, there is NO BETTER method to mechanically clean and prep the surface of cast iron than sand blasting, period. I'll put money on that. Soda blasting is great for paint removal, more environmentally friendly, and will not harm the substrate; this is great for fiberglass hulls, but for cast iron keels you really want the sand blasting because it leaves a very nice clean & abraded surface for the epoxy barrier coat to 'bite'. The acetone or denatured alcohol rinse serves two purposes, rinses off sand blasting dust but also displaces moisture. Cast iron can begin to flash rust IMMEDIATLEY after the paint is removed just from moisture in the air, so don't skip the rinse and try your best to blast and paint on fair weather day (warm, sunny, low humidity). If you can trust anything you read on this forum, trust this statement... It is totally worth it to sand-blast your keel. It will give you the best results possible.
Yes, Interprotect is a barrier coat and a primer for bottom paint... the bottom paint will stick to it very well. You can wait up to 6 months between applying coats of Interprotect without sanding between coats... that's what the literature says but please don't test that theory. It's best to 'hot coat' this product... roll it on and give 45 minutes to 3 hours (depending on temp and humidity) then do the knuckle test. Touch the paint with your knuckle, if you can leave a little bit of a print in the paint but no paint comes off on your knuckle then it is not fully cured but dry enough to roll on the next coat. What this does is allows the successive coats of epoxy paint to have a chemical bond rather than just a mechanical bond. You can actually hot coat the bottom paint to the last coat of Interprotect and it is actually recommended for certain types of bottom paint.

 

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[BigEasy]

Had the keel on my previous boat, a hunter 33.5 sand blasted because of severe rusting at about the 12 year mark.
Once the blasting equipment was set up, it took about an hour to blast the entire keel down to bright shiny metal.
I coated it immediately after washing with an acetone rinse.
If you can get a contractor to do the job at a reasonable cost, blasting is the way to go.
Not sure if this would work, but there are hydroblasting attachments that can be used with gas powered
power washers. I have talked to friends who use this method along with "play yard" sand ,that can be purchased at the big box stores for about $3/ bag, to hydroblast metal.... I don't know if this would be a viable method to blast a keel at an economical cost. Maybe someone on the site has experience with this.

 

[PAC3142]

Tom,
I've wintered at HHN for the past three boats. My last boat, a 1990 hunter 30g, had an iron keel, and needed some serious work. Osprey, who I assume you talked to, sand blasted and coated the keel in vinylester, and did an ok job. Ok meaning I wasn't thrilled, but I wasn't displeased either. I can't remember the cost, but I didn't regret doing it. I probably had it done in 2007-8, and it was still pretty good in 2015 when I sold the boat. I think my boat may have been one of the first they did in VE. I work in the composites industry, and had a long chat with them before agreeing to go VE vs epoxy. At the time they were using very high quality VE resins.

If you do have it done, I recommend
1. Wait until it gets warm before doing it. The resins are optimized to cure at room temp plus or minus a bit. If it is cold, they will take longer to cure, and moisture will collect on the uncared surface, not helping (here one of my chemical engineer colleagues could help out drawing hexagonal benzine rings on the whiteboard with bad things happening). You may want to consider launching with some bottom paint slapped on the rust, then hauling for two weeks when it is hot, and their workload is down.

2. Make sure there is a very clear understanding of how smooth you expect the keel to be. Mine had resin drips on it, even though I'd asked them to make sure it was smooth.

3. The keel has to stand on something while they work, so there will be overlapping areas. They missed a spot on mine because of that and it took two years to get it right. Inspect the boat frequently during the process.

I think they are a good enough outfit. That sounds like damning through faint praise, but there are a lot of seriously crappy companies out there - don't get me started on diesel mechanics! I've had them do 4 big (to me) jobs over three boats, and I would go back again, but I have learned to be very clear about my expectations, and check on the work.

By the way, I went through some trouble, including carrying a magnet around with me, to make sure my next boat had a lead keel.

PM me if you'd like to talk more. I'm hauled at HHN this winter also.

Paul

 

[Tom Lampley]

Great inputs from everyone! Given that I now live in NC and my boat is in MD, I think I'll have to bite the bullet and have a professional (Osprey in my case) do the job. This may be more than I can do myself being geographically separated. Hopefully if done right, I'll not have to do this again! Given that this is only a 6 yr old boat, seems Hunter did a poor job protecting the iron keel to start with!

Thanks again to all who responded!

 

[Crazy Dave Condon]

Tom;
I am not sure what part of North Carolina you are at and whether or not you plan to bring the boat down but I was a Hunter dealer in North Carolina for many years but now retired in the mountains of Virginny.
To answer Cloudiver, for years Hunter Marine has used vinlyester resins on the hulls which will include this boat we are talking about. Not sure when they went back to cast iron keels. However your boat would appear to be such. If it is rust, my suggestion is to remove everything off the keel down to the cast iron. Before any epoxie barrier coats are applied, I would strongly urge you to apply a metal primer that contain Zinc Chromate on the can or whatever it is. In north Carolina I did that religiously and it worked to help prevent rusting. As for the final barrier coat, it will need to be scruffed up for good adhesion of any anti fouling paint is allowed to dry completely but I do have a question in a another paragraph. As for what works the best in North Carolina, it is suggested Petit Trinidad SR or the latest and greatest in Trinidad. Remember the Pamlico and Albemarle are affected by wind tides and be careful of the shallow areas. If going thru the ICW, no issue with mast height for the 38 except for one bridge in Oriental that has a clearance of 45 feet. If on the ICW, do not attempt to navigate the Alligator River at night. I used Sailcraft to do my work in Oriental but there is also two others there as well who are respected.

Recently, I purchased a gallon of Interprotect 2000E and noticed something. Is it me seeing a different paint as the final coating felt rough as if no sanding is needed anymore? Oh crap, it is snowing outside.
Gotta run.

 

[Crazy Dave Condon]

Tom;
sent you a private message. recheck to see if cast iron or lead keel. I was a dealer then and the keels were still lead. If no help from Marlow Hunter with your hull ID number, then call Mars Metals who fabricated the keels for Hunter to see if they can help resolve that issue. They are located in Canada.

 

[seadaddler]

I have a 2007 H-36 and is lead but was told the new Hunters that year
including mine was cast but not so it is lead.
Nick

 

[DayDreamer41]

I seen to have read somewhere that Hunter changed back to CI keels in 2008.

 

[Scott B]

Warranty on the boat when new was 1 year and 5 years on the hull. I would imagine rust on the keel would also fall under a maintenance issue. Besides that, Marlow did not take on any warranties when it obtained the Hunter line.

 

[BrianRobin]

Easy check, a magnet won't stick to lead, but will to cast iron.

 

[quadrille38]

Tom;
sent you a private message. recheck to see if cast iron or lead keel. I was a dealer then and the keels were still lead. If no help from Marlow Hunter with your hull ID number, then call Mars Metals who fabricated the keels for Hunter to see if they can help resolve that issue. They are located in Canada.

My 2008 38 has a lead keel. When we bought her the dealer told us it was one of the last of the lead keels and that Hunter was switching to cast iron.

 

[Crazy Dave Condon]

I think everyone is hitting on the mark about timing but take a magnet to be sure. If it sticks to the keel then you know it is cast iron vs. lead. Good idea Brian