53 DeFever POC build questions

Hi everyone,
I am considering a 1986 DeFever 53' POC for purchase. The broker is telling me the hull is "cored" with foam. I wanted to see if anyone has has any experience with this type of construction? I prefer a solid fiberglass hull. Since there is no wood in the coring, I'm assuming there won't be many problems with this type of design? Obviously, a marine surveyor will be used to I.D. any issues, but before I spend the money on that, I thought I'd check with you all.

Thank you for any experience or issues with this,

Still boatless,

TARAS

Almost all boats are cored to some extent, usually decks and superstructure but a very few manufacturers also used it below the waterline. It makes for a lighter weight boat than a completely solid fiberglass layup. Balsa is the most common coring material. PVC and other polymer foams are also used.

Foam is slightly better than balsa as it doesn't rot. But it can delaminate if water gets inside, particularly in freezing conditions.

You have to take care of it. All screws and bolts into a cored structure must first have the core gouged out around the penetration and then filled with epoxy. Once the epoxy cures then drill through for your bolt or screw.

Many lower cost builders don't do this, they simply seal the stanchion base or whatever with 5200 or similar. This works as long as the sealant seals. But if it fails, water will get into the coring and if balsa it will rot.

Rotted core is very expensive to repair. A few square feet will cost several thousand dollars.

Your surveyor will check the entire hull for rotted sections by tapping with a hammer and checking any suspicious areas with a moisture meter.

So be aware of the precautions to take in the buying/surveying and in the maintenance and you will be fine with a cored boat.

David

Taras said:

Hi everyone,
I am considering a 1986 DeFever 53' POC for purchase. The broker is telling me the hull is "cored" with foam. I wanted to see if anyone has has any experience with this type of construction? I prefer a solid fiberglass hull. Since there is no wood in the coring, I'm assuming there won't be many problems with this type of design? Obviously, a marine surveyor will be used to I.D. any issues, but before I spend the money on that, I thought I'd check with you all.

Thank you for any experience or issues with this,

Still boatless,

TARAS

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I'd give more consideration to "DeFever" than worry about their "Coring". DeFever are well built boats and most should serve you well. Of course, I'd get it surveyed and that should tell you of any issues. I don't honestly know whether that specific boat is cored below the waterline, but I do know DeFever made good boats. I also know there are some excellent boats with cored hulls. Done right you gain performance and don't lose in other ways.

Cored boats get a bad rep due to low quality or small no-name yards with no quality control. I've seen pictures of broken hulls from accidents with evidence of crappy and high quality hull cores. The words crappy and DeFever are seldom if ever seen in the same sentence.

Due diligence, survey and all that good stuff but would not concern me.

With hull number in hand, you may consider going to the www.poctadefever.com website and try contacting Wilson Lin with your questions. On a 27 year old boat previous owner care will tell the story along with a good survey. DeFever models are being built by Pocta still to this day with a 70 footer being completed last year and several in progress.

The 53 Defever was built by the POCTA yard based on my boat the 49 RPH but extended to 53 and a full 16' beam. I would think its cored above water line but not below. I know on my Defever from all the plugs that came from various parts of the boat during drilling for through hull etc that it is solid glass.

That's why at 49' its very solid and weighs in on the lift at 60,000 lbs.

The Defever Rendeavous starts this Friday at Old Port Cove in North Palm Beach and I believe Wilson the long time builder of Defevers will be there as he was last year.

Bottom line a good boat with great lines and I can attest it will handle much nastier weather than you will be able to handle.

The 53 POC isn't the same as the 53 RPH (which I have). I don't think POCTA made the POC - you might want to ask on the DeFever Cruising Adventures Facebook group - there might be someone who knows more specifics about the POC there.

Jeffrey S said:

The 53 POC isn't the same as the 53 RPH (which I have). I don't think POCTA made the POC - you might want to ask on the DeFever Cruising Adventures Facebook group - there might be someone who knows more specifics about the POC there.

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Thanks Jeff I did phewpa on that one.

"Cored" can have dozens of meanings , and there are many many different stules of core matyerial.

The worst is plywood , then balsa.

Foam has dozens of variations AIREX seems too be the best , it is used mostly for military or pilot boats world wide , where its cost is less of a problem.

The methods of foam construction vary , workmanship is as critical as the foam core mateerial.

A solid GRP bottom to well above the WL is preferred by most..

FF said:

"Cored" can have dozens of meanings , and there are many many different stules of core matyerial.

The worst is plywood , then balsa.

Foam has dozens of variations AIREX seems too be the best , it is used mostly for military or pilot boats world wide , where its cost is less of a problem.

The methods of foam construction vary , workmanship is as critical as the foam core mateerial.

A solid GRP bottom to well above the WL is preferred by most..

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I hope this does not start another round of controversy but I can not stand by and accept the statement that plywood and balsa are worst. With all building materials be it steel aluminum wood solid FG or various composites it is not so much the substance used as it is how it was used and who put it together with what care and then how it was maintained. Some solid FG boats are crap and some PLy or balsa boats are excellent and visa versa. I can not speak to what is preferred by most, and popular opinions are not always based on good information.

I own a 1986 Defever 53 POC. All of the POC models used foam coring in the entire hull to allow for lighter hulls and greater hull speed than the full displacement models. At a Defever rendevous I talked with Art Defever and Wilson Lin about this issue and was assured by them that there wasn't a problem with their boats. Art Defever built a couple of his personal yachts with cored hulls. If you would like to talk further contact me at mburmandds@aol.com

There is nothing wrong with a foam cored hull. In general a foam cored hull will be both lighter and somewhat stiffer than a solid glass hull. The foam also acts as a thermal insulator. Of course, this assumes that the coring was done properly. Many high end boats now have foam cored hulls (Hinckley is an example).

The integrity of a foam cored hull depends on proper building methods. Basically that means that the core was either vacuum bagged (better) or the entire hull was built by resin infusion (best).