I have an offer in on a 96 IP 40.... I know the pros and cons of the boat itself, but have a very specific question (or 2) about her chainplates.

She is very well maintained, beautifully kept and is outfitted with everything I want in a boat. Her standing rigging is about 5 years old.... above the chainplates.... Which are now 25 years old. Without getting into all the issues IP (and all glassed-in chainplates) has had, I'm a bit concerned... Because without being able to see them, you can't assess their condition... So, I would want them replaced. However, the process to remove and re-glass the plates is a HUGE and expensive job. I met with a rigger this AM who suggested external plates. I don't mind the look myself (she's kind of a classic looking boat anyway), so aesthetics aren't really an issue for me (maybe for my wife).... but what issues am I not considering?

Strength of the rig bolted straight to the hull seems like it would be fine... maybe stronger... But the original design is all 3 plates welded to a crossmember, all glassed straight to the hull, acting as one strong unit (lots of area to spread the load) - vs 3 individual plates, bolted to/through the hull itself, without regard to where the bulkheads are placed, and not necessarily reinforced. Is this a concern? or will the hull itself provide adequate strength? I assume it will, but I'm not a boat builder or naval architect.

How about resale, if we decide to sell her someday? I assume that just solving the chainplate issue, would be a selling point for some.... But others don't like the look of external plates. Then there's the fact that they would drill holes through the hull, trim the toe rail, etc.... Plus there would be holes / access ports in parts of the interior, which to me would be good for inspection.... But sure will be obvious to others.

Thanks for any input!

B

if the chainplates are bronze, titanium or 2205 stainless then they should be ok

if they are 316 stainless, the original design was not a good one..

Much easier you bolt them to the outside of the hull, but don't make the same mistake and use 316 this time.

Worse yet, they are 304 stainless.... They need to be changed, just trying to figure out the best way! Thank you!

From Bill Bolin
Island Packet Ancestory





Over the course of the past, almost three years, administering Island Packet Ancestry, I have distilled and tabulated what I feel is the “treatise” on Island Packet chainplates. Some of this information has been previously released, but here are the highlights; please feel free to share:

• Chainplates prior to the 1996 model year were constructed of 304 grade stainless steel. These, to date, are the only ones that have failed (to the best of my knowledge).
• During the 1996 model year (that’s roughly September 1995 to August 1996) the transition was made to 304L, an alloy with better corrosion resistance than 304. This was a “running change” and there is no hull-number-specific documentation on what boat first received the 304L. I can only say that the 1996 model year was a “transition” year. No 304L chainplates have failed to my knowledge.
• So while it may be safe to say boats built late in the 1996 model year are likely to have 304L, I feel it is also safe to say that all 1997 model year boats and newer have 304L (until 2000).
• GE Silpruf 2000 sealant (a superior bedding compound to 3M’s 5200 which had been used earlier) was also introduced along with the 304L.
• As the 2000 model year boats were being built (summer/fall 1999), IP transitioned to 316 and then 316L stainless, an even more corrosion resistant alloy. No failures have been reported with 316 or 316L to my knowledge.
• An annealing step was added as one further way to fight corrosion at the welds sometime during 2001 or 2002; no failures have been reported on new annealed 316L chainplates either.

IP's have had zero chain plate problems since using 304L or 316L stainless. If you have 304 then you may have a problem but looks like you may be OK.


These guys can X ray your plates non destructively to ensure they are sound....I'm sure there are other outfits also https://windroseinspections.com/

If you buy the IP 40 just add another 12k to redo them with 316L or titanium. The boat is worth the proper refit.


Any IP owner knows to ensure the chain plates are sealed properly with Silpruf and inspected once every couple seasons.


External plates detract from the good looks of your boat. (Grats on the purchase!!)

Thank You!!!!

Great advice from someone with real knowledge about these fine yachts.


Frankly

Bill Bolin was my broker on the boat I bought. We looked at IPs but eventually went to a Catalina. We talked a bit about the chain plates. One also needs to think about the water tanks. If they are original they will need replacement and the original placement on most IPs is buried under the floor and furniture. Also a major refit.

__________________
Sailing a Catalina 470; now retired

One of the design trade offs that produces so much storage volume in IPs is to put the tankage under the salon floor. With the water and fuel that seems like a reasonable approach, but I suspect that Bob Johnson has asked "what was I smoking when I decided to put the holding tank there also (some later models)". The chainplate issue is that if you wait until failure then you have a potential catastrophic event, holding tank less so (nobody going to get hurt by a leaking holding tank). My aluminum water tank developed a small leak 5 years back. A little West Gflex and still doing fine. My guess is when designed, the builder of these "cut above the standard production models" would have thought 25 year life, fine. Now some of us are thinking how about 50 year life. Just going to have to fix a few expensive items (looked at the new prices lately).

Maybe my son will one day "wonder if I can stretch this old thing out for another 25 years because sure is a fine yacht."


Frankly

Is there a way to nondestructively test to find out which metal you have? Perhaps file off a little bit and send in to a lab?

Thanks all! The water tanks and holding tank have already been replaced and seem to be OK.

As far as the CP metal goes, according to what I've found, in the 1996 models, they were still using 304 stainless.... The biggest problem is, they encapsulated the plates (and crossmember they're welded to) in fiberglass - starving them of O2 and allowing any water to stay trapped. It also precludes any inspection of the metal's condition. Above the surface the metal can look fine, but once ground out, apparently it's common to find significant corrosion... Sometimes so bad, failure was imminent.

The plates need to be replaced, one way or another.... I'm just trying to figure out if changing them to external plates (rigger's suggestion), is a good way to go about it.

Supposedly, there are a few riggers and repair operations in the US that have great experence doing this. Suggest you find and work with one of them. I think Snead Island in Palmetto, FL is on of them.

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Sailing a Catalina 470; now retired

The IP chainplates get a lot of discussion for sure. Yet many other boats are built with trapped plates. It's a dilemma. IF the boat was maintained well was there ever any leakage into the plates? We dont know. Can you drill a couple small holes at the bottom to look for seepage?
I have no answers for you, but often wonder if we worry too much.
Any one find a record of a rig lost... ever ....due to the plates on an IP?
Is that any different than 25 year old outside plates where you dont know the condition of the trapped SS bolts?

__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard

There have been failures at sea, and a few were lucky to have the failure dockside. While the trapped water is a problem, cracking of the tang just above the cross angle is most common. Welding causing some metallurgical changes is the the culprit here which was the reason for the change to 304L, then 316L, and finally annealed 316L. This area is just not observable without removal, although there is at least one outfit claiming successful xray testing (at about 1/3 the cost of replacement).

Typical replacement is with 3 individual units vice the 3 tang assy and external replacement attempts to drill into original structure as I understand it. Garhauer Marine is the OEM and cost for the replacement hardware (port, stbd, aft) is about $1400.

Fix it as original, IMO external look like crap on an IP.


Frankly

OP, you might contact A64pilot here on CF, for he had his chainplates professionally replaced with Titanium, somewhere in Florida IIRC. He could give you some actual experienced costs...

And a minor gripe: when IP found that the original CPs needed upgrading, why in the world did they faff around with the 304L and 316 stages? The difference in cost between those grades and the 316L (or better yet 2205) is so very small compared to the cost of the boat, and would have removed the angst from so many owners minds.

Jim

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Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.

There is a member here on CF (A64pilot) that had the original 3 tang chainplates fabricated in titanium. He mentioned the additional cost was nominal relative to the total cost of the replacement. I seem to remember he posted pics of the replacement process as well.