External Chain Plates IP35

Added external Chainplates, now this was not decided over nite, I've planned this for over 6 months, discussed it with 2 experience riggers and Alot of emails and voice calls with the Chainplate maker in Texas, the plates are 2" wide, 18" long and 3/8" thick, with 5 1/2" carriage bolts. The first 2 bolts go thru the original plates glassed in hull, I just cut the tabs off even with the deck. The force and stress on the original plates is glassed in the hull are now shared by the external plates bolted on the outside in the exact same place as the internal! In the inside of the boat I drilled 3" access holes to each bolt and coved it up with teak strips! It took about a week me and my wife doing this, now it can be done quicker but we were in no rush and wanted to make sure it was done right! And yes it took about 2 days after everything was ready to go before I could get the courage to drill into the side of my boat!

Exce3llent - This is what I have decided to do if I ever have the need. The beauty of this is that they can be inspected and replaces.

A question: What did you do inside the hull to spread the load - if anything? I have wondered about the need to bond/glass some plates to the inside where the bolts come thru?

Thanks
George S/V Delicia IP40

The first top bolt is Drilled thru the original plates glassed in hull, the others are just 2" washers, there is extra fiberglass there and being bolted into the original glassed in plates keeps the loads original distribution, I just cut the tabs off the top even with the teak cap rail and capped it with some teak. You need a heavy duty drill to go thru the original plates, I burned up 3 bits! Chainplates express out of Texas helped a lot! Take accurate measurements and make sure the bolt holes will be aligned to bolt thru the original plates and your golden!

Great work there pal
And thinking " outside the box"
Drilling right thru the old chainplates was a great idea

And can u post some more pictures
Showing how u cut off the original chainplates,
And then drilled them thru

I just used a reciprocating saw and cut the tabs flush!
Before I tackled this project, I walked several marinas and looked at different size sailboats with external Chainplates, from 10" x 1" with 3 bolt holes on 35 to 40' boats and 15"x1.5" with 4 bolt holes on 40 to 50' sailboats. So I think I'm fine with 18"x2" 3/8" thick with 5 bolts on a little 35' sailboat! I also noticed most boats were 1 size smaller on there standing rigging!

Kurtclem wrote: The first top bolt is Drilled thru the original plates glassed in hull, the others are just 2" washers, there is extra fiberglass there and being bolted into the original glassed in plates keeps the loads original distribution, I just cut the tabs off the top even with the teak cap rail and capped it with some teak. You need a heavy duty drill to go thru the original plates, I burned up 3 bits! Chainplates express out of Texas helped a lot! Take accurate measurements and make sure the bolt holes will be aligned to bolt thru the original plates and your golden!

In one post you said the first two bolts are through the original chainplates. Is it one or two? Just wondering if I can do this.

Kurt
I need to change the chainplates n my IP35 this fall
Do you remember the hole spacing on the new chainplates?
Can you share it with me?
Thanks
Ed

Hi Ed, well changing plates is a very difficult job, and very difficult to actually drill that first hole in your boat and hope it's the right move! You can call or email chainplatesexpress.com they have all my measurements and bends degrees which would probably save you a little time and hair pulling to get it right the first time because there is no second time! If you would to pick my brain while you tackle this project, you can email me at This email address is being protected from spambots. You need JavaScript enabled to view it. or text 337-739-3286 and I would be happy to share how i accomplished this task! Good luck

Kurt
Well, I finally got the Chainplates replaced on my IP 35.
I followed your example, so thanks for your leadership.
The top two bolts are drilled thru the existing original chainplate horizontal cross pieces, and the other 3 bolts are just thru the fibreglass hull.
On the holes that are just thru fibreglass I used Aluminium backing plates made from 1/4 by 1.5" Aluminium. And I will use a construction grade adhesive caulk, recommended by the local commercial fishermen, to further 'glue' in the backing plates.
I posted some photos in"New Topics"
Thanks for your help..
Ed

I broke a chainplate and ended up in St Pete for awhile getting them all replaced and all new standing rigging. Here is a video of describing how they fixed them. I'm set now for years to come.

Salty thanks for posting that.
Well if there good enough for "the yacht rigger" and the Island Packet reps.
Then they sure are good enough for me...
Actually mine are bolted thru the existing chainplate and have 3 new bolts thru the fibreglass itself.

Hello Ed,
I have an IP32 and worry, like all IP owners, about the chain plates. Where did you get the measurements and position of the IP installed plates so as to use the vertical or horizontal legs of the IP plates for bolting your external plates?. Thanks

Jim Stevens
This email address is being protected from spambots. You need JavaScript enabled to view it.

Jim
I started in the rear locker, because the Chainplate there was easy to access.
First I used a dremel tool and cut the fibreglass away from the chainpplate exposing just 1 sq. inch of the chainplate metal. Then I drilled right out through the lower crossbar in the chainplate.
Next I just measured the distance between the lower chainplate and the upper one from the inside where it is revealed.
And then went outside and drilled back in , in through the upper chainplate.
I think the distance was 2 3/4" Center to Center... Knowing this distance on the holes, I had the first two Chainplates manufactured with the holes at this distance.
The forward Chainplates were more difficult to access,. I took out some of the interior cabinetry, which was easier then I thought actually. The very forward Chainplates were inaccessible. So I measured down from the lower chainplate again a nominal 2 3/4" , and drilled the first hole right out thru the fibreglass hull , and then went outside the boat, measured up 2 3/4" and drilled back in thru, thus drilling thru the lower chainplate. Then I measured up another 2 3/4 " and I drilled a third hole in thru, striking the upper chainplate.....
Drill bits and 'technique'
My cousin is a professional machinist, and he helped me thru it over the phone with lots of advice...and coached me along with encouragement..
He said Drilling thru two pieces of 1/4" Stainless is a challenging job for an amateur...He suggested that I drill a pilot hole first, so I started with a 1/8" drill bit, then moved up to 1/4" then finally 3/8" finished size. That's the best and easiest way to do it...
Also I purchased quality drill bits from a commercial " welding supply " store. They were much better then the hardware store quality...I used 3 of the 1/8" drill bits, because I accidentally cracked them off.
As well I used a corded electric drill, as this is too big a job for a regular cordless drill, 8 holes thru 1/2" Stainless plate will likely burn up the cordless ...
Lastly, when drilling a hole in Stainless or any hard metal it's easier( you must use ) if you use an oil based lubricant to cool the drill bit and lubricate the hole as you drill it. And you might want to practise on a scrap piece of 1/2" plate first.
Be careful, measure twice, drill once. haha...
But, You can do it.
Bolt size.... I used 3/8" bolts, while the bigger the bolt the more stress and strain it will hold, but will it fit? The upper crossbar chainplate was just 1" so, subtract the 1/4" for the 2nd leg of the angleAnd that leaves you with just 3/4" on the inside for the holes. And you need some room to get the 'nut and lock washer' on the back of the bolt....So I used 3/8" Stainless Steel bolts.
Sometimes , manufactured Chainplates come with square bolt holes, rather then round bolt holes, I ordered round holes in the Chainplates...
I used 4 holes in the two stern Chainplates and 5 holes in the remaining six Chainplates..
Finally when I got the new Chainplates installed I used a welders'mini grinder' and a special cut off wheel. -a zip cut, to cut off the old Chainplates at the deck line
Don't hesitate, just Contact me if you need anything else.
Ed

If I may ask, how has your installation held up over the past 2 years sailing? Do you have a way to
check the interior part of the installation for any stress problems?

I took some (but not all) of the interior cabinetry off and had a look.
Those visible were all fine., so I concluded that they were all fine.
And it’s just been one season , not two for me
Ed

Thanks Ed. I wonder how Kurts installation has done over the past two seasons. I predict within five years first generation IP models will all move to external chain plates. We need some engineer owners to weigh in on the stress / Hull issue. I believe backing plates or even adding second suspender glass around the bottom bolts would provide the same or even higher strength to the whole area. To me they look like your new external chain plates belong there - beautiful job! I am certainly considering them for contented turtle