Chainplates from grainger
 

Hi I am paying a rigger to install new rigging and have decided to make new chainplates myself. I notice grainger sells 316 stainless plate blank stock that can be shipped to my local store in two days. Is there anything wrong with buying from grainger, or is 316 316?

Re: Chainplates from grainger
 

I think you will find Metal Supermarkets | Buy Stainless Steel, Aluminum, Hot-Rolled, Cold-Rolled, Alloy, Bronze, Copper, Brass, Tool Steel, Galvanized a LOT less expensive, and they will cut any size you need. They have 65 stores plus online, but oddly the online selection is more limited than local stores. I think the closest to you is in Austin.

- Rusty

Re: Chainplates from grainger
 

Grainger only wants 66 dollars for a 6' long piece of the size I need, so it's more about convenience. I have tools to cut it with.

Re: Chainplates from grainger
 

Metal supply businesses will shear it into whatever lengths you want. Had them cut the proper width bar stock to the needed lengths. That left the drilling and polishing. Saved a step.

Re: Chainplates from grainger
 

Whelp as usual I am over analyzing things and I am now wondering about alternative chain plate materials, as well as mixing dissimilar metals.

If I go the 316ss route, what about hardware? I can't find anywhere local that has 316 bolts. They are all 304. Is it critical to use 316 hardware with 316 plates? They bolt down below where they should not(under ideal circumstance) be exposed to any moisture.

That whole little issue got me to the mode of thinking about switching them to bronze...but now there's another issue. The only bronze in the size I need is aluminum bronze...not an issue, except the only local hardware I can find is silicon bronze lol
Is there any issue with mixing the two different bronzes?

I am now leaning toward bronze plates. The fact that I won't need to buy anything to polish with if I go bronze is what has me sold on it...but then what about above deck? I will have bronze plates with stainless steel rigging hardware touching in an area that get's wet with seawater often. Is this an issue?

Re: Chainplates from grainger
 

A couple thoughts:
-Be sure when you buy the SS that is flat bar not sheared from plate. It will be a whole lot less work and the edges etc wont be sharp and very rough requiring a lot of grinding... and wont have stress risers from shearing.
-Anything you grind the ends when you cut should not have been used to grind steel previously or you will embed rust starters. if you cut with a steel saw blade, be sure to grind enough material off so you get rid of all possible embedded steel from the blade.
- You should be able to fine the 316 bolts you need. might have to online. Personally I don't think 316 or 304 is a big deal.
- When it comes to 316, low carbon (316L) is better.
-Bronze and SS go well together, in fact many turnbuckles combine the two.

Re: Chainplates from grainger
 

Hmmm...it really is starting to look like bronze is the better option; Better corrosion resistance, easier to work with, no polishing...I'm really digging the no polishing part.
It IS substantially more expensive. I am looking at almost twice the cost and that is just for the flat bar. The fasteners can really add up too. I noticed some were in the 3 dollar per bolt range.

Re: Chainplates from grainger
 

You are probably going to round the end of the chainplate anyway, so will remove all the cut area I would assume.
How are chainplates on an Islander 28 bolted? I figured they were just glassed in.? I looked at a 28 once a couple years back. Seemed a like a pretty stout little boat. The rudder shaft was huge! I don't remember seeing any bolts....for chainplates?

Re: Chainplates from grainger
 

Mine is a Newport 28(capitol yachts. I wish I had an Islander!)

Anyways it's my first cruiser, so I don't have much to compare it to.

So far the only issue I've had from a manufacturing standpoint is that the deck fittings are back with regular little 1/4" washers and I ripped a cleat right up through the deck.
All other projects I've had to tackle I would say are more from neglected maintenance. After I finish this re-rig and hull paint, I suppose I'll have had done enough to earn the right to rename her! She may not have been the strongest boat made, but she sails like a dream.

Anyways back to the chain plates...
There are two on the transom which bolt thru the outside of the hull, another two that go through the deck and bolt to the bulk head inside the cabin and the one up front that bolts through the hull, like the rear.
For the time being I am only replacing the two big ones that run through the hull and bolt to my bulk head. Those are straight, so will be the easiest to fabricate.
I plan on doing the others later on down the road. I need to research a good place to have the bends made...it's the one's in the cabin that have me nervous, since they are hidden from view and there is evidence of water getting onto the bulkhead at some point. The wood doesn't look rotted, but it is discolored.

Re: Chainplates from grainger
 

I wasn't going to mention it since you seemed like you had it pretty well settled...

For the price of bronze I would go to G2 Titanium. Depending on the supplier (I would recommend calling Allied Titanium) it will be about the same price as low zinc siliconized bronze, but substantially more corrosion resistant and much stronger.

As for metal issue. You can look at a galvanic chart to see if the specific alloys will work together. Generally SS and Bronze work fine together with one major caveat. Non-passivated SS will act as an anode for almost everything. So if you use SS it must be passivated before installation, and really needs to be electropolished (which luckily also passivates the metal at the same time).

Re: Chainplates from grainger
 

I would probably just go with the stainless.... what....... the originals are likely 304 or 302 SS and have lasted......40 years? and still not broke right? :>)
Sometimes we can over think these things.

Re: Chainplates from grainger
 

Stainless is less costly, for sure, than Silicon Bronze. You can take a look at Tobin Bronze (aka Naval Bronze C46400 it is not a low zinc bronze though) it is much more affordable than Silicon Bronze. Also more affordable and very strong would be C67500 Manganese Bronze (a Tin Bronze typically used for cast things) which we used for cast bobstay iron as well as bowsprit stay chainplate castings. Our rudder stock and chain plates were Tobin Bronze -- lasted 75 years and we replaced the chainplates with the same in 2008. Figured that's better than the typical life of stainless steel. As I recall, it was a similar price to stainless. We had 3/8" bar stock cut to length and just did the rounding of the tops, and drilling. We used a lot of bronze stock and bronze fasteners in our rebuild so we became familiar with good suppliers. We purchased the Tobin bronze for chainplates via Alaskan Copper--it was a good price in 2008 and you might want to check into it now. We bought our bronze carriage bolts from TN (Top Notch) Fastener company for installing the chain plates. You can get bronze carriage bolts and other large diameter fasteners as well as custom bronze keel bolts from them at a great price. They sell bronze fasteners in their own TN Fastener Schooner Chandlery store at same or better prices than via their TN Fastener store--so if you see something you like in their store but it's not in their Schooner Chandlery store, just make a product inquiry to them via our site for a great deal. When we rebuilt our boat, we used them for most of our larger fasteners because no one could match their pricing on fasteners.

We got the pre-cut bar via UPS (from Alaskan Copper) in about a week and just had to cut the top (half-round) with a bandsaw and drill the hole for 5/8" clevis pin.

https://farm3.staticflickr.com/2387/...0907f9cc_z.jpg

Some of the tobin bronze chain plates are shown here (an old chainplate with backing plate of oak next to them)
https://farm3.staticflickr.com/2181/...182a48d6_z.jpg


The plates were bent onto the new laminated mahogany backing plates and bolt holes pre-drilled

https://farm3.staticflickr.com/2256/...4c5e7c88_z.jpg

Re: Chainplates from grainger
 

You can save old stainless steel chainplates and cut to use as backing plates for some deck fittings. You can also use wood blocks as backing plates.

Re: Chainplates from grainger
 

Use the 316 and order 316 hardware for it.

McMaster-Carr is a great source.

Re: Chainplates from grainger
 

Well I pulled the old chain plates yesterday and I must say I agree! I am having a hard time believing these are original.
Did boat builders outsource thing like chain plates? These have a logo printed into them. It is an "S" with a dolphin/whale going through the center of the "S".

I am tempted to re-use them, but if these are original, they are 38 years old. so yeah.

It's amazing that there is almost no rust in the crevice corrosion area. The only visible rust appears to have come from the old rigging cables that I am about to replace dripping rust onto them.

Yeah, I was selling myself on the bronze due to the "no polishing"...However when I actually pulled the chain plate yesterday and measured, it turns out that it's 3/16" thick, not 1/4" like i thought.
I'm having trouble finding 3/16"X2" bronze flat bar for sale anywhere online. I can get 1/4" all over the place, but not 3/16".
I can get 316SS local and i can buy a polishing kit for 30 dollars, so that right there makes the price about the same for the flat bar...factor in hardware price which is on average about twice the price of 316, the difficulty of finding the correct bronze hardware and the fact that my old SS plates are showing very little rust and none in the area that passes through the deck after 38 years(allegedly)...suddenly 316SS starts looking better and better.

I could probably even fit a piece of 1/4" stainless steel into the slot if I wanted further rust insurance. The price difference is very small.