Chain plates Hunter 49

[artboas]

Wow.
Thanks for the images. One never knows till the hidden is exposed.

Your rub rail will need a termination where cut. If not fixed in place it will move due to heat/cooling expansion and contraction.

It appears as though they welded the top piece at an angle to the bottom instead of bending it in a press brake. They must have had their reasons for this.
I wouid expect that the part was counterbored for the studs, and then filled with weld. Don’t think they went all the way through, as you’d see it from outside.
Think you were right in pulling this part for replacement

 

[Screen Saver]

It's with a stainless steel company now and he asked me today what grade SS it is, whether it was stressed, harden or anything. I assume not and that its straight 316. He also asked if it was mirror coated or finished. He is suggesting the cracks we are seeing could be in a mirror coating, it similar to chrome platting rather than in the stainless. Anyway more will be revealed when he starts to grind into it.

 

[Georgedoyle]

Here is what ours looks like For comparison. It's the same all the way around on both sides.

 

[Screen Saver]

Here is what ours looks like For comparison. It's the same all the way around on both sides.

Thanks, yea my other side looks like that to

 

[American_Mainsail]

This is a great thread. Thanks for posting it. I've been wondering for a while how to replace those chain outer chain plates with the rub rail going over them. I ran across a blog post, at one point, describing taking off the entire rub rail and remounting it to fix damage to the hull-deck joint. The writer hired a yard to do the work, stating that it was a difficult job.

To my eye, the overall construction of that chainplate is very robust. The corrosion is worrisome though. You're doing the right thing by removing it. The way that crack formed is strange. I'm wondering if there was a casting defect in it since birth.

 

[Screen Saver]

So just to finish this off. I had a new chainplate made and we counter sunk the studs and welded them in which we now believe is how the original ones were made. Most of the welders nearby said grinding the hair line cracks on the original chainplate was not going to lead to a conclusive result of what was going on. They basically said to know for sure it would need to be x-rayed. Portable x-ray is about $600-$800aud where I am, or its send off. So in the end I had a new one made. The re-rigg is complete and I now have a pretty good understanding of the rig. The rigger I used bascily supplied the parts and made of the cables, everythng esle I did. He then inspected each aspect before I touched it and after. Doing it this way I learnt something and saved more than 1/3, near enough to half of the cost. One of the oppositions to doing this rig without pulling the mast off was the difficulty of getting the pins out on the crosstree ends. Now knowing what I do the sensible way to do this in place would be to pull the end caps out of the crosstree's. This is very simple, just small pin and a split in and the end caps come off, then you can put the whole thing on the ground. From there you could replace all the wires and fittings very simply and put the whole lot (Cap at a time) back. This is effectively what I did on the ground and I simply used a G-Clamp and hammer to drive the pins out. Up the mast out at the cross tree ends this would be a hassle for sure (which is what all the riggers bitched about doing it in situ). However some lateral thinking as described it would be simple. I also replaced the forestay fitting on the mast and this also could easily be done with the mast in place as described by the Seldon notice. After 16 years and apart from the chainplate there were no other issues and I have now replaced the lot. Sadly while I had the furlex bearings and cups, the screws holding the two halves together on the upper portion had 2 nuts set in the fitting that were turning and I could not get it apart. The only way to get it apart would have required its destruction, so will keep my eye out for another furlex upper head section. Thats it, so hopefully now Im good for another 16 years, then it will probably be trading sail power for horsepower. I also fixed my wind speed anemometer, the very small ceramic bearings had collapsed

 

[American_Mainsail]

Thanks for following up on the job!

How did you deal with the rub rail? I’m guessing by you not mentioning it, it wasn’t a big deal to pull a small portion around the chain plates loose to remove them?

 

[jssailem]

Way to GO @Screen Saver .
Now looking forward to seeing you sail that boat. Pictures of you blasting through Sydney Harbor sails filled, would be fun.