Chain plate bolts

[vistech1]

Hi all

I am in the process of inspecting the chain plates reattaching and sealing on my newly purchased triton 26 (Australian made) and I have to replace some bolts
My query is the use of stainless bolts or high tensile steel. is the latter ok? are there pros and cons to either? (besides the corrosion factor)
There are 3 chain plates through the deck on each side each having 2 x 10 mm bolts holding the chainplate.
This is my first yacht so any advice is most welcome.

[DeepFrz]

Make sure you check each chain plate very carefully for cracks using a dye penetrant.

[Stumble]

We do a lot of replacement chainplates. The single biggest issue is the corrosion that occurres in the blind spot between the top of the deck and the bottom. In all but the very best installations there will be some water and salt that collects there, leading to serious crevice or poultice corrosion. Rarely are the bolts alone the problem.

Assuming the chainplates are ok, then replacing the bolts with 304/316 stainless is probably a minor issue. But using hss is guaranteed to lead to problems.

[vistech1]

Thanks for that I did purchase HHS bolts because that's what are on her at the moment it seems like the washers they used rusted out more so than the bolts and the seals around the plates have gone adding to the problem,
But I think I will revert to stainless.
Would it be right in thinking that when I re install the chain plates that I re tension the rigging wire befor I fully tighten the chain plate bolts so as to take up the slack and then seal?

[Wotname]

Originally Posted by vistech1

.........
Would it be right in thinking that when I re install the chain plates that I re tension the rigging wire befor I fully tighten the chain plate bolts so as to take up the slack and then seal?

Well I'm no rigger but I would say NO.
Tighten up the chain plate bolts and seal, then re-rig and tension.

The load on the plates are not only taken by the shear of the bolts but also the friction of the plate against the hull (bulkhead, frame or whatever). The bolts need to tight to create the friction.

[Stumble]

Never tighten the rigging or even install it until the chainplates are completely installed. As Wotname pointed out it is the friction of the chainplate and the glass that keeps them in the boat, the bolts are there to create the friction.

[vistech1]

Thanks for the great info cheers

[Viking Sailor]

Isn't there a torque spec for chainplate bolts?

[s/v Jedi]

Originally Posted by Viking Sailor

Isn't there a torque spec for chainplate bolts?

Use the standard torque specs for bolts. Size, material and lubricant are the important factors.

[Wotname]

Originally Posted by Viking Sailor

Isn't there a torque spec for chainplate bolts?

Originally Posted by s/v Jedi

Use the standard torque specs for bolts. Size, material and lubricant are the important factors.

Yep, use a standard size spanner (wrench) and torque for T for tight and not F for ......

[ErikFinn]

Would it be absolutely not recommended to replace the chainplate bolts (6) one by one with the rigging and mast up, only removing and replacing one bolt at a time?
My chainplates are attached to the hull with six bolts and are all quite accessible.

[Viking Sailor]

Originally Posted by Wotname

Yep, use a standard size spanner (wrench) and torque for T for tight and not F for ......

Damn, I was hoping someone would post a nice torque chart. No such luck! So, here is a nice pdf file that all can save for future reference.

http://www.fastenal.com/content/feds...s%20Torque.pdf

Enjoy,

[taildragerdrive]

I broke one of my chain plates last fall while sailing. Fortunately there was no other damage since we were able to turn into the wind and drop the sails and motor to a nearby marina.

I've done a lot of work on aircraft, car and tractors but am new to boats. I took off two of chain plates the long one of the mid side plate and the broken short one a rear side plate. I delivered these two chain plates to a nearby machine shop to make new plates.

I have received the new chain plates back and am ready to install them.

During the removal of the plates I "spun" galled I believe two of the bolts one on each chain plate. I am now putting a lot of penetrating oil on the bolts of plates still to be removed.

I'm trying to figure out how to remove the "Spun" bolts. These are internally mounted chain plates. They are on fiberglass "knees" I believe they called. There is a nut plate behind the "knee" that is inaccessible. The bolts are long enough that they have threads that extend behind the nuts. The result is the bolts spin but don't come out of the hole. I ground the heads off to get the plates out.

I have not been able to figure out how to remove these nuts. I have not tried to drill them out. Dose anybody have any suggestions how I can best get these bolts out?

I plan to replace these bolts after they are removed by tapping out new threads and replacing with slightly larger stainless bolts. Am I on the right track here?

Thanks

[DeepFrz]

EricFinn, the best thing you can do is remove each chain plate and thoroughly inspect it. You may need to take them to a machine shop and have them magnaflulxed. If the bolts need replacing it is likely that the chain plates need replacing as well.

[taildragerdrive]

I am in the process of replacing all the chain plates. I'm just stuck at this point trying to remove these "spun" bolts so I can put in the new chain plates.

Thanks