chainplate replacement advice

T

tominny

.
Sep 6, 2011
5
T 2 NYC
I am considering to replace the chainplates on my 1977 Tartan 34C. There is pitting on some where the plates leave the deck, but no cracks.

Question: Is the pitting enough of a reason to replace them?

I was just quoted $135 per chainplate. They are 3/8" thick, 1/2" wide and a 1 foot long. And I need 5. It seems quite expensive.

Question: Does anyone know how and where to get them done cheaper?

Material: I assume it should be 316 SS and #7 polishing?

Any advice on what to request/look for would be much appreciated.
 
Delezynski

Delezynski

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Jan 22, 2008
551
NorSea 27 Az., Doing the To-Do list
Tominny,

How old are they? I replaced ours not long ago and I did NOT see any cracks, TILL I tried to remove them!! :eek: :eek: :eek: :eek:

You might want to take a look at my short Youtube video of my replacement at;
http://youtu.be/z3MeKoKC5-0

NOTE: This video is in 3D, but you can turn that off by going to the bottom and clicking on the gear symbol at the bottom right, then "3D", then selecting off.
 
G

gettinthere

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Nov 26, 2008
1,970
Endeavour 42 Cruisin
If you are doing the removal and install yourself and the mast is down, you could send them anywhere to be copied.
Several rigging shops in Annapolis and also consider Mack Sails in Stuart Fl. They do a lot of chainplate replacements and rates for labor seem much cheaper in Fl than the NE.
 
Ted

Ted

.
Jan 26, 2005
1,278
C&C 110 Bay Shore, Long Island, NY
Mcmaster-Carr http://www.mcmaster.com/#9083K42 sells unpolished 316 stainless steel bars that are 3/8" x 1 1/2" x 12" for $32.46 each. You can save yourself $100 per chainplate and make it a DYI project. You'll quickly see that maybe the price you were quoted isn't too bad. If you're handy and have some extra time, it's not a difficult project. If you do one at a time, you won't have to drop your mast which will save you some more money.
 
S

sd1953

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Nov 8, 2012
30
Endeavour 38 Center Cockpit Ft. Pierce
A brief description of pitting on the NACE website...

http://www.nace.org/Pitting-Corrosion/

The visible pits are not the whole problem, there may be cracks not visible originating in the pits. The pits may be evidence of crevice corrosion where the plates are covered by the deck. The problem with pits is that it is evidence of other more serious issues that do not show. That means the plates should be removed and inspected at the very least. But if you are going to that much work/trouble, why not just replace them?
So, is pitting reason enough to replace them? All the answers seem to say yes.
 
jibes138

jibes138

.
Jan 27, 2008
3,092
ODay 35 Beaufort, NC
The pits should be a reason to remove them and have them dye checked for cracks with a penetrant that shows up under a black light. If they don't have any signs of cracks all the pitting should be ground and/or polished off. If removing the pits reduces the cross section area by any significant amount at all then replace them, so it really depends on the depth of the pits, a few thousandths shouldn't be a big deal given the tolerances of the raw metal stock but if you start losing a 64th of an inch or so I'd deep six them. A note for all...when you buy raw materials that are hot and cold rolled depending on how you ordered the material will determine the surface condition. A certain depth of the surface will typically not meet the material specifications due to contaminants, decarburization, folds, laps, seams, etc. Kind of like "bark" on a tree. You need to remove a certain amount of stock to get to "good" metal. Aerospace standard AS1182 provides this information. For a safety item like a chainplate I would make sure they are passivated as a final step in making them to make sure they are in a minimally reactive state to start with. I never see this done but glass bead peening them or shot peening them for fatigue resistance would probably be a good practice as well.
 
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