Re: Embedded Chain plate maint/replacement
In this particular case.
1. The exterior plates would be just a strong as the oringal, stronger do to compression as the location on the hull does not change, expect as it is not directly on the inside of the hull, but now directly on the oustside.
2. Rig geometry changes are very miniumal as the new attachement is maybe an inch outboard.
3. The glassed in chain plate is oxygen starved, this combined with moisture is what allows crevice corrosion to occur on the plate. It would be quite fine for an external chain plate to leak as far as the intergety of the plate is concerned, but not so for a glassed in plate. If the internal plate leaks and the moister finds its way into a low oxygen environement that's bad news.
4. Industrial inspection companies are all over, but in the US to inspect our chainplates with xray, really it's gamma ray that is used, ranged between $1100.00 and $1700.00 depending on whether they could do it in a full day or half day all of this done onsight at my location. These are US east coast prices and I check with half a dozen companies.
I talked with two separate surveyors and both were quick to say forget the inspection and just replace them. One surveyor said that on any boat with thirty year old plates he has never seen an radiographic inspection come back that wouldnt recommend replacement anyway... ie don't waste your money.
4. External chainplates can be inspected, the internal, even if bolted on the inside can not with out tearing apart a lot of the interior. This may just be the case on my Irwin 65, but on her they are a serious bugger to get to.
All that being said many boats have the chain plates much farther inboard than on the Irwin. Moving the plates outboard on the hull on these guys could be a bad idea for some of the reasons Stumble mentions above.
Last edited by Total Chaos; 01-29-2014 at 10:42 PM.