I need a survey with x rays of chain plates.Please provide marine survey company capable of undertaking. Thank you. Best regards, Bob R. reviewermanagement@hotmail.com
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It would be REALLY helpful if you mentioned
where the boat is (which might be soemwhere near where you live).
where the boat is (which might be soemwhere near where you live).
Wow...
now that's a survey! Let us know what it cost... when all said and done. I would go with the new chain plates... like Ross suggested. Don't forget to x-ray the standing rigging.
now that's a survey! Let us know what it cost... when all said and done. I would go with the new chain plates... like Ross suggested. Don't forget to x-ray the standing rigging.
Maine sail, What is the safety factor on standing rigging?
X-ray inspection is for haz-mat pipelines and aircraft components. In this case do they bring the equipment to the job site or does the client bring the material to the lab?
X-ray inspection is for haz-mat pipelines and aircraft components. In this case do they bring the equipment to the job site or does the client bring the material to the lab?
Xray diffraction analysis will be more than the cost of a new plate
If you are in doubt about fatigue strength simply estimate how close you are for 1 million load cycles (about 1 circumnavigation) and replace at that limit. If these are made from 300 series stainless, you can also 'back calculate' and if the design calculates to more than 30K psi fiber stress ... just throw them away and get new. If the plate has any funny bends or kinks .... replace much sooner. Any zone of dullness or change of surface luster should be suspect as fatigue. Sometimes fatigue (suspicion) will show up with ultrasonic equipment ... but not always. You can do a dye penetrant analysis (dyes, etc. used to be available from WM ... if not currently listed in their cat. then use WM special order services for "magnaflux dye penetrant" . You can also take the plates to an automotive machine shop who specializes in 'magnaflux' analysis. Rolled metal such as plate wont show other discontinuities without micro analysis (usually destructive). If this just a 'are my plates are OK'. Suggest you take them to an automotive machinist for magnafluxing ....... or simply replace them- then you WILL know the history.
If you are in doubt about fatigue strength simply estimate how close you are for 1 million load cycles (about 1 circumnavigation) and replace at that limit. If these are made from 300 series stainless, you can also 'back calculate' and if the design calculates to more than 30K psi fiber stress ... just throw them away and get new. If the plate has any funny bends or kinks .... replace much sooner. Any zone of dullness or change of surface luster should be suspect as fatigue. Sometimes fatigue (suspicion) will show up with ultrasonic equipment ... but not always. You can do a dye penetrant analysis (dyes, etc. used to be available from WM ... if not currently listed in their cat. then use WM special order services for "magnaflux dye penetrant" . You can also take the plates to an automotive machine shop who specializes in 'magnaflux' analysis. Rolled metal such as plate wont show other discontinuities without micro analysis (usually destructive). If this just a 'are my plates are OK'. Suggest you take them to an automotive machinist for magnafluxing ....... or simply replace them- then you WILL know the history.
Does magnaflux work with stainless?
I have used it extensively with steel tramway components, but it seems to me it needs to be able to be magnetized to work.
I have used it extensively with steel tramway components, but it seems to me it needs to be able to be magnetized to work.
Not accessible
It sounds like there is an assumption the chainplates are accessible and easy to access. If this is the case it seems the only logical thing would be to replace them. My guess is the chainplates are embedded in the hull fiberglass and can not be accessed or viewed in any way. Only the top portio is visible and the portion inside the encased in the hull is hidden. I have the same type of chainplates and have wondered the same thing. Replacing these requires a lot of grinding away of fiberglass which is not I am sure an easy job. I read an article in one of the big sailing mags a while back about someone having this done. Don't know where you would go for it though.
It sounds like there is an assumption the chainplates are accessible and easy to access. If this is the case it seems the only logical thing would be to replace them. My guess is the chainplates are embedded in the hull fiberglass and can not be accessed or viewed in any way. Only the top portio is visible and the portion inside the encased in the hull is hidden. I have the same type of chainplates and have wondered the same thing. Replacing these requires a lot of grinding away of fiberglass which is not I am sure an easy job. I read an article in one of the big sailing mags a while back about someone having this done. Don't know where you would go for it though.
Ross is correct!
magnafluxing will only work on ferrous metals. i don't think x-rays would be econimically feasable. dye penatrent might work, but i doubt that it would show up anything unless there was actually a crack. in which case, a high powered magnafying glass would show the same. i don't know of any non destructive testing that would show up any fatique problems in the metal. if in doubt i would just replace them. S/V Que Pasa?
magnafluxing will only work on ferrous metals. i don't think x-rays would be econimically feasable. dye penatrent might work, but i doubt that it would show up anything unless there was actually a crack. in which case, a high powered magnafying glass would show the same. i don't know of any non destructive testing that would show up any fatique problems in the metal. if in doubt i would just replace them. S/V Que Pasa?
Sorry guys .... must be the onset of Dame Brammage.
302 and 304 can become mildly magnetic, especially if they get any coldworking (an error). But most well rolled 18-8 stainless is not magnetic ... especially the 'good stuff'. Now, let me try to remember where I hid all those Easter eggs.
302 and 304 can become mildly magnetic, especially if they get any coldworking (an error). But most well rolled 18-8 stainless is not magnetic ... especially the 'good stuff'. Now, let me try to remember where I hid all those Easter eggs.
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