Ultra sound for checking hidden areas?
- Thread starter Roger R
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I haven't heard that . It might be true but I have my doubts. A fiberglass hull is quite dense and I am not sure ultrasound would penetrate it. Ultrasounds also don't work well when there are gas pockets in your abdomen. I have not seen ultrasound on a hull but I have had more than a fair share of ultrasounds done on me!
Yes seasick, oh that feeling of having your inspected parts rubbed with mint jelly while the operator scans the area with her handheld device, as you silently pray you do not hear an "oh my god" before completion. Once asked the operator "did you spot any thing unusual?....." "can't talk about that"..........ok thanks for the encouragement I mumbled to myself, I could be dying and no one is going to let me know until it is far too late.
Hookup1
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Getting old isn't for the faint of heart. Wait until your urologist tells you we need to do a trans rectal ultrasound!
Back on subject! The 56' F&S my friend has is cold molded construction. Essentially the whole boat is cored. During purchase survey the surveyor picked up moisture (with a meter) in the area of the rudder board just short of the transom. Upon investigation it was confirmed that an improper repair job when the rudder bearing were replaced a few years ago led to water intrusion. Boat was sent to Warton Creek yard in MD to do the repair by F&S. Amazing workmanship! Engine room and under deck areas have topside finishes. $75,000 later they finished the work and my friend closed on the boat. Broker who took the boat in trade for a new 63' Viking did not bother to survey the boat. Not warranty so it came out of the brokers pocket.
My point is use a good marine surveyor - they all price out the same - they know what to look for and have the tools. And no I have never heard of them using ultrasound.
Back on subject! The 56' F&S my friend has is cold molded construction. Essentially the whole boat is cored. During purchase survey the surveyor picked up moisture (with a meter) in the area of the rudder board just short of the transom. Upon investigation it was confirmed that an improper repair job when the rudder bearing were replaced a few years ago led to water intrusion. Boat was sent to Warton Creek yard in MD to do the repair by F&S. Amazing workmanship! Engine room and under deck areas have topside finishes. $75,000 later they finished the work and my friend closed on the boat. Broker who took the boat in trade for a new 63' Viking did not bother to survey the boat. Not warranty so it came out of the brokers pocket.
My point is use a good marine surveyor - they all price out the same - they know what to look for and have the tools. And no I have never heard of them using ultrasound.
Doc Stressor
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Ultrasound is used for inspection of steel hulls on commercial shipping. It's a good way to detect corrosion since there is a big discontinuity in transmission between solid and voided corroded areas. I've never heard of its use on fiberglass hulls. Whether or not it would work would depend on the differential between wet and dry areas. It should be able to pick up delamination, but that's a pretty extreme condition that can usually be detected by inspection or sounding with a hammer.
As usual Doc, you are correct based on some research. Ultrasound is common on steel ( and aluminum) hulls. Who wudda thunk?
One of the advantages is that it can penetrate rather thick layers of null paint. Since it measures the steels thickness, the surveyor has to take a lot of readings as well as have a general idea of how thick an area should be.
Next project: see what I can find about ultrasound on fiberglass
One of the advantages is that it can penetrate rather thick layers of null paint. Since it measures the steels thickness, the surveyor has to take a lot of readings as well as have a general idea of how thick an area should be.
Next project: see what I can find about ultrasound on fiberglass
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Every day is something new. It seems that ultrasound is used for both fiberglass and composites like carbon fiber to look for defects and voids.
On the steel hull topic, here is an interesting video I found.
On the steel hull topic, here is an interesting video I found.
After a weekend of looking, I have not been able to find a video of a fiberglass hull being untrasounded ( I think I made up that word) . I have read many articles about using untrasound on composites and fiberglass but they are all geared towards finding defect or voids in the materials and specifically thickness differences. So for uniform composites where you know the thickness, ultrasound can detect changes in the thickness. I am not convinced that it is a good method to scan fiberglass boat hulls. So if anyone finds a video, let us know.