Sandwich Cored Structures

[GordMay]

Other than "hammer sounding", has anyone any experience with surveying Cored Hull &/or Decks. I'm seeking techniques for evaluating possible disbonding & delamination, water intrusion, etc - where visual examination is not revealing.
Regards,

[duluthboats]

I think there are some infrared camera techniques that will show water in a core. For delamination, the easiest way is tapping not hammering. Use a heavy piece of metal about the size and weight of a silver dollar. Tap rapidly across the surface, it is very easy to hear a bad area. You will hear tick tick tick tuck, the dull sound is likely a delam.

Gary

[SailDesign]

Gary - isn't that why we all carry pocket knives? Just tap with the "heel" of the knife

[duluthboats]

I do carry a small pocket knife, but I have much better results ( more consistent ) with a brass token I carry just for checking for delams. I don’t often get to practice on boats but cored panels on aircraft are much the same.

Gary

[GordMay]

Any additional information or references on Infra-Red thermography for evaluating hulls?
How much experience does it take to interpret the I.R. results?
Thanx,
Gord

[duluthboats]

I’m only know what I have read. Most recently an article in Pro Boatbuilder, # 85.
That article mentions Todd & Associates, http://www.boatman.com/Infrared/Thermography_info.htm , I don’t have much other information on the subject.

Gary