Saturday, February 27, 2016

Carbon Fiber Rudder Inspection


I am finishing up a two day inspection of two Gun Boat Rudders at the Hinckley Yard in Stuart, FL.
I used multiple forms of NDT; tap testing, thermal imaging and ultrasound (UT). For heating the rudders for the thermal imaging I used infrared lamps that are made for paint and resin curing. These lamps a great for this use, they heat evenly and slowly. 
It is very important not to rely on just one form of inspection. Using multiple inspection techniques is how you can see the "big picture". I start out with thermal imaging, which I then process in software. This allows me to locate the anomalies that I will be using tap testing and UT to confirm.
Often it is possible to use an iPad with the software to due the processing on the job site. This is a way I can confirm what I see in the camera is an anomaly and then use the camera's built in later pointer to mark the anomaly. 

This image is thermal blending. It is the blending of a digital image and an IR image.
The laminate is visible in this IR image.

The light grey lines are foam stringers inside of the rudder.

Using an Olympus Epoch 600 flaw detector to confirm any anomalies found using thermal imaging.

Wednesday, February 3, 2016

Inspecting Sailboat Rigging

In the January issue of the Boat US Marine Insurance Magazine I have written an article on how to inspect your rigging. I did this because a lot of us sailboat owners are in areas where it is difficult to locate a rigger to do inspections for us. We as sailboat owners need to be able to keep an eye on our rigging. You can read the article online at: Seaworthy

Here are some photos of what to keep an eye out for. 

Look closely for the cracks in the stainless steel.
Rust is often a sign of crevice corrosion. 

Tuesday, February 2, 2016

Inspecting Chainplates

In the latest issue of Professional Boatbuilder Magazine I have an article about inspecting chainplates on sailboats. I find while surveying sailboats chainplates are not always inspected. At least not inspected well. This is not only by the boat owner, but by the last marine surveyor and sometimes the rigger who have last inspected the boat. It is true that it is not always easy to inspect chainplates where they are hidden by the deck and/or interior cabinetry. Some cracks are visible above deck level, see photos. Signs of water intrusion are often visible below decks and even if the chainplate does not have signs of corrosion, this is still a reason to pull the chainplate for further inspection. Below are some photos of chainplate corrosion. In future blog post I will go into more detail on how to inspect for chainplate corrosion.

Not all cracks and corrosion are hidden.

This Hans Christen had been recently surveyed, without recommendation to replace the chainplates. Photo curtesy of Rigorous Rigging
In the photo below we can see there is wide spread stress crack and crevice corrosion.
Closeup view of crevice corrosion.