Recent Thermal Imaging From Surveys in South Florida

[SuenosAzules]

I thought I would share some recent thermal images from surveys. I do not just use the thermal imaging camera. I use the phenolic camera, moisture meter, and of course just visual observation. However it is the thermal image that kills most if not all doubt when you put it in a survey report. Here are some recent ones:



A digital image of a fiberglass deck with a soft spot and high moisture readings



A thermal image of the same deck showing the deteriorated wood core under the fiberglass deck



A digital image of an exhaust riser on a MerCruiser gasoline engine with signs of corrosion on the riser at the manifold



The same exhaust riser while the engine was running showing a leak at the flange where it meets the exhaust manifold



An overheating 12 volt fuse connection at the helm station. Notice the high temperature of the fuse



Normal injectors on a diesel engine taken while the engine was running at wide open throttle



Hull delamination. Water was trapped in the fiberglass hull below the waterline. Phenolic hammer sounding suspected this. Some fiberglass weeping and this thermal image confirmed it

[Snore]

Thanks!


Great use of technology, if I ever buy another boat I know to ask the surveyor if he does thermal imaging.

[rebel heart]

I have a diesel mechanic friend who said it's a good idea to take IR gun readings of various engine areas. If you have a problem in the future, you can compare temperatures with a known good benchmark. Seemed like a good idea.

[minaret]

JR Overseas GRP-33 = Good moisture meter. I own two, they're all I'll use.

[Snore]

Originally Posted by rebel heart

I have a diesel mechanic friend who said it's a good idea to take IR gun readings of various engine areas. If you have a problem in the future, you can compare temperatures with a known good benchmark. Seemed like a good idea.

After reading your post I wondered...each year (at my day job) we inspect all our high amperage/voltage connections by shooting them with an IR gun, looking for hot spots. Wonder if heat would be a leading indicator of corrosion on a 12v system?

[transmitterdan]

Originally Posted by Snore

Wonder if heat would be a leading indicator of corrosion on a 12v system?

Yes, it is. But Rebel is right that you usually need some reference measurements to know if things are getting worse or if it's normal heating.

[belizesailor]

What make and model of camera did you use?

[sy_gilana]

Originally Posted by belizesailor

What make and model of camera did you use?

+1 on the what camera question.

Many years ago those things were very expensive, had to carry a flask of liquid nitrogen and the camera was a Polaroid. I used to hire a guy to do all the switch panels in the hotels I ran. Saved a fortune in predictive maintenance. Found hot bus bars, contactors, cables and terminations, especially useful on the 11Kva stuff.

Its on my wishlist....

[Roy M]

rebel heart, I put bright yellow dots on various parts of my engine with quick dry paint (actually, nail polish). Then I put a number on it with a fine tip felt pen. You can then take regular temp readings on a bunch of spots and make a table, or even a chart, showing the "normal" variations. Just shoot the laser light beam at the number and write down the reading.

[SVTatia]

Originally Posted by Roy M

rebel heart, I put bright yellow dots on various parts of my engine with quick dry paint (actually, nail polish). Then I put a number on it with a fine tip felt pen. You can then take regular temp readings on a bunch of spots and make a table, or even a chart, showing the "normal" variations. Just shoot the laser light beam at the number and write down the reading.

That's a great idea, and cheaper than the camera. But...

All of this is only good if you know how to interpret the results. I for one have no idea - what does it mean if on a diesel engine one spot is hotter than in the past?

[Therapy]

Your delamination pics seem obvious.

I bet it isn't that easy.

[Roy M]

SVTatia, When someone goes to visit a doctor for a checkup, the physician usually starts with recording aspects of the patient's current condition to help establish a baseline. Each of us is slightly different from another, but we all exhibit changes according to our personal baseline when we are undergoing stress or disease. So, the idea is to begin recording things when we are feeling "normal", and comparing things when we are not. Whether it's blood pressure, blood chemistry, body temperature, heart rate, or whatever, it's very helpful to a medical professional (and ourselves) to know what is our personal "normal" and what is not.

I like to keep aware of several critical factors. If I shoot the heat gun laser beam on the seawater intake valve, I have a pretty good idea of the current water temperature. After running the engine for a few minutes, at idle and neutral, I can take a look at the cooling water temperatures at several points along the pathway: at the saltwater impeller casing, at the water temp sensor, the heat exchanger casing, and the inlet to the exhaust manifold, as well as the outlet side, a couple inches away (or even the exhaust hose. This gives me the basic info to know what is happening under no load conditions, how efficiently the heat exchanger is doing its work, and how well the exhaust/seawater mixer is doing its thing.

Then, with the dock lines secured, run the boat in forward gear at about normal low idle speed for ten minutes. Take the range of temps and record them. Increase the speed to normal cruising RPMs and do the same. You can also record this static test at higher RPMs if you trust your dock cleats. Then take the boat out for a spin and get the same range of temp testings.

If, over time, with similar seawater temperatures, you notice that the temperature is rising significantly, especially at the temp sensor, the inlet to the exhaust mixer and the exhaust hose at the connection to the mixer, you might want to consider further examination of the possible causes: an impeller that is starting to go bad, issues with the heat exchanger, or possible blocking of the exhaust elbow by corrosion. This gives you an easy way to regularly check the engine's performance, based on temperature data. I also record temperature at a number of other spots, just because I'm curious. These include the alternator case, the transmission box, the injectors, the shaft log, and shaft bearings. Think, anything that might go bad, will, especially if you aren't paying attention to them. Heat guns are relatively cheap and provide a great deal of info, but only if they are used in a regular and consistent manner, and the results are recorded. I like to keep mine in the engine maintenance log for future playing around with on the Excel program. You can have a ball making charts that might be very useful when discussing performance with your mechanic.

[cdreid]

To you guys who want to do thermal imaging there are two cheap options. One is a film camera and ir film of course (an slr)

the other is to simply remove the filter from the front of a digital camera or webcam. That and a visible light filter are the difference between an expensive "digital thermal imaging camera" and .. digital camera. The filter usually blocks ir and uv.