FLIR Infrared Camera for finding internal chainplates?

[Jeff on Aurora]

Good morning all!
Has anyone used a FLIR or similar infrared camera for examining hidden hull structures? I need to accurately find the hidden edges of the chainplates on my boat.


I love my Island Packet 38 and have cruised her for 20 years. She was built in 1988 and I'm now facing the dreaded internal chainplate replacement. I have not broken any (yet) but I want to replace them all with EXTERNAL chainplates before resuming my offshore sailing. (Editorial: these are fantastic boats, but why did they make this dumb design decision??!!)

It is difficult (near impossible) to accurately find the edges of the existing chainplates because they are heavily fiberglassed directly to the inside of the hull. My plan is to map out the old chainplates, then use them as backing plates for new external ones.

I am interested in hearing from anyone who's had a similar problem and hearing about how they tackled it.



Thanks in advance,


Jeff

[LakeSuperior]

A FLIR would work best under conditions of high thermal gradient between the inside of the cabin and the exterior hull.

For example, image the areas of interest when there is direct solar on these exterior areas first thing in the morning. The surface over the chainplates will be cooler as the conduction is higher through the metal.

Another approach is to heat the interior cabin on a cold day. In this case the area over the chain plates should be warmer due to the increased conduction.

Least favorable time to image is when the interior and exterior temperatures with no solar are equal.

There may be confounding factors due to geometry and construction but my guess is the above should work. In fact, I would go with the second approach above. Lots of luck.

[massnspace]

Can you drill a series of (very) small holes to map out where the original chainplate is?

Cover the holes with a wood plate or something later…

[JBP]

Electronic stud finder?

There are also places that specialize in Island Packet chain plate repair that could advise you.

[boatpoker]

Easy with a moisture meter, they measure capacitance, not moisture.
Moisture Meter Mythology and Flir thermal imager

[jharding]

I had mine xrayed, all was good

[boatpoker]

Originally Posted by jharding

I had mine xrayed, all was good

X-ray'd in place ?
Cost ?

[Flatswing]

Originally Posted by boatpoker

Easy with a moisture meter, they measure capacitance, not moisture.
Moisture Meter Mythology and Flir thermal imager

Yep, my Skipper moisture meter screams as it passes over backing plates, depending on the hull geometry you may be able tobmap the edges to within 1cm/1/2” I would think.

[Jeff on Aurora]

Originally Posted by boatpoker

Easy with a moisture meter, they measure capacitance, not moisture.
Moisture Meter Mythology and Flir thermal imager

Jackpot! What a wealth of information and real-world experience! Thanks so much for posting this.



A local surveyor stopped by earlier and used a combination FLIR IR camera and moisture meter. Any opinions on this piece of (expensive) gear?

https://www.bhphotovideo.com/c/produ....html/overview

[LakeSuperior]

I would wait until they upgrade the unit with speakers, Bluetooth, and hot and cold running water.

Seriously, as said earlier, doing the measurements and interpreting the data requires technical skills. One needs to be a engineer or trained technician or live at a Holiday Inn Express full time. It's a piece of test gear for a professional that understands the phenomenology.

[boatpoker]

Originally Posted by Jeff on Aurora

Jackpot! What a wealth of information and real-world experience! Thanks so much for posting this.



A local surveyor stopped by earlier and used a combination FLIR IR camera and moisture meter. Any opinions on this piece of (expensive) gear?

https://www.bhphotovideo.com/c/produ....html/overview

Yes, I have an opinion
It's at the bottom of my article on Moisture Meters.

[jharding]

Hello, as posted earlier I had my chainplates xrayed while in the boat by a company that x-rays pipelines etc. Company was Fugro, I was in Kemah TX, took about an hour cost $ 1000 very professional, no doubts

[boatpoker]

Originally Posted by jharding

Hello, as posted earlier I had my chainplates xrayed while in the boat by a company that x-rays pipelines etc. Company was Fugro, I was in Kemah TX, took about an hour cost $ 1000 very professional, no doubts

Wow ! Thats a great price. I've never heard of it being so cheap.