Need to add inspection port, baffles?

[Mach_cat]

I need to add inspection ports to my fiberglass tanks.
Need to know where the interior baffles are before cutting into the tanks.
Each tank is approx 200gal.
I can see nothing on the outside of the tank where baffles might be.
Are there stud finders out there that might locate a baffle?
Thanks Ed

 

[Lepke]

Rarely is there construction signs from interior baffles. Baffles are glassed in, all on the inside. You might try flexing the top and see where there is resistance. Otherwise sound. Maybe tap the surface. Or if you know someone with the sonic tool for gauging the thickness of steel hulls. Possibly a depth sounding transducer moved over the top?
Stud finders find fasteners unless there's a sonic version.

 

[twistedtree]

Any chance of getting a small inspection camera into the tank through a level sender port or something similar?

Glassed in baffles are interesting in the context of an inspection port. With glassed in baffles, you might not be able to inspect beyond the segment where the port is located. Our tanks have removable baffles for exactly that reason. You gain access through the inspection port, and can then subsequently work your way to access the rest of the tank. It's something to think about.

 

[Northern Spy]

Stud finders find fasteners unless there's a sonic version.

Most stud finders from the last 10 (20 probably) years or so are sonic. It would work fine. Used one to find frames through my boats hull.

 

[Simi 60]

Tap tap, then cut small hole then the bigger one after you have figgered out where the baffles are.

 

[kapnd]

Tapping works best if the tank is empty, or at least low.
This got me thinking about the same issue in my own boat, which is full of fuel, so I went for a boatride to warm up the fuel, then shot it with the thermometer gun, and was able to clearly define where the first baffle is, and since that is about a third of the tank, deduced that there is likely another at 2/3.

 

[Mach_cat]

Great thought

 

[Tom.B]

Tap tap, then cut small hole then the bigger one after you have figgered out where the baffles are.

Yea... with the luck I have with boat repair? I would hit the baffle first try. [emoji35]

 

[DHeckrotte]

How long are your tanks? My (limited) observation is that baffles are spaced about 24" apart. Divide the length of your tanks by some whole number which results in about 24" +/- 4". As suggested above, drill an exploratory hole and then probe/peek. Your exploratory hole should be arranged so that it will be included within the full-sized access (so you don't have to fix it).

 

[kapnd]

DHeckorette,
Assuming anything about the way a boat is built is likely to be a mistake!
There are obviously going to be existing holes, filler, vent, supply, return, that would be usable entry points for a borescope of just a piece of bent wire to "feel" for the location of the baffle.
A U shaped wire inserted to the apex of the bend will give a pretty good indication of where the bottom half of the wire is.
There is very limited room above the tanks on my vessel, so I'm probably going to have to cut holes in the floor to create access ports, so gotta get it right first time.

 

[Mach_cat]

Hmmm Kapnd, you gave a direction I had not thought about.
I could cut a hole through the walk around and be directly above the tank. I have full covered walk around, So the access port then could be on top instead of the side of the tank.
Easier to clean after when done. My tanks are glass so even if some moisture could get in it woul be safe. I like it!
Thanks.