Dry Hull Hydrostatic Testing

[Fishb0y]

I'm stuck at a data analytics software conference in New Orleans for the next couple of days. The organizer wisely decided to not bring out caffeine until 3:15. Needless to say, it's been difficult to concentrate until 3:20.

With all of that...I've been wondering how to perform leak tests on my dry hall Type IX.

With the telemetry data with my FrSky reciever, I am thinking of using the Altitude sensor to determine a "leak rate" over time after pressurizing the hull with the pistons.

Of course, this is all theoretical until I reinstall my pistons and seal off my hull.

Thoughts?

[JHapprich]

Put it in the water and check for leaks?

[Fishb0y]

The goal is to verify prior to getting to the water.

[He Who Shall Not Be Named]

Charles's Law will trip you up unless you can work temperature changes into your read-out.

David

[DrSchmidt]

It's an Engel Type IX, right? So it has piston tanks. Drill a hole into the dyr hull and install a brass tube, e.g. 2 mm ID. connect a little pressure gauge to the tube using a rubber hose. Then put the tanks in full-position. That will raise the air pressure in the dry hull. Monitor the pressure. If it drops -> leak

For leak detection take soap water (or snoop https://www.sigmaaldrich.com/DE/de/p...0aAkSCEALw_wcB) and put some drops on suspicious connections and places. If there's a leak, you'll see bubbles.

[DrSchmidt]

If the boat has piston tanks, the air pressure is provided by putting the tanks into dive position

[redboat219]

He has already gutted the boat so it's just the hull. Think he wants to test the hull before he puts the internal back.

https://forum.rc-sub.com/forum/builder-threads/174373-type-ix-refit

[DrSchmidt]

Then it's a valve and an air pump...

[Fishb0y]

Because of the size of the model and the volume of the dry hull, I am trying to use an out-of-the-box (pardon the pun) solution to verify integrity before I head out to a pond for the day. I've monitored plenty of hydros in my career, as well as some intimate time with "Chuck's law" by taking a reactor loop/pressurizer solid a few times.

The new receivers from FrSky have the ability on monitoring Altitude, which is what I'll use to record the internal hull pressure. As was mentioned earlier, pressurizing the hull would be through placing the pistons in dive then monitoring the "altitude" and temp over time to determine leak rate.

I'm actually cutting another couple of access holes in the dry hull for better servo placement. When I have the boat all buttoned up, I'll readdress my hydro procedure.