"The smoking lamp is out."

[redboat219]

Gas ballast system usung a disposable Bic lighter to blow the tank and a small diaphragm pump to vent the tank to dive.

[RCSubGuy]

That is out of the box thinking! I never thought of using a pump to vent the tank. Should work really well. Great idea using the BIC, too. If it was readily accessible, it would be easy to swap out after the first one is depleted. Would be interesting to implement as a gas backup system!

Thanks for sharing!

[redboat219]

A gentleman from down under Chris Mckay (forum name Oztruck) did an I-25 build using the 1/72 Lindberg kit. He used a pair of diaphragm pumps to vent and blow his sub's ballast tank.

https://forum.rc-sub.com/forum/build...i-i-25-in-1-72