Warning For Water Hunters At This Time Of Year:help:

[John-Edmonton]

Sometimes the laws of physics are at play without us even being aware of them. For instance, if you take a plastic sealed container, put a small pin hole in it and submerge it hot water, you will notice shortly that air bubbles will start to leak out under pressure, simply because the inside temp is warming up, causing a positive pressure.

Now reverse the conditions. Warm the plastic container up, and place it in cold water. What happens? The cooling of the temperature caused a low pressure or vacuum to appear inside the container, and in order to reach an equilibrium, it sucked in water.

Watch how hot your equipment is before you submerge it in cold water. A metal detector in the car trunk or in the car with the sun shining on it will cause it to get extremely hot. By putting it in the cold water, you are causing a tremendous amount of vacuum to be produced as the the inside of the coil, connector or electronics box tries to reach an equilibrium of pressure. Create enough vacuum in the coil, connector, splicing, electronics and you might get some leakage. Please......cool your equipment off before suddenly submerging it in cold water. This is true for all makes and models of detectors. Although leaks can occur for many other reasons, this should surely help.

 

[mudpuppy]

John, I've often wondered about that...concerning the AtPro...we have all done that experiment in school where a guy heats up a glass milk bottle with a little water in it, and puts an egg on top, to watch the egg get sucked down inside when the bottle cools!...The Pro's battery box should behave the same way, neg pressure from the temp change...That said, I leave my Pro out in the hot car with a towel draped over the box..sure, I generally hunt mornings, when everything is sort of cool and balanced, never had a problem with this temp differential dynamic, but I do know it exists, I have wondered if it would be a good idea to open the battery box, let the temp balance, and then reseal it before submerging the rig in cold Lake Mi waters...sure couldnt hurt to pay attention to this phenomenon and at least be aware of it and take appropriate measures to ensure a successful hunt. Has anybody else experienced this issue with the Pro? I have not, no matter how shamefully I take care of and go out of my way to abuse this rig, it seems to be just fine! Good food for thought, Thanks John!
Mud

ps, I wonder what kind of rigorous testing was done by Garrett regarding this? must have been a lot, still, it would be cool to know exactly what that box can take from a temp diff standpoint....'130 degrees F to 40 degrees F' and so on..

 

[upnorth]

Thanks for the heads up guys. I never found water detecting to be a primary area of interest, but that may change. I always try to be careful in regard to not leaving a detector in a hot car etc. So..... is the idea behind this to give the machine some cool off time before water use, if hot. Maybe I'll dribble or hand flick some shoreline water on to the coil and brain box housing for a lite cool off, on a scorcher day, if going in.

 

[ajaj]

John,

This is most excellent advice!

aj

 

[mudslingers8]

The gulf of Mexico down here is 90 degrees, bath water! Thanks for the good advice.

Mudslinger

 

[senda]

Thanks John, good advice.

 

[JimmyCT]

Thanks for the tip. Much appreciated.

 

[surf n turf]

Thanks John, I will remember this in Daytona next month.

 

[togamac]

n/t