Froze beer and foam ?

Ok, I had my keg set up and nicely balanced (no foam) but......

I'm now down to about 1 Gal in the keg and I think my freezer is much colder on the bottom than at the top where I placed the thermostat. Which caused that one gallon to freeze a bit. So I took it out and thawed it out and vented the keg hooked it back up at about 13PSI and I get foam like crazy. I gave it 8 hours on the 13PSI and same thing. Do I just need to take it off the gas and vent the keg a little (how long?) or what? I'm not sure why my beer slushy would be causing this problem. I have since added a small computer fan to circulate the air in the freezer.

Also I have 3/16 inch line at 6ft.

I think I know why this happened.

When the beer froze, it could not hold the dissolved CO2 in suspension any longer and thus forced it out (the ice crystals have no place to store gas molecules). This would cause the pressure inside your keg to jump way up above the 13psi you had it set at. If you did not vent the keg and release the pressure, and you didn't give the beer time to reabsorb the gas, then it would force the beer through the lines and out of the faucet with way to much force and foam all over the place.

Does this sound right? (I knew my engineering degree would be useful somewhere)

FYI, beer doesn't last long in my 2-tap kegerator. Therefore, I don't really have to worry about CO2 coming back out of the beer after being carbonated. I say this because if this is your case, and you aren't storing your beer for a long time at "serving pressure" then you can turn your regulator way way down. I run mine at about 3 psi. It pushes the beer out nice and slow and never foams.

That makes some sense, but after I disconnected it from the Co2 and vented the keg and hooked it back up to 13psi (my carbing and serving pressure) it should have came out fine if that were the case. Maybe flat I guess, but not foaming like crazy. I'm gonna check it again tonight and if It is still foaming I'm gonna disconnect it from the gas and vent it over the next 24 hours or so and hook it back up and see what happens.

I think you might be on to something, but I don't think that explains it 100%. I'm sure with all the weekend chemists on this board that we will figure it out.

my guess is there is ice in your lines or faucet.

It is mostly likely both. If you did vent the keg right before serving, then there must be some sort of blockage in the line.

But yes, the beer will be flat if not given the time to re-carbonate.