Kegged Soda Foams!!

I've had quite a bit of trouble with my kegged sodas. What always ends up happening is I try to pour the soda and it just comes out as pure foam, and then loses a ton of carbonation.

Previously, I've attributed this to things like, oh there are pieces of cherry in it so that is why it is foaming. Or, I made this root beer from scratch, so something in it is foaming up.

I decided to go easy this time and made some root beer from an extract. It tastes great, but it does the same foaming nonsense as all my other sodas. When I pour a glass after its been sitting for a while the soda in the line comes out fine, but then after it runs a bit it starts foaming up. What can I do to try and help this? Is it coming out too fast?

Here is my set up for the soda:
Kegerator is around 39 degrees F
Pressure is between 30-35PSI
The line from the keg is 3/16 ID and 25-30 feet long(don't remember exactly how long)

Thanks in advance! I hope someone can help with this. It is driving me crazy... At least my beer doesn't do this!

 

A whole bunch of people here took to using those two part epoxy mixing sticks, and pushing one or two down the diptube to create some internal resistance.
Been awhile since I read that thread, but I seem to recall something about reducing the flow rate before the tubing, while still maintaining pressure is key. I think there was a commercial device for this as well.
If you search for "epoxy mixing soda keg" it will probably come up close to the top.
35 psi @ 42F through 15 ft works for me with plain water. Flavor changes the game.

Edit: the search feature on the phone app could not be worse if it returned random results from 1998.
This is the link:
www.homebrewtalk.com/f35/cure-your-short-hose-troubles-100151/

 

Maybe the reason it works is that the dip tubes ID is too large? Therefore, the flow in the dip tube is too high and knocks the carbonation out before it even gets to the 3/16" hose?

 

Yeah... So I got those epoxy mixers, but I still have the problem. I didn't cut the 30ft of hose back at all and just put the mixers in the dip tube.

The soda still foams up on its way out. It is foaming up before it even gets out of the faucet, it foams up about a third of the way into the line. Whats that all about?

Also, I am using vinyl line. Is there something about vinyl that makes this problem worse? Is PVC better for this kind of thing?