foamy pours on nitrogen (beergas) tap

I built a double nitro tap keezer recently.
I force carbed on the nitro @ 30-psi (burped keg each day for 4 days)
I serve also at 30-psi
Nitro-tap with restrictor plate (guinness style taps)
My particular gas tank is 70% nitrogen and 30% CO2
My temp controller is set to 42-F (it sits between 35-41)
Beer lines out to tower are 10-ft long
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pours 100% foam that 50% or more turns back into liquid in a minute or 2
(guinness wait time avg)
now i dont YET have the copper tubing surrounding the beerlines in the tower but after pouring one checked the tap,it was cold to the touch.So i poured a 2nd beer immediately.It also was 100% foam.
I pour into beer glasses pre-chilled in the food freezer (not the keezer)
The keezer sits in the garage where it is easily 90-F (it IS new mexico after all)
The beer i am pouring also has a pretty hefty amount of lactose in it.
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Basically i'm trying to narrow down why it's all foam on the pours
or figure out if it truely is the combination of the things i mentioned above.
I've read some (prolly guinness) reccomend 38-psi and not 30-psi.
Any stout tap dial in experts out there?
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TY in advance
Paps

 

First thing. Do not use glasses from the freezer. This will cause a lot of foam. Use room temp glasses.

Here is my technique for my nitro tap. I carb the beer using CO2. I set it at 5-8 lbs for at least a week. I then switch the keg to the beergas set at 35 lbs. My kegerator is set at 45. I get a nice pour with some foam, let it settle and top off. Nice cascade.

Hope this helps.

 

I've never used beer gas, but I can't figure out why carbing with CO2 and then switching would make any difference. Enlighten me please.

 

It has to do with CO2 efficiency.CO2 strives to reach an equlibrium with the headspace in the keg.Beergas being only 25% CO2 means you have to re-introduce CO2 into your headspace.This is done by `burping` the releif valve each day to let more CO2 flow into your keg.By using straight CO2 you just plug it in once and no `burping` is needed.Basically it means less trips to the welding supply store to refill your gas.

I've poured into room temp glasses as well. No change whatsoever,all foam.
Hopefully once i get the copper cooling pipes installed into my tower it will diminish the foam.

 

Ah gotcha. That makes sense. Thanks for explaining it.