R/C Naval Combat

HI every one. I'm new to this world of battle ships and i need alittle help for my ship.

I am setting it up for fast guns. Right how i'm planning on having a gun facing on the starboardbow and portbow and 2 off the stern. I have 3 2port poppit valves and plan on running the stern guns together since i only have a 4 channel radio and i needed a way to turn a pump on and off

What i would like to know is "should i run an expansion tank for each of the guns or can i use 1 tank to feed them all?"                                    If it will help i can post a pic of my radio box i9n the ship to give a better idea of what i have and if i can get a pic or a link to show me what to do that would be a great help

I would use two small ones, one for the back to run the duals and one up front for the sides. An expansion chamber gives the Co2 a place to turn to gas. Long hose will act the same but two small ones ( 2" X 3/4 pipe) should do.

if you need a place for co2 to turn to gas you need to examine your bottle set up. You do _not_ want to be passing liquid co2 out of your bottle through the reg to the low pressure side. This is how you blow things out.

For our hobby the term 'expansion tank' is a misnomer. We use regulated co2 and have a distinct low pressure side that should not be subjected to the pressure created by expanding liquid co2. The 'expansion' chambers we use are merely accumulation vessels, a place to have a ready supply of gas near to the guns, when you combine them with back-flow prevention at their input they create dedicated supply for each gun to ensure that firing one gun does not rob the other. Long hose runs to your firing valves act in a similar way by providing a holding area of sorts for each gun.

Edit: more Topically:  I would agree with Tugboat's suggestion, give each stern gun a dedicated tank with a mpa and mav2 (or solenoid), trigger the mav2s (via the MPA) with a single mav-3 (it has to be a 3 because you need the pressure in the line to drop after you release it).

Trying to fire two guns off of a single mav-2 can result in spotty performance as others have noted here.  The biggest problem is that as once one gun fires the pressure to the other can/will drop as the gas can now freely flow out of the cleared cannon. 

Of course, it really depends on how much space you have in your ship, if you're building something small, space may be at a premium and you just can't fit the ideal world in. 

Both points absolutely correct and no, I'm not dumping liquid co2 into my system. Always make sure your bottle neck is pitched up in it's mount.

 No offense taken. anything that keeps someone new from getting hurt or building something unsafe is good. I'm sure the dangers of liquid co2 in the system are not know to someone starting out.

I was only using the titan because i can put them in a deep V later down the road, the same with the ESC. Payed $20 for both motors  

uummmm...........there are.........12.....turn....titans             very BIG drag props needed LoL

I'm not the best with fiberglass but i see where you're heading with it. The Concreate filler i was going to use comes in a tube. From what i've been told its more rubbery then concreate and the ships i've seen with it in seem to be fine

Now that i looked at the batteries they are 6V 7.2Ah lead acid