I used to exchange at Roberts, and yes they would take your nice shiny empty tank, and give you a crappy beat up filled tank in exchange.
Better price is to get your tank filled at Fire Line in Leesburg. I can't remember what I paid, but was cheaper than Roberts.
Fire Line Corporation
12 Cardinal Park Drive Southeast
Leesburg, VA 20175-4402
Thanks - but they dont' do beergas there just CO2. Tried all the known shops in the area and nobody does beergas fills just exchanges. And it seems the only options for Co2 fills are fire extinguisher repair shops or bars by bud...who wanted $60 for a 20# fill and 23.xx for a 5# fill! Roberts has better tanks now and is $22 for a 20# exchange or something like $19 for a 5# exchange. Fireline is $17 to fill a 5# and 28 to fill a 20#.
Oh well, did a fill at fireline but will probably just start doing exchanges at roberts from now on since its right near my house...
for anyone else reading there is also arcet in manassas.
Also roberts will allow you to swap a 5# co2 tank for a 20cu ft nitro/co2 (beergas) tank.
last tank my buddy got from roberts last year wasnt actually too bad, aluminum, only a few marks on it, but no big deal.
Arcet does beer gas, but not fills. In fact they aren't allowed to fill at the Manassas location. Arcet actually supports bars and restaurants as well as welders. A couple of the guys there are beer drinkers. The best thing about them is you find an old tank that is out of hydro date, take it there and turn it in and get one that is full and with a good hydro date. They also do trade up like you mentioned on our website today. I orchestrated a trade up from CO2 to Beer gas for someone else and it wasn't too bad a deal.
Back to Arcet, park at the dock on the left side (you aren not supposed to carry bottles through the front door) set your tanks on the dock, you will see the filled tanks there. If you see a nice pretty aluminum tank in the filled area, ask if you can get that one. I don't care anymore about my tanks I've got two 20lbs, a 10 and a 5. the 5 is the only one that's aluminum.
I have also suggested to the owners of Sterling Silver SCUBA to sell CO2. Jason one of the owners is going to look into it. IF it is profitable, they may start selling it. They fill SCUBA tanks already so they are hip to the Hydro date stuff on the tanks. We'll see. Beer gas would come after that IF they go down that road and it works for them, I would think. We'll see.
Their address is 1102 W. Church Rd in Sterling, VA 703-421-3483. Their website is silverdivers.com I don't know if they would put the CO2 stuff on the website since it isn't really the focus of their business.
Like was posted - is it just a Nitrogen/CO2 combination?
If so, what's the ratio? Does it change the flavor/taste of beer? I was under the impression that most bars just used straight CO2 to run the taps.
Curious about the beergas mix... would it be possible to run regulators on two separate tanks that would let you have a separate Nitrogen and CO2 tank, and fill both separately, rather than trying to find beergas (if it's that much of a pain to find)
Best deal in the DC / NOVA / Maryland area: $25 for 20lb refill (!!).
There are only 2 Robert's Oxygen locations left that do offer CO2 refills (not only offer exchange like the other locations). One is in Gaithersburg, MD and the other one is in Temple Hills, MD which is closer to NOVA.
The 20lb refill costs less than $25 including tax (as of November 2012). Can't beat that! They do refills for bars and restaurants in NOVA too so their gas is definitely stored in clean tanks (good to use for Sodastream / beer brewing). Paint ball shops don't have strict requirements about how to store their gas as it is not intended for ingestion and may even contain small amounts of Dioxane, depending on how it is stored.
So, for those who want to have peace of mind and not break the bank, give them a call. The employee I talked to at the Temple Hill branch was very nice and he said that they will fill have filled your tank by the next day (as they wait for more than just one tank to fill).