Another carbonation question

Hey all!

I recently picked up a SWEEEEET craigslist two tap kegerator. In order to reduce the amount of (justifiable) grief I get from SWMBO for another CL acquisition I had to sell this as a "family kegerator!!!" One tap dedicated to support my brewing, and one for soda for the kiddies.

My current brew has a way to go, and while I'm trying to find a place to put this new beast in my house, it sits in the garage unplugged. I figured I could at least get started carbonating some water.

I filled a 5gal corny to about 6 inches from the top with tap water, then hooked up my CO2 and set the reg to 40psi. It's been sitting for two weeks and I've given the keg a few good shakes here and there, but it's still coming out of the tap flat. I see a few bubbles dancing around, but it's basically flat.

I know CO2 gets absorbed more efficiently with cold water, but shouldn't it still work with room temp? I also thought maybe I filled the keg too full, but I would assume it would still take on CO2 since it is being pressurized from the tank and regulator.

Am I missing something, or do I just need to drop the temp?
I'm relatively new to brewing, but my brews to date have turned out great. Now I'm a little embarrassed I can't even make water fizz...

Thanks in advance for any advice!!!

Just checking; Did you leave it with the pressure on all the time or did to set it to 40psi then turn off the gas?

Left on all the time. Initially set at 30psi for a week, then after a weak showing I bumped it up to 40psi.

Thanks!

You may want to chill the water as cold as possible to better absorb co2, then force carb at 30-40psi and constantly shake. Don't just shake here and there. I've seen people talk about setting the keg on the floor while watching tv and shaking it back and forth with their feet for a while. Once it finally stops hissing (co2 going in), it'll be carbonated.

You need to chill it to get what you are after. At 80+ degrees, 40psi doesn't lead to very much carbonation at all. 40psi at 35 degrees will get you into the soda pop range.

Really helpful - thank you!!!

Shaffer is right. Soda and water don't seem all that carbonated until you get into the 4 volumes range and that isn't going to happen at 40psi/70F. Beer will absolutely get carbed (too much) in that situation. The real culprit here is trying to serve it warm. While you can carb anything at room temp with enough pressure, once that pressure is released it won't stay in solution at ambient pressures. Ever open a warm bottle of soda, drink about half of it and recap it? The next time you open it, it's flat. You can really only dispense carbonated liquids that are cold if you want them to retain any of the gas while it's being poured and consumed.

Also, what's the length of your serving line? That might have something to do with it as well.

Pretty short - about 5 feet.

I'm planning on either extending the line to around 25' like I've seen posted, or try a keg insert like described in this post. https://www.homebrewtalk.com/f35/cure-your-short-hose-troubles-100151/

I assumed that if I had good carbonation to start with I'd see more bubble and see them dissipate into flat - like opening a shaken soda water bottle. I don't see any of that...just flat water.