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Bottlecaps are touch and go.

3K views 22 replies 12 participants last post by  Daemonfly 
#1 ·
Hey all, I'm doing the typical DIY yeast CO2, with silicone as a sealant for my bottlecaps (where the tubing runs through). Does anyone have experience with a more durable seal? I thought silicone would do it, but I guess not.

--cich :?
 
#2 ·
Try Liquid Nails, clear caulklike stuff from the hardware store. I've used it on bottles that were leaking in use, under pressure: tear away as much as possible of the silicone, then goop on the liquid Nails.
 
#3 ·
I have had 200% success with these...

http://www.rittenhouse.ca/images/products/commercial/big/hose_barb_swivel.jpg

they're called hose barb adapters. I got them at home depot for about $1.19 each and work so well, no glue/sealant is needed. I was even able to stand on the two liter bottle putting 160 pounds of weight on them w/o a hint of a leak.

There is a certain way to attach them or it won't work. First drill or puncture a small hole in the cap. Then taking one blade of a scissor, insert it into the tiny hole and gradually twist it 360deg. until the hole has be worn slightly smaller than the threaded part of the hose barb. The hole should be so tight that you won't be able to screw it in with your hand but need a wrench or ratchet. Good luck!

BTW, some people say not to use metal fixtures because the acidic environment in the reactor bottle will rxn them away...I have yet to see any problems.
 
#4 ·
ok i've heard of two things that may work.

i know rex has had good success in some settings with drilling a 11/64 inch hole and pulling airline tubing through the hole.

also you could use a piece of rigid tubing and a cork. glue the cork onto the inside of the bottle cap. next, drill a hole slightly smaller than the tubing through the cap and the cork. shove the tubing through the hole, hopefully shouldn't leak.
 
#5 ·
Actually, this makes me wonder. We all know not to use anti-mildew caulking in the tank, but what about for this? Is there a risk of it poisoning the watercolumn?

And anonapersona, do you have a problem with the Liquid Nails curing in the tube? I have two tubes of silicone here, rock solid.

--cich
 
#6 ·
cich said:
Actually, this makes me wonder. We all know not to use anti-mildew caulking in the tank, but what about for this? Is there a risk of it poisoning the watercolumn?

And anonapersona, do you have a problem with the Liquid Nails curing in the tube? I have two tubes of silicone here, rock solid.

--cich
I never used it inside the bottle, just on the outside, since I didn't think it could be fish-safe.

The tube I have is getting thick, I've opened it and used it maybe 6 times or so. But it is still working, and I don't think it was new when I first used it, it was laying around the garage. A small tube would be a better idea.
 
#7 ·
I ended up picking up some kind of plummer's sealant that has both plastic and rubber in its list of compatible surfaces. I'll be careful to keep it on the outside only.

Thanks All.
 
#8 ·
Hmm, the sort of adhesion that is required to seal againt gasses under pressure may be different than against liquids, but I don't know.

I think plumbers sealers are designed for use between wider surfaces and for water intrusion under no pressure, like the chrome bathtub drain aginst the porcelain tub. Just guessing on that though.
 
#10 ·
cich said:
I was wrong about it being for plumming. It's more of an all-purpose sealant and adhesive. My bad.
Hello all.
I don 't kow what all this fuss about the seal on the bottle is about.read and learn.
Take a piece of your tubing and go to your nearest hardware store. Take your tubing an measure with the little gadget they use to measure the drills.
buy a drill two sizes smaller tha the tubing.
after you drill the hole on the bottle cap.
cut the tubing at a sharp angle.
if done correctly the tubing wil partialy go through the hole in the cap.
Use a pair of needle nose pliers and pull the tubing trhough the hole in the cap.
you will notice that there is no way that it will ever leak.
I recomend you go for the silicone tubing. It works really well.
Any dought e-Mail me at ptaquati@hotmail.con
 
#11 ·
Yep! I can vouch for that meathod. I used sealent 2 times now, after twisting the bottle for a refill... Pretty much gone... :(

So I did ptaquati way.

But instead I just used a plyer and stuck a nail about smaller slighty then the air tube to it and carefully put cap on ground and used plyer to get a hole of the nail and push it into the cap, Cut the airtube on a angle so it was sharp, stuck it in, got a bit stuck, used plyers to pull the rest down.

Tested it by filling full of water, turning upside down no water leaked, Squeed it no water leak besides going out of the air tube. 8)
 
#12 ·
That's never worked for me... ALways have to seal it.

ptaquati said:
I recomend you go for the silicone tubing. It works really well.
Just recently we've been talking about how silicone tubing is the WORST to use with CO2. It's just too permiable by the gas. I still use it though LOL

--cich
 
#13 ·
I suspect that permeability is not so bad under very low pressures like we have in DIY CO2. It would take a bigger pressure differential to drive much leakage.
 
#14 ·
Yeah, you're probably right... I get good flow with mine, but the only silicone is on the bottlecaps. I should try doing the sealant-free method, just making very sure that the inside of the hole is very smooth and almost polished. That's what's been stopping me I'm sure.

--cich
 
#15 ·
Just understand that the tight fit that you have creates an obstruction to flow. Probably not important.

Being a belt and suspenders sort of person, I couldn't trust the tight fit to hold perfectly, so I sealed it on the outside anyhow.

Some leaked, some didn't, some were really smooth, some were not smooth enough. The stuff I use holds, so I don't worry anymore.
 
#16 ·
I have used the drill and pull method on many DIY bottles and on my external reactors. It creates on restriction to the flow of the gas since gas pressure is going to be equal though the system. Also I have NEVER had one fail. I do replace the tubing on my external reactors every year though.
 
#17 ·
:arrow: Hi, it's Pete again.
My original reply is about 5 replies above this one.
If you want to be extra cautious and make sure the tubing doesn't pull loose. Put a 1/4" long piece of rigid tubing inside of the silicone tubing,"just inside the bottle cap",and then pull the tubing fom the opposite side...
 
#18 ·
Of course, the ultimate, fool proof solution is to replace the DIY with pressurized co2. On my 55 gal I now have to think about co2 about once every eight months. When the tank gets low, I cut the tubing off the needle valve and take the whole thing to the fire extinguisher place. He removes the regulator, fills the tank and reattaches the regulator - with just the right torque. Then I clip off the stub of tubing, reattach and I am done for another 8 months.

Bob
 
#20 ·
Thanks bob! I am wondering where can i refill this tank!
*i thought they will use vehicle gas* :oops:
 
#21 ·
I just cobbled up a "Home Depot special" for a pop bottle generator because my techie side wouldn't permit me to just stick some tubing through a hole in the cap, seal it, and hope for the best. I found that if I ground off most of the male threads on the bottle that a garden hose female connector threads on quite nicely. So I picked up a female-to-male garden hose adapter with integral ball valve (for disconnecting the set-up without mess) from H-D's garden center, then I wandered over to the plumbing section and picked up a garden hose female to ½" NPT female brass adapter and a ½" male NPT x ¼" tube fitting nylon adapter. Hook it all together and you have a nice leak-proof pop bottle top with integral shut-off valve and tube fitting.

Derek
 
#22 ·
Just tried the bottle cap hose connector. It seems like too many people are complicating this. I took a pepsi cap and drilled a 5/32 hole from the outside. Changed bit size to 3/16 and drilled again from the outside. I use two drills so the hole does not go out of round. I drill from the outside in so the extra foam from the bottle cap seal is facing down into the bottle. I cut a piece of rigid airline(from undergravel filters) about a inch or so. I place some silicone tubing on the rigid tubing as far on it as I could and force it down into the hole until the silicone hits the top of the bottle.Very simple very strong . Passes mouth test with ease. Time 3 min.
.......Mark
 
#23 ·
When I need a good seal on air/CO2 lines I drill a clean hole the same diameter as the silicone tubing or just only slightly smaller. Push the tubing through, leaving about a 1/4" out of the hole. Take some ridig tubing & cut off about an inch, then force rigid tubing inside the silicone tubing (chamfer the end of the ridig tubing to make it easier to insert). This expands the silicone tubing and it gets squeezed between the rigid tubing and the hole you drilled. Just attach another piece of silicone to the other end of the rigid tubing.

I've never had a leak yet.

Similar to oldfarmhouse's method, if I read his post right
 
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