Dropped Better Bottle, how to remove dent

[Skins_Brew]

Sweet! A Science Fight!

 

[keithd]

No, lordbeermestrength's understanding is low.

We're not talking about putting hot water in it, corking it, and leaving it. Sure, over a long time (several hours) it will cool and then contract.

You put hot water in it, cork it, and it *will* expand - the heating of the air above the water causes that. Shake it, and it expands even more. I know this every time I clean my kegs - fill with hot water and OxyClean, seal the lid, and push on the poppet - pssshhh! goes the poppet. I would have to let it cool overnight before it would start to pull a vacuum.

Gosh, and I didn't even get a 4-year degree.
-keith

 

[MoRoToRiUm]

No, lordbeermestrength's understanding is low.

We're not talking about putting hot water in it, corking it, and leaving it. Sure, over a long time (several hours) it will cool and then contract.

You put hot water in it, cork it, and it *will* expand - the heating of the air above the water causes that. Shake it, and it expands even more. I know this every time I clean my kegs - fill with hot water and OxyClean, seal the lid, and push on the poppet - pssshhh! goes the poppet. I would have to let it cool overnight before it would start to pull a vacuum.

Gosh, and I didn't even get a 4-year degree.
-keith

The oxyclean has a lot to do with the expansion in that situation- Oxyclean is a bicarbonate cleaner, right?

 

[BargainFittings]

To see what boiling water will do to your better bottle, try it on a 2 liter bottle first. PET plastic does not like boiling water.


A more interesting experiment would be to ferment a batch in the dented bottle and cap it shut until the dent pops out. Probably will have to duct tape the cap shut.

Video/pictures would be great!

 

[lordbeermestrength]

No, lordbeermestrength's understanding is low.

We're not talking about putting hot water in it, corking it, and leaving it. Sure, over a long time (several hours) it will cool and then contract.

You put hot water in it, cork it, and it *will* expand - the heating of the air above the water causes that. Shake it, and it expands even more. I know this every time I clean my kegs - fill with hot water and OxyClean, seal the lid, and push on the poppet - pssshhh! goes the poppet. I would have to let it cool overnight before it would start to pull a vacuum.

Gosh, and I didn't even get a 4-year degree.
-keith

I don't beleive my understanding is low. I just read what was said by Neunelfer. Did I misunderstand? Doesn't look like it.

If you fill it with hot water and then cork it, it will force the water to expand and create a higher pressure and will probably fix the dent, assuming it's not on a crease.

Yes and no.

When the hot water gets into the tank it will still be vaporizing. If the water vapor has nowhere to escape since you capped it and it is an expanding gas it will increase the pressure. Once the gas cools (which will take a bit) then it will condense back to liquid form.

 

[Neunelfer]

I don't beleive my understanding is low. I just read what was said by Neunelfer. Did I misunderstand? Doesn't look like it.

The problem here is that I used vague terms so that the average Joe could understand. The expansion comes from the gas, a combination of the water vapor from the hot water and the gas already inside the bottle. If you keep the volume and moles of gas constant and increase the temperature the pressure has to increase. You can see this from the ideal gas law: Pressure x Volume =moles x Gas constant x Temperature. Since V, n and R are constant it is basically the relationship of pressure = temperature. You do believe that the temperature of the gas inside the bottle will increase if you add hot water correct?

I never suggested using boiling water, that was another user. I also do not even know if it would create enough pressure to press out the dent, it was just a friendly suggestion. However, if you add hot water to a gas container under pressure the pressure will increase. I hope you also understand that water is still water if it is a gas, liquid or solid.

If I am missing something or my logic is somehow flawed, please point it out... I come here for fun not to have some question what I "obviously" have or have not taken. If you want to debate the topic, feel free... but no need to be rude about it.

 

[Poobah58]

Mythbusters did an episode where they pressure tested standard 5gal water bottles and they held 95 psi. I would guess a better bottle could do the same, so if you stay under 30 or so it should be doable.

Either way though, I would rig something and have it at the end of a 50' air hose. If it works your better bottle is fixed. If it doesn't you have a $25 firecracker.

Even at 30 psi it can hurt you. Try calculating how many pounds of air would be in the carboy. That's 30 lbs/sq inch times the amount of cubic inches in a carboy. You should fill the carboy with warm water at least 75% full, THEN put 30 psi on it. Much safer!