PVC Container Will Not Stay Dry

[+WebChimp]

This is something I've made a work-around for, but I'd like to know if anyone has a real solution.

 

I placed a geocache container that was a two-foot piece of 2" PVC pipe. One end has a PVC cap cemented onto it, with lots of cement. An absolutely solid connection between the two. This end goes up, as the container is vertical, and not on the ground.

 

The other end has a threaded fitting glued into it, with a screw-on cap. This is the "down" end of the vertical container.

 

So, here's this pipe, mounted vertically. Top end is sealed tight. The lower end is where the screw on cap is. There are no holes drilled in the pipe anywhere.

 

The inside of this thing will NOT stay dry. It won't. Even in a moderate rain season, the contents get wet. It's about 15' off the ground, and I cannot keep the inside of this thing dry.

 

I did a work-around for the log by placing a second, sealed container inside the container for the log, but I'd like for cachers to be able to use this for trade items, too.

 

Every PVC pipe container I've ever seen stayed wet inside. Is it just our infernal Mississippi humidity, or is there some grand secret of the universe I've not yet become privy to?

[+WatchDog2020]

I have a PCV cache and used a 'clean out plug'. The plug goes inside the pipe and has a gasket and a wing nut that tightens it. They are made to hold water back - thus will hold water out as well. Over a year with mine and dry as a bone.

 

 

 

Sometimes they call them inspection or test plugs.

Edited May 27, 2009 by WatchDog2020

[jholly]

the water wicks up the screw thread.

 

Jim

[+Knight2000]

You need to use a test plug as mentioned in post #2. I have one that uses a test plug but I am not sure how well it works as it rarely gets found the log signed.

Edited May 27, 2009 by Knight2000

[+Allanon]

From the description, I'd be more worried about the fact that it looks like a pipe bomb.

[+wkmccall]

If PVC pipes weren't water-tight, plumbers wouldn't use them.

I worked as a plumber during the summers growing up and if you know how to use PVC glue and a test cap, it will stay dry....

AS LONG as the last cacher to find it screws the test cap on tight.

Any big-box store will know what a test cap is for a pvc pipe. They run anywhere from .80c each to 2.25 each depending on the size.

 

The screw caps will not keep condensation out of the inside unless you use something like pipe-dope, but I don't think anyone would want to get that all over them by reaching inside the container.

[+wkmccall]

From the description, I'd be more worried about the fact that it looks like a pipe bomb.

 

Don't know many of those made out of PVC, but I guess you could if you wanted to.

This is also why you choose the location somewhere else besides under a bridge or next to a building.

 

The ones I use are out in the middle of nowhere. I have them anywhere from 2" pipe to 4" pipe.

Edited May 27, 2009 by wkmccall

[+briansnat]

I have a PCV cache and used a 'clean out plug'. The plug goes inside the pipe and has a gasket and a wing nut that tightens it. They are made to hold water back - thus will hold water out as well. Over a year with mine and dry as a bone.

 

 

 

Sometimes they call them inspection or test plugs.

 

The only PVC pipes that I evernfound that were dry used something like the one at the top

[+Renegade Knight]

the water wicks up the screw thread.

 

Jim

 

That would be my SWAG As well. The clean out plug seems like it would solve the wiking problem.

[+9Key]

PVC makes a poor cache container in my opinion. If you need a container that is cylindrical try a mortar tube - you can find these one ebay for a decent price. Also on ebay you can find welding rod containers made by Hobart. These are waterproof and fairly inexpensive.

[+j.ollie]

The screw caps will not keep condensation out of the inside unless you use something like pipe-dope, but I don't think anyone would want to get that all over them by reaching inside the container.

 

Teflon tape works well too, but you'd need to replace the tape every time you opened/closed the cache.

[knowschad]

The screw caps will not keep condensation out of the inside unless you use something like pipe-dope, but I don't think anyone would want to get that all over them by reaching inside the container.

 

Teflon tape works well too, but you'd need to replace the tape every time you opened/closed the cache.

 

May 27 by knowschad (13596 found) Teflon tape needs replacing again. Would the cache owner please fix this?

[+paleolith]

Two problems: first, you can't make the threads airtight without making it so you need wrenches to open it. Second, when the air pressure changes, air is pulled in and out. This allows moisture to get in. When the temperature drops, it condenses. Once that happens, it won't get back out except via multiple cycles of air pressure change in a very dry place. It might be dry most of the time in southern Arizona, but almost never in Mississippi.

 

This is why all good cache containers have something flexible where they seal -- the rubber gasket of ammo cans, the O-rings of bison tubes and waterproof matchboxes, the seal in the groove of lock-n-locks, the flexible cap of decon boxes, and the expandable ring of the test plugs mentioned here. I've never seen a dry cache container without a flexible seal.

 

Since you have it set up so the loose end is down, you would actualy be much better off drilling a hole at the lowest point to let the condensation out. You'd have to maintain that inner container, but the outer container would have only a very small amount of moisture in it.

 

I've found a couple of the test-plugged pipes, but the plugs were either loose or else very difficult to loosen. I don't recommend this method unless you have a way to attach a longer handle to the thumbscrew.

 

Edward

[Clan Riffster]

I've found a couple dozen PVC pipe hides. With one exception, every single one was either damp or soggy inside. The openings varied from test caps, screw in caps and unglued end caps. The theory that "PVC keeps water in, it must keep water out" has been disproven so often it amazes me that anyone would even consider using these as caches, especially when there are viable alternatives available.

 

The one dry PVC cache I found used a screw in cap, and the owner put a bead of silicon where the base of the cap bottomed out.

[+Vinny & Sue Team]

the water wicks up the screw thread.

 

Jim

Zackly! Those threaded plug caps were not designed to be waterproof. The answer is to use a waterproof cap or plug, such as the one suggested by a recent poster.

[+gof1]

the water wicks up the screw thread.

 

Jim

Zackly! Those threaded plug caps were not designed to be waterproof. The answer is to use a waterproof cap or plug, such as the one suggested by a recent poster.

 

Or a better container.

[+Isonzo Karst]

I've found a couple of the test-plugged pipes, but the plugs were either loose or else very difficult to loosen. I don't recommend this method unless you have a way to attach a longer handle to the thumbscrew.

 

True dat.

Moreover, after a year or less, the test plug will fail - at least in Florida, and I suspect in Mississippi as well. Stuff gets onto the rubber (i assume people put it on the ground) and damages it or creates a wicking point.

 

A cacher local to me hid quite a few of these, mostly because he already had the PVC and the caps. They were sorta okay for a while and wet thereafter.

I found one of them shortly after it was hidden, and would have DNF'ed it, being unable to open the darn thing, but I went back to my truck for a wrench.

 

PVC pipes aren't good cache containers. They rate on the "keeping stuff dry" scale down there with film cans.

 

Cache of this type placed 4/21/04 dry until 9/14/04 and then, even with a couple of owner maintenance visits to replace the plug, continuously wet until final archive ~ five years later.

[+Knight2000]

Two problems: first, you can't make the threads airtight without making it so you need wrenches to open it.

 

I've found a couple of the test-plugged pipes, but the plugs were either loose or else very difficult to loosen. I don't recommend this method unless you have a way to attach a longer handle to the thumbscrew.

 

Edward

Absolutely, a tool would be needed.

 

I agree about the test plugs. I worry about women cachers. We'll see.

[+Unkle Fester]

Two problems: first, you can't make the threads airtight without making it so you need wrenches to open it.

 

I've found a couple of the test-plugged pipes, but the plugs were either loose or else very difficult to loosen. I don't recommend this method unless you have a way to attach a longer handle to the thumbscrew.

 

Edward

Absolutely, a tool would be needed.

 

I agree about the test plugs. I worry about women cachers. We'll see.

I worry about women cachers too... <wife with fryingpan> WHACK!!! </wife with fryingpan>

 

I used to build houses (before the crash) and used PVC for the building inspectors copy of the plans and permit. but everything stayed wet. The plugs worked good for a while but eventually one would get diirty or not get tightened. We started using mailboxes, always stayed dry. Film canisters were mentioned, they are only successful out this way (NorthWest) when they have secondary containment - a plastic bag.

 

I'm waiting for the 4" wide film canisters to be developed and sold to caches as the macro micro... Then would be the oversized guardrails sold to DOT's for hiding them in. I'm in the wrong business.

[+Nature Kids]

Flip the container over so water does not catch in the lip & wick up the treads. With the cap on top, it works like an umbrella. People think plastic gallon jugs upside down will stay dryer.....its same thing, water catches in the lid lip, & wicks up & everything is wet, flip them over & they stay dry.

[+bittsen]

The reason the cache will get wet is due to "capillary action". It is the phenomenon of liquids defying the natural tendency to follow the path of least resistance. Water film will creep up the threads faster than if there was a hole in the bottom. The reason it will do this is because the film of water, in essence, is creeping up a ramp (the threads).

Add into the capillary action the barometric changes to the container and the container will actually suck the water inside with temperature changes. On top of the, the dew point inside the container will be lowered as the humidity inside the container rises. It is a no win scenario. Each night there will basically be a rain storm inside the container which will, as you already know, saturate everything.

 

The only way to make an easily removable, watertight seal, on PVC (or ABS, as I suspect is actually being used) is with the use of a compression fitting as illustrated in post 2.

[+Arrow42]

I'd had good luck using silicone grease to get a water-tight but still movable threads with PVC. (applications not related to caching)

 

It would require maintenance from the owner - it needs to be re-greased regularly depending on how active the cache is.

 

Not an ideal solution, but it could be made to work.

Edited June 4, 2009 by Arrow42

[knowschad]

June 3 by knowschad (13597 found) This is my 2nd log about this. The teflon tape needs replacing yet again. Would the cache owner please fix this again? Edited June 4, 2009 by knowschad

[+bittsen]

June 3 by knowschad (13597 found) This is my 2nd log about this. The teflon tape needs replacing yet again. Would the cache owner please fix this again?

 

You know they would have to be reading this thread to get the message.

 

Why not go to the page and send them an Email.

[+Arrow42]

June 3 by knowschad (13597 found) This is my 2nd log about this. The teflon tape needs replacing yet again. Would the cache owner please fix this again?

 

You know they would have to be reading this thread to get the message.

 

Why not go to the page and send them an Email.

 

I suspect that this was a log entry he copy/pasted. If the cache owner wants e-mails about it they will get an e-mail about when someone leaves this kind of log.

[+Arrow42]

(nothing to see here...)

Edited June 4, 2009 by Arrow42

[+CraigsOutside]

O-rings can be found in a variety of sizes at hardware auto parts stores. Also, get a tube of door/window exterior silicone caulk. squirt a small bead around the base and let it dry thoroughly. Once dry, it will act as an o-ring, keeping insides dry.

[Clan Riffster]

Or, (and I shudder at even suggesting such a radical solution), you could just use containers which haven't been demonstrated time and time again to be crappy.

Ammo cans come to mind.

[knowschad]

June 3 by knowschad (13597 found) This is my 2nd log about this. The teflon tape needs replacing yet again. Would the cache owner please fix this again?

 

You know they would have to be reading this thread to get the message.

 

Why not go to the page and send them an Email.

 

That was humor. Or, at least, intended to be.

[+IN_Darel]

In my opinion, the cap needs to be tight and would make impossible for cachers tp open with out tools. Hand tight just simply won't keep the water out.

[+narcissa]

Around here we call them "Cliffy tubes" (based on an old cacher) and we always expect that they'll be wet and mouldy inside. I have never found a dry one.

 

Those fittings are meant to keep water IN, and are not so good at keeping water OUT, especially around here where they're exposed to extreme temperature changes.

[+Larry the pool guy]

This is something I've made a work-around for, but I'd like to know if anyone has a real solution.

 

I placed a geocache container that was a two-foot piece of 2" PVC pipe. One end has a PVC cap cemented onto it, with lots of cement. An absolutely solid connection between the two. This end goes up, as the container is vertical, and not on the ground.

 

The other end has a threaded fitting glued into it, with a screw-on cap. This is the "down" end of the vertical container.

 

So, here's this pipe, mounted vertically. Top end is sealed tight. The lower end is where the screw on cap is. There are no holes drilled in the pipe anywhere.

 

The inside of this thing will NOT stay dry. It won't. Even in a moderate rain season, the contents get wet. It's about 15' off the ground, and I cannot keep the inside of this thing dry.

 

I did a work-around for the log by placing a second, sealed container inside the container for the log, but I'd like for cachers to be able to use this for trade items, too.

 

Every PVC pipe container I've ever seen stayed wet inside. Is it just our infernal Mississippi humidity, or is there some grand secret of the universe I've not yet become privy to?

This is something I've made a work-around for, but I'd like to know if anyone has a real solution.

 

I placed a geocache container that was a two-foot piece of 2" PVC pipe. One end has a PVC cap cemented onto it, with lots of cement. An absolutely solid connection between the two. This end goes up, as the container is vertical, and not on the ground.

 

The other end has a threaded fitting glued into it, with a screw-on cap. This is the "down" end of the vertical container.

 

 

 

 

Looks like I made the same mistake too. I put out eight caches in the Mountains all made from 3 inch pvc pipe with a drain screw opening on one end and a glued cap on the other. Of course I put the sign log in a plastic baggie. For fun I wrote not a bomb on the outside. Might get away with it for awhile because I live in California where rain is a blessing.

[+brslk]

Around here we call them "Cliffy tubes" (based on an old cacher) and we always expect that they'll be wet and mouldy inside. I have never found a dry one.

 

Those fittings are meant to keep water IN, and are not so good at keeping water OUT, especially around here where they're exposed to extreme temperature changes.

 

Having a degree in engineering.. how can one keep water in without keeping out water without a valve designed to do so. Please explain.

[+bittsen]

Having a degree in engineering.. how can one keep water in without keeping out water without a valve designed to do so. Please explain.

 

Ball valves typically include a rubber seal of some sort. This seal is designed to stay wet all the time by keeping water in. If the seal isn't exposed, constantly, to water then it can dry out, crack and then allow water to get in.

 

[+cerberus1]

"Every PVC pipe container I've ever seen stayed wet inside"...

 

If that's so, why try to fix something that you've seen doesn't work ?

 

The Cherne test plugs probably won't help much either. Everyone doesn't have the strength to tighten 'em, and quite a few won't do it, cause it takes time.

I think maybe in more arid conditions a thick-walled pipe (w/test plug ) might hold up, but in your area, forget it and go to a lock'nlock or ammo can.

[knowschad]

the water wicks up the screw thread.

 

Jim

Yup. Not to mention that a single grain of sand can cause the threads to lock up tight. PVC almost always sucks as a cache container, I'm afraid. Besides.... looks like a pipe bomb to many.

[+chachi44089]

Sometimes I think too much emphasis is place on making the container "air tight" or "water tight".This can cause the humidity inside the container to condense,"sweat".Sometimes its better to let it breathe,or vent.Drill a small hole in the bottom of the screw on cap that you have on the bottom of the tube.Rain should stay out but the tube will be able to breathe,keeping the contents dry.Might be worth a try.Mailboxes are not water tight but the contents stay nice and dry,same with tackle boxes.This is not for all situations,but it may work for yours.

[+Vater_Araignee]

<off topic>

PVC containers look like pipe bombs.

What a waste of explosive force.

Comparing a PVC pipe bomb to a steel pipe bomb is like comparing 2 black cats to one M-90<--cardboard tube with 2 standard fire crackers inside

M-90 wins every time.

 

Only place I would ever worry about seeing PVC as a pipe bomb is a location that requires passing through metal detectors to gain entry.

 

PVC the container of choice for wasteful children and idiots everywhere!

</off topic>

 

PVC is bast left at the camouflage stage for the actual cache container.

[+Gitchee-Gummee]

PVC makes a poor cache container in my opinion. If you need a container that is cylindrical try a mortar tube - you can find these one ebay for a decent price. Also on ebay you can find welding rod containers made by Hobart. These are waterproof and fairly inexpensive.

 

Would that be a 60mm, 81mm, or a 4.2"?

 

I haven't fired one of those in years!

[+SSO JOAT]

I've got a PVC cache that is mounted on the vertical just like the OP. No problems with moisture or access as I modified the threaded plug so it can't be tightened all the way and remains very loose. Water wicks into tight spaces, not loose ones. Because it is a threaded plug (not a cap) there is no "umbrella" effect with the cache being larger than the plug and having a sharp drip line all the way around the outer edge.

 

I also have drilled large vent holes at the bottom to allow free air movement. Inside the PVC is a 2-gallon zip-bag with a metal rod taped to the bottom. You roll the bag around the rod to slide it back up into the cache. The instructions are clearly written on the front of the bag. Contents stay perfectly dry.

 

As for "bombs"... aside from this being in the middle of the wilderness, it is painted to match the host it is straped to and I also engraved "Geocache" in big block letters on the sides. And there is a yellow geocaching.com sticker on it. Ammo cans look much more threatening than this thing.

[+narcissa]

 

Having a degree in engineering.. how can one keep water in without keeping out water without a valve designed to do so. Please explain.

 

My degrees are not in Engineering. I have 1200+ cache finds of experience that tells me that caches made out of ABS or PVC pipes hold water in and don't let it out. They are almost always a slimy, mouldy mess.

 

I've found many other common cache containers with leak problems - ammo cans, peanut butter jars, lock-and-locks - and none of them ever come close to the mouldy, stinky mess that almost always comes out of these caches. I am not alone in this observation - these things are so notorious around here that we've coined a nickname for them, as I mentioned in my original comment.

 

If you're an engineer (I presume that's what you were trying to say), perhaps YOU can explain why it is that a leaky ammo can seems to let water in AND out, whereas a leaky ABS container mostly keeps the water in?

Edited March 29, 2010 by narcissa

[k_statealan]

I made one that had a regular screw-on cap that had threads, but not a middle section. Inside that I put a center that was partly a large, thick rubber gasket. It made it so that the tighter it was turned, the better the seal was. And it didn't take much of a seal to keep it dry. One end was glued shut with PVC cement. I had no idea how my contraption was going to work, as I just assembled it walking through the pile of parts at the hardware store. It's been in an underwater cache for going on 3 1/2 years and the only moisture that's made it in was from the hands touching the contents. Just as a precaution, I put the log in a waterproof match container, though.

[+narcissa]

I made one that had a regular screw-on cap that had threads, but not a middle section. Inside that I put a center that was partly a large, thick rubber gasket. It made it so that the tighter it was turned, the better the seal was. And it didn't take much of a seal to keep it dry. One end was glued shut with PVC cement. I had no idea how my contraption was going to work, as I just assembled it walking through the pile of parts at the hardware store. It's been in an underwater cache for going on 3 1/2 years and the only moisture that's made it in was from the hands touching the contents. Just as a precaution, I put the log in a waterproof match container, though.

 

I was just thinking back to see if I could remember a single pipe cache that wasn't a wet mess.

 

I remembered one.

 

And it was one that was kept underwater.

[+brslk]

 

Having a degree in engineering.. how can one keep water in without keeping out water without a valve designed to do so. Please explain.

 

My degrees are not in Engineering. I have 1200+ cache finds of experience that tells me that caches made out of ABS or PVC pipes hold water in and don't let it out. They are almost always a slimy, mouldy mess.

 

I've found many other common cache containers with leak problems - ammo cans, peanut butter jars, lock-and-locks - and none of them ever come close to the mouldy, stinky mess that almost always comes out of these caches. I am not alone in this observation - these things are so notorious around here that we've coined a nickname for them, as I mentioned in my original comment.

 

If you're an engineer (I presume that's what you were trying to say), perhaps YOU can explain why it is that a leaky ammo can seems to let water in AND out, whereas a leaky ABS container mostly keeps the water in?

 

Why are you attacking me again? It is a simple principle that things that hold water can also keep water out. I never mentioned ammo cans.

I have no idea what you are trying to say when you wrote "I presume that's what you were trying to say".

Are you questioning my education?

I guess you have no plumbing in your home... if you did you would know how ABS works.

 

Again Please stay on topic and not make it personal. I did not attack you so please do not attack me or send your boyfriend to attack me when you cannot.

Edited March 29, 2010 by brslk

[+bittsen]

Why are you attacking me again? It is a simple principle that things that hold water can also keep water out. I never mentioned ammo cans.

I have no idea what you are trying to say when you wrote "I presume that's what you were trying to say".

Are you questioning my education?

I guess you have no plumbing in your home... if you did you would know how ABS works.

 

Again Please stay on topic and not make it personal. I did not attack you so please do not attack me or send your boyfriend to attack me when you cannot.

 

I think you are forgetting that ABS has a mystical property that allows air (as long as it contains moisture) to penetrate the wall of the ABS pipe as long as it is going INTO the center. It's sort of like a microscopic singularity that only lives within the confines of a plastic tube that only attracts moisture. That's why ABS doesn't let water out but somehow seems to let water in.

There are microscopic one way valves built into the walls of plastic pipe that let water flow through the plastic pipe to the middle. That, in conjunction with the micro singularities explains the premise that ABS lets water in but not out.

 

Didn't they teach you this in Engineering school?

 

[4wheelin_fool]

PVC pipes are designed to be sealed once, and not to be opened and closed multiple times. Water will enter up the threads via osmosis or condensation.

[+narcissa]

 

Why are you attacking me again? It is a simple principle that things that hold water can also keep water out. I never mentioned ammo cans.

I have no idea what you are trying to say when you wrote "I presume that's what you were trying to say".

Are you questioning my education?

I guess you have no plumbing in your home... if you did you would know how ABS works.

 

Again Please stay on topic and not make it personal. I did not attack you so please do not attack me or send your boyfriend to attack me when you cannot.

 

You responded directly to me. If you don't wish to converse with me because of past disagreements, you can simply ignore my comments and respond to others. I don't usually pay much attention to the name beside a comment - I prefer to address the comment itself.

 

That being said, it's a little silly to reply to me (I commented first, again), ask me a question directly, and then get angry when I attempt to answer it.

 

I certainly wasn't "questioning" your education, but I'm still not clear about what your first post was trying to say about someone being an engineer. I'm not an engineer. Are you an engineer? Is the geocache an engineer?

 

I'm explaining what I've observed in the field after finding many of these caches.

 

For some reason, water seeps in to ABS/PVC caches, but doesn't come out again (unless the cache is opened and the water is dried out). The contents of these caches are always very wet, even after a period of dry weather, and are usually covered in some sort of mould or algae with a very distinctive smell.

 

Contrast this with a broken ammo can, where the contents will be wet or damp when there's been rain, but the contents will be dry after a dry spell. These containers sometimes have mould (hard to avoid in the forest), but they don't have the same smelly, slimy mould that the ABS/PVC caches do.

 

I'm not a plumber, but I'm pretty sure that the plumbing in my house is mostly protected from the harsh temperature extremes, snow, ice, dirt, and frequent handling that an ABS geocache is exposed to where I live.

 

I suspect these conditions contribute to the vast difference in performance between my home plumbing, and the (probably dozens of) ABS or PVC pipe geocaches I've found.

 

This is merely an anecdotal report of my in-field observations of geocaches, and is not intended to be taken as a comment on anything beyond the nature and performance of geocaches.

[+brslk]

PVC pipes are designed to be sealed once, and not to be opened and closed multiple times. Water will enter up the threads via osmosis or condensation.

 

Ahhhhh Osmosis... How could I have been so stupid...

[+brslk]

 

Why are you attacking me again? It is a simple principle that things that hold water can also keep water out. I never mentioned ammo cans.

I have no idea what you are trying to say when you wrote "I presume that's what you were trying to say".

Are you questioning my education?

I guess you have no plumbing in your home... if you did you would know how ABS works.

 

Again Please stay on topic and not make it personal. I did not attack you so please do not attack me or send your boyfriend to attack me when you cannot.

 

You responded directly to me. If you don't wish to converse with me because of past disagreements, you can simply ignore my comments and respond to others. I don't usually pay much attention to the name beside a comment - I prefer to address the comment itself.

 

That being said, it's a little silly to reply to me (I commented first, again), ask me a question directly, and then get angry when I attempt to answer it.

 

I certainly wasn't "questioning" your education, but I'm still not clear about what your first post was trying to say about someone being an engineer. I'm not an engineer. Are you an engineer? Is the geocache an engineer?

 

I'm explaining what I've observed in the field after finding many of these caches.

 

For some reason, water seeps in to ABS/PVC caches, but doesn't come out again (unless the cache is opened and the water is dried out). The contents of these caches are always very wet, even after a period of dry weather, and are usually covered in some sort of mould or algae with a very distinctive smell.

 

Contrast this with a broken ammo can, where the contents will be wet or damp when there's been rain, but the contents will be dry after a dry spell. These containers sometimes have mould (hard to avoid in the forest), but they don't have the same smelly, slimy mould that the ABS/PVC caches do.

 

I'm not a plumber, but I'm pretty sure that the plumbing in my house is mostly protected from the harsh temperature extremes, snow, ice, dirt, and frequent handling that an ABS geocache is exposed to where I live.

 

I suspect these conditions contribute to the vast difference in performance between my home plumbing, and the (probably dozens of) ABS or PVC pipe geocaches I've found.

 

This is merely an anecdotal report of my in-field observations of geocaches, and is not intended to be taken as a comment on anything beyond the nature and performance of geocaches.

 

The same can be said for what you are doing now. YOU

[+fizzymagic]

It is a simple principle that things that hold water can also keep water out.

Really?

 

Too bad you're wrong. Take Gore-tex, for example. Or your GPS unit. Note that in both cases, water vapor acts quite differently from liquid water, and that has a big effect on the transport into/out of the container.

 

OTOH, at least I know how to spell "mold."