Building a truly waterproof geocache

A friend whose family has access to a fairly large pond invited me and a group of friends out for a day of swimming and boating. While out enjoying a lovely Kansas day, I found a spot on the pond — an island — that I thought would make a perfect spot for a geocache. In general I’m a fan of caches that are fun to get to but not super hard to find (no one wants to hike 8 miles and then spend three hours looking under rocks) so this island would be perfect — the cache wouldn’t be too hard to find, but it wouldn’t be a park and grab either.

While a lot of places sell “waterproof” containers, most are built to get splashed, or maybe briefly dunked. But when you’re hiding a geocache in a pond where it could potentially be submerged for months at a time, not to mention frozen in the winter and baked by the sun in the summer, you’ll need a stronger build. I decided to make my cache out of PVC, and I wanted to explain how I went about doing that. I should preface this post by saying that I really have no experience with plumbing in general, so this post is written assuming no expertise, and if you see anything that can be improved let me know.

Parts list

These are just the parts I used, most of them could probably be substituted for similar things — in particular the ginormous tent stakes were only necessary because this cache is going into some pretty deep mud:

Here’s a picture of the parts that went into my geocache (except instead of thread seal tape, I have a small tube of dope in this picture — I ended up returning it and getting some tape before I built the geocache):

Geocache Parts
The parts used to make my geocache

Building the Geocache

Once you have the parts, putting everything together is pretty straightforward. There are really only three steps:

  1. Cut the PVC pipe to a more usable size.  I chose around 8″ because that would give me enough room to store the pencil and Lego guy.
  2. Glue the end cap and the thread adapter onto the pipe.  Being a PVC noob, I found this video pretty helpful. Basically, you…
    1. Apply some primer to both the male and female sides of the joint.
    2. Apply some cement to both sides.
    3. Join the two sides of the joint with a 1/4 turn and hold them together for a few seconds (the video says 5ish, the cement can says 30) so they don’t come apart.
  3. Secure the steel cable to both the pipe and the stakes.
    1. I used a noose knot to secure the cable to the pipe, and made sure it was tight enough that it wouldn’t slip over the the caps. Though the steel cable is kind of tough to work with, its inflexibility helps make it harder to slide over the cap end.
    2. Once you have the knot tied, apply one of the clamps so it can’t come undone — basically you can just clamp it right next to the knot.
    3. I used another noose knot to secure the cable to the stake, although I think the knot choice is probably a lot more flexible here. I was originally planning on tying the knot through the loop at the top of the stake, but if you look closely there are actually small holes just below the top of the stakes, and the cable I had fit perfectly through these so I ran the cable through them instead.
    4. Finally, use the other clamp to secure this second knot.

Once all of this is done, you just need to write / print a “Geocache Note” (see the right-hand column of the Hide & Seek a Geocache page). Since I was using waterproof paper, I hand wrote my note.  Here’s a picture of the trimmed, glued-together cache and note (I should’ve taken this picture after I tied the cable on — sorry that step is not photographed here):

Geocache Build
The geocache after being shortened and glued together

Placing the Geocache

Once everything is built, putting the geocache in the ground is the easy part.  Some friends and I found a nice spot on the side of the island — an 8″ vertical, muddy wall — that wouldn’t get stepped on (whether you were walking on the island or wading through the pond) and wouldn’t interfere with boating. Then all we did was drive in the stakes, wind the geocache around the hooks on their tops (similar to the cord on a vacuum cleaner) and call it good.

Geocache Home
The geocache’s new home

So that’s all there is to it! If you have any questions or feedback, let me know in the comments!

Cold Weather Grilling

Our two grills, shortly after lighting.Well, it’s officially winter break: it’s sleeting outside, I’m putting off wrapping gifts, and I’m at my parents house with very little to do.  I had a pretty decent semester, and my one class (Advanced WWW Technologies) is now complete, so I can focus full time on my master’s work.  In a sort of neat twist, however, my course-long project was to build a graphical front-end for my the software I’m building (currently named λ (lambda) — discussed in the preceding post as well).  That user-interface is now complete, and at some point I’ll post up a link to the server I have which runs λ.  That day is not today, however.  Today is a day for discussing winter grilling.

I know a lot of people aren’t big fans of winter, which bums me out, because it’s my second favorite season (the top slot goes to Fall).  I understand a lot of the complaints — being cold is lame, you’re not on summer vacation, and it’s not very pleasant outside so your ability to do fun stuff is restricted.  While all of these are valid, one particular fun activity, grilling, has not ceased just because it’s below freezing outside.

During the summer, my roommate(s) and I got into the habit of grilling every week on Sunday.  We’ve continued this tradition as the months progressed, and are planning on trucking through the winter.  We have a cookbook on simple grilling recipes, and they’re really pretty good — a recent weekend’s menu was chipotle-peach glazed chicken and buttered new potatoes, for example.  Grilling in inclemency takes a bit more effort than your standard Memorial Day weenie roast; there are in fact several unique factors to consider.

First, there’s wind / rain / snow which can slow down your fire when it’s first getting lit.  Second, there’s the fact that it’s considerably colder outside — note that both this and the first factor can be remedied by adding more charcoal briquettes (propane is lame) to get stuff up to the appropriate temperature.  Third, you have to wear more clothing while lighting the fire and tending the grill, and this clothing gets smoky.  This happens during the summer, too, but I have a lot more t-shirts than I have hoodies and coats.

There is one definite advantage to grilling in the winter, however, and that’s that no one else is using their equipment.  When our friends retired their grills for the season, they donated / loaned some of their equipment to us, so we now have a smaller, secondary grill we use for heating up our side dish while the proverbial “big meat” roasts on the main grill.

Climbing Manhattan Hill

Me on top of Manhattan HillSo yesterday my buddy Matt came into town.  He's from Lincoln, so we don't get to hang out as often as we used to, but neither of us have class on Thursdays, so everything sort of worked out.  We didn't have any big plans, so it was a lot of video games, barbecue, and just hanging out.  We did go visit one of Manhattan's landmarks though, the giant "MANHATTAN" letters on the aptly-named Manhattan hill.

The letters are made of concrete and painted white (and are more than visible on google maps) but have recently been covered in purple cloth for some reason.  I've heard it's part of a fundraiser, but I don't know any details.  I originally thought the letters were only reachable from the bottom of the hill, so we ended up climbing up some short but pretty steep trails.  Once we got to the letters, however, we found that you can get to them from the parking lot / picnic area at the top of the hill really easily.  Whoops.

There were some other really interesting areas, like what appears to the foundation of an old building (a large, smooth concrete surface) which is now covered in paintballs and broken glass.  It's inaccessible by road, so I imagine it's been a while since it was used for anything legitimate.  It did have a neat devil face painted on a concrete post though.

All in all, it was fun to see Matt again and visit the huge letters in person.  I may have to start exploring more places around Manhattan — it's a really nice time of year for it.

The devil-painted concrete post.