- A piece of PVC pipe, about four feet long
- Post-hole Digger
- Power drill and some drill bits (read below to figure out what sizes)
- A bolt, two washers and two nuts (see below for details)
- A tube shaped cache, small or micro sized
- A magnet
- Superglue (preferably a kind that's designed for outdoor use)
When you are ready to get supplies, the first thing to decide on is the cache container. You will need a tubular shaped cache. For our design, we'll use a waterproof matchstick container. They are easy to find in any camping store or department. The reason we need to figure out the cache container first is that the width of the container will help us pick the PVC pipe you'll need.
The cache will need to fit easily inside the PVC pipe, so after you figure out what container you are using, either measure it's width or take it to the hardware store with you. You need a section of PVC pipe that is at least a half inch wider than the cache container. Also, make sure it's about four feet in length. You can bump that to five feet if you'd like.
Next, we need a magnet. Aim for a magnet that is between half as wide to the full width of the cache container. Try not to get one that is wider than the magnet, or else you'll need to widen the PVC pipe to account for that. Just make sure you have some superglue (or another adhesive) designed for outdoor use. You may want a second one, and we'll come to why later.
Last of all, the bolt. You need to get a bolt that is wider than the PVC pipe. Aim for one that is about two - three inches wider. Get washers and nuts to go with it, and make sure you have a drill bit wide enough to make a hole for the bolt. There is one more thing. If you can, get a bolt made from a non-magnetic metal. There are some out there, you just have to look. If you can't find one, then scrap the second magnet I mentioned in the above paragraph and talked about below as it will actually hinder the cache.
Now you should have all the supplies you need. Let's start building by attaching the magnet to one end of the cache. I would suggest attaching it to the end of the container opposite the lid. You don't want someone to accidently remove the magnet. Be thorough with gluing it on.
While that is drying, let's get the PVC pipe. You'll need to place about a foot of this into the ground so measure a foot from one end of the pipe and mark that spot with a line around the pipe. Next, measure about one inch further up the pipe and mark that spot with two dots on opposite sides from each other. Measure another inch and repeat. Do this two more times. You will drill holes through each of these dots. Two of the holes need to be drilled wide enough to fit that bolt we talked about. The bolt should not be placed in the bottom set of holes. Ideally, try to place it in the last set, farthest from the line. The remaining holes are the drainage holes, hence why you want the bolt in the highest set of holes. When you put this pipe into the ground, those holes will help make sure the pipe can drain any water that collects inside. The bolt will help hold the cache up out of the water when the pipe fills.
By now, the glue is likely dry (unless you used Gorilla Glue). Grab the newly drilled pipe, your post-hole diggers, the cache container, and a logsheet. I'd recommend a small baggie for the logsheet (can be found in any crafts store or department near where they have bead supplies). Time to go to the cache site.
At the selected cache site, you'll need to dig that hole. This is why you need permission. Once you have the hole dug, pack some of the dirt into the end of the PVC pipe that you measured. Try your best to keep this packed dirt under that line, as you want to keep those drainage holes clear of dirt. If you can, use something to stick in the top of the pipe to help pack down the dirt at the bottom, be it a stick or a hiking pole. Once this is ready, stick the pipe into the hole and fill the surrounding hole up with dirt. If done right, the line you drew should be level with the ground. Make sure you pack down the dirt to help secure the pipe. If you are able to find a spot close to a fence or other structure, you can even help tie the pipe to that structure to help hold it up.
Now for the tricky part. Make sure you place the geocache into the top of the pipe so that the magnet is facing up. For security purposes, you can always attach a magnet at both ends of the container just in case a geocacher puts it in upside down. But don't do this unless you can get a bolt that won't attract magnets. If you do, and you place a container with magnets on both ends into the pipe, the bolt will grab hold of the magnet and nobody will be able to retrieve the cache. If you are forced to use a bolt that will attract the magnet, make sure to include a line in the cache description about being careful replacing the cache (you don't have to say way, just that they need to be careful).
The cache works like my Magnetic Micro cache, but on a larger scale. A geocacher will have to bring something that they can lower down into the pipe to "Attract" the magnet on the geocache, then pull it up to retrieve. Now it should make sense why we placed drainage holes and why we put the bolt in there, alongside why I made a big deal about the magnetism of the bolt and using two magnets.
Oh, and you can easily modify this one a bit. Here is a design that MrDSW took of just this kind of cache (used with permission):
Note that the pipe used is attached to a girder for stability. Also, the unique idea of placing this lure makes it feel more like fishing, which is essentially what geocachers will be doing. If you look carefully at the cache container, you can get an idea of how they built it using PVC parts, a hook to attach to the hole at the back of the lure, and the tongue of the lure to attach the magnets too.
There are some other variations of this design, which I'll introduce in the next post.
By the way, I mentioned designing log books in my last post. Sorry I haven't posted since as I've been busy, but that is on my list. I'll give you a quick preview here: LOGBOOK SNEAK PEAK