How to Make a Periscope From a PVC Pipe and Mirrors

There are all kinds of situations where you will be well served by scoping out your surroundings without exposing yourself. Maybe it’s a riot nearby, societal unrest, or a full-blown government crackdown. There are all kinds of advanced technology that can help you do that, but one of the best tools for the job is an old one. The humble periscope.

You don’t need some huge, professionally assembled apparatus to gain the benefits, either. You can put together a pretty effective periscope using nothing but PVC piping and a common mirror cut down to size. I’ll tell you what you need to make your own and how to do it in this guide.

Tools and Supplies

PVC Pipe, Straight, 4-inch: any kind of PVC pipe will work for this periscope project, but larger diameter stuff will allow better visibility overall and much better clarity because it will let more light through to the mirrors. 4-inch diameter schedule 40 stuff is my pick. Get a straight section that’s three to four feet long, or else you’ll have to cut down a longer piece.

PVC Pipe, 90° Elbows, 4-inch: a pair of compatible 90° standard elbows that will fit the above length of pipe. Make sure they don’t have any internal diameter reduction, baffling, or anything like that. Just simple, normal elbows!

Mirror Glass: repurpose or buy any standard mirror for this project as long as it’s glass. Plastic mirrors aren’t sturdy enough, typically, and they aren’t nearly as clear. Any size will work, but you can avoid waste by using a sheet that’s about 5 by 10 in and cutting it in half.

Hacksaw: any hacksaw or other cutting tool suitable for cutting through your PVC pipe. A handyman’s crosscut saw will work in a pinch.

Glass Cutter: a roller-style glass cutter is a must for cutting and snapping the glass safely, cleanly, and easily. If you don’t have one, get one. They are cheap and they’re good to have for other projects.

Marker: a permanent marker in a contrasting color to the PVC piping will help you make accurate marks that will produce a superior finished product.

Square or Ruler: a flat drafting square or the kind that students use for geometry homework makes the hard part of this project a breeze. Lacking that, you can use a standard ruler.

PVC Adhesive: since we aren’t using these pipes for containing liquids, you can use any sort of PVC-compatible adhesive that you want. I still prefer using standard plumbing PVC adhesive for ease of use and durability. Whatever you go with, read the instructions to familiarize yourself with cure time and how it behaves.

Hot Glue Gun and Sticks: this will be needed to adhere the mirrors to the cuts we make in the PVC pipe.

You won’t need anything else except a little time and patience, and the instructions below.

Step by Step Instructions

Step 1: Find center point in bend of elbows. The first and most important step is the trickiest, but it’s not hard if you know a few tricks of your own. Look at the elbows of your pipes and you should notice a mold seam running around the circumference on both sides of the bend, and another seam that follows the bend on one side from one end to the other.

Lay the elbow flat on the table. Using your square or ruler, measure 2 inches from each of these seams towards the apex of the elbow. Refer to the picture. These lines should be perpendicular, and where they intersect will be the center of the elbow. Draw your lines and then place a dot where they intersect as shown. Repeat this process on the other elbow:

Step 2: Mark angle line for cuts in elbows. Starting at the center point you marked, use your square to measure a 45° angle off of either line. Draw and extend this line as shown. This is where you will make your cut to install the mirror.

If you are using a ruler, it may be helpful to first draw a line between the two seams where we measured from originally. Draw a line connecting these origin points, and you can use that as a guide for placing the second line (the one at the top in our photo) where you will make your cut.

Again, repeat this process on the other elbow. The hard part is over!

Step 3: Cut off elbows with hacksaw. Placing the elbows on a sturdy work surface, grab your hacksaw and, taking care to stay upright and plumb, cut vertically through the elbow where you made your cut mark.

Check the picture to see what they should look like:

Step 4: Trim main pipe to length, clean up cuts as needed. If the straight piece of pipe is overly long, now’s the time to cut it down to a good length. Three to four feet is good for this periscope.

Make sure you cut it off square so your elbow will still fit properly. On the ends of the straight piece of pipe, use a little bit of sandpaper or a sharp knife to clean up any burrs as needed.

Step 5: Cut mirror with glass cutter. Now cut down your mirror using the glass cutter. It only needs to be slightly larger than the opening in your pipe, easily accomplished with a rectangle shape. If you’re starting with a smaller sheet of mirror, you can just cut it in half.

Be careful! Wear gloves if you have them and take your time. Make the cut using the glass cutter and a straight edge. Your square or ruler should work fine. Once the cut is established, carefully snap the sheet of glass in two using the edge of your work surface.

Step 6: Glue mirrors in place on elbows, check alignment. Heat up your hot glue gun, set to high temperature, and run a generous bead of glue around the cut you made in one pipe elbow.

Press your mirror into the glue bead with the reflective side facing the interior of the pipe. Hold it in place for a few seconds until the glue firms up. Repeat this process with the other pipe elbow. Look through both completed elbow assemblies to make sure you can see out the bottom.

Step 7: Fit elbows on pipe as shown. Check visibility and make witness mark. Now fit the elbows, without any glue, to the straight section of pipe, with each elbow opening facing opposite directions. It’s easy to make sure both are perfectly aligned if you lay the pipe on a flat work surface. Refer to the picture:

Now is the time to look into both ends of your periscope and confirm you can easily see out the other side. Make adjustments if you can’t. Once it is set make a
witness mark, a short line, going from each elbow onto the straight pipe so you can quickly and easily put them back in the correct position for the next step.

Step 8: Apply PVC adhesive according to instructions, align sections. Remove the elbows, apply adhesive to your piping according to the instructions, then put the elbows back in place, matching up your witness marks.

Step 9: Set aside and allow to cure fully. Let the adhesive to fully cure so it won’t come apart when you least expect it.

Step 10: Done! Your DIY periscope is finished. It’s perfect for peeking out of windows without exposing yourself, looking around corners, or getting a view over taller obstacles.