Introduction: PVC 101
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NOTE: The PVC Toddler Bed Guard has returned to Instructables in all of its glory. Check it out here.
There have been some other Instructables out there that have identified some basics, such as cutting and painting PVC, but I thought it best that I try to aggregate some of the ideas into one big, ultimate Instructable: PVC 101.
I work as a Design Engineer for an architecture/product design firm and I use PVC repeatedly to create prototypes and mock-ups, some of them even to ¼” scale, so one could say that I have a lot of practice with PVC. And since PVC is the ultimate make-anything-toy-set for adults, I only thought it wise to share my experience and knowledge of it on Instructables.
Let face it. PVC is awesome. It’s easy to obtain, cheap, easy to manipulate and you just push it together (and cement if you like) and presto. You can pretty much make anything you can think of by just using some fittings and pipe, and I’ll augment that basic idea along with some tips, and other information for PVC in this Instructable.
There are tons of PVC-based step-by-steps available out on Instructables. Search for one and I bet there is something you will want to make. Last I checked, there were over 1140 Instructables involving PVC.
So if you are new to PVC, or if you are a constant user like me, please peruse. If you have other tips that I have not mentioned in this Instructable, please feel free to add your comments, as I’m always looking for more ideas.
Step 1: Pipe Sizes
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I’m only covering basic, white PVC available in most home stores, as ABS is too brittle (and weak) and PEX is just not as friendly.
I’ve broken down the sizes into categories below:
1/2”: Super-uber flexible, but not very strong. It can actually kink when bent. This works well for kites and other light structures, but not so much for something you want to mount anything to. Plus, it’s so small you would need tiny screws to attach anything to it.
3/4”: Very bendable, ideal for just about any project that requires flexibility, specifically hoop houses, green houses, pet agility hoops and other curved frames. This is also good if you need elasticity in your project, as it will spring back perfectly (be careful though!).
1”: Only slightly flexible, but still fairly rigid. This is if you want a bit of sway to your project, but still need a strong framework, 1” is good. Marshmallows fit in them nice and snug.
1-1/4”: This is probably the most ideal size for very rigid, lightweight project. This is perfect for framing, structure, and anything else you might need to build a strong sturdy platform, shelf, table or wall with. It still has SOME flexibility, but not much.
1-1/2”: Pretty much rigid as it gets, except for 2” (below). It’s heavy though.
2”: Probably as strong as you could ever need, will hold tons of weight. It is very heavy and very expensive in relation to other just as strong sizes. However if your project is requiring a good foundation, 2” is perfect. It also works well for canister-style projects (in conjunction with end caps), like garbage bag holders, etc.
Summary: For most projects, either 3/4” or 1-1/4” are ideal. If you need flexibility, go 3/4”, for rigidity, go 1-1/4”.
Step 2: Fittings and Connectors
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Plumbing Grade: These are the fittings that were designed solely for the purpose of plumbing drainage and sewer systems for homes and business dwellings. They perform their task admirably, for basic construction of PVC assemblies. They don’t look too pretty however, as they are usually marked with ink, barcodes or raised/embossed lettering on them, but they are cheap. You can find these at your local Home Depot, Lowes or other hardware store. They are usually made by Nibco (www.nibco.com).
Furniture Grade: Furniture grade fittings are where the magic happens; they are what make PVC the tinker-toy system that it can be. While you can get basic Tees and 3-Way fittings from your Home Depot and Lowes, furniture grade fittings expand upon the basic idea, and add 4-Way and 5-Way fittings, fancy end caps, hinge elements and even caster inserts to put wheels on your project. In my previous post I recommended a store online called Formufit (www.formufit.com), which sells practically all the fittings you need to make any type of structure. In fact, a lot of the tips I explain in this Instructable, I borrowed from their website. They are a PVC project builder’s playground.
Whichever fitting type you choose you can find most of what you need either at HD, Lowes or Formufit, or you can also check eBay.
Step 3: Cautions
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Elasticity: OK, this is obvious, but needs mentioning. When working with PVC, especially in its smaller forms, such as 1/2” to 1”, and your project requires a pipe to be bent or curved, make especially sure that it is secured at both ends…strongly. Once a PVC pipe is bent it will attempt to go back to its original shape (straight) and try to do it quite quickly. If PVC is released after being bent you can, as your Mom probably used to say, ‘take an eye out’ or at least leave you with a nasty welt.
PVC can be ‘trained’ to stay in a shape after it has been in a particular curved position for a while (or heated, see caution on THAT below), but to be safe, always secure it at both ends either with cement or screws/fasteners.
Toxicity and Out-Gassing: At room-temperature, PVC is as safe as any other plastic. In fact, PVC is made from the same vinyl products that other plastic items are made out of. PVC can be somewhat dangerous in other forms though, specifically when it is melted.
When melted, PVC emits chlorine and dioxins, which are toxic chemicals that can cause harm to the human body over a long period of exposure. When melting or heating PVC, it is recommended that a person be in a properly ventilated area or wear a respirator to reduce the exposure to the chemicals. The best thing to do is only melt PVC if it is entirely necessary, such as in the case of bending using heat.
Additional Chemicals: The PVC pipe cleaner, cement and Acetone I mention in this Instructable are all volatile and toxic chemicals. Do the chemical activities outside, or in a garage with the door(s) wide open. Just be safe. No huffing!
Step 4: Design
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There are some tools out there to help design PVC projects. One is Google SketchUp. I use it all the time to make mine, and Formufit has downloadable components of all their PVC fittings on their website (formufit.com) in their Downloads section, and you can also find them on the Google 3D Warehouse. If you don’t know how to use SketchUp, look it up on Instructables or YouTube. It’s marvelous.
When designing PVC projects that involve fittings/connectors, there are a few things to keep in mind:
Include the fitting: This is obvious, but I have to say it. The length of any pipe that is attached to a fitting must include the fitting. Duh, right? Well, I’ve made a mistake or two on this one. If you make a project that is a square box and you use fittings on the ends, and you want it to be 2’ square, you need to cut the pipe shorter than 2’, as the fittings on each end will take up extra length themselves. So if your fittings take up an extra 1” at each end, the pipe needs to be cut to 1’-10”, to accommodate the fittings.
The distance that the pipe goes into the fitting is equal to its diameter (normally): Sound complex? It isn’t. To embellish on this, you need to also remember that the pipe usually goes into the fitting a certain amount (so you can cement or screw it), and is different for the pipe size. There is a detent inside of each fitting that stops the pipe from going too far in. For instance, a 3/4” pipe will go into a 3/4” fitting about 3/4” of an inch. A 1-1/4” pipe will go into a 1-1/4” fitting about 1-1/4”, and so on and so forth. Make sense? So if you are building something you need to make sure that you account not only for the fitting length, but the amount of pipe that actually goes into the fitting itself. Try it out; you’ll see what I mean.
Use the right pipe: If you have something that is going to bear weight, be it a person, or a structure, make sure you use at least 1-1/4” pipe or above. 1” or lower is not going to hold much weight and will flex. And you will fall on your bottom.
Step 5: Cutting
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Hacksaw: The most basic and most widely used tool is the hacksaw. Even I still use one when I need to make more detailed cuts or simple adjustments. Using one is pretty simple: mark your PVC where you want it cut and saw away. Just watch your cut and don’t let the saw drift to make a nice straight cut.
The upside to the hacksaw is that you probably already have one, and if you don’t they are cheap. The downside is that if you want to make a lot of cuts, it can take a while.
PVC/Plastic Pipe Cutter: There are two kinds of PVC pipe cutters; scissor style and ratcheting style. Scissor style works great for 1/2” to 1” PVC pipe. I will work for larger sized pipes, but it takes some additional lower arm and hand strength. You basically put the pipe into the half-moon shaped lower part of the cutter, and squeeze the blade down onto it until its cut. However, for larger pipe, well, that’s where the ratcheting style pipe-cutter comes into play. It’s a similar premise to the scissor style, but it uses ratcheting action to slowly go through the pipe, and use less arm strength.
The upside to the pipe cutters listed above is that they cut a lot of pipe in a short time, and are fairly inexpensive ($4 for a ratcheting-style at Harbor Freight). The downside is that they do not cut the pipe square, leaving you with a wavy or curved end of pipe (but if it’s going into a fitting, no big deal…).
Miter Saw: If you have one, I highly recommend using a miter saw. You don’t need a special blade. I use a standard 10 Tooth per Inch (TPI) wood blade, which came with my saw and it works perfectly. If you don’t have a miter saw and want to make a PVC project that requires A LOT of cutting (like some of mine), I highly suggest investing in one. You simply place the PVC pipe under the blade where you need your cut, secure it with a work clamp, start the blade and bring it down at a fairly slow to medium speed. Works like a charm.
The upside to a miter saw is that they can cut a boatload of PVC in a short amount of time. The downside is that miter saws are loud and scary to some, and they are expensive, however you can land a Ryobi for under $90 at Home Depot.
NOT RECOMMENDED: I don’t recommend the use of the following to cut PVC pipe:
Band Saws (Bad): The blade moves too slow, and unless you are using a very fine-toothed blade, it can actually catch on the inside diameter of the pipe, causing it to crack and chip and you to freak out.
Table Saws (BAD BAD): This is a BIG no-no. PVC pipe is curved. A table saw surface is flat and often smooth to allow wood to travel across it easy. Pushing a PVC pipe into a table saw could cause you to slip and bring about SERIOUS harm to you. Or if it causes pushback or startles you, you could kill yourself. I recommend avoiding this method altogether. Please.
Metal Pipe Cutters (Doesn’t work): They rely on the pipe being slowly notching a groove into itself, which is even and straight. PVC doesn’t let metal pipe cutters do that. It just makes a pretty swirly line around the pipe.
Regular wood saws (Just silly): The teeth on the blade are too far apart. They just don’t work.
Step 6: Cleaning
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You can clean up standard plumbing-grade pipe and make it look pretty decent by performing the following steps:
To clean PVC pipe you need:
– Steel Wool
– Cloth Rags or Paper Towels
– Latex Gloves (don’t use Nitrile gloves)
1. Put on the latex gloves. I mention not to use Nitrile gloves (the blue ones) because the Acetone will cause them to disintegrate and tear apart. Use latex gloves as they won’t break down (as quickly).
2.Soak, or pour, the Acetone onto the steel wool. Using a circular motion, scrub the PVC pipe where the lettering and dirt is and it will come off magically. Do about 1’ of a section at a time and then QUICKLY wipe away the wet ink and Acetone with a cloth or paper towel.
3. Repeat for every one foot, replacing the steel wool every 10’ that you clean (it will retain the ink and smudge after about 10’ of usage).
4. Enjoy your clean pipe!
Step 7: Shining/Glossing
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You can make standard PVC pretty by ‘glossing’ it. This takes away the dullness and makes it match the glossiness of the furniture grade fittings. It does not help with the yellowing however. You need to read my section on ‘Painting’ PVC pipe to make it match the pure white color.
There are two methods to ‘gloss-ify’ the pipe:
Liquid Tire Shine: This is the best method. This lasts for months (if untouched). All you do is spray some liquid tire shine (use the liquid in a spray bottle, not the spray can) onto a paper towel and apply it to the PVC pipe. Voila! Super shiny! The problem with this method is that is makes it INCREDIBLY slippery and very unsafe if climbed on or used as any type of foothold. But it looks great!
Mineral Oil: You can, with a paper towel, apply mineral oil to PVC pipe to give it some shine. The problem with this method is that it only lasts until the mineral oil evaporates, and depending upon your humidity could be a month, or could be a couple of hours.
Step 8: Assembly
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There are three methods to assembling PVC pipe and fittings:
Compression Method (temporary): This is where, after you have cut all of your pieces to size, you assemble them into the fittings via pressing them hard into place and pray it does not come apart. Also known as the ‘push-and-pray’ method, this version works well for temporary structures and times that you want to re-use fittings for another project.
PVC Cement (permanent): PVC cement is the old standby, and what plumbers use to weld the pipes to the fittings. The PVC cement chemically melts the two pieces of PVC (pipe and fitting) together for a PERMANENT, yet super-strong bond. This is the best method to use if you want your structure to bear wear or torque. To use this method following the steps below:
To assemble PVC via cement you need:
– PVC Pipe (cut to your desired length)
– PVC Fittings
– PVC Cement
– PVC Pipe Cleaner (optional)
1.Make sure you have DRY FIT everything together to test that it assembles correctly before you proceed.
2.Gather your PVC pipe and fittings. You will want everything close by, as things will need to occur rather fast.
3.You can optionally clean the outside of the PVC pipe and the inside of the PVC fitting with PVC Pipe Cleaner, for a cleaner bond.
4.Apply PVC Cement to both the outside of the PVC pipe and the inside of the fitting (if you use PVC Pipe Cleaner first, you don’t have to wait for it to dry).
5.Press the pipe and the fitting together firmly for 30 seconds. You may have to use a hammer and a wood block (to protect the PVC) to knock it into place. It should set in as far as it can until it hits the detent in the fitting.
6.Repeat for each additional fitting joint.
Set Screw Method: In this method, you assemble the PVC pipes into their fittings and tap a wood screw into the fitting and pipe on both sides. This is one of the methods I prefer most as it is temporary (the screws can be removed and the fittings re-used), but still incredibly strong. What even better is if you mess up one of your pipe lengths, you just remove the screw, re-cut your pipe, and then put it back in. And it’s relatively clean looking.
To perform the Set Screw method, do the following:
To assemble PVC via the Set Screw method you need:
– PVC Pipe
– PVC Fittings
– 1/8” Drill Bit
– 1/2” to 3/4” Wood Screws
– Screwdriver Bit
– Countersink Bit (optional)
1.Gather your PVC pipe and fittings.
2.Assemble your structure as you designed it. Press the pipes firmly all the way into the fittings as far as they will go until they hit the detent in the fitting.
3.Using a 1/8” Drill Bit mounted on a drill, drill a hole into the fitting where it meets the pipe.
4.And optional step is to use a countersink bit to hide the head of the wood screw. This leaves everything smooth and clean. Use the countersink bit to add a small indentation to the hole you just made in the fitting.
5.Using a screwdriver bit mounted on a drill; drive the wood screw into both the fitting and the pipe.
6.Repeat on other sides of the pipe/fitting until you reach the level of comfort for durability.
Step 9: Painting
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Many attempts in the past to paint PVC resulted in failure, or a pretty short-lived paint job. PVC is difficult to paint because of its molecular makeup: it basically provides no rough surface to adhere to. If you try to paint PVC with standard paints, you end up with a layer of paint that is flaking, peeling, or bubbling, and often just won’t stick.
That was the case until the invention of Krylon Fusion Paint for Plastics. It’s honestly the only paint available which can actually, and successfully, stick to PVC, since that’s what it was designed for. It comes in a plethora of colors and is available at Home Depot, Lowes or your local hardware store.
If you are using glossy white furniture grade fittings, use Krylon Fusion color 2320, which matches the fitting color and gloss perfectly.
As with any paints, you still need to abide by the old painting laws: start with a clean surface, rough it up a bit and use light coats. Here’s a step-by-step for painting PVC:
NOTE: If you are going to paint PVC, dont use the Shining/Glossing steps I outlined earlier. The PVC will not stick to the Mineral Oil or Liquid Tire Shine.
To Paint PVC, you need:
– 120-200 Grit Sandpaper
– Krylon Fusion for Plastic Paint
1.Clean the pipe as per my instructions in the ‘Cleaning’ section.
2.Take sandpaper (220 grit is preferred) and ‘rough up’ the surface of the pipe.
3.In a ventilated area, spray a light, thin coat, with an even side-to-side motion along the length of the pipe section.
4.Allow 10 minutes between coats.
5.Repeat the light, thin coats until the desired build up is achieved.
6.Voila! Even prettier PVC!
Step 10: Bending
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To bend PVC pipe you will need a few supplies. The first is a PVC Bending Jig, whichI have uploaded plans for, located here for SketchUp. This jig will allow you to bend PVC controllably and easily. The trick of bending PVC is that your bend may not end up exactly where you want it in the overall position of the pipe length, so it is suggested that you bend the pipe FIRST, and then cut it to length.
To bend PVC pipe you need:
– PVC Bending Jig (free plans available here)
– PVC pipe
– Heat Gun or Propane Torch
– Sand or Cat Litter
– PVC End Caps or Duct Tape
1.Place duct tape over one end of the PVC pipe segment to be bent. This will allow you to fill the PVC pipe with filler.
2.Pour sand or cat litter into the opposite end, filling the entire PVC pipe to be bent with the filler. Shake to distribute and top off if necessary. You’ll need to fill the entire pipe.
3.Place an additional duct tape over the remaining opened end of the PVC pipe segment.
4.Heat up the PVC pipe with a heat gun or propane torch along the area to be bent. Apply heat until the area appears pliable. Don’t overdo it, or you will deform the PVC.
5.Once the desired softness of the PVC pipe is achieved, place the softened area into the joint position on the PVC bending jig.
6.Using the force of your hand, move the top part of the jig to the desired angle and hold in this position for about a minute or until you think it has cooled. You can use the holes in the jig to hold the peice in place. Make sure it is completely cool before removing from the jig.
7. Perform the cuts on each end of the newly curved pipe as needed.
Step 11: Recycle
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If your local recycler or recycling program accepts #3 vinyl recycling products, you should be able to include your extra PVC pipe and fitting bits in with the lot. Since my place of business does not have a recycling program, we take our extra and used PVC to our local recycler. You can find a recycler close to you by going online to http://www.earth911.org and putting in your zip code.