Material guide
PVC & plastic
What works on PVC and other plastics: how to cut pipe square, primer and cement times, which plastics glue won't hold, and how to drill without cracking.
Quick facts
- Know your plastic
- Check the code: 3 = PVC, 2 = HDPE, 4 = LDPE, 5 = PP, 6 = PS. Codes 2, 4 and 5 are the hard ones to glue.
- Best glue for PVC pipe
- Primer, then PVC solvent cement. Push in with a 1/4 turn and hold 30 seconds.
- Set time (1/2 to 1-1/4 in pipe)
- Handle after about 2 minutes at 60 to 100°F. Wait 15 minutes before pressure up to 180 psi.
- Won't glue easily
- Polyethylene, polypropylene and PTFE. Use a primer kit made for them.
- Cut
- Square cut, then remove burrs and bevel the end about 15°
- Never test with air
- PVC pipe can burst under compressed air or gas. Test with water.
"Plastic" covers dozens of materials, and they don't all behave the same way. PVC, ABS and acrylic are hard and glue well. Polyethylene and polypropylene feel waxy, and most glues just peel off them.
So the first job is to find out which plastic you have. Look for the number in the small triangle molded into the part. A 3 means PVC. A 2, 4 or 5 means polyethylene or polypropylene, the hard ones to glue. No code? Check the maker's label or spec sheet.
PVC pipe is joined a special way. The primer and cement soften the plastic, and the pipe and fitting fuse together. That's why a clean, square cut and a quick, wet assembly matter more than how much cement you use.
Most plastics melt before they cut. A dull blade or a fast drill makes gummy chips and rough edges. Sharp tools, a steady feed and a solid backer fix most problems.
Drill into PVC & plastic
Clamp the part over scrap wood so the bit exits into something solid. Start slow and ease off as the bit breaks through, or it can chip and crack. Keep holes away from the edge. If chips melt and string, slow down.
What to use: Sharp twist bit or plastic bit + scrap backer
Guides
- Drill PVC and plastic without cracking (coming)
Cut PVC & plastic
Cut pipe as square as you can, with a handsaw in a miter box, a power saw or a plastic tubing cutter. A crooked cut leaves less glue area. Then remove every burr inside and out, and bevel the outside edge about 15° so it won't scrape the cement off.
What to use: Ratcheting PVC cutter + deburring tool
Guides
- How to cut PVC pipe straight (and without a saw) (coming)
- Circular saw blade guide: tooth count, kerf, and which blade for what (coming)
Glue PVC & plastic
PVC pipe isn't glued, it's solvent welded. Dry fit first. Prime both parts, then coat them with cement and push together with a 1/4 turn. Hold 30 seconds. For PVC parts that aren't pipe, super glue works. Polyethylene and polypropylene need a primer kit.
What to use: Primer + PVC cement; plastics primer kit for PE and PP
Guides
- PVC cement vs glue, and do you need purple primer? (coming)
- Identify the plastic before you glue it (recycle codes and tests) (coming)
- Glue for polypropylene and polyethylene (the plastics nothing sticks to) (coming)
- Does Gorilla Glue work on plastic? (Which plastics it can't bond) (coming)
- What super glue won't stick to (and what to use instead) (coming)
- Glue PVC to wood or metal (coming)
- Best glue for plastic to metal (tested) (coming)
- Waterproof glue for outdoor wood and plastic (coming)
- Super glue won't stick or won't dry: what's wrong (coming)
- How to remove super glue from glass, plastic, and skin (coming)
Screw or anchor into PVC & plastic
Don't thread PVC pipe. Use molded threaded adapters with PTFE tape, hand-tight plus 1/2 to 1 more turn. Don't screw metal male threads into plastic female threads unless the fitting is metal-reinforced. To mount plastic sheet, drill clearance holes and use washers.
What to use: Molded threaded adapters + PTFE tape
Guides
- Types of screws: the 14 you'll actually meet (and what each is for) (coming)
- Glue PVC to wood or metal (coming)
Sand or finish PVC & plastic
Clean the plastic, then sand very lightly to dull the shine so paint can grip. For PVC pipe outdoors, a thick coat of exterior water-based latex paint blocks the sun. Light colors keep the pipe cooler.
What to use: Fine sandpaper + exterior latex paint
Guides
- Sandpaper grit chart: which grit for which job (coming)
Safety basics
- Air out the room. PVC primer and cement give off strong, flammable vapors. Work outside or with fans, and keep flames and sparks away.
- Wear safety glasses and gloves. Cement stings eyes and skin, and cut edges are sharp.
- Never test PVC with air. Compressed air or gas can make the pipe burst into sharp pieces. Test with water.
- Clamp what you cut and drill. Round pipe rolls and thin sheet can grab a bit.
Sources
- ASTM revises the Resin Identification Code standard D7611: codes 1-7 (ASTM International)
- How to solvent weld and set-up/cure time charts for PVC, CPVC and ABS cement: 1/4 turn, hold 30 s, no primer on ABS, 50% more time when humid, no air testing (Oatey catalog)
- IPEX PVC DWV handling and installation: square cut, deburr, 15° chamfer, primer, quarter turn, threaded adapters, latex paint, never use compressed air (IPEX)
- LOCTITE Plastics Bonding System technical data sheet: activator for polyethylene and polypropylene (Henkel)
- LOCTITE Super Glue Gel technical data sheet: bonds PVC; do not use on PE, PP, PTFE (Henkel)
- Drilling plastic: backing board, slow feed at entry and exit, holes away from the edge, washers (TAP Plastics)
- OSHA 29 CFR 1910.133: eye and face protection