Best Epoxy Putty for Pipe Leaks: What the Makers Say

Plumbing Picks is reader-supported. As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.

Quick answer from a licensed plumber: In my view epoxy putty is a stopgap for a small leak you can reach, not a repair to trust behind a wall. If you want a stick, our pick is J-B Weld WaterWeld: its maker says it sets under water and states a 500 PSI water-pressure figure, and NSF lists it with a pipes-and-fittings limit. Shut the water off first, wear gloves and eye protection, and call a plumber for gas, in-wall or burst pipe.

Our pick for most small pipe leaks: J-B Weld WaterWeld epoxy putty stick. Check the J-B Weld WaterWeld on Amazon

This page compares four putty sticks on what their makers’ data sheets, safety data sheets and NSF’s public listings say. We did not test them. Putty suits a pinhole or small crack on a pipe you can reach, once the water is off and the spot is dry. A clamp is the better stopgap for a split (see the best pipe repair clamp). A cut-out and a push-fit or soldered repair is the lasting fix (see push-to-connect fittings and pinhole leaks in copper pipe). For the emergency steps, start with how to stop a leaking pipe. This is not plumber’s putty, the soft sealant for drains and faucet bases.

Epoxy Putty Sticks Compared

Stick	NSF/ANSI 61 (our check)	Set and cure, per maker	Heat and pressure, as stated	Cures wet?
J-B Weld WaterWeld	Listed; pipes-and-fittings limit	Sets 25 min; hard in 1 hr	250°F; water pressure up to 500 PSI	Sets under water
RectorSeal EP-200	Listed; area and mixing limits	Use within 2 to 3 min; hard in 15 to 20 min	500°F continuous; pressure tested to 1300 psi (test not described)	Hardens under water
J-B Weld SteelStik	Listed; tank footnote only	Sets 5 min; drill after 60 min	350°F; no pressure figure	Not stated
PC-Plumbing 3-Pack	Maker says rated; not found in NSF list	3 min work time; 60 min to service	No pressure figure; heat range on listing only	Wet or dry, per listing

All four were in stock, sold and shipped by Amazon, on September 29, 2026.

Our Pick: Best Documented for Water Pipes

J-B Weld WaterWeld Epoxy Putty Stick (2 oz)

Two-part putty stick · 2 oz · sets in 25 minutes, hard in 1 hour per J-B Weld · 250°F and water pressure up to 500 PSI per J-B Weld · on NSF’s NSF/ANSI/CAN 61 list, with a pipes-and-fittings limit · sold and shipped by Amazon

J-B Weld’s page says WaterWeld plugs or seals leaks, names plumbing, drains and potable water tanks among its uses, and says it sets even under water. It gives a 25-minute set time, hard in one hour, and says it withstands water pressure up to 500 PSI and temperatures up to 250°F. Those are the maker’s figures; we did not test them. The FAQ lists most rigid plastics, including PVC and CPVC, and does not recommend it for flexible plastics, polypropylene or polyethylene. Nothing on the maker’s pages says to apply it to a leak with water still running, so shut the water off first (my advice).

NSF’s public listing (checked September 29, 2026) shows WaterWeld as a sealant at the commercial-hot test temperature, 180°F by NSF’s key, with a footnote that limits exposed sealant in pipes and fittings to 1.3 sq. cm per liter (0.2 sq. in. per liter). The safety data sheet (2018) says Warning: causes skin irritation and serious eye irritation, and may cause an allergic skin reaction. It says to wear protective gloves, clothing and eye or face protection.

Maker says it sets even under water
Maker states a 500 PSI water-pressure figure
NSF footnote names pipes and fittings

J-B Weld’s own pages and the Amazon listing give different strength numbers (see below)
Not for polyethylene, per J-B Weld’s FAQ
Skin sensitizer per its safety data sheet

Verdict: The pick for a small leak on a shut-off, dried pipe when you want a stated pressure figure and an NSF entry that names pipes.

Check the J-B Weld WaterWeld on Amazon

Best Stated Heat and Test Pressure

RectorSeal EP-200 Epoxy Putty (2 oz)

Two-part putty stick · 2 oz · use within 2 to 3 minutes of mixing, hard in 15 to 20 minutes per RectorSeal · 500°F continuous, pressure tested to 1300 psi per RectorSeal · on NSF’s NSF/ANSI/CAN 61 list, with mixing and area limits · sold and shipped by Amazon

RectorSeal’s product data sheet lists pipes (copper, steel, PVC), joints, drains and water heaters among its uses, says it hardens under water, and calls it a permanent repair. It says the putty is pressure tested to 1300 psi, withstands continuous temperatures up to 500°F and has a tensile strength of 2000 psi. It does not say how the 1300 psi test was run. Directions: wear gloves, knead to one color, apply at once and use within 2 to 3 minutes. It starts to harden in 5 to 10 minutes and can be sanded or drilled after an hour.

The data sheet says certified to NSF/ANSI/CAN 61. NSF’s listing shows EP200 at the commercial-hot test temperature with two footnotes: a maximum surface-area-to-volume ratio of 0.3 sq. in. per liter in pipe, and a mix of a piece at least 3/4 in. long but no more than one-third of a stick, mixed 60 to 90 seconds. The safety data sheet (validated March 2022) is the strictest of the four: signal word Danger, H350 “may cause cancer” (its symptoms section says by inhalation), skin and eye irritation, and skin sensitizer. It says to wear gloves, safety glasses or goggles and a mask, and to store it locked up.

Only stick here with both a test pressure and a continuous heat rating
Hard in 15 to 20 minutes per RectorSeal
Data sheet and NSF listing both name potable-water certification

Safety data sheet: Danger, H350 may cause cancer
Use within 2 to 3 minutes of mixing
NSF footnotes limit how much putty may touch water

Verdict: The pick for a hot-water line or the highest numbers on paper, if you will wear gloves, eye protection and a mask when sanding.

Check the RectorSeal EP-200 on Amazon

Best for a Dry Metal Pipe or Fitting

J-B Weld SteelStik Epoxy Putty Stick (2 oz)

Two-part steel-reinforced putty stick · 2 oz · sets in 5 minutes, drill after 60 minutes per J-B Weld · 350°F and 4000 PSI strength per J-B Weld · no water-pressure figure · NSF entry has a tank footnote only · sold and shipped by Amazon

J-B Weld’s page calls SteelStik a steel-reinforced, non-rusting putty for metal. It gives a 5-minute set, says it can be drilled or painted after 60 minutes, rates it at 4000 PSI and says it withstands temperatures up to 350°F. The FAQ lists all metals, plus PVC and CPVC. The page says water resistant, but gives no under-water claim and no water-pressure figure. A 5-minute set leaves a short working time, though RectorSeal (2 to 3 minutes) and PC (3 minutes) give even less.

NSF lists SteelStik as a sealant at the commercial-hot temperature. The footnote on its entry limits exposed sealant in a tank to 0.60 sq. cm per liter (0.095 sq. in. per liter); WaterWeld’s pipes-and-fittings footnote is not on it. J-B Weld’s TankWeld carries the same tank footnote, and WaterWeld, PlasticWeld and MultiPurposeStik carry the pipes-and-fittings one, so my reading is that SteelStik is listed for tank contact, not pipe contact. Confirm with J-B Weld before using it on a drinking-water line. The safety data sheet (2019) says Warning: Part A is a skin sensitizer and an eye and skin irritant; Part B is a skin sensitizer. It says to wear gloves, clothing and eye or face protection.

5-minute set per J-B Weld
350°F figure from the maker
J-B Weld’s FAQ points to it for metal

No water-pressure figure and no under-water claim from the maker
NSF entry has a tank footnote, not a pipes-and-fittings one
Skin sensitizer per its safety data sheet

Verdict: The pick for a dry, drained metal pipe or fitting where you want a fast set. Not for a drinking-water line until J-B Weld confirms the listing.

Check the J-B Weld SteelStik on Amazon

Best Three-Stick Pack

PC Products PC-Plumbing Epoxy Putty (2 oz, 3-Pack)

Three 2 oz putty sticks · 3-minute work time, in service in 60 minutes per PC Products · no pressure figure · heat range on the Amazon listing only · maker says NSF rated, not found in NSF’s list · sold and shipped by Amazon

PC Products sells PC-Plumbing as an emergency repair putty. Its page says to turn off the water, relieve the pressure and drain the pipe if necessary, roughen the surface, wipe it with alcohol or acetone, mix for 60 seconds and apply at once. Its data sheet gives a 3-minute work time and 60 minutes to return to service, and its FAQ says it sticks to rigid PVC and ABS pipe. The Amazon listing adds that it cures wet or dry and gives a -20 to 250°F range; neither is on the PC pages we read, and no page gives a pressure figure.

PC’s data sheet says NSF rated safe for potable water contact, and the Amazon listing repeats it. On September 29, 2026 we searched NSF’s public NSF/ANSI/CAN 61 listings by product name (PC-Plumbing, PC Plumbing, PC) and by company name (Protective Coating, PC Products) and found no entry. PC’s data sheet does not name the standard or give a listing number, so ask PC Products for the certificate before using it on a drinking-water line. The safety data sheet (2019) says Warning: skin irritation, serious eye irritation, may cause an allergic skin reaction. It lists crystalline silica at 0.1 to 1.0% and says to wear chemical-resistant gloves and chemical safety goggles.

PC’s page gives shut-off, prep and mixing steps
Three sticks for spare repairs
Sticks to rigid PVC and ABS per PC

3-minute work time
No pressure figure, and the heat range is on the listing only
NSF claim not found in NSF’s public list
Skin sensitizer; sanding dust needs a mask

Verdict: The pick for spare sticks on small repairs, once you have PC’s NSF certificate for any drinking-water pipe.

Check the PC-Plumbing 3-Pack on Amazon

I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.

How to Apply Putty to a Pipe

Shut the water off and drain the line. Open a low faucet, then dry the spot. Only PC’s page says to relieve the pressure; I would for all four (my advice). See how to shut off your water main.
Clean and roughen. RectorSeal says to remove grit, grease and paint and roughen with emery cloth or a file. PC says to roughen and wipe with alcohol or acetone. J-B Weld’s FAQ says acetone or lacquer thinner, not alcohol (see below).
Glove up, cut and knead until the putty is one uniform color, as J-B Weld and RectorSeal say. PC says 45 to 60 seconds. NSF’s EP-200 listing says 60 to 90 seconds, and no more than one-third of a stick.
Press it on firmly and past the edges of the leak, smooth it, and remove the excess before it hardens (my advice on overlap).
Wait out the longest time on your stick’s label. J-B Weld says temperature and humidity change set and cure times, and PC says a patch below curing temperature needs warming. Then turn the water on slowly and watch the patch.
Check it daily for a week and book the real repair (my rule for a patch on a supply pipe).

Gloves, Goggles and What to Do If It Goes Wrong

Read this first. All four safety data sheets rate these sticks as skin or eye irritants, and all say they may cause an allergic skin reaction (a skin sensitizer), so wear gloves and eye protection and wash your hands after. RectorSeal’s sheet adds Danger and H350. Sanding cured putty makes dust: PC says wear a NIOSH mask. Keep sticks away from children and pets, per PC, and avoid breathing the dust, per all four sheets. First aid, by sheet. Eyes: all four say rinse and remove contact lenses if easy to do; J-B Weld says rinse 15 to 20 minutes and get medical advice if irritation persists; PC says at least 15 minutes, lifting the eyelids, and consult a physician; RectorSeal says rinse immediately with plenty of water and get medical attention if pain, blinking or redness persist. Skin: take off contaminated clothing, wash with soap and water, and get medical advice if irritation or a rash occurs (all four); wash the clothing before you wear it again. Swallowed: J-B Weld says rinse the mouth and seek medical attention if irritation, discomfort or vomiting persists; RectorSeal says rinse the mouth, do not induce vomiting and get emergency medical attention; PC’s sheet says rinse the mouth, drink plenty of water, do not induce vomiting and seek medical advice, and the caution text on its data sheet says call a doctor and give water or milk. RectorSeal and PC say never give anything by mouth to an unconscious person. Follow the sheet for your stick, and call poison control at 1-800-222-1222, a number both J-B Weld sheets list.

When Putty Is the Wrong Call

You cannot shut the water off. Call a plumber.
Pressure supply lines. Oatey’s page says its Fix-It Stick is not for pressure pipe repair. J-B Weld and RectorSeal give pressure figures. The makers disagree, so I would use one only on a small pinhole, never a burst (my advice).
PEX. J-B Weld’s FAQ and PC’s Amazon listing both list polyethylene as a poor bond, and PEX is cross-linked polyethylene (our note). See push-fit vs soldered repairs.
Gas lines. None of the four makers says its putty is for gas piping. If you smell gas, leave and call the gas utility or 911 from outside.
Leaking joints. Fix the joint. See a compression fitting leaking under a sink.
Water heater tanks, in-wall pipe and burst pipe. Call a licensed plumber (my advice; RectorSeal lists water heaters among its uses and J-B Weld names potable water tanks). See what a burst pipe repair costs.

Not linked: Oatey’s Fix-It Stick. Oatey says it works on wet or dry surfaces and with potable water. The Amazon listing we found on September 29 was a third-party seller with 3 left.

Where the Documents Disagree

WaterWeld strength and heat. J-B Weld’s page says 4370 PSI and 250°F, and its FAQ says 4730 PSI and 250°F. The Amazon listing bullets say 1300 psi lap shear with 300°F continuous and 350°F intermittent; the listing description says 900 psi tensile and 300°F. On set time, the product page and FAQ say 25 minutes, while J-B Weld’s project page and the listing description say 15 to 25. Use the lowest heat figure.
SteelStik. J-B Weld’s page says 4000 PSI, 350°F and a 5-minute set. The listing bullets say 900 psi lap shear, 350°F continuous and 450°F intermittent; the listing description says a 3 to 5 minute set, 900 psi tensile and 300°F. The bullets also say NSF certified and safe for contact with potable water, while NSF’s entry carries only the tank footnote. Use the lowest heat figure.
Cleaning. J-B Weld says not to use alcohol on the surface. PC says to wipe with alcohol or acetone. Use the prep on your stick’s own label.
J-B Weld and drinking water. J-B Weld’s FAQ says its products are non-toxic when fully cured but “not rated food-safe,” and it does not recommend them where they directly touch food or beverage. Its WaterWeld page names potable water tanks, and NSF’s drinking-water list (NSF/ANSI/CAN 61) shows WaterWeld and SteelStik, each with an area limit. The two do not settle each other: NSF/ANSI/CAN 61 covers parts of drinking-water systems, and the FAQ line is about food and drink contact (our note). If the patch will touch drinking water, keep within NSF’s limit or ask J-B Weld first.

FAQ

Is epoxy putty a permanent fix for a pipe leak?

The makers do not agree. RectorSeal’s data sheet calls its putty a permanent repair, PC Products sells PC-Plumbing as an emergency repair, and J-B Weld’s WaterWeld and SteelStik pages use neither word. My advice as a plumber is to treat a putty patch on a supply line as a stopgap until you can cut out the bad section.

Can I apply it while the pipe is still leaking?

No maker page we read tells you to. J-B Weld and RectorSeal say their putty sets or hardens under water, which is about curing, not stopping a live leak. PC’s page says to turn off the water and drain the pipe if necessary. Shut the water off, drain the line and dry the spot.

Is epoxy putty safe on drinking-water pipes?

Only where a certification says so. NSF’s NSF/ANSI/CAN 61 list shows WaterWeld with a pipes-and-fittings limit and EP-200 with area and mixing limits. SteelStik is listed with a tank footnote only, by our reading, and we found no NSF entry for PC-Plumbing though PC’s data sheet says NSF rated. J-B Weld’s general FAQ also says its products are not rated food-safe; see where the documents disagree, above.

Will it stick to PEX, CPVC or PVC?

J-B Weld says its sticks suit most rigid plastics, including PVC and CPVC, and lists polyethylene among surfaces it will not bond well to. PC says PC-Plumbing sticks to rigid PVC and ABS, and its listing says it will not bond to polyethylene. PEX is cross-linked polyethylene (our note), so I would not count on putty for PEX. Use a push-fit or crimp repair.

When should I use a clamp or call a plumber instead?

Use a clamp for a split or a larger hole. Call a plumber for anything inside a wall or floor, a leak you cannot shut off, a water heater tank, or a patch that weeps again. In my experience a pinhole in old copper is often the first of several. Never patch a gas line: if you smell gas, leave and call the gas utility or 911 from outside.

Why Trust Plumbing Picks

Plumbing Picks is written by a licensed Georgia journeyman plumber. Every size, rating, dimension and spec on this page comes from the manufacturer pages and documents listed below, which we opened and read, or from the Amazon listing we link; nothing here comes from hands-on testing. Each linked product was shipped or sold by Amazon, new and in stock, when we checked on September 29, 2026. Where a link goes to Amazon we may earn a commission at no extra cost to you. Nobody pays to be included here. More on who writes this and how we pick.

Sources

Bottom Line

Shut the water off, dry the pipe, and use putty only on a small leak you can reach. WaterWeld is our pick, and every stick here is a skin sensitizer. Treat the patch as temporary and cut in a real repair soon.