Heat-resistant adhesive for metal: which composition will withstand +300°C, +600°C and above?

Why does ordinary glue break down when heated - and what to do?

Have you ever tried to glue metal parts that then heat up to 200–300°C? Regular “superglue” or epoxy from the hardware store simply melts under such conditions, loses strength, or begins to smoke. It's all about thermal degradation of polymers: most adhesive bases decompose already at +100...+150°C, and at higher temperatures they turn into a brittle mass or completely burn out.

Automotive repairs, furnace manufacturing, heating system manufacturing, or even exhaust pipe assembly require special heat-resistant adhesives for metal. They not only withstand extreme heat, but also maintain adhesion to rust, oxidized surfaces and alloys with different coefficients of thermal expansion. But how to choose the right composition among dozens of brands and types? Let's figure out which adhesives can cope with +300°C, +600°C and even +1000°C - and where to use them.

Spoiler: there is no universal solution. For exhaust system one composition is suitable for turbine repair - another, but for furnace boilers need a third one. And this does not even take into account the requirements for resistance to vibration, chemical media or pressure.

5 Types of Heat-Resistant Metal Adhesives: Comparison by Temperature and Application

All high-temperature adhesives are divided into groups according to chemical composition and maximum operating temperature. Here are the key categories to consider:

• 🔥 Epoxy adhesives - up to +200...+300°C (sometimes up to +400°C with fillers). Suitable for household tasks, but require precise mixing proportions.
• 🛢️ Anaerobic sealants — up to +250…+300°C. Ideal for threaded connections (for example, in an engine), as they polymerize without access to air.
• 🧪 Silicone sealants — up to +260…+315°C. Flexible but weak in tensile strength - used for compaction rather than bonding loads.
• 🏭 Ceramic adhesives — up to +1000…+1500°C. They can withstand open flames, but are fragile and require high-temperature drying.
• 🔧 Cyanoacrylates with heat-resistant additives — up to +180…+250°C. They set quickly, but are not suitable for constant loads.

Important: do not confuse "heat resistance" and "heat resistance". The first means that the adhesive retains its properties under prolonged heating (for example, +300°C for hours), and the second means that it can withstand short-term exposure to an open flame (for example, +1000°C for minutes). Exhaust systems for automobiles require heat-resistant compositions, and for stove boilers - heat resistant with high adhesion to cast iron.

Why do ceramic adhesives require firing?

Ceramic compositions (for example, Cotronics 907 or Sauereisen No.1) contain inorganic binders, which crystallize only when heated to +600...+800°C. Without firing, they remain brittle and crumble easily. This process is called sintering — it converts the paste into monolithic ceramics that are resistant to thermal shock.

TOP 5 heat-resistant adhesives for metal: characteristics and prices (2026)

We analyzed the market and selected the most reliable compounds for various tasks. The table below contains key parameters that will help you choose the adhesive to suit your needs:

Glue name	Max. temperature	Type	Polymerization time	Price for 50 g, ₽	Where to buy
Permatex Ultra Copper	+260°C (short term +315°C)	Anaerobic sealant	1–4 hours	800–1200	Auto stores, Wildberries
J-B Weld ExtremeHeat	+537°C (long-term)	Epoxy two-component	4–6 hours	1500–1800	Ozon, Amazon
Cotronics 907	+1370°C (after firing)	Ceramic	24 hours + firing	3500–4200	Special stores, AliExpress
Loctite 5926	+200°C (long term)	Heat-resistant cyanoacrylate	5–30 seconds	600–900	Leroy Merlin, Castorama
Sauereisen No.1	+1093°C	Ceramic (for ovens)	48 hours + firing	5000–6500	Industrial suppliers

Please note: prices shown are for retail packaging. Wholesale quantities (from 1 kg) are 30–50% cheaper. For example, J-B Weld ExtremeHeat in a can of 85 g costs ~1800 ₽, and a kilogram package for workshops costs ~12,000 ₽ (that is, 2 times more profitable).

How to properly glue metal: step-by-step instructions for heat-resistant compounds

Even the most expensive glue is useless if the application technology is violated. Here is a universal algorithm that is suitable for most heat-resistant compositions (except for ceramic ones - they require separate firing instructions).

Clean the surface from rust using sandpaper (P80–P120 grit)

Degrease with acetone or a special cleaner (for example, Loctite 7063)

Apply primer (if required, see glue instructions)

Heat the parts to +40…+60°C for better adhesion (not for all compounds!)

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Step 1. Surface preparation. The metal must be clean, dry and rough. Use a metal brush or sandblaster to remove oxides. For aluminum and stainless steel, be sure to use primers (for example, 3M Scotch-Weld DP490).

Step 2. Applying glue. For two-component epoxy adhesives (e.g. J-B Weld) mix the components in a 1:1 ratio on a glass or plastic surface. Apply a thin layer (0.1–0.3 mm) - a thick layer conducts heat worse and may crack.

Step 3. Fixing and drying. Connect the parts and secure with clamps. The polymerization time depends on the type of glue:

• 🕒 Cyanoacrylates (Loctite 5926) - 5–60 seconds.
• ⏳ Epoxy (J-B Weld) - 4–24 hours (full strength after 15–24 hours).
• 🔥 Anaerobic sealants (Permatex) - 1–4 hours (without air access).

Step 4. Heat treatment (if necessary). Some adhesives (eg Cotronics 907) require gradual heating to +200...+800°C for final polymerization. Do this in an oven or burner, avoiding sudden changes in temperature.

3 critical mistakes when working with heat-resistant glue

Even experienced craftsmen sometimes make mistakes that ruin all their efforts. Here are the most common mistakes and how to avoid them:

⚠️ Attention: If you are gluing parts that will come into contact with food (such as grill parts), use only certified adhesives labeled NSF/ANSI 51 or FDA-compliant. Most heat-resistant compounds are toxic when heated!

Mistake 1: Ignoring the coefficient of thermal expansion. Metals expand differently when heated. For example, aluminum expands 2 times more than steel. If you glue them together with hard epoxy glue, the joint will crack when heated. Solution: use elastic heat-resistant sealants (for example, Permatex Ultra Black) or adhesives with reinforcing fibers.

Mistake 2: Applying glue to an oily or wet surface. Even an invisible film of oil or condensation reduces adhesion by 50–70%. Always degrease metal isopropyl alcohol or acetone and dry with compressed air.

Error 3: Exceeding the maximum temperature. If the glue is designed for +300°C, and you operate the part at +400°C, it will not “tolerate” - it will simply collapse. Always take the composition with a temperature reserve of at least 20–30%. For example, for the exhaust system (where the temperature reaches +600°C) you need glue with a threshold of +800...+1000°C.

What to do if the glue does not set?

If the connection is weak after polymerization:

1. Remove remaining adhesive mechanically (with sandpaper or scraper).

2. Degrease the surface again methyl ethyl ketone (it is more aggressive than acetone).

3. Apply primer (eg Loctite SF 7649) to improve adhesion.

4. Use glue with higher viscosity (eg. J-B Weld SteelStik instead of liquid epoxy).

Where to buy heat-resistant glue for metal: verified stores and prices

In Russia and the CIS, heat-resistant adhesives are sold in four types of outlets:

• 🚗 Auto stores — Permatex, Loctite, ABRO. Suitable for repairing engines and exhaust systems. Prices are 10–15% higher than on the Internet, but you can buy them right away.
• 🏭 Industrial suppliers — Cotronics, Sauereisen, Resbond. They sell ceramic adhesives and specialized compositions for stoves here. Disadvantage: high IOC (from 1 kg).
• 🌍 Foreign marketplaces - Amazon, eBay, AliExpress. Rare brands can be found (eg. Pyro-Putty), but delivery takes 2-4 weeks.
• 🛒 Construction hypermarkets — Leroy Merlin, Castorama. Yes Loctite and Momento, but the choice is limited.

Tip: If you need glue for turbine repair or oven assembly, look for it at foundry stores or refractory material suppliers. For example, in Moscow these are the companies “Termokeramika” or “OgneuporSnab”.

When purchasing, pay attention to:

• 📅 Expiration date — two-component adhesives deteriorate after 1–2 years.
• 🌡️ Storage conditions — some compositions require a temperature of +5...+25°C.
• 🔍 Certificates — for critical work (for example, in boilers) a certificate is needed GOST R or ISO 9001.

Glue Alternatives: When is it better to use welding or soldering?

Heat-resistant glue is not always the best solution. In some cases, traditional methods of joining metals are more reliable:

Method	Max. temperature	Pros	Cons	When to use
Welding (MIG/TIG)	Up to +1500°C	Maximum strength, tightness	Metal deformation, skills required	Critical loads (frames, high pressure pipes)
Soldering (solders)	Up to +450°C (tin-lead solders)	Good thermal conductivity, maintainability	Weaker welding, not for high temperatures	Electronics, radiators, copper pipes
Heat resistant glue	Up to +1500°C (ceramics)	Without heating the metal, for thin parts	Less strength, load restrictions	Repairing cracks, sealing, inappropriate connections

Glue is worth choosing if:

• 🔧 It is necessary to connect thin-walled parts (for example, exhaust system corrugation), which may become deformed from welding.
• 🔥 You work with metals that are difficult to weld (for example, cast iron or high alloy steel).
• 🛠️ No access to welding equipment or soldering skills.

⚠️ Attention: If you are repairing parts that are subject to vibration loads (for example, turbine mounting), the adhesive must be reinforced (with the addition of fiberglass or metal powder). Regular epoxy will crumble after a few heating/cooling cycles.

Frequently asked questions (FAQ)

Can heat resistant glue be used to repair a muffler?

Yes, but only heat-resistant compounds with operating temperature from +600°C (for example, Permatex Ultra Copper or J-B Weld ExtremeHeat). Regular epoxy will melt. Before application, clean the metal from carbon deposits and rust, and after repair, allow the glue to completely polymerize (at least 24 hours).

Important: the glue is only suitable for small cracks or joints. If the muffler has burned through or fallen apart, it is better to use welding or a bandage.

What glue can withstand open flame?

Suitable for direct contact with fire only ceramic adhesives (for example, Cotronics 907 or Sauereisen No.1). They can withstand up to +1300…+1500°C, but require firing at +600…+800°C. Alternative - fireproof mastics based on aluminosilicates (for example, Pyro-Putty 600+).

Conventional heat-resistant adhesives (even J-B Weld) burn in an open flame, even if their maximum temperature is higher.

How long does heat-resistant glue last on metal?

Service life depends on operating conditions:

• 🔹B dry environment (furnace, boiler) - 5–10 years.
• 🔹 When cyclic heating/cooling (exhaust system) - 1–3 years.
• 🔹B aggressive environment (acids, salts) - 6–12 months.

To extend service life, apply a thin layer of adhesive and avoid mechanical stress on the joint.

Can I paint over heat resistant adhesive?

Yes, but only heat-resistant paints (for example, Bosny High Temp or Rust-Oleum 206999). Regular enamel bubbles and peels off when heated. Before painting:

1. Wait for the glue to completely polymerize (see instructions).
2. Sand the surface with sandpaper (P220 grit) for better adhesion.
3. Apply a high temperature primer (eg VHT SP129).

How to remove heat-resistant glue from metal?

It is difficult to remove polymerized glue, but you can:

• 🔧 Mechanically - a drill with a brush attachment or a sandblaster.
• 🧪 Chemically - epoxy solvents (for example, Loctite 7649 or DMSO). For ceramic adhesives, only mechanical cleaning is suitable.
• 🔥 Thermally - heat the part to +200...+300°C (if the metal allows) to soften the glue.

Do not use acetone to remove J-B Weld or Permatex - it is ineffective. It’s better to take specialized washes.