Cures Quickly to Seal Hydraulic and Pneumatic Pipes and Fittings
Our 3Mâ„¢ Scotch-Weldâ„¢ Low Viscosity Air/Hydraulic Sealant HP42 is a one-component, anaerobic sealant that cures and seals hydraulic and pneumatic pipes and fittings. This general purpose, low viscosity pipe sealant is fast-curing, sealing almost instantly. It is formulated to resist pressure and vibration as well as lock and seal medium to coarse straight and tapered threads.
Recommended Applications
- Pressure vessels
- Air compressors
- Hydraulic and pneumatic systems
Features of a Rapid Seal
Our 3Mâ„¢ Scotch-Weldâ„¢ Low Viscosity Air/Hydraulic Sealant HP42 provides an almost instant low-pressure seal. A high-pressure seal results when the bond is fully cured. It seals quickly to stop leaks when applied to threads or compression fittings of most metal and certain plastic pipes, without shredding, evaporation or shrinkage. In addition, this sealant prevents galling as well as helps eliminate the waste and mess of leaking hydraulic fluids, oil, fuel and lubricants.
Formulated for Speed and Strength
Offering a rapid seal that withstands heat, pressure and vibration, 3Mâ„¢ Scotch-Weldâ„¢ Low Viscosity Air/Hydraulic Sealant HP42 is an excellent solution for fast results. Resilient and durable, this pipe sealant is formulated to produce the strong seal necessary for a wide variety of demanding applications.
Understanding Anaerobic Adhesives
Anaerobic adhesives are uniquely formulated to cure in the absence of oxygen. The term “anaerobic” means “living without air” and when the oxygen is excluded, a chemical chain reaction begins that causes the adhesive to polymerize. Contact with metal speeds the polymerization process and rapidly accelerates the curing process, forming tough cross-linked plastic that provides aggressive adhesion with effective shear strength.
More commonly referred to as threadlockers, pipe sealants, retaining compounds, and gasket makers, these adhesives are often used to enhance the seal, or holding force, in the threads of joined fastener systems such as nut-and-bolt assemblies. A nut-and-bolt assembly may have as little as 15% metal-to-metal contact and even a small amount of anaerobic adhesive readily fills any air voids between the threads and then hardens to a thermoset plastic. These unique adhesives are easy-to-dispense, cure rapidly, and provide effective torque strength while resisting temperature and vibration and sealing out moisture and gasses to protect against corrosion. Anaerobic adhesives can decrease manufacturing costs, enhance equipment reliability, minimize aftermarket breakdown, and reduce warranty claims.

3M 20230, Scotch-Seal Metal Sealant 2084, Silver, 5 Gallon Drum (Pail), 7000046344
3M 19768, Utility Cloth Sheet 314D, 9 in x 11 in P180 J-weight, 7000000356
Dynabrade 60052 .1 hp Straight-Line Quick-Change Pencil Grinder, Rear Exhaust, 35,000 RPM, 3/32" Collet
3M 95725, Venture Tape Metal Building Facing Tape 1552CW, White, 72 mm x 45.7 m, 7010313505
Insize 0120-IM24, INDUCTIVE MOISTURE METER, 0~100%, 6974029776588
3M 26125, PPS Series 2.0 Adapter, Type S29, 8 mm Male, 1.25 mm Thread, 7100135955
3M 22396, Roloc Disc 361F, 36 YF-weight, TR, 1-1/2 in, Die R150S, 7000045091
3M 62714, Scotch-Weld Stainless Steel High Temperature Pipe Sealant PS67, White, 50 mL Tube, 7100039216, 10/case
3M 10118, Synthetic Steel Wool Pads, 10118NA, #0 Fine, 7000126148
3M 11137, Roloc Disc 361F, 50 YF-weight, TR, 1-1/2 in, Die R150S, 7000045094
Dynabrade 60051 .1 hp Straight-Line Quick-Change Pencil Grinder, Rear Exhaust, 60,000 RPM, 1/8" Collet
3M 76624, Roloc Disc 777F, 60 YF-weight, TR, 1 in, Die R100N, 7000045620
3M 10120, Synthetic Steel Wool Pads, 10120NA, #000 Extra Fine, 7000126149
Standard Abrasives 880316, Buff and Blend GP Wheel, 2 in x 3 Ply x 1/4 in A VFN, 7100095225
3M 20967, Portable Utility Cloth Roll 314D, P240 J-weight, 1 in x 20 yd, 7010290604
3M 65033, Scotch-Brite Diamond Wheel, 645DC 6 in x 1/2 in x 1 in, 7010365574, Box of 3
ACS CX1250 Diamond Belt, 1/2" X 24" 175u 
