⚡ Sn97Cu3 soft soldering paste, 100 g, with brush

ARMACK AMASAN LF No. 3 soldering paste is a professional, lead-free tin-containing paste intended for soft soldering copper pipes and fittings. It is ideal for hot and cold drinking-water installations and central-heating systems with an operating temperature of up to 110°C.

The paste is a mixture of micro-grained Sn97Cu3 solder powder, containing 97% tin and 3% copper, and a suitably selected flux. Its homogeneous consistency makes it easy to spread over the prepared surface and helps to produce a correctly soldered joint.

A major convenience is the brush fitted directly into the lid, allowing a thin layer of paste to be applied conveniently and precisely to the pipe or fitting.

✅ Key benefits of ARMACK LF No. 3 paste

• Lead-free Sn97Cu3 composition – 97% tin and 3% copper.
• For drinking-water installations – suitable for copper pipes and fittings.
• For central-heating systems with an operating temperature of up to 110°C.
• High durability of the soldered joint.
• Low solder consumption – the paste enables precise preparation of the surface for soldering.
• Good adhesion to prepared surfaces.
• Consistent, homogeneous consistency for even application.
• Brush built into the lid – the product is ready for convenient application without additional accessories.
• Flux residues are water-soluble, making it easier to clean the joint after soldering.
• The product has PZH and DVGW approvals.

✅ For soldering copper pipes and fittings

LF No. 3 paste was developed primarily for capillary soft soldering of copper pipes and fittings. When applied to the cleaned surface, it helps prepare the joint area and ensures the proper flow of the solder.

The product is particularly useful when installing new systems and carrying out servicing and repairs on copper installations.

✅ Application

ARMACK AMASAN LF No. 3 paste can be used, among other applications, when carrying out:

• cold drinking-water installations,
• hot drinking-water installations,
• central-heating systems up to 110°C,
• copper pipe and fitting joints,
• installation and assembly work,
• repairs and upgrades of copper installations.

✅ Lead-free Sn97Cu3 alloy

The paste contains micro-grained powder of S-Sn97Cu3 solder, consisting of 97% tin and 3% copper. This is a lead-free alloy used to make joints by soft soldering.

The manufacturer recommends using the paste together with lead-free No. 3 Sn97Cu3 soft solder. This combination enables a properly filled and durable soldered joint.

✅ Brush in the lid – convenient application

The container is fitted with a brush mounted directly in the lid. It allows a thin, even layer of the product to be applied precisely to the surface intended for soldering.

This solution eliminates the need for a separate brush and makes work easier both in the workshop and directly at the installation site.

✅ How to use LF No. 3 paste

First, the end of the pipe must be thoroughly cleaned mechanically, for example using a suitable non-metallic cleaner. Then use the brush to apply a thin layer of paste to the surface.

Insert the prepared pipe fully into the fitting socket, then heat the joint area evenly.

Under the influence of heat, the grey paste begins to turn into tin. When the solder held against the edge of the socket begins to melt freely, feed in an appropriate amount of solder until a visible, closed ring of solder forms around the joint.

✅ Correct cleaning after soldering

After soldering, carefully remove flux residues with a damp cloth. For installations, flush the system with water afterwards in accordance with the applicable requirements.

Removing flux residues is very important – it reduces the risk of green deposits on the copper surface and pitting corrosion.

✅ Technical data

• Manufacturer: ARMACK
• Series: AMASAN
• Type: LF No. 3
• Product type: lead-free tin-containing paste for soft soldering
• Alloy: Sn97Cu3
• Solder composition: 97% tin / 3% copper
• Solder classification: DIN EN 29453
• Flux classification: DIN EN 29454-1 3.1.1.C (F-SW 21)
• Form: paste with brush in the lid
• Mass: 100 g
• Application: soft soldering of copper pipes and fittings
• Maximum operating temperature of the installation: up to 110°C
• Approvals: PZH, DVGW

✅ Important application information

Flux residues must be removed thoroughly after every soldering operation. Leaving product residues on the copper surface may lead to green deposits and increase the risk of pitting corrosion.

For a complete joint, the manufacturer recommends using lead-free Sn97Cu3 soft solder. Before starting work, the surfaces of the pipes and fittings should be thoroughly cleaned.