Corrosion is a big enemy, as certain materials can be affected by environmental effects, which can cause direct and indirect problems and damages. Therefore, corrosion protection must receive the attention it deserves. In this article, we explore this topic.

What is corrosion?

Corrosion is a chemical process that occurs on metal surfaces and other materials when exposed to the environment. This natural effect has direct and indirect consequences. The direct impact is that the damage caused by corrosion leads to the need to replace parts of the equipment, which has a financial burden. The indirect consequence is the disruption of operations due to the necessary repairs. This is considered a time burden.

Corrosion is caused by moisture. As there is less dissolved oxygen under the water droplet, rust is formed from the ions present. Consequently, corrosion starts forming. Corrosion thus is usually triggered by natural phenomena such as humidity or precipitation.

Forms of corrosion

The corrosion process can take several forms, which are described below. Let's see what types of corrosion there are.

• Uniform corrosion: in this case, the loss of material is uniform, and the underlying cause is typically chemical corrosion or electrolytic dissolution.
• Pitting corrosion: pitting corrosion appears locally, in the form of small pits. It is most often found in humid environments or defects in protective coatings.
• Galvanic corrosion: occurs due to the non-homogeneous nature of metals as a result of environmental influences.
• Crevice corrosion: this phenomenon occurs when high tensile stresses occur in addition to the corrosion effect.
• Fretting corrosion: this type of corrosion occurs when frictional, abrasive forces are applied to the surface. Typical occurrences are rivet joints, screw joints, hinges, and joints.
• Filiform corrosion: this type of corrosion occurs under surfaces that have been painted or coated. Defects in the protection allow water to interfere, thereby causing corrosion below the layer.

Corrosion protection technologies

There are several ways to protect surfaces. Let's look at them!

Use of corrosion-resistant materials

A common method of corrosion protection is to use chemically stable materials that resist corrosion. Examples include the following materials:

Precious metals: Precious metals such as gold, platinum and iridium are well tolerant of environmental influences, but silver, rhodium and ruthenium can be sensitive to certain substances. As the price is quite high, they are mostly used as coatings.

Titanium: Titanium is resistant to corrosion and is therefore used as a structural material, coating and alloying material.

Metal alloys: alloying is used to make different metals more resistant to corrosion. Examples include stainless steel, acid-resistant steel and brass-copper alloys.

non-metallic materials: porcelain, silicon rubber and quartz glass are also popular.

The special design of the structure

Corrosion protection starts at the design stage of the metal structure, with the most important corrosion protection aspects to be considered. All elements must be accessible so that mandatory maintenance can be carried out easily.

Structures that have no or few corners are much less vulnerable to the damaging effects of corrosion. Care should also be taken to ensure that surfaces that are joined to concrete and that closed sections are sealed airtight. Particular attention should be paid to corrosion protection where the elements are fairly thin.

Forming protective coatings

There are two main aspects to consider when designing coatings: what you want to coat and what the conditions are. You need to think about the conditions in which the structure will be used, the material, the quality of the surface, the type of bonding, the intended service life and how long the structure will be expected to last. In terms of the coating, the function it will perform, the means available to form the coating and the climatic conditions at the time of construction are all important.

The following coatings and coating systems can be used for preventive purposes:

• hot-dip galvanising: hot-dip galvanising, is mainly used for light steel structures.
• paint coatings: these can be primer coats and coating layers. The former provides corrosion protection and the latter gives the appearance.
• combined coating systems: they have the advantage that the de-oxidation process can be omitted, but they are more expensive than the previous solutions.

A prerequisite for the application of the coating is that the surface is dry and free of contamination. It is fortunate if the air temperature is within 3 degrees Celsius of the dew point and the equipment used is suitable and has been stored properly.

Coatings can be applied in a variety of ways, such as by painting, roller, brush or spraying, using different specialised materials. Care should be taken to ensure that the drying time between coats is observed and that different coloured coats are used to ensure traceability.

Coatings can be very diverse depending on the application. For example, there are wind turbine blade protective coatings, but also coatings that are specifically fuel resistant.

Cathodic protection

The essence of cathodic protection is that the structural potential of the metal in the metal-electrolyte system is changed in the negative direction so that the rate of corrosion can be reduced by DC polarisation. It creates a galvanic current through the oxidising medium, the electron surplus of which renders the surface inert to the corrosive material.

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The cable tie is a very practical and versatile tool. It is used to fix groups of electrical wires and cables, but due to its simplicity and speed of use, it can be found in many environments.

Durable fixing with cable ties

A cable tie is a fastening tool made of nylon, i.e. plastic, consisting of a longer-shorter (depending on the type) flexible stem and a head. One part of the stem is ribbed and serrated, and this is pulled through the opening of the head until it touches the surface-to-be-fixed and tightens. The teeth create a strong bond that cannot be untied, so once the binder has been pushed together, it cannot be taken apart. Cutting is the only way to separate.

Where does the cable tie come from?

In 1958, Thomas & Betts, a power tools company, first launched the cable tie as Ty-Rap. It was invented by Maurus C. Logan, an employee of the company who eventually became Vice President of Research and Development. Initially, the teeth on the binder were made of metal and were used to secure aircraft wiring.

What types of cable ties are available?

There are several types of cable ties. There are, for example, beaded cable ties, which allow multiple uses, and releasable types with a snap lock. There are marker binders, which can be used to communicate information about the items being bundled, and metal cable ties, which are typically made of stainless steel.

This subheading also includes plastic seals, which may be metal or plastic, the latter being a pull-tight seal and a single-point seal. They are most used for sealing extinguishers, gas meters, containers, and boxes. They do not provide physical protection but their damages are visible to all.

There are also types available that can be used outdoors, which are resistant to most external influences, such as UV radiation, or various chemicals. Some sealants can be used in a radiating environment. In places exposed to high heat, it is advisable to give preference to stainless cable ties. Cable ties are available in different sizes, both small and large.

You can trust cable ties, just like prison guards tying the hands of dangerous criminals.

The cable ties can therefore only be cut off if they are single-used, i.e. non-detachable. For this reason, you can also buy cable tie tensioning and cutting tools from DIY shops, which can be used to easily cut the tie or remove the excess once the stem has been threaded into the header.

Is there any special use for cable ties?

As we've already said, the cable tie is extremely versatile, and the only limit is your creativity. Let's look at some examples!

• It makes an excellent handle, all you have to do is pull the binder through the holes of the missing handle.
• It can also do a great job if you want to fix something, like a distributor, to the wall. Tie two crossed ties to the distributor, attach the third one, and use it to fix the distributor to something on the wall, such as a pipe.
• You can easily make a booklet out of the binder! All you need are two stiff sheets of paper, a piece of paper, a hole punch and some binders.
• A cable tie can be helpful if you want to "seal" the lighter. To do this, you need to run the binder under the gas outlet and tighten it.
• You can easily turn it into a zipper pull by pulling the stem through the zipper to create a loop.
• Use the tie to organise the plethora of cables running around your electronics.
• You can easily make shower curtain hoops out of it by looping a tie-wrap through the holes in the curtain.
• Cable ties can also be useful in the kitchen. Tie it to the handle of the lid and leave a long stem so you won't burn your fingers.

The characteristic of heat shrink tubes, as the name suggests, is that the diameter of the tube can be reduced by exposing it to heat, i.e. it shrinks. This property makes it very a versatile tool, not to mention the fact that it is very easy and quick to use. In this post, we'll look at what heat shrink tubes are and what they can be used for!

What is a heat shrink tube?

A heat shrink tube, due to its reduced diameter when heated, takes the shape of the object, forms a protective shell, and provides insulation. It is important to note that only the diameter of the tube shrinks, the length does not change, so it is possible to shrink it onto the conductor, almost coating it.

Heat shrink tubing was invented in 1964 by Raychem Corporation and has been used for nearly 60 years to insulate electrical conductors and increase wear resistance, repair insulation damage, secure conductors in bundles and insulate contacts and connectors. As it comes in a variety of colours, it is an excellent way of marking things, for example, to distinguish one wire from another.

Heat shrink tubes are always made of a thermoplastic material, such as PVC, fluoropolymer (e.g. PTFE, Kynar, FEP), polyolefin, neoprene, Viton or even silicone elastomer. During the manufacturing process, the properties of the material are adjusted using various additives. For example, if it is used outdoors, it is treated with a UV stabiliser to prevent damage from radiation.

Types of heat shrink tubes

Heat shrink tubes can be classified according to their wall thickness and rigidity. On this basis, there are thin-walled flexible heat shrink tubes, thick-walled rigid heat shrink tubes and resin heat shrink tubes.

Flexible tubes are made of polyethene, are not fusible and can shrink very quickly, making them particularly useful in situations where the coated material must remain flexible. The rigid versions do not melt, do not crack and are extremely robust, so they can be used outdoors. Resin heat shrink tubing is the strongest version and can provide a high level of protection against external harmful effects. This means that the inner wall of the heat shrink tube has an extra layer of resin which melts and adheres to the surface.

It is important to note that there are cold shrink tube options too, in which case no heat is needed to reduce the diameter of the tube. This works by shrinking the pipe onto the conductor by pulling out an internal plastic retaining spiral.

Flanker offers a wide range of shrink tubes. For example, there is thin-wall shrink tubing, cold shrink tubing, hot heat shrink tubing and thin-wall glueless shrink tubing.

 The tubes are usually available in mixed packs, i.e. different sizes can be ordered at the same time.

How is heat shrink tubing made?

Additives such as colourants and stabilisers are added to the base material. A starting tube is created, extruded from the base material, and then cross-linked by an electron beam. The tube is heated above the crystalline melting point of the polymer and its diameter is modified. It is then cooled. The point is that cross-linking creates a kind of "memory" so that when the user heats the material while using the shrink tube, it can shrink back to its original extruded size.

The extent to which a shrink tube can shrink depends on the material and additives, usually in the range of 1:2 to 1:4.

Use of the heat shrink tubing

A good quality heat shrink tube ensures coated materials are resistant to environmental, chemical, mechanical and electrical external effects.

The use of heat shrink tubing is quite simple for professionals and non-professional users alike. Heat, i.e. warm air, is needed to perform the shrinking process, and this can be provided by a heat reflector, a heating cabinet, a heat gun or even an infrared heater. If you don't have one of these to hand, a lighter may do the trick, although it's not exactly a professional solution.

There are a few pitfalls in using a heat shrink tube, but one that can be missed is choosing the right size. On average, shrink tubes can shrink by 50%, meaning that if you choose too large a diameter, it won't be able to cover the surface.

You must heat the tube to at least 120 degrees Celsius, working from the centre towards the edges in a nice, even way so that the tube eventually coats the wire. That's it, and you're done insulating the wire.

Contact Flanker for more advice! Look around our webshop and choose from a selection of quality products!

One of the easiest ways to smooth surfaces is to use a sanding sponge. Hard-to-clean places are easily reached, and gliding and polishing are a breeze. Let's see what you need to know about hand sanding tools and sanding sponges!

Hand sanding

Surface sanding can be accomplished by using specific machines or our hands. Usually, the latter is chosen when the surface is jagged or small and difficult to access. This method is labour-intensive, but it is more cost-effective than machine sanding.

Hand sanding can be done in a variety of ways, using a selection of tools. The most common of these are described below.

Simple and great solution: sanding hand pads

Hand pads are very common and easy to use and can be bought in rolls or cut into A4 pieces almost anywhere, but you're sure to find them on the shelves of a supermarket. The hand pads’ base, on which the sanding grains are placed, can be made of paper or canvas. The size of the grains ranges from P40 to P240.

A similar, but more robust solution is the use of sanding boards or hand blocks. The same coiled abrasive material used for vibratory sanders can be used for these, which is more durable. Cut a piece of the roll of the right size with a small margin, fix it and you're ready to work!

Universal metal sponges for all situations

Metal sponges have a wide range of uses, suitable for working on any metal including softer ones. However, they are not recommended for wood, as the metal fibres tend to break up and get stuck in the wood, damaging its quality.

The degree of fineness of metal sponges is expressed by numbers on a scale of 5. It is important to wear protective gloves when working with metal sponges.

The practical plastic abrasive cloth

The plastic abrasive cloth is loose, and the abrasive particles adhere to these loose fibres. Thanks to its construction, it adapts easily to the shape of the surface and bends well, so it can be used widely. It can be used for both coarse and fine sanding.

Plastic abrasive cloth can be purchased in A4 sheets but is also made into abrasive discs. The material does not clog due to the loose fibres and is easy to clean with running water.

Smooth surface with waterproof papers

Waterproof papers are used when the surface has already been primed, painted, or treated with a substance. They can be used on a wetted surface, which is made possible by an elastic resin layer between the backing paper and the abrasive particles. This has the advantage that the abrasive surface does not clog, and the abraded surface is less likely to be damaged. By using this type of sander, smooth surfaces can be produced, provided the material can withstand the wet medium.

Efficient fine sanding with a sanding sponge

Sanding sponges and sanding blocks are very simple and effective aids when it comes to sanding. They can be used to get to places that are difficult to reach, with edges, corners, and grooves. They are the most practical tools for hand sanding and can be used to easily polish rounded edges, thanks to the fact that the abrasive on the sponge is shape-following, i.e. it follows the curve of the surface.

They can work efficiently because they have an abrasive surface on both sides of the abrasive sponge and all 4 sides of the abrasive lap. They are available in different grades of fineness, for example, fine abrasive, medium abrasive, superfine abrasive, and ultrafine abrasive sponges.

The process of sanding is not one that most people prefer, as it is quite messy, not to mention that using the wrong abrasive can make the whole process an agony. To avoid this, it is recommended to use sanding stones and sanding sponges that can be used to get the job done quickly and efficiently.

Click here to see what products we offer for hand sanding at Flanker!