If equipment is handled carefully and the right thermal spraying safety procedures are followed, then it’s actually not a dangerous technique at all.
It is allowed in places where safety is extremely important, including oil and gas refineries, demonstrating that coatings can be applied safely even in the most dangerous environments with more extreme risk assessments as method descriptions.
Like every manufacturing system, there are several risks which an operator needs to be aware of and guard against using particular safety measures based on the methods being employed.
So in this Alphatek blog, we’re going to cover some safety considerations to think about when thermal spraying.
Noise
Compressed gases are used in arc and flame spraying equipment which makes noise. The material being sprayed, the operational conditions, as well as the type of spraying equipment being used can all affect the sound levels.
Measured 1 metre from the arc or flame spray nozzle, the average sound pressure intensity is 102-104 dB(A). Therefore, specialised enclosures should be applied to mitigate these levels. Operators and bystanders should wear high-quality ear protection where this isn’t possible.
The same procedure goes for HVOF and Plasma spraying equipment, too, as the sound pressure levels from them can be upwards of 132 dB(A).
Compressed Air/Gas
Spraying pistols have a high pressure air supply – it shouldn’t be aimed at individuals. The engine air supply is coated so breathing apparatus should never be attached to it.
Air of breathable quality must be delivered to any breathing apparatus that is being used during the thermal spraying processes.
Similarly, the standard safety procedures must be adhered to when handling compressed gases, which may include gases such as propane, acetylene, argon, or nitrogen as these are also used in operations.
Fumes & Dust
When molten material are atomized, some dust and gases are produced. So in order to minimise the trapping of re-frozen particulates in the sprayed coatings (and to ensure personal safety), efficient removal facilities are essential.
Where components cannot be separated, it is strongly advised to wear breathing masks with appropriate filters.
Specific known risks are present in some materials and no dispersed metal particles should be permitted to gather together – they’re all, potentially, pyrophoric (so can ignite spontaneously). Hydrogen will be released when particular elements react with water. These may base metals such as aluminium or zinc.
Fume extraction equipment must take specific safety precautions because this could be explosive.
Light Intensity
The powerful flame that is produced by combustion spraying equipment has a peak temperature that can exceed 3,100 degree Celsius, meaning it is also incredibly luminous. Plus, ultraviolet radiation from electric arc spraying may harm fragile bodily tissue.
That’s why spray booths and enclosures need to have dark, ultraviolet-absorbing glass installed. Nearby individuals and operators should use safety eyewear made of BS Grade 6 Green Glass when dark glass is not practical. Instead, spraying vicinities should have opaque screens placed around them.
The emissions of UV from the Plasma Spray process can seriously harm exposed skin, resulting in sunburn and tanning as well as modifications to skin cell growth. Skin, therefore, needs to be entirely concealed because repeated exposure on a regular basis could increase the risk of skin cancer.
Heat
Pistols for combustion spraying utilise fuel and oxygen and the fuel gases have the potential to explode. Acetylene particularly can only be used in specific circumstances where it’s been permitted by the Health and Safety Authority.
Despite not being explosive itself, oxygen is a big helper in sustaining the burning of many materials. Some will even spontaneously combust with a plentiful amount of oxygen. Consequently, the oxygen supply (and the fuel gas) must be isolated when not being used. To avoid leakage, care needs to be taken.
Electricity
Some models of electric arc pistols can be safely handheld as they operate at a low voltage. However, they are connected to 440 volts AC source supply units.
No matter how low the voltage operation is for the machinery, it’s more dangerous when being used in an environment that is a high conductor. An environment such as a spray booth. It’s important to always consider this a hazard so the necessary precautions are always taken.
Precautions such as wearing rubber gloves, keeping the gun and cable in good working order, and avoiding touching the thermal spray gun. Uncovered skin and wet clothing is not acceptable when going into a spray booth.
And if the insulation on the cable of the spray gun is broken or damaged at all, it must not be used.
Contact Alphatek Now
Regardless of the sector in which you work, Alphatek provides solutions that are suitable for a numerous amount of application. We can even help you choose.
Do you want to boost efficiency or decrease wear and friction? Our low friction and anti-corrosion coatings will solve those issues.
With over 20 years of experience in the thermal spraying industry, we can provide bespoke metal spray coatings that fit your exact specifications. Have confidence in our well-skilled, highly experienced team.
Contact Alphatek by dialling +44 (0)1706 821 021. You may also send us an email at postbox@alphatek.co.uk.
