Spraying Masonry Paint - Everything You Need To Know

Spray Machines

The first place when it comes to talking about spray machines is with the difference between the various types of sprayers. The two most common types are spray machines are airless spray machines and HVLP spray machines.

Airless spray machines push paint out at high pressure to achieve even surface coating. An airless sprayer is used for large interior & exterior surfaces as they operate on a pressurised paint system that can reach 2000 psi. This allows it to apply a large amount of paint quickly & efficiently.

HVLP spray machines in contrast offer high volume and low pressure, hence the name HVLP. The paint is applied through the paint being moved by a low pressure of air flowing from the machine. The paint is then atomized and dispensed through the gun. HVLP machines dispense paint at roughly 10 psi, allowing them to dispense paint in a much more controlled manor. This means that HVLP machines can achieve an accurate distribution of the paint, making them perfect for spraying finer details such as woodwork & UPVC.

Ultimately, both airless & HVLP spray machines are used to spray exterior surfaces, with airless spray machines used for the large broadwall areas such as masonry and HVLP spray machines used for the finishing touches such as doors, soffits & UPVC.

Spraying Vs Rolling

While masonry paint can be sprayed or rolled, there are a number of things to consider when choosing how to paint masonry:

Prep

The preparation is a crucial part of spraying. The set-up of the machine & all of the masking that is involved in protecting the surfaces you do not want to spray will take time. Using a roller will give you much more control over the application of the paint, thus less masking is required.

Cost

The cost involved in spray painting does have an initial surge when you have to buy all of the equipment you will need. Having said this, the time saved in labour & the cost of materials that you save by spraying can see the long-term value of spraying become an attractive proposition.

Time

The amount of paint you can apply by spraying far exceeds that of rolling. An experienced sprayer can spray a full house in 3 hours, while rolling could take as long as 2 days.

Finish

The finish you can achieve with a spray machine is better than if you use a roller, although the quality of the paint you use is an even bigger factor in this. A high opacity masonry paint such as Emperor Masonry Paint can help prevent flashing & allow you to achieve a beautiful finish no matter the equipment you use.

Clean-Up

The proper maintenance of spray machines is crucial for their long-term performance. If they are not cleaned properly, they will gain a multitude of issues that can cost you. The clean-up involved with rolling is nothing compared to properly cleaning the spray gun, line, tips, filters & manifold.

Overall, like anything there is always benefits & drawbacks to both rolling and spraying. The method you choose depends on your level of experience & your long-term goals.

The Best Sprayer For Masonry

There are a number of fantastic airless spray machines available that are perfect for spraying masonry paint. We particularly recommend the options from Tritech as all of their spray machines are made with the highest quality materials and come with a lifetime warranty,

In the airless spray machine range from Tritech, there are four main versions, the T4, T5, T7 & T8. These vary in terms of size, with the T4 being the smallest and T8 being the biggest. If you are going to be doing a lot of exterior painting, the T7 and T8 are more suitable as they can run longer without maintenance, while to T4 and T5 can be great options if you want a smaller and more compact airless spray machine that can be used every so often.

If you are looking for an entry level machine at the lowest price, the Tritech T4 Airless Sprayer - Carry is an excellent option. The compact machine is designed for occasional use and comes in a carry form, making it easy to transport.

In terms of value for money, we recommend the TriTech T8 Airless Sprayer - Hi Cart for a number of reasons. The machine can be ran flat out 24/7, can apply most water or solvent based coatings. It is also available at the best price for what you are getting, at just under £2,500 as it will serve you for constant use for years to come.

Both machines comes with TritTech T360 Contractor spray gun, TriTech Contractor 517 airless tip, TriTech Contractor safety guard & 1/4" x 15m textile hose assembly.

How To Spray Masonry

Health & safety when spraying is hugely important due to the potentially dangerous nature of airless spraying.

• Using the safety catch is crucial when spraying.
• Always ensure that the safety catch on the spray gun is engaged at all times when not using the machine. This includes when the power is turned off.
• High pressure fluid from spray can penetrate the skin. If not promptly & properly treated, the injury can cause permanent disability or amputation so you must ensure that you take all precautions.

Step 1: Prep

The first port of call when painting any surface is the preparation. Once you have completely cleaned the masonry using a fungicidal wash & made any required repairs to the masonry, mask the surfaces that you do not want to paint.

There are a wide range of masking solutions for various surfaces, from window film to tape & drape. Unlike when rolling, the masking must cover all surfaces that will not be painted, as any overspray will coat these areas.

Step 2: Set up the machine

Once the surface is prepared, it is time to set up the spray machine ready for application.

1. Insert suction filter into the material
2. Set the pressure gauge low ready to prime
3. Remove the guard from the gun
4. Plug the unit in and turn on at the power switch
5. Turn the prime switch to start priming the material (use an empty bucket)
6. Once the material is drawing out of the prime hose, reverse the prime switch to now prime the material through the gun
7. In the empty bucket, draw material through the line & gun - once the material is primed, the gun is ready to use
8. Switch the safety catch on and refit the guard & tip to the gun
9. On a test area, find your desired pressure by gradually turning the gauge up

Step 3: Spraying

You are ready to get spraying! The tip size to use will vary slightly depending on what the paint manufacturer recommends & the machine you are using, but a 517 or 519 tip size is generally recommended.

Prevent ‘fanning’ by ensuring the gun remains directly in front of the surface. If you don’t do this you will create overspray which will lose you material and it will cause less material to be applied to certain areas, leaving heavy shades on the surface.

The standard optimum distance from the surface you are spraying is 12 inch or 30 cm. It is crucial to apply the triggering technique when spraying by starting your motion before pressing the trigger. If you don’t do this, you will build up thick lines at the end of each pass.

Masonry paint manufacturers recommend using a primer if the surface you are painting has not been previously painted. Once the primer has fully dried if you have applied one, you can then apply your first coat of masonry paint. You can water down your first coat of masonry paint by the recommended amount, as instructed by the manufacturers data sheet. Once fully dry, you can then apply the second coat of masonry paint.

Step 4: Clean up

Every time you properly clean a spray machine, it will ensure the parts on the unit last 2-3 times longer than if unit is not cleaned thoroughly after every use.

A well cleaned maintained unit also means less downtime fixing issues that can arise when the machine is mistreated.

1. Run 2 gallons of white spirit through unit (oil-based paints only)
2. Run 2 gallons of water though the unit to clean through any paint
3. Remove the filters from the unit and clean
4. Remove the gun from the hose and clean
5. Refit the filters & gun to the machine
6. Run another 2 gallons of clean water through the unit to completely flush it out
7. Finally, oil the piston once the full unit is cleaned

When running water through the machine, ensure you run at half speed.

Frequently Asked Questions

How do I know what size spray tip to use?

A spray tip will have 3 digits for example: 417. When spraying approx 10" from the surface the fan width will be double the first digit so 4 = 8". The second two digits represent the orifice which will control how much paint is allowed to pass through. This is measured in thousandths of an inch (17= 0.017") A larger fan will cover more area however if you were painting skirting boards you would only need a small fan so you might opt for a 211. Then you would need to consider what speed you want to be moving at because a larger orifice would allow you to apply more paint & work faster so then you could go for 213 instead.

How often should I change my filters?

Smaller machines would have 2 filters; a suction filter & a gun filter. A larger machine would usually have 3 filters; a suction filter, manifold filter & gun filter.

The suction filter is visible at all times so its quite easily to tell when it needs to be replaced as it will either be covered in dry paint or the mesh may have been damaged. If the suction filter is covered in paint it may be possible to soak in gunwash or paint stripper to remove dry paint & reuse. However if the mesh has been damaged it would be advisable to change ASAP.

The Manifold Filter is attached to the machine. On the TriTech T5 you would unscrew the cover to take out the manifold. If you are using your machine regularly this would be advisable to do once a week. You don't need to replace with a new one every week you just need to clean with water / thinners & remove any excess paint.

If the machine is being used every day then the gun filters should be replaced every week.

How often should I oil my machine?

We supply Q Lube for lubricating the Piston. This product is specifically designed for using on pumps. You simply need to put 2 drops into the piston once a week or after each use if you are only using the pump occasionally. Q Lube will prevent paint from drying on the piston and damaging the packing's.

Can I use other brands of tips in my spray gun?

If you wanted to use a TriTech tip with another brand of gun you can do this providing you use the TriTech guard and the gun has a 7/8" thread. If it was the other way round you would need the matching guard for the brand of tip you are using.

What are the potential issues that I may encounter?

There are a number of issues that can arise when using a spray machine:

• Blockages to filters – suction filter, manifold filter, pencil filter

• The bearing can seize – this means the unit will not prime properly

• The line can leak – this is often due to people not checking the line is connected properly to the unit

• Piston seal packers can leak - this can only happen over a short space of time due to misuse

We hope this has answered any questions you may have had regarding spraying masonry paint. Why not shop the range of trade paint, decorating tools & supplies we have in stock here at Painters World, all with FREE next working day delivery available.