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Mobile Power Pressure Wash Procedure and Chemical Usage Guide

 

Mobile Power Pressure Washing:Tips, Techniques, and Chemical Usage Guide

Getting the Most Out of Your Mobile Pressure Washer

SUMMARY: Simply choosing the right pressure washing equipment is only the start. After receiving proper training in how to use it, all the elements must be put together properly for optimum effect. This article provides information on how to get the most out of your pressure washer and equipment.

In this article, you will find advice to help you get the most out of your mobile pressure washer. For further information, contact customer service at Powerwash.com at 1-800-433-2113. Our experienced power wash professionals will be glad to assist you.

Washing Tips and Techniques
Nozzle Selection
Understanding PSI (Pounds per Square Inch)
Wet Sandblasting
Soda Blasting
Painting after Paint Stripping
Stain Removal
Removing Carbon Deposits (smoke) from Engine Exhaust
To Stop Spotting
Cleaning Copper Trim
Spider Webs
Chemical Selection Guide for Powerwash.com Products
Mixing Instructions
Car Washing
Pickup and Van washing
Tractor and Trailer Washing
Trailer Decal Removal
High Pressure Wax Rinse
Heavy Equipment Washing
Engine Steam Cleaning
Aircraft Washing
Building Fire Damage Washing
House Washing
Boat and Ship Washing
Aluminum Siding Washing
Vent-A-Hoods Washing (Non-Asian Restaurant)
Vent-A-Hoods Washing (Asian Restaurant)
Asphalt Road Washing
Concrete Washing
Asphalt and Tar Removal
Aluminum Trailer Brightening
Masonry Cleaning
New Masonry
Paint Stripping
Fabric Awning Cleaning
Vinyl Awning Cleaning
Related Articles

Washing Tips and Techniques

  1. Always fog or presoak the surface with a detergent, degreaser, or chemical presoak. Presoaking reduces wash time and chemical cost.
  2. Hot water is a better solvent than cold water.
  3. Always rinse detergent off the surface before it dries.
  4. Commercial contractors generally use 4 to 6/gpm at 1500 to 3,500/psi for most cleaning applications. An exception to this is wood cleaning. Here 500 to 2,000/psi is preferred with chemical cleaning to reduce the furring of the wood. Water flow rates of less than 4 gallons per minute - found on general consumer (homeowner) units - are not high enough to be competitive because of increased cleaning time, which raises labor costs.
  5. Chemical dilution is largely a matter of personal preference. For most mobile power washing work, chemical costs run from three to five percent of gross sales, labor accounts for 30 to 45 percent, and fuel for heat is two to four percent. If chemicals and heat costs are reduced, labor costs increase because of increased work time. A slight increase in chemical and fuel costs actually reduces labor costs, because work time decreases. Work smarter - soap and heat are cheaper than labor – not harder.
  6. Washers with chemical injection before the pump, start out with the metering valve open 1/4 turn. Then adjust as needed.
  7. W-200 Spray Wax is similar to spray wax used in coin-operated car washes. Apply the wax hot and follow with a cold rinse for fine surfaces like cars and pickups. On heavier surfaces, like homes and trailers, the cold rinse is not necessary. The application of wax extends the life of the wash job, makes subsequent cleaning easier, and enhances the overall appearance. Note: Because the application of wax will extend the life of a wash job, some contractors choose not to use it because they prefer to wash more often. There are two sides to this. While the use of wax may reduce your income because of the extended life of your cleaning, the enhanced appearance and extended life may generate more business because of the perceived quality of the work.
  8. For fleet washing, wax in the rinse water reduces dirt adhesion and lessens subsequent washing time. In heavy concentrations, wax reduces cement adhesion on concrete trucks.
  9. The tips provided in this section will reduce brushing to about five percent of the total workload. Typically, contractors only brush in the spring or the fall, or as needed. Brushing once or twice per year at a specified time allows the contractor to prepare and schedule extra, short-term, help for those designated times.
  10. For Environmental Power Washing Techniques read Report 507.

Nozzle Selection
There are two factors that need to be considered when choosing the proper nozzle: the nozzle orifice size and the spray angle. These determine the gallons per minute at a particular pressure of the water flow. To determine a nozzle size you need to know the GPM (gallons per minute) and PSI (pounds per square) necessary for the job you are doing. Please consult the nozzle chart in the Powerwash.com on-line catalog or in the Powerwash.com Blaster.

When the nozzle size increases, the psi of your pressure washer is reduced while the flow remains the same. By reducing the pressure of your washer with the unloader, you will decrease both the psi and gpm. Knowledgeable contractors reduce the psi of their pressure washers by increasing nozzle size in order to keep the gpm at its maximum.

Choices for spray angle range from zero to 65-degrees. 25-degree angles fit the natural wash pattern of most contract cleaners. However, many contract cleaners prefer a 40-degree spray angle because they can hold the nozzle closer to the surface, obtaining the same width of contact, while at the same time delivering greater impact pressure and higher temperature at the point of contact. It is necessary to keep the nozzle a consistent distance from the surface.

A zero-degree nozzle concentrates all of the cleaning power in a very small area with a high degree of cleaning power at the center of impact. While this provides tremendous power and cleaning ability, it can cause streaking similar to chicken tracks, and sometimes the entire track of the wand’s wash pattern is visible. A zero-degree rotating nozzle like the ST-58 or Rotomax, solves this problem. They provide the power of a zero-degree nozzle and the coverage of a fan nozzle and, when used properly, do not leave the wand marks (tracers). Consult our catalogue for detailed information on nozzles.

Understanding PSI (Pounds per Square Inch)
Water pressure from the pressure washer is measured in pounds per square inch or psi. This pressure is the amount of force delivered to the surface being cleaned, and is the critical factor in breaking debris from that surface. PSI is determined by the orifice siz of the nozzle tip and the flow rate (gallons per minute).For labeling purposes, the standard nozzle size for measurement is a #4 orifice, which delivers 4.0/gpm at 4,000psi.As nozzle sizes increase or decrease, psi fluctuates accordingly. The nozzle chart in our catalogue lists the psi with different flow rates and nozzle sizes. Nozzle selection depends on the work, and the amount of pressure a surface can withstand before it is damaged.

While psi is a constant at the tip of the nozzle, the pressure decreases as its distance from the targeted surface increases. Experienced power wash contractors understand how to manipulate these distances for maximize both cleaning power and their time.

Because the pressure that contractors need varies a great deal, they get the most out of their equipment by adjusting the distance between the nozzle and the surface being cleaned. For less pressure and heat in the application, they hold the nozzle back, thereby increasing the distance from the surface. For increased pressure and heat, they hold the nozzle closer. Larger contract cleaners will use pressure washers that produce 4 to 6 GPM at 3,000 to 3500 psi at 200º F for concrete cleaning. Vehicle washing can be accomplished using 1,500 to 2,000 psi.
Heat provides a tremendous advantage when cleaning grease and oil. A few Vent-a-Hood cleaners will use steam heated to 310º F, while others will use units that deliver 3,000psi at 200ºF. However, some vent cleaners use electric, 1,000 PSI cold water washers hooked up to hot water (they must hand scrape more for this to be effective).

The psi for decks and other wood surfaces varies from 200 to 3,000, and must be carefully tested first, as too much pressure will cause the wood to fur. If this happens, you will need to sand the affected areas with fine sand paper or steel wool to knock off the furred surface. Many professional deck cleaners use a variable pressure wand (like the ST-54 36" Double Lance Wand) so they can adjust the pressure as necessary. Using low pressure, and letting the chemical (like Powerwash.com's DSR-49 Deck and Siding Restorer or DSR-50 Deck and Siding Restorer plus Stripper) do the work helps avoid furring. Test the effect of pressure on the underside of the deck.

Wet Sandblasting
A wet sandblasting attachment for a pressure washer with 4/gpm at 3,000/psi will use fifty pounds of sand for every twenty minutes of continuous use, making it half as effective as a commercial air sand blasting unit. As such, the market for wet sandblasting is profitable only for small jobs on which the pressure wash contractor is already working, environmental jobs where wet sand blasting is required, or for some building restoration jobs in areas where chemical cleaning does not work.

Soda Blasting
Baking soda blasting is an environmentally friendly alternative to sandblasting, and does not require any clean up because of the materials used. It is also a milder abrasive that will remove surface material without damaging the underlying materials. There are several industrial applications for this technology, including monument and statue cleaning.

Painting after Paint Stripping
Note: The measurement of whether a surface is acidic or alkaline is a number on the pH scale. The scale runs from one to fourteen, with seven being neutral. Color-coding is also used, with red being most acidic, deep blue highly alkali, and green neutral. Most paints need to be applied to a neutral surface. As paint strippers are high in pH, it is necessary to neutralize the surface after stripping it, before a coat of paint is applied. This requires application of an acid that has a lower pH. You will need pH (litmus) test paper to tell you what the pH level is. Oxalic acid, phosphoric, and aluminum brighteners are commonly used as neutralizing agents.

For concrete, masonry, and used equipment, using A-400 Aluminum Brightener, followed by washing with R-109 to neutralize the A-400, and then finishing with a clear water rinse has been successfully used as a paint prep.
Stain Removal
Stains are difficult, and no single product removes all stains. Three things affect stain removal:

  • Source of the stain
  • How long the stain has set
  • The surface into which the stain has set

For stains on concrete or masonry surfaces, use an aluminum brightener, like A-400 or Delta 60™. Scale Away De-liming Acid Coil Cleaner is also a good stain remover.

For stains on painted surfaces, try DNB-1430 undiluted (caution: undiluted DNB-1430 can remove some paints) then A-400 or A-402 Aluminum Brightener.

Removing Carbon Deposits (smoke) from Engine Exhaust
Pre-spray with V-500 or DNB-1430 Liquid Concentrate cut 5 to 1. Wash with R-109, DNB-1430, or V-502. Alternately, pre-spray using A-400 Aluminum Brightener cut 20 to 1, and then wash using R-109 or DNB-1430.

Brushing also helps on heavy carbon deposits and smoke.

To Stop Spotting
Try the following procedures in the order given (the least expensive is first).

  1. Add W-200 Spray to your rinse. Refer to the section on W-200 Spray Wax for more information.
  2. Add RA-130 Liquid Concentrate to your rinse water, cut 50 to 1.
  3. Add a water softener.
  4. Add a de-ionized (DI) or a reverse osmosis (RO) water rinse. Call Culligan to see which option is less expensive in your area. This always works, but costs have to be considered.

Cleaning Copper Trim
Almost any over the counter toilet bowl cleaner will clean and restore copper trim.

Spider Webs
Nothing will dissolve spider webs without dissolving paint and wood as well. D-limonene based cleaners and ammonia work fairly well but may streak the paint, so it is best to test them before using. Both 15- and Zero-degree nozzles (like the X-jet) work well for removing spider webs when using your pressure washer. Grocery stores and janitorial supply stores sell "Spider Web Brooms" for removing spider webs. Fabric softener sheets will drive spiders away, so leave some scattered around, if possible.

Chemical Selection Guide for Powerwash.com Products
MATERIAL SAFETY DATA SHEETS for the chemicals listed below are available

Mixing Instructions
Mix all powders using 1/2 pound (8 oz.) per gallon of water to make a liquid concentrate.

W-200 Spray Wax - Mix two cups of wax to five gallons of water to make a liquid concentrate.

DNB-1430 Mix Kit - Dissolve in 55 gallons of water to make a liquid concentrate.

Car Washing
Dilute R-109 or V-505Liquid Concentrate 100 to 1. For a wax-like sheen, cut R-111 Concentrate 100 to 1. (Note: R-111 is also an excellent hand wash detergent).

Pickup and Van washing
Dilute R-109 or V-505Liquid Concentrate 75 to 1. For a wax-like sheen cut R-111 Concentrate 75 to 1.

Tractor and Trailer Washing
Mix R-109 or V-505 Liquid Concentrate 50 to 1. For very dirty rigs, boost with R-202 in a 3 to 1 ratio, or use DNB-1430 presoak cut 5 to 1. Some fleets clean up quite well simply by presoaking with DNB-1430 and following with a hot water rinse.

Trailer Decal Removal
VR-3 Trailer Decal and Truck Paint Remover is the best product for this job. Most decals are on aluminum or stainless steel tanks, and VR-3 decal remover will not affect most aluminum or stainless steel, but testing is required. With skill, a decal can be removed from a painted surface by just applying PVR-3 to the surface of the decal.

High Pressure Wax Rinse
Cut W-200 Liquid Concentrate 75 to 1. For even application and spot reduction on cars and pickups, it is best to apply it hot and follow with a cold rinse. On heavier surfaces like homes and trailers, the cold rinse is not necessary. This process reduces dirt adhesion, enhances appearance, and extends the life of your wash job.

  • Cut W-200 Liquid Concentrate 20 to 1 to reduce surface adhesion on Read -Mix Concrete Trucks and other heavy equipment.

Heavy Equipment Washing
Mix R-109 or V-505 Liquid Concentrate 40 to 1. For very dirty rigs boost with R-202, cut 3 to 1, or use DNB-1430 presoak cut 5 to 1. DNB-1430, cut 40 to 1, can also be used as the detergent.

Engine Steam Cleaning
Cut R-109 or V-505 Liquid Concentrate 30 to 1. Presoak with a liquid concentrate, cut 5 to 1, made from R-109, V-505, DNB-1430, or V-502.

Aircraft Washing
Mix R-109 or V-505 Liquid Concentrate 50 to 1. Scrub heavy carbon exhaust areas with DNB-1430, cut 30 to 1.

Building Fire Damage Washing
Pre-spray a liquid concentrate of R-109, V-502, V-505, or DNB-1430 cut 10 to 1, and wash with a liquid concentrate of R-109, V-505, or DNB-1430 cut 40 to 1. This will kill the smell and remove the smoke damage, but you will not be able to remove the char from the brick, masonry, or wood. During a normal cleanup following a fire, after removing the smoke residue, everything close to the heat source will be charred and you will be able to see the heat gradient in the walls and flooring.

House Washing
Cut R-109, or V-505, DNB-1430 Liquid Concentrates 50 to 1. To kill mold and mildew, add one-part bleach to four parts of your liquid concentrate. (Note: There is a lot of controversy about using bleach to kill mold and mildew, however approximately half of the contract cleaners use bleach because of availability, price, and effectiveness)

Another method of using bleach is not as a cleaner, but as a way to retard the growth of mold and mildew. Its residual effects disappear as soon as it is rinsed off. A ratio of 8 to 1 works well. This is something that the homeowner should be encouraged to do to help extend the life of your cleaning job.

To remove black spots and black streaks from gutters and siding, cut DNB-1430 5 to 1, or use it undiluted.

Caution: Undiluted DNB-1430 can remove some paints and coatings. Be sure and test a hidden area to determine the strength required to remove the spotting without removing the paint.

Adding wax to your rinse water will extend the life of the power wash job and enhance its appearance. Refer to the information in the section about W-200 Spray Wax for more details.

Boat and Ship Washing
Cut R-109 or DNB-1430 40 to 1. For mossy areas, pre-spray with A-400 Aluminum Brightener cut 20 to 1.

Aluminum Siding Washing
Cut R-109, V-505, or DNB-1430 50 to 1. Some Contractors pre-spray with DNB-1430 cut 10 to 1, and follow with a hot wax rinse. The wax reduces the amount of cleaning needed and makes the next cleaning easier. The cost of the wax is about twenty cents.

Vent-A-Hood Washing (Non-Asian Restaurant)
Pre-spray with V-501, or V-502 Liquid Concentrate cut 5 to 1 for heavy build-up, then wash with V-501, or V-502 Liquid Concentrate cut 40 to 1.

Caution: V-501 and V-502 may etch some aluminum hoods if contact time is too long.

Pre-spray heavy carbon deposits with OD-100 cut 10 to 1. Wash with V-500 cut 10 to 1.

Vent-A-Hoods Washing (Asian Restaurant)
Pre-spray with OD-100 cut 10 to 1. Wash with V-502 cut 20 to 1.

Asphalt Road Washing
Cut R-109, V-505, or DNB-1430 Liquid Concentrate 40 to 1. Pre-spray oil spots with R-109, V-505, or DNB-1430 cut 5 to 1.

Caution: Asphalt is a petroleum-based product, and high concentrations of R-109, V-505, and DNB-1430 can break down the asphalt. In order to cut the oil and grease and not the asphalt, you need the proper strength and the correct dwell time. This takes a little practice to achieve the desired results. Call Powerwash.com at 1-800-433-2113 for further assistance with how to clean asphalt safely.

Concrete Washing
Pre-spraying the concrete and allowing the detergent/degreaser some dwell time in order to soften the dirt, grease, and grime will save time. Try to not allow the chemical to dry, but if it does, pre-spray lightly again. Depending on the extent of surface contamination, you may have to wash with a chemical after pre-spraying or just use a clean water rinse. On heavily contaminated surfaces, your liquid concentrate pre-spray should be cut somewhere between 5 and 10 to 1. For washing, it should be between 20 and 40 to 1. Popular chemicals for this application are R-202, R-109, V-505, or DNB-1430.

  • Note: Some contractors like to sprinkle R-202 dry powder on the concrete, fog it lightly with water, brush it, and then use a high pressure hot water rinse.
  • Another technique is to boost the power of R-109 with a 3 to 1 ratio of R-202 for difficult cleaning situations.

Asphalt and Tar Removal
Pre-spray with R-103LX mixed 10 to 1 with diesel fuel. Soak from two to 12 hours depending on the thickness of the asphalt or tar. Dwell time during the heat of the day in direct sunlight also helps. Wash with DNB-1430, DSR-50, or R-109 Liquid Concentrate cut anywhere from 10 to 20 to 1.

Aluminum Trailer Brightening
Cut A-400 or A-402 20 to 1. Apply from the bottom up, then wash with R-109, V-505, or DNB-1430, cut 40 to 1, from the top down (the detergent neutralizes the acid in A-400). Rinse with clean water.

Masonry Cleaning
Masonry cleaning is hunt and peck type of work since one chemical or procedure does not do all jobs. Testing is required on all jobs, and it is not unusual for each side of the building to require a different technique. To start, testing should be done with and without heat, with and without detergent (R-109, V-505, DNB-1430, V-502, DSR-50, or R-202), and Rotating Zero Degree Nozzles (Rotomax or ST-58). Because of environmental concerns, many contractors are changing to cold water and Rotating Zero Degree Nozzles so that the runoff can go into the storm drain.

If none of the above work, the next step is to try Aluminum Brightener. Cut A-400 or A-402 40 to 1. Caution: A-400 and A-402 can etch glass and some architectural aluminum.

If these methods do not work, sand blasting, soda blasting, or using restoration chemicals are the next steps. For restoration chemicals, we recommend Diedrich Products at 1-800-323-3565 or by Fax: 414-764-6993

New Masonry
Bricklayers have a lot of control over whether this type of job can be profitable or not. Sloppy work by masons can greatly increase the costs of pressure washing masonry. The most common acid used by bricklayers is muriatic acid, which is harsh and reacts with the oxides in some brick, turning the brick a different color. A test with muriatic acid should be done allowing the acid to dry for 24 hours then inspecting for discoloration. Both SureKlean and Diedrich Chemicals have commercial acid cleaners with buffers in them to avoid this problem.

The basic procedure is to remove all the heavy build up of mortar with a scraper or chipping hammer. Then wet the surface just before applying the acid. This keeps the acid on the surface. This work needs to be done while the mortar is still green (fresh). The longer the mortar cures, the harder it is to remove. The acid will only remove a thin layer (scum) of mortar. After applying the acid, use your high pressure washer for cleaning. Most contractors use 2,000 to 3,500 PSI. Zero-degree rotating nozzles, like the RotoMax, and ST-457, will add greatly to your cleaning ability. Exercise caution to avoid blowing out the joints.

Apply acids with special acid sprayers or special acid brushes like Tampico brushes.

Paint Stripping
Chemical coverage: Normally, paint strippers will cover 100ft²/gal. when brushed or 200ft²/gal. when sprayed. When using airless spraying equipment, you will need units with stainless steel pick up parts and PTFE packing.

Paint Stripping Buildings: allow one hour per layer of paint. There are many environmental disposal problems to address when dealing with paint, especially if the paint is lead based. For more information call Diedrich Products at 800-323-3565 or Fax them at 414-764-6993.

For truck, pickup, car, and heavy equipment paint stripping, use VR-3 Trailer Decal and Truck Paint Remover.

Fabric Awning Cleaning
Use AC-12 Awning Cleaner cut 5 to 1.

Vinyl Awning Cleaning
Use AC-22 Awing Cleaner cut 10 to 1.

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