STIHL SG 20 - Professional Sprayer Manual

Guide to Using this Manual

Read Instruction Manual thoroughly before use and follow all safety precautions – improper use can cause serious or fatal injury.

Allow only persons who fully understand this manual to operate your sprayer.
To receive maximum performance and satisfaction from your STIHL sprayer, it is important that you read, understand and follow the safety precautions and the operating and maintenance instructions in chapter "Safety Precautions and Working Techniques" before using your sprayer. For further information you can go to www.stihlusa.com.
Contact your STIHL dealer or the STIHL distributor for your area if you do not understand any of the instructions in this manual.

Because a sprayer is a tool for spraying chemicals, some special safety precautions must be observed as with any other tool to reduce the risk of personal injury. Careless or improper use may cause serious or even fatal injury.
This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process with electronic systems.

Pictograms
All the pictograms attached to or embossed on the machine are shown and explained in this manual.

Symbols in Text
Many operating and safety instructions are supported by illustrations.
The individual steps or procedures described in the manual may be marked in different ways:

• A bullet marks a step or procedure.

A description of a step or procedure that refers directly to an illustration may contain item numbers that appear in the illustration. Example:

• Loosen the screw (1).
• Lever (2)...

In addition to the operating instructions, this manual may contain paragraphs that require your special attention. Such paragraphs are marked with the following symbols and signal words:

Indicates a hazardous situation that, if not avoided, will result in death or serious injury.

Indicates a hazardous situation that, if not avoided, could result in death or serious injury.

NOTICE
Indicates a risk of property damage, including damage to the machine or its individual components.

Engineering Improvements
STIHL's philosophy is to continually improve all of its products. As a result, engineering changes and improvements are made from time to time. Therefore, some changes, modifications and improvements may not be covered in this manual. If the operating characteristics or the appearance of your machine differs from those described in this manual, please contact your STIHL dealer or the STIHL distributor for your area for assistance.

Safety Precautions and Working Techniques

Because the backpack sprayer is a tool for spraying chemicals, special safety precautions must be observed to reduce the risk of personal injury.

It is important that you read, fully understand and observe the following general safety precautions and warnings. Read the instruction manual and the safety precautions periodically. In addition, read and follow the chemical manufacturer's instructions for the chemical products being applied. Since such products may vary greatly in handling/application requirements and risks, the chemical product label is normally your best guide for safe and effective use.

Read the label each time before mixing or using the chemical and before storing or disposing of it. Do not trust your memory. Careless or improper use may cause serious or fatal injury.
Have your STIHL dealer show you how to operate your sprayer. Observe all applicable federal, state and local safety regulations, standards and ordinances.
All operating and servicing personnel should be trained and familiarized with the proper handling procedures for the chemical products being used, as well as with first aid/emergency care, and liquid chemical disposal regulations.

Do not lend or rent your sprayer without the instruction manual. Be sure that anyone using it understands the information contained in this manual.

The chemicals sprayed with your backpack sprayer may contain toxic and/or caustic substances. Such chemicals can be dangerous and cause serious or fatal injury to persons and animals and/or severe damage to plants and the environment.
Avoid direct contact with chemicals. Follow the chemical manufacturer's instructions with respect to any contact with its product.
Use your backpack sprayer for spraying chemicals and other liquids to control pests and weeds in fruit, flower and vegetable gardens, on trees and bushes and on other plants, such as coffee, tobacco and cotton. It is also useful in the maintenance of young trees, controlling the bark beetle and other plant diseases.

Do not use it for other purposes, since misuse may result in personal injury or property damage, including damage to the sprayer itself.

Minors should never be allowed to use this backpack sprayer. Bystanders, especially children, and animals should not be allowed in the area where it is in use. Make sure that unauthorized persons do not use it.
Most of these safety precautions and warnings apply to the use of all STIHL backpack sprayers. Different models may have different parts and controls. See the appropriate section of your instruction manual for a description of the controls and the function of the parts of your model.
Safe use of a backpack sprayer involves

1. the operator
2. the backpack sprayer
3. the use of the backpack sprayer
4. the handling of the chemicals to be sprayed.

THE OPERATOR
Physical Condition
You must be in good physical condition and mental health and not under the influence of any substance (drugs, alcohol, etc.) which might impair vision, dexterity or judgment. Do not operate this backpack sprayer when you are fatigued.

Be alert – if you get tired, take a break. Tiredness may result in loss of concentration and control. Working with any backpack sprayer can be strenuous. If you have any condition that might be aggravated by strenuous work, check with your doctor before operating this backpack sprayer.

Proper Clothing

To reduce the risk of injury when working with chemical agents, the operator should wear proper protective apparel when filling, using and cleaning the backpack sprayer. Always follow all of the chemical manufacturer's instructions with respect to proper eye, skin, nose and mouth protection. They may differ from and exceed the following precautions.

	To reduce the risk of injury to your eyes never operate your sprayer unless wearing goggles or properly fitted protective glasses with adequate top and side protection complying with ANSI Z87 "+" (or your applicable national standard). Check the product label for the chemical you are spraying.
	Always wear rubber/chemical-resistent gloves when handling the backpack sprayer.
	For some chemicals it is advisable to wear impermeable coveralls or an impermeable work apron. Check the product label. If you are spraying overhead or if the spray may reach head height, wear a wide brim hat or other suitable head covering. Do not wear shorts, sandals or go barefoot.
	Wear rubber/chemicalresistent boots.

THE BACKPACK SPRAYER
For illustrations and definitions of the backpack sprayer parts see the chapter on "Main Parts and Controls."

Never modify this backpack sprayer in any way. Only attachments supplied by STIHL or expressly approved by STIHL for use with the specific STIHL model are authorized.
If this tool is subjected to unusually high loads for which it was not designed (e.g. heavy impact or a fall), always check that it is in good condition before continuing work. Check in particular that the container system is tight (no leaks) and that the controls are working properly. Do not continue operating this backpack sprayer if it is damaged. In case of doubt, have it checked by your STIHL servicing dealer.

Make sure the hose is securely attached and in good condition before pressurizing the container. Never attempt to pressurize the unit by any other method than with the pump module provided.

HANDLING OF CHEMICALS
Chemicals can be harmful to individuals, animals and the environment if improperly used. In addition, some chemicals that are caustic, corrosive or poisonous should not be used in your sprayer.
Carefully read the labels on chemical containers prior to use. Chemicals are classified into categories of toxicity. Pesticides regulated by the EPA, for instance, use signal words to indicate the product's potential to make you sick. "Caution" appears on pesticides found to be least harmful to humans. "Warning" indicates a product that is more poisonous than those in the "Caution" group. Pesticides with the signal word "Danger" on the label are very poisonous or irritating. They should be used with extreme care. Finally, pesticides labeled "Danger – Poison" are for restricted use only and generally must be used under the supervision of a certified applicator. Similarly, the EPA rates herbicides with the signal words "Caution", "Warning" and "Danger." Each category will have unique handling characteristics. Familiarize yourself with the characteristics for the category you are using.

Mix only compatible pesticides and/or herbicides. Wrong mixtures can produce toxic fumes.
When handling chemicals and when spraying, make sure you are operating in accordance with local, state, and federal environmental protection rules and guidelines. Do not spray in windy conditions. To help protect the environment, use only the recommended dosage – do not overuse.

Do not eat, drink, or smoke while handling chemicals or while you are spraying. Never blow through nozzles, valves, pipes or any other component by mouth. Always handle chemicals in a well-ventilated area while wearing appropriate protective clothing and safety equipment. Do not store or transport chemicals with food or medicines, and never reuse a chemical container for any other purpose.
Do not transfer spray materials to other containers, especially food and/or drink containers.

In case of accidental contact or ingestion of chemicals or in case of contamination of clothing, stop work and immediately consult the chemical manufacturer's instructions. If in doubt as to what to do, consult a poison control center or doctor without delay. Have the product's label available to read to or show the persons you consult.
Clean all chemical spills immediately. Dispose of any residue in accordance with state or federal laws and regulations.

Keep chemicals out of reach of children, other unauthorized people or animals. When not in use, store chemicals in a safe place. Follow the manufacturer's recommendations for proper storage.

THE USE OF THE BACKPACK SPRAYER
Transporting the Backpack Sprayer
Empty container when transporting it in a vehicle; properly secure it to prevent damage to the unit.

Filling the Container
Before using the sprayer with chemicals, fill it with fresh water to assure that you have it properly assembled; pressurize it and practice spraying. Also, check for any leaks at this time. When thoroughly familiar with the sprayer operation, follow normal operating procedures.
Fill your backpack sprayer in wellventilated areas, outdoors.

Do not use:

• flammables in the sprayer, which can explode causing serious or fatal injury;
• caustic or corrosive materials in the sprayer, which could result in damage to the unit; backpack sprayer
• liquids with a temperature above 120°F (50°C) to avoid scalding and damage to the unit. Do not leave pressurized sprayer in the hot sun or near any heat source.

To fill the backpack sprayer, place it on a level surface. To reduce the risk of contaminating the surrounding environment, be careful not to overfill the container with chemical solution.
If you fill the container with a hose attached to a central water supply, be sure the end of the hose is out of the solution to reduce the risk of backflow, i.e. the chemicals being sucked into the water supply in the case of a sudden vacuum.
Calculate the correct amount of chemical solution so that it is used up at one time, with no extra solution left in the container.

To reduce the risk of personal injury and/or property damage from solutions that are too strong, make sure that chemicals that require dilution are diluted properly. When filled to the maximum mark, the tank contains approximately 4.76 gal. (18 l). See the Specifications for the exact amount.

Check for leakage while refilling and during operation. A leak from the container or a loose fitting could soak your clothing and come into contact with your skin.

Before Spraying

Always inspect your sprayer before and after each use. To reduce the risk of leakage and skin contact with chemicals, check that the cap and all connections are tight, and be sure the hose is securely attached and in good condition before pressurizing the container.

Never use a backpack sprayer that is damaged or not properly maintained.

Your backpack sprayer is a one-person tool. Do not allow other persons in the general work area.

During Operation
Holding and Controlling the Backpack Sprayer

The backpack sprayer is operated with the right hand on the trigger valve and the left hand on the hand lever.
The backpack sprayer is carried as a backpack.

Adjust carrying harness to suit your size before starting work.
In order to keep the container upright and reduce the risk of spillage, do not bend at the waist. Bend only at the knees and support yourself as required to ensure proper balance.
Remember that a sprayer filled with liquid has a significant amount of weight. Use caution when bending, leaning or walking.

To reduce the risk of injury from loss of control, never work on a ladder, in a tree or on any other insecure support.

Working Conditions
Operate your backpack sprayer only in a well-ventilated area. Operate it under good visibility and daylight conditions only. Work carefully.

Inhalation of certain chemicals can cause susceptible persons to have an allergic or asthmatic reaction.
Substantial or repeated inhalation of certain chemicals may cause respiratory disease, cancer, birth defects, or other reproductive harm. Control the chemical spray at the source where possible. Use good work practices, such as operating the unit so that the wind or operating process does not blow the spray back on the operator. Follow the recommendations of EPA/OSHA/NIOSH and occupational and trade associations with respect to proper usage. When the inhalation of the chemical being sprayed cannot be avoided, the operator and any bystanders may need to wear a respirator approved by NIOSH/MSHA for the type of chemical encountered. Consult the label of the chemical product being used.

If you are unfamiliar with the risks associated with the particular chemical at issue, review the product label and/or material safety data sheet for that substance and/or consult the material manufacturer/supplier. You may also consult your employer, governmental agencies such as the EPA, OSHA and NIOSH and other sources on hazardous materials. The state of California and some other authorities, for instance, have published lists of substances known to cause cancer, reproductive toxicity, etc.

Operating instructions

Pay attention to the direction of the wind, i.e., do not work against the wind. When spraying, stand so that the wind does not blow towards you or bystanders.
Keep children and pets away from areas that have just been sprayed. After the use of some chemicals, especially agricultural pesticides, a notice must be posted on the treated area that a "Restricted Entry Interval" (REI) is in effect. See the product's label and any applicable governmental regulations.
Never spray in the direction of humans, animals or property which might be injured or damaged by spray formula.

Your backpack sprayer is not insulated against electric shock. To reduce the risk of electrocution, never operate this backpack sprayer in the vicinity of any wires or cables (power, etc.) which may be carrying electric current. Do not spray on or near electrical installations.

After Finishing Work
Always wash thoroughly with soap and water after spraying or handling chemicals. Shower immediately, and wash all protective clothing separately from other items. Follow any additional recommendations of the chemical manufacturer.
Always clean dust and dirt off the backpack sprayer.

Empty, rinse and clean the container and sprayer assembly after each use. This helps to prevent the solution from crystallizing, which could later cause clogging and chemical damage to the unit. In addition; residual chemicals may have undesirable effects during subsequent spraying with a different type of chemical (e.g., residual herbicide may damage or kill plants being sprayed with a pesticide).
Disposal of contaminated rinse should be in accordance with applicable ordinances. Observe the precautionary instructions of the chemical manufacturer.
Do not store sprayer under pressure or with spray solution in the container.

Maintenance, Repair and Storing

Use only identical STIHL replacement parts for maintenance and repair. Use of non-STIHL parts may result in personal injury or property damage.
Strictly follow the maintenance and repair instructions in the appropriate section of your instruction manual. Please refer to the maintenance chart in this manual.

Always release pressure in the pump and the pressure chamber prior to cleaning or servicing the sprayer. To release the pressure, keep the trigger valve depressed without operating the hand lever until there is no more air or liquid coming out of the nozzle.
Do not attempt any maintenance or repair work not described in your instruction manual. Have such work performed by your STIHL servicing dealer only.

Harness

• Adjust the harness straps so that the backplate fits snugly and securely against your back.
  

Threading the harness straps

Tightening the harness straps

• Pull the ends of the straps downward.
  

Loosening the harness

• Lift the tabs of the sliding adjusters.
  

Filling the Container

• Fit the strainer (1). N Stand the sprayer on a level surface.
  
• Fill up with thoroughly mixed spray solution – do not overfill (no further than max. mark – arrow).
• Gasket (2) in the cap (3) must always be well lubricated with grease and in good condition.
  
• Fit the cap and tighten it down firmly.
  

Spraying

Before Spraying

• Oil the pump piston (1).
  
• Oil the spray gun's valve plunger (2).
  
• Put the unit on your back.
  
• Operate the hand lever (2) slowly and steadily with the gun closed – 8 to 10 strokes are required to build up pressure.

Spraying

• Pull the spray gun's trigger (1).
  
• Operate the hand lever 3 to 6 times per minute to maintain a uniform spray pressure.
• Rotate the nozzle (2) to adjust the spray pattern.
  

For continuous operation:

• Pull the trigger.
• Engage the U-clip (3) in direction of the arrow – the trigger is locked.
  

Storing the Machine

• Empty the tank in a well-ventilated location.
• Dispose of any residual spray solution in accordance with environmental requirements – follow instructions of the chemical manufacturer.
• Rinse the tank with clean water.
• Fill the tank with about 1 1/4 gal. (5 liters) of clean water, pump and spray until the tank and hose system are empty and no longer under pressure. Do not store the sprayer under pressure or with spray solution in the tank.
• After finishing work, clean the filter (1) in the spray gun.
  
• Allow the unit to dry with the cap removed.
• Store the unit in a dry place protected from frost.

Maintenance and Care

The following intervals apply to normal operating conditions only. If your daily working time is longer or operating conditions are difficult (very dusty work area, etc.), shorten the specified intervals accordingly.		before starting work	after finishing work or daily	weekly	monthly	every 12 months	if problem	if damaged	if required
Complete machine	Visual inspection (condition, leaks)
	Clean
Filter in spray gun	Clean
Tank, pipe and hose system	Drain
	Clean
Tank, pressure vessel, pipe and hose system	Visual inspection (condition, leaks)
Pump piston	Lubricate with oil
Gasket in cap	Lubricate with grease
Vent in cap	Clean
All accessible screws and nuts	Retighten
Safety labels	Replace

Main Parts

1. Backplate
2. Pressure Vessel
3. Harness
4. Spray Gun
5. Filter
6. Spray Wand
7. Nozzle Holder with Nozzle
8. Cap
9. Vent
10. Gasket
11. Strainer
12. Container
13. Pump
14. Retainer
15. Hand Lever
    # Serial number

Definitions

1. Backplate.
   Helps to protect the user's back.
2. Pressure Vessel.
   Stores pressure produced by pump and the pressurized spray solution.
3. Harness.
   For carrying the sprayer.
4. Spray Gun.
   Opens and closes the valve. Starts and stops spray jet.
5. Filter in Spray Gun.
   Helps prevent impurities entering and blocking the nozzle.

6. Spray Wand.
   Feeds spray solution to the nozzle.
7. Nozzle Holder.
   Accommodates the nozzle.
   Nozzle.
   Atomizes the spray solution.
8. Cap.
   Closes the spray solution container.
9. Vent.
   Allows air into container to avoid vacuum.
10. Gasket.
    Seals the container.
11. Strainer. Helps prevent impurities entering the container.
12. Container.
    Contains the spray solution.
13. Pump.
    Produces the spray pressure.
14. Retainer.
    Holds spray gun when it is not in use.
15. Hand Lever.
    Pump lever for producing spray pressure.

Specifications

Troubleshooting

Before starting troubleshooting, operate the unit until it is no longer under pressure – if pressure is not released, solution may escape unexpectedly when working on the hose and pump system.
After servicing, carry out test run with clean water.

[1] ⁾ STIHL recommends an authorized STIHL servicing dealer.