BOSCH GEX 12V-125 Professional Cordless Random Orbit Sander Instruction Manual

GEX 12V-125 Professional
HEAVY-DUTY

Original instructions

Safety instructions

General Power Tool Safety Warnings

WARNING Read all safety warnings, instructions, illustrations, and specifications provided with this power tool. Failure to follow all instructions listed below may result in electric shock, fire, and/ or serious injury.

Save all warnings and instructions for future reference.
The term “power tool” in the warnings refers to your mainsoperated (corded) power tool or battery-operated (cordless) power tool.

Work area safety

• Keep work area clean and well lit. Cluttered or dark areas invite accidents.
• Do not operate power tools in explosive atmospheres, such as in the presence of flammable liquids, gases or dust. Power tools create sparks which may ignite the dust or fumes.
• Keep children and bystanders away while operating a power tool. Distractions can cause you to lose control.

Electrical safety

• Power tool plugs must match the outlet. Never modify the plug in any way. Do not use any adapter plugs with earthed (grounded) power tools. Unmodified plugs and matching outlets will reduce risk of electric shock.
• Avoid body contact with earthed or grounded surfaces, such as pipes, radiators, ranges and refrigerators. There is an increased risk of electric shock if your body is earthed or grounded.
• Do not expose power tools to rain or wet conditions. Water entering a power tool will increase the risk of electric shock.
• Do not abuse the cord. Never use the cord for carrying, pulling or unplugging the power tool. Keep cord away from heat, oil, sharp edges or moving parts. Damaged or entangled cords increase the risk of electric shock.
• When operating a power tool outdoors, use an extension cord suitable for outdoor use. Use of a cord suitable for outdoor use reduces the risk of electric shock.
• If operating a power tool in a damp location is unavoidable, use a residual current device (RCD) protected supply. Use of an RCD reduces the risk of electric shock.

Personal safety

• Stay alert, watch what you are doing, and use common sense when operating a power tool. Do not use a power tool while you are tired or under the influence of drugs, alcohol, or medication. A moment of inattention while operating power tools may result in serious personal injury.
• Use personal protective equipment. Always wear eye protection. Protective equipment such as a dust mask, non-skid safety shoes, hard hat, or hearing protection used for appropriate conditions will reduce personal injuries.
• Prevent unintentional starting. Ensure the switch is in the off-position before connecting to power source and/or battery pack, picking up or carrying the tool. Carrying power tools with your finger on the switch or energising power tools that have the switch on invites accidents.
• Remove any adjusting key or wrench before turning the power tool on. A wrench or a key left attached to a rotating part of the power tool may result in ersonal injury.
• Do not overreach. Keep proper footing and balance at all times. This enables better control of the power tool in unexpected situations.
• Dress properly. Do not wear loose clothing or jewellery. Keep your hair and clothing away from moving parts. Loose clothes, jewellery, or long hair can be caught in moving parts.
• If devices are provided for the connection of dust extraction and collection facilities, ensure these are connected and properly used. Use of dust collection can reduce dust-related hazards.
• Do not let familiarity gained from frequent use of tools allow you to become complacent and ignore tool safety principles. A careless action can cause severe injury within a fraction of a second.

Power tool use and care

• Do not force the power tool. Use the correct power tool for your application. The correct power tool will do the job better and safer at the rate for which it was designed.
• Do not use the power tool if the switch does not turn it on and off. Any power tool that cannot be controlled with the switch is dangerous and must be repaired.
• Disconnect the plug from the power source and/or remove the battery pack, if detachable, from the power tool before making any adjustments, changing accessories, or storing power tools. Such preventive safety measures reduce the risk of starting the power tool accidentally.
• Store idle power tools out of the reach of children and do not allow persons unfamiliar with the power tool or these instructions to operate the power tool. Power tools are dangerous in the hands of untrained users.
• Maintain power tools and accessories. Check for misalignment or binding of moving parts, breakage of parts, and any other condition that may affect the power tool’s operation. If damaged, have the power tool repaired before use. Many accidents are caused by poorly maintained power tools.
• Keep cutting tools sharp and clean. Properly maintained cutting tools with sharp cutting edges are less likely to bind and are easier to control.
• Use the power tool, accessories and tool bits, etc. in accordance with these instructions, taking into account the working conditions and the work to be performed. Use of the power tool for operations different from those intended could result in a hazardous situation.
• Keep handles and grasping surfaces dry, clean, and free from oil and grease. Slippery handles and grasping surfaces do not allow for safe handling and control of the tool in unexpected situations.

Battery tool use and care

• Recharge only with the charger specified by the manufacturer. A charger that is suitable for one type of battery pack may create a risk of fire when used with another battery pack.
• Use power tools only with specifically designated battery packs. Use of any other battery packs may create a risk of injury and fire.
• When battery pack is not in use, keep it away from other metal objects, like paper clips, coins, keys, nails, screws, or other small metal objects, that can make a connection from one terminal to another. Shorting the battery terminals together may cause burns or a fire.
• Under abusive conditions, liquid may be ejected from the battery; avoid contact. If contact accidentally occurs, flush with water. If liquid contacts eyes, additionally seek medical help. Liquid ejected from the battery may cause irritation or burns.
• Do not use a battery pack or tool that is damaged or modified. Damaged or modified batteries may exhibit unpredictable behavior resulting in fire, explosion, or risk of injury.
• Do not expose a battery pack or tool to fire or excessive temperature. Exposure to fire or temperature above 130°C may cause explosion.
• Follow all charging instructions and do not charge the battery pack or tool outside the temperature range specified in the instructions. Charging improperly or at temperatures outside the specified range may damage the battery and increase the risk of fire.

Service

• Have your power tool serviced by a qualified repair person using only identical replacement parts. This will ensure that the safety of the power tool is maintained.
• Never service damaged battery packs. Service of battery packs should only be performed by the manufacturer or authorized service providers.

Safety Warnings for Sander

• Only use the power tool for dry sanding. Water entering a power tool will increase the risk of electric shock.

• Warning: Danger of fire! Avoid overheating the workpiece and the sander. Always empty the dust container before taking a break from work. Sanding dust in the dust bag, microfilter, paper bag (or in the filter bag or vacuum cleaner filter) can spontaneously ignite under unfavourable conditions. This risk is increased if the sanding dust is mixed with paint or polyurethane residue or with other chemical substances and if the workpiece is hot as a result of prolonged work.

• In case of damage and improper use of the battery, vapours may be emitted. The battery can set alight or explode. Ensure the area is well ventilated and seek medical attention should you experience any adverse effects. The vapours may irritate the respiratory system.

• Do not open the battery. There is a risk of short-circuiting.

• The battery can be damaged by pointed objects such as nails or screwdrivers or by force applied externally. An internal short circuit may occur, causing the battery to burn, smoke, explode or overheat.

• Only use the battery with products from the manufacturer. This is the only way in which you can protect the battery against dangerous overload.
  Protect the battery against heat, e.g. against continuous intense sunlight, fire, dirt, water and moisture. There is a risk of explosion and short- circuiting.

• Always wait until the power tool has come to a complete stop before placing it down.

• Secure the workpiece. A workpiece clamped with clamping devices or in a vice is held more secure than by hand.

Product Description and Specifications

Read all the safety and general instructions. Failure to observe the safety and general instructions may result in electric shock, fire and/or serious injury. Please observe the illustrations at the beginning of this operating manual.

Intended Use
The power tool is intended for dry sanding of wood, plastic, filler and coated surfaces.

Product Features
The numbering of the product features refers to the diagram of the power tool on the graphics page.

1. On/off switch
2. Complete dust bag
3. Rechargeable battery A)
4. Battery release button A)
5. Rechargeable battery charge indicator A)
6. Orbital stroke rate preselection thumbwheel
7. Sanding disc
8. Handle (insulated gripping surface)
9. Sanding sheet
10. Screws for sanding disc
11. Sanding disc holder
12. Extraction outlet
13. Dust bag
14. Adapter for dust bag
15. Extraction hose A)

A) Accessories shown or described are not included with the product as standard. You can find the complete selection of accessories in our accessories range.

Technical Data

+50
Recommended rechargeable batteries| | GBA 12V…
Recommended chargers| | GAL 12…
GAX 18…

A) Depends on battery in use
B) Limited performance at temperatures <0 °C

Noise/Vibration Information

Noise emission values determined according to EN 62841-2-4.
Typically, the A-weighted sound pressure level of the power tool is less than 70 dB(A). The noise level when working can exceed the volume stated. Wear hearing protection!
Vibration total values ah (triax vector sum) and uncertainty K determined according to EN 62841-2-4:
ah  < 2.5 m/s 2 , K = 1.5 m/s 2 ,
The vibration level and noise emission value given in these instructions have been measured in accordance with a standardised measuring procedure and may be used to compare power tools. They may also be used for a preliminary estimation of vibration and noise emissions.
The stated vibration level and noise emission value represent the main applications of the power tool. However, if the power tool is used for other applications, with different application tools, or is poorly maintained, the vibration level and noise emission value may differ. This may significantly increase the vibration and noise emissions over the total working period.
To estimate vibration and noise emissions accurately, the times when the tool is switched off or when it is running but not actually being used should also be taken into account. This may significantly reduce vibration and noise emissions over the total working period.
Implement additional safety measures to protect the operator from the effects of vibration, such as servicing the power tool and application tools, keeping their hands warm, and organising workflows correctly.

Assembly

• Remove the battery from the power tool before carrying out work on the power tool (e.g. maintenance, changing tool, etc.). The battery should also be removed for transport and storage. There is risk of injury from unintentionally pressing the on/off switch.

Battery Charging

• Use only the chargers listed in the technical data. Only these chargers are matched to the lithium-ion battery of your power tool.

Note: The battery is supplied partially charged. To ensure full battery capacity, fully charge the battery in the charger before using your power tool for the first time.
The lithium-ion battery can be charged at any time without reducing its service life. Interrupting the charging process does not damage the battery. The lithium-ion battery is protected against deep discharge by the “Electronic Cell Protection (ECP)”. When the battery is discharged, the power tool is switched off by means of a
protective circuit: The application tool no longer rotates.

• Do not continue to press the On/Off switch after the power tool has automatically switched off. The battery can be damaged.

Follow the instructions on correct disposal.

Removing the Battery (see figure A)
To remove the battery (3), press the release buttons (4) and pull the battery out of the power tool. Do not use force to do this.

Battery charge indicator
The battery charge indicator (5) on the power tool consists of three green LEDs. It indicates the battery’s state of charge for a few seconds after the power tool is switched on and off.

The three LEDs in the battery charge indicator flash quickly when the temperature of the battery is outside the operating temperature range of -30 to +70 °C and/or the overload protection has been triggered.

Changing the Sanding Sheet (see figure B)
To remove the sanding sheet (9), lift it from the side and pull it from the sanding pad (7). Remove dirt and dust from the sanding pad (7), e.g. with a paintbrush, before attaching a new sanding sheet. The surface of the sanding pad (7) is fitted with a hook-andloop fastening, allowing sanding sheets with a hook-and-loop backing to be secured quickly and easily. Press the sanding sheet (9) firmly onto the underside of the sanding pad (7).
To ensure optimum dust extraction, make sure that the punched holes in the sanding sheet (9) are aligned with the drilled holes in the sanding pad (7).
To increase the sanding pad’s service life, in particular when using net abrasives (e.g. Bosch M480), apply the Pad Saver (accessory) between the sanding pad and abrasive.

Selection of the Sanding Plate
The power tool can be fitted with sanding discs of various hardnesses, depending on the application:

• Soft sanding disc: Suitable for sensitive sanding even on curved surfaces
• Medium-hard sanding disc: Suitable for all sanding work, universal application
• Hard sanding disc: Suitable for heavy sanding on flat surfaces

Changing the sanding pad (see figure C)
Note: Replace damaged sanding pads (7) immediately. Pull off the sanding sheet. Unscrew the 4 screws (10) completely (using a T20 screwdriver) and remove the sanding pad (7). Attach the new sanding pad (7) and retighten the screws.
Note: When attaching the sanding pad, make sure that the teeth of the catch mate with the recesses in the sanding pad.
Note: Damaged sanding disc holders (11) must only be replaced by an after-sales service centre authorised to work with Bosch power tools.

Dust/Chip Extraction
The dust from materials such as lead paint, certain types of wood, and minerals can be harmful to human health. Touching or breathing in this dust can trigger allergic reactions and/or cause respiratory illnesses in the user or in people in the near vicinity.
Certain dusts, such as oak or beech dust, are classified as carcinogenic, especially in conjunction with wood treatment additives (chromate, wood preservative). Materials containing asbestos may only be machined by specialists.

• Use a dust extraction system that is suitable for the material wherever possible.
• Provide good ventilation at the workplace.
• It is advisable to wear a P2 filter class breathing mask.

The regulations on the material being machined that apply in the country of use must be observed.

• Avoid dust accumulation at the workplace. Dust can easily ignite.

Self-generated dust extraction with dust bag (see figures D–F)
Place and move the complete dust bag (2) onto the extraction outlet (12) until it lines up precisely with the power tool.
To empty the dust bag(13), pull the complete dust bag (2) away from the extraction outlet (12). Unscrew the adapter (14) from the dust bag (13) and empty the dust bag.
Note: Empty the dust bag (13) in good time to ensure optimum dust extraction. When working vertical surfaces, hold the power tool in such a manner that the dust
bag (2) faces downward.

External dust extraction (see figure G)
Fit a dust extraction hose (15) onto the extraction outlet (12). Connect the dust extraction hose (15) to an extractor. You will find an overview of connecting to  arious dust extractors at the end of these operating instructions. The dust extractor must be suitable for the material being worked.
When extracting dry dust that is especially detrimental to health or carcinogenic, use a special dust extractor. When working on vertical surfaces, hold the power tool with the dust extraction hose facing downwards.

Operation

Starting Operation
Switching On/Off

• Make sure that you are able to press the On/Off switch without releasing the handle.

To switch on the power tool, press the on/off switch (1).
To switch off the power tool, press the on/off switch (1) again.

Preselecting the orbital stroke rate
You can even preselect the orbital stroke rate during opera-tion using the necessary orbital stroke rate preselection thumbwheel (6).
1–2 Low orbital stroke rate
3–4 Medium orbital stroke rate
5–6 High orbital stroke rate

The required orbital stroke rate is dependent on the material and the work conditions and can be determined using practical tests.
The Constant Electronic keeps the orbital stroke rate at no load and under load virtually consistent, guaranteeing uniform performance.
After working at a low orbital stroke rate for an extended period, you should operate the power tool at the maximum orbital stroke rate for approximately three minutes without load to cool it down.

| Application/Material| Abrasive| Speed setting
---|---|---|---
Removing| • Removing old paint and varnish
• Sanding wood| P60–P100| 4–6
• Sanding thermoplastic synthetic materials| P60–P100| 1–3
Preparing| • Sanding wood and veneer prior to painting
• Edge chamfering on wooden materials
• Smoothing wooden surfaces before staining| P120–P180| 4–6
• Intermediate lacquer sanding and sanding undercoats
• Intermediate lacquer sanding on edges| P220–P280| 1–3
Finishing| • Sanding wood
• Sanding solid wood edges and veneer edges| P150–P180| 4–6
• Lacquer sanding on stained surfaces and edges| P240–P320| 1–3

Working Advice

• Remove the battery from the power tool before carrying out work on the power tool (e.g. maintenance, changing tool, etc.). The battery should also be removed for transport and storage. There is risk of injury from unintentionally pressing the on/off switch.
• Always wait until the power tool has come to a complete stop before placing it down.
• This power tool is not suitable for bench-mounted use. It must not be clamped into a vice or fastened to a workbench, for example.

For fatigue-free work, you can hold the power tool from above, from the side or from the front, depending on the application (see figure H).

Sanding Surfaces
Switch the power tool on, place the entire sanding surface against the surface of the workpiece and apply moderate pressure as you move the sander over the workpiece.
The material removal rate and sanding result are primarily determined by the choice of sanding sheet, the preselected orbital stroke rate level and the contact pressure. Only immaculate sanding sheets achieve good sanding performance and make the power tool last longer. Be sure to apply consistent contact pressure in order to increase the lifetime of the sanding sheets. Excessively increasing the contact pressure will not lead to increased sanding performance, rather it will cause more severe wear of the power tool and of the sanding sheet. Use only original Bosch-sanding accessories.

Rough Sanding
Attach a coarse grit sanding sheet.

Apply only light pressure to the power tool so that it runs at a higher orbital stroke rate and a higher material removal rate is achieved.

Fine Sanding
Attach a fine grit sanding sheet.
You can reduce the sanding plate orbital stroke rate by lightly varying the contact pressure or changing the orbital stroke rate level; the random orbit motion will be retained.
Move the power tool with moderate pressure flat on the workpiece in a circular motion or alternately along and across it. Do not tilt the power tool in order to avoid sanding through the workpiece, e.g. veneers.
Switch the power tool off after completing the operation.

Maintenance and Service

Maintenance and Cleaning

• Remove the battery from the power tool before carrying out work on the power tool (e.g. maintenance, changing tool, etc.). The battery should also be removed for transport and storage. There is a risk of injury from unintentionally pressing the on/off switch.
• To ensure safe and efficient operation, always keep the power tool and the ventilation slots clean.

After-Sales Service and Application Service
Our after-sales service responds to your questions concerning maintenance and repair of your product as well as spare parts. You can find explosion drawings and
information on spare parts at: www.bosch-pt.com
The Bosch product use advice team will be happy to help you with any questions about our products and their accessories.
In all correspondence and spare parts orders, please always include the 10‑digit article number given on the nameplate of the product.

Great Britain
Robert Bosch Ltd. (B.S.C.)
P.O. Box 98
Broadwater Park
North Orbital Road
Denham Uxbridge
UB 9 5HJ
At www.bosch-pt.co.uk you can order spare parts or arrange the collection of a product in need of servicing or repair.
Tel. Service: (0344) 7360109
E-Mail: boschservicecentre@bosch.com

You can find further service addresses at:
www.bosch-pt.com/serviceaddresses

Transport
The contained lithium-ion batteries are subject to the Dangerous Goods Legislation requirements. The batteries are suitable for road transport by the user without further restrictions.
When shipping by third parties (e.g.: by air transport or forwarding agency), special requirements on packaging and labeling must be observed. For the preparation of the item being shipped, consulting an expert for hazardous material is required.
Dispatch battery packs only when the housing is undamaged. Tape or mask off open contacts and pack up the battery in such a manner that it cannot move around
in the packaging. Please also observe the possibility of more detailed national regulations.

Disposal
Power tools, rechargeable batteries, accessories, and packaging should be sorted for environmental-friendly recycling.
Do not dispose of power tools and batteries/rechargeable batteries into household waste!

Only for EU countries:
According to the Directive 2012/19/EU, power tools that are no longer usable, and according to the Directive 2006/66/EC, defective or used battery packs/batteries, must be collected separately and disposed of in an environmentally correct manner.

Battery packs/batteries:
Li-ion:
Please observe the notes in the section on transport (see “Transport”, page 17).

| 2 608 000 714 (medium)
---|---
| 2 608 000 351 (soft)
| 2 608 000 352 (hard)
| 2 608 000 689 (pad saver)
| 2 608 000 715
| 2 605 411 233

EU Declaration of Conformity
Random orbit sander Article number
We declare under our sole responsibility that the stated products comply with all applicable provisions of the directives and regulations listed below and are in conformity with the following standards.
Technical file at: *

GEX 12V-125| 3 601 C72 1..| 2006/42/EC
2014/30/EU
2011/65/EU| EN 62841-1:2015
EN 62841-2-4:2014
EN 55014-1:2017+A11:2020
EN 55014-2:2015
EN IEC 63000:2018
---|---|---|---
| * Robert Bosch Power Tools GmbH
(PT/ECS) 70538 Stuttgart, GERMANY
Henk Becker
Chairman of Executive
Management
| Helmut Heinzelmann
Head of Product Certification

Robert Bosch Power Tools GmbH, 70538 Stuttgart, GERMANY Stuttgart, 08.07.2020

Robert Bosch Power Tools GmbH
70538 Stuttgart
GERMANY
www.bosch-pt.com
1 609 92A 5NU (2020.11) O / 2 1 0

1 609 92A 5NU

Documents / Resources

| BOSCH GEX 12V-125 Professional Cordless Random Orbit Sander [pdf] Instruction Manual
GEX 12V-125 Professional, Cordless Random Orbit Sander, Random Orbit Sander, Orbit Sander, GEX 12V-125 Professional, Sander
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