GMC GGOS150, Manual

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GB

k)  Work surfaces and sandpaper can become very hot during use. If there is evidence of burning 

(smoke or ash) from the work surface, stop and allow the material to cool. 

DO NOT touch work 

surface or sandpaper until they have had time to cool

l)  DO NOT touch the moving sandpaper
m)  ALWAYS switch off before you put the sander down
n)  DO NOT use for wet sanding.

 Liquids entering the motor housing can cause severe electric shocks

o)  ALWAYS unplug the sander from the mains power supply before changing or replacing sandpaper
p)  Even when this tool is used as prescribed it is not possible to eliminate all residual risk factors. 

If 

you are in any doubt as to safe use of this tool, do not use it

Product Familiarisation

1.  Front Grip
2.  Mode Selector Switch
3.  Auxiliary Handle Installation Hole
4.  ON/OFF Switch
5.  Main Handle
6.  Speed Control Dial
7.  Dust Extraction Port
8.  Hook and Loop Backing Pad
9.  Sanding Disc
10.  Auxiliary Handle

Accessories (not shown): 

•  3 x Hook and Loop Sanding Discs (1x 100grit, 1 x 150grit, 1 x 240grit)
•  1 x Screwdriver
•  1 x Woollen polishing bonnet
•  1 x Polishing foam

Intended Use

Mains-powered rotating dual-mode sander and polisher. Can be used on wood, plastics, metals, composite 
materials, paint/varnish, fillers and similar products, using compatible accessories such as sanding discs and 
polishing sponges/bonnets.

WARNING:

 This tool may only be used for dry sanding applications; it is unsuitable for wet sanding.

Unpacking Your Tool

•  Carefully unpack and inspect your tool. Fully familiarise yourself with all its features and functions
•  Ensure that all parts of the tool are present and in good condition. If any parts are missing or damaged, 

have such parts replaced before attempting to use this tool

Before Use

Fitting a Hook & Loop Backing Pad

 WARNING:

 Always disconnect from the power supply before removing or attaching the Hook and Loop 

Backing Pad.

Note: 

This sander is supplied with its regular Hook and Loop Backing Pad (8) factory pre-installed. It 

may, however, become necessary to remove and replace the Hook and Loop Backing Pad, in order to fit 
replacements, perform maintenance or to clean the device thoroughly.
1.  Switch the Mode Selector Switch (2) to fixed orbit mode (see ‘Selecting Sanding Mode’)
2.  Remove the Sanding Disc (9) (if fitted) by peeling it from the Hook and Loop Backing Pad
3.  Use a suitable screwdriver to remove the 4 x screws then remove Hook and Loop Backing Pad from the 

device

4.  Clean Hook and Loop Backing Pad (if required) and replace back on to the device, or install replacement 

Hook and Loop Backing Pad (if required)

5.  Screw in 4 x screws, but do not over-tighten
6.  Apply a Sanding Disc and continue work

IMPORTANT:

 Be careful not to damage the screws during the removal or re-application process. If you have 

any problems, consult a qualified GMC technician.

Selecting the right grade of Sanding Disc

•  Sanding discs are available in a variety of different grades: coarse (60 grit), medium (120 grit),                

and fine (240 grit)

•  Use a coarse grit to sand down rough finishes, medium grit to smooth the work, and fine grit to finish off
•  Always use good quality sanding discs to maximise the quality of the finished task
•  It is advisable to do a trial run on a scrap piece of material to determine the optimum grade of sanding disc 

for a particular job. If there are still marks on your work after sanding, try either going back to a coarser 
grade and sanding the marks out before recommencing with the original choice of grit, or try using a new 
sanding disc to eliminate the unwanted marks before going on to a finer grit and finishing the job

Fitting a Sanding Disc

 WARNING:

 Always ensure that the tool is switched off and the plug is removed from the power supply, 

before fitting or removing sanding discs.

Note:

 DO NOT continue to use worn, torn or heavily clogged sanding discs. Ensure foreign objects, such as 

nails and screws, are removed from the workpiece before starting to sand.

 WARNING:

 DO NOT use a sanding disc on wood that has previously been used on metal. This may cause 

scouring on the wooden surface.
•  In order for the dust extraction system to function (if connected), this sander must only be used with 

punched sanding discs with holes that match the holes in the Hook and Loop Backing Pad (8)   
(Images A and B):

1.  Remove the old Sanding Disc (9) (if fitted) by peeling it away from the Hook and Loop Backing Pad
2.  Remove any dust or debris from the Hook and Loop Backing Pad
3.  Match the holes in a suitable Sanding Disc with the holes in the Hook and Loop Backing Pad
4.  Press the Sanding Disc on to the pad to attach it

Note:

 To maximise the life of the Hook and Loop base, peel the Sanding Disc off slowly rather than rapidly 

removing it to avoid damage to the Hook and Loop system.

 WARNING:

 Take care to regularly clean out the build-up of dust on the base underneath the Sanding Disc 

and not to let the disc wear completely down before replacing it. Failure to observe these two precautionary 
measures can lead to damage to the hooks and loops on the base, and the Sanding Disc will not attach 
properly.

Installing the Auxiliary Handle 

Note: 

The Auxiliary Handle (10) can be installed on either side of the Random Orbital Sander. There is an 

Auxiliary Handle Installation Hole (3) on either side for left or right-handed use.
•  Screw the Auxiliary Handle into one of the Auxiliary Handle Installation Holes on one side of the  

sander (Image C)

Dust extraction 

Note: 

This sander is designed to be connected to a household vacuum cleaner hose or workshop dust 

extraction system. This is the preferred and most effective method of dust extraction.

 WARNING:

 ALWAYS ensure that the tool is switched off and disconnected from the power supply before 

attaching or removing any accessories.

 WARNING

: If the sanding dust contains harmful substances, such as particles from old paint, varnish, 

surface coatings, etc. ALWAYS connect the sander to a suitable vacuum cleaner or workshop dust extraction 
system. Always dispose of harmful dust according to laws and regulations.

 WARNING

: Take special care to guard against harmful and toxic dusts when sanding lead-based painted 

surfaces, woods and metals, particularly if you are unsure about the exact substances involved. All persons 
entering the work area must wear a mask specially designed for protection against the toxic dust and fumes 
involved. NEVER allow children and pregnant women to enter the work area. DO NOT eat, drink or smoke in 
the work area.

•  Push a suitable vacuum hose on to the Dust Extraction Port (7), which is designed to fit a 32mm diameter 

hose

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