Sanding pad
Sanding pads are tools for hand-held concrete grinders or plaster cutters , which are used to sand mineral substrates, but also to remove old coatings. Basically, a sanding pad always consists of a metal base, which has been provided with a suitable abrasive . Two methods are primarily used to attach the sanding pad to the concrete grinder .
- The traditional way of clamping using a clamping flange and clamping nut, as is common for cutting discs on angle grinders .
- Modern tools have a built-in clamping nut (usually M14), which prevents the tool from slipping even under extreme conditions.
Different abrasives
Diamond segments
A sanding pad equipped with diamond segments is used to sand mineral substrates (such as screed , concrete or stone ). In the arrangement of the segments, a distinction is made between star and ring arrangements. The rule here is that with a star arrangement, the full working width of the tool cannot act on the ground, as the segment parts lying on the edge of the sanding plate round off after a short time. This has the advantage that if the concrete grinder is tilted slightly, there are no major quirks on the surface. The ring arrangement , on the other hand, always uses the full working width of the tool, but does not forgive any tilting of the tool on the ground when working.
Star arrangement, here with integrated clamping nut
Ring arrangement, here for clamping flange and clamping nut
PCD segments
A sanding disc equipped with PCD segments is used to remove screed, filler, carpet adhesive and even thick, strong thermoplastic old coatings. PCD grinding discs should only be operated on a concrete grinder with extraction due to the potential for dust generation . Most tools, however, also fit standard angle grinders . Due to the extremely hard PCD segments, a PCD milling disc should always have a buffer element. This is the only way to ensure that the sanding pad z. B. can avoid a hard pebble. In the case of cheap PCD grinding discs (without a buffer element), a hard pebble would break a PCD segment in the worst case . In the case of PCD grinding discs without a buffer element, material fatigue was also observed in the steel carrier disc, which led to the tool breaking. Due to the buffer element required, a PCD sanding pad may only be used on the entire surface of the substrate, as tilting would render the buffer element ineffective and lead to the breakage of individual PCD segments.
The market now distinguishes between two different types of PCD grinding discs for angle grinders . Here are the main advantages and disadvantages of these types:
- Tools with a few large PCD segments
- Advantages: inexpensive to manufacture.
- Disadvantage: high vibration values, as the tool has only a few points of contact with the surface. These types of PCD grinding wheels have problems complying with the noise and vibration occupational safety regulations.
- Tools with many smaller PCD segments
- Advantages: significantly less vibrations.
- Disadvantage: higher price, since several small segments have to be applied very precisely to the base carrier.
PCD grinding disc 115 mm with buffer element
PCD segments as close-up (version with many small segments)
PCD carrier with 2 PCD segments and a round support segment for the floor milling machine
Carbide chippings
A sanding pad fitted with hard metal chippings is used to remove old coatings. A distinction is made between flat and curved shapes . The rule here is that with a planar design, the removal is maximum, but this tool clogs up after a short time with plastic or bitumen-containing old coatings due to the large friction surface. The curved design offers the advantage that only 1/6 of the tool is actively working on the ground, while the remaining 5/6 of the tool run through the air without friction and cool down in the process. This means that bituminous roofing felt can also be removed without smearing the sanding pad.
Sanding pad in a flat design
Sanding disc in a curved design
