For vacuum grippers, glass is actually the ideal surface: smooth, airtight and flat. Even so, glass panes are among the trickiest loads, because when something goes wrong they do not just fall, they break, and their edges cause serious cuts. This guide shows how to pick up, carry and set down panes, mirrors and window units safely with a vacuum lifter.
How heavy is glass?
Glass weighs 2.5 kg per square meter per millimeter of thickness. That lets you estimate any pane quickly:
| Glass type | Typical makeup | Weight per m² |
|---|---|---|
| Mirror | 4 mm | 10 kg |
| Single glazing | 4 mm | 10 kg |
| Tempered safety glass for shower enclosures | 8 mm | 20 kg |
| Laminated safety glass for railings and balustrades | 2 × 8 mm with interlayer | approx. 40 kg |
| Double glazing | 4 + 4 mm | approx. 20 kg |
| Triple glazing | 4 + 4 + 4 mm | approx. 30 kg |
A 90 × 200 cm shower screen in 8 mm tempered safety glass therefore weighs about 36 kg, and a 120 × 150 cm triple-glazed unit about 54 kg, without the frame. From about 25 kg, two people should handle the pane. The guide How to assess load capacity correctly explains how much reserve a vacuum lifter needs here.
Important for glass: panes are almost always carried on edge. The load then pulls parallel to the seal, and the pane is held by friction. In this position, a vacuum gripper holds considerably less than its rated load; reckon with a quarter at most.
Rubber or foam on glass
On smooth glass, the rubber seal is the first choice. It conforms over its entire surface and builds up the highest vacuum. In the database, 453 models are listed as suitable for glass. They have a median price of €64; 89% of them have a rubber seal, and only 9% a foam seal. You will find the selection under Vacuum grippers for glass.
Foam is not needed on smooth glass and comes with a lower median load capacity: 140 kg compared with 240 kg for rubber. It makes sense on patterned glass with an embossed surface. There, place the gripster on the smooth side if possible. Rubber vs. foam shows the general comparison.
Rubber can leave light or gray rings on glass. Non-marking seals avoid this; otherwise, the marks can be removed with glass cleaner. For glass that will later be bonded or sealed, always clean the contact points thoroughly.
Cleanliness: glass and seal
Because glass carried on edge is held by friction, cleanliness matters even more here than with tiles.
- Clean the contact point: With glass cleaner or isopropyl alcohol, then wipe dry. Fingerprints and grease reduce friction.
- No water film: Wet glass lets the seal slip under shear load, even if the display shows enough vacuum.
- Remove the protective film: Many panes are delivered with a film. A vacuum gripper on the film holds only the film.
- Check the seal: Glass splinters and sand damage the sealing lip and can scratch the pane.
With mirrors, always place the gripster on the glass side, never on the painted back. The coating can come off and cannot withstand the vacuum. With coated or frosted glass, choose the smooth, uncoated side.
Temperatures
Cold has a twofold effect. Rubber hardens and seals less well, and condensation forms on cold panes as soon as they are brought into a warm room. Wipe the contact point dry, check the vacuum display more often and, in freezing conditions, only work on glass with a dry, ice-free surface. Let the vacuum lifter warm up before use.
Heat is less critical. Panes that have been lying in the sun can get very hot. The seal becomes softer and leaves marks more easily. The battery should not lie in direct sun.
Protecting the edges
The edge is the weak point of every pane. A knock on an edge or corner is enough for float glass to crack or for tempered safety glass to shatter instantly into small fragments.
- Edge protection: Rubber or plastic profiles, edge protector corners or folded cardboard on all exposed edges.
- Set down softly: Never stand panes directly on concrete, tiles or metal; use wooden blocks, rubber blocks or carpet offcuts.
- Do not slide over edges: A pane pulled over a table edge or a stair step can break at the point of support.
Carrying and transporting correctly
- Carry on edge: Panes are carried upright, never flat. Lying flat, they sag and break.
- Place the vacuum lifter above the center of gravity: That way the pane hangs stably and does not tip. Keep a few centimeters away from the edge.
- Second hand on the bottom edge: Support and guide the pane from below, wearing a cut-resistant glove.
- Two people for large panes: Each person with their own gripster, with commands agreed beforehand.
- Watch the wind: Outdoors, a large pane acts like a sail. In gusty wind, postpone the move.
- In the vehicle: Secure panes on edge at a slight angle on a glass rack or transport stand, fix them with straps and separate them with spacers.
An automatic re-pump is particularly useful with glass, because panes are often carried over longer distances and up stairs. 31% of the glass-suitable electric models offer one. Even so, check the display and do a short test lift before every carry.
Installing windows, insulating glass and mirrors
Vacuum lifters help not only with carrying, but above all with installation, where there is no room for hands on the pane.
Insulating glass: Place the gripster on the outer, smooth pane. Low-E coatings usually sit on the inside, in the cavity between the panes, where they are protected. For window sashes, add the weight of the frame and hardware, which can quickly equal that of the glass itself. The pane is set down on glazing blocks in the rebate and only then tilted into the frame. Release the vacuum gripper only once the pane is standing firmly and has been secured.
Mirrors: Large mirrors are fixed to the wall with mirror adhesive. Two vacuum grippers on the glass side let you position the mirror precisely without touching the surface with your fingers. Support the bottom edge with spacer blocks during the curing time instead of leaving the mirror hanging from the vacuum lifter.
Shower screens and glass doors: Here, holes and cutouts for hardware are the most sensitive points. Place the gripster at a distance from holes and carry the pane so that the holes do not take any load.
Quick check before every lift
| Checkpoint | What to look for |
|---|---|
| Weight | Area in m² × thickness in mm × 2.5 = kg |
| Contact point | Clean, dry, no film, smooth side |
| Seal | Undamaged, free of splinters and sand |
| Vacuum display | In the working range, test lift without pressure drop |
| Edges | Protected, set-down spot with soft support prepared |
| Route | Clear, doors open, no gusty wind |
Protective equipment for transporting glass
- Cut-resistant gloves with a grippy coating.
- Arm guards for large panes, because broken edges mainly endanger the forearms.
- Safety shoes with protective toe caps.
- Safety glasses when cutting and when handling damaged glass.
- Long sleeves made of sturdy fabric.
A vacuum lifter, often called a gripster in the trade, makes glass safe to grip when seal, surface and carrying technique work together. The guide Working safely with vacuum lifters sums up the general rules for handling vacuum grippers.