Description
Unlike the texture and closing pads that follow it, the DED77670 is a flattening tool — a 400 mm rigid PVC float disc for the Dedra DED7767 that sets the plane of a lime-cement, gypsum, or basecoat wall before any texture is worked, holding straightness under load where softer discs flex.
Where the DED77670 Plastic Pad Performs Best on UK Render Sites
For floating freshly applied lime-cement or gypsum plaster across large elevations, the DED77670 PVC disc delivers the rigid, abrasion-resistant face the job demands — a 400 mm working diameter held by four Velcro fasteners on the Dedra DED7767 base plate. It is stocked in the Renders World power floats and sponges range as the flattening-stage disc of the seven-pad system. PVC gives the disc its character: stiffer than foam, harder-wearing than sponge, and tolerant of the grit and aggregate that pull softer pads out of shape.
The plastic stage occupies a specific point in the workflow — after stripping and grit work, before the polystyrene and sponge discs refine the surface further. Applicators consistently report that the plastic stage is where wall flatness is set: downstream pads adjust texture, but they cannot rescue an uneven plastic pass, so the flatness locked in here carries through the rest of the finish.
Why Trade Specifiers Choose the DED77670 Plastic Pad
- Rigid PVC working face: stiffer than foam discs, holding flatness across the full 400 mm diameter under load — the disc the trade reaches for when straightness matters.
- True 400 mm coverage: a larger contact area than 375 mm-class machines, reducing pass count and visible track lines on long elevations.
- Four-point Velcro fastening: robust hook-and-loop holders keep the disc square under continuous 110 rpm rotation, with no centre-bolt to loosen.
- Plaster-tolerant material: PVC resists abrasion from sand-cement aggregate and lime fines that quickly degrade softer foam discs.
Technical Specifications — DED77670 Plastic Disc Data
| Property | Value |
|---|---|
| Disc material | PVC (rigid plastic) |
| Diameter | 400 mm |
| Mounting | Hook-and-loop (Velcro), four-point |
| Compatible machine | Dedra DED7767 power float (710 W, 110 rpm) |
| Application surfaces | Lime-cement plaster · gypsum plaster · render basecoats |
| Function | Floating and smoothing wear disc (flattening stage) |
The disc is a system component rather than a standalone tool. The 400 mm diameter and four-point Velcro pattern match the DED7767 base plate without an adapter, which is why swapping between this disc and a texture or sponge pad takes seconds. Renders World stocks it alongside the DED77670 mounting pad that carries it when the base plate Velcro is worn.
How to Apply the DED77670 — Flattening Passes and Machine Fit
Run the DED7767 at its full 110 rpm working speed and keep the disc moving in overlapping arcs, because the rigid face works best with light, even pressure across the full 400 mm contact area — loading one edge tilts the pad and prints arc marks into the plaster that the next stage struggles to remove. The disc suits freshly applied lime-cement plaster, gypsum plaster, and traditional sand-cement renders during the working window when the surface is firm but still workable, and it handles the floating stage on basecoats over EPS or mineral wool where preserving flatness before mesh embedment is critical.
The disc fits the Dedra DED7767 platform only — it is not interchangeable with the smaller DED7769 (375 mm class) or competing brands using different mounting geometry, so confirming the machine model before ordering is the simplest way to avoid the most common cause of returns in this category. In a full finishing run the disc follows the stripping disc and grit work, then hands off to the polystyrene texture pad; the Renders World guide to power floats for render finishing sets out the full sequence with the temperature and humidity windows for each stage.
Installation Notes — Mounting, Pressure, Replacement
Inspect the Velcro mounting before each session, because PVC discs survive plaster grit well but embedded fines on either the disc back or the machine plate reduce the four-point grip and let the pad creep under load. A brush-down between elevations keeps the fastening secure and extends working life. Engage all four corners cleanly before powering up, and confirm the disc sits flat with no visible gap after a short test arc.
Replace the disc once the PVC face glazes. A polished face stops cutting the plaster and starts skating across it, and a fresh disc costs less than the time spent re-floating an elevation that should have closed cleanly the first time — which is why finishing trades keep a spare on the van. Matching light, even pressure to the substrate window typically extends usable disc life well beyond a foam disc on equivalent work.
Pro Tips From UK Installers Using the DED77670
The most common mistake on PVC pads is treating them as a finishing tool rather than a flattening tool. This is the disc that sets the plane of the wall — texture comes later — so installers who get the cleanest final finish accept that the surface will not look finished at this stage and leave that job to the polystyrene and sponge pads. Keep the disc moving, keep the pressure even, and lock in flatness while the plaster is still in its working window.
- Treat it as a flattening tool: the plane of the wall is set here; downstream pads refine texture but rarely correct an uneven plastic pass.
- Keep the disc moving in overlapping arcs: stationary or edge-loaded contact prints arc marks the next stage cannot lift.
- Retire glazed discs promptly: a polished PVC face skates rather than cuts, and re-floating costs more than a fresh disc.
- Brush the Velcro between elevations: embedded fines cost grip before they cost anything else.
- Keep a spare on the van: a fresh disc for the final elevation holds finish quality consistent across the day.
Is the DED77670 Plastic Pad Right for Your Project?
- Flattening lime-cement, gypsum, or basecoat surfaces: a strong fit — the rigid PVC face holds flatness where softer discs flex.
- Texture-setting after flattening: the DED77674 polystyrene pad is the correct next step, and the DED77671 sponge pad closes finer after that.
- Coarse stripping or grit work: the DED77675 stripping disc and grit pads come first — the plastic pad works a surface that is already clear.
- Decorative thin-coat silicone render topcoats: these are hand-floated with a plastic trowel, so the disc is rarely the topcoat tool.
- Power floats outside the DED7767 platform: disc geometry and the Velcro pattern will not match — confirm the machine model first.
FAQ — DED77670 Use, Compatibility, Replacement
How long does one DED77670 disc typically last in render service?
Working life depends on substrate aggressiveness and pressure, but a PVC disc generally outlasts a polystyrene disc by a comfortable margin on equivalent work, since the plastic face resists abrasion better than foam. Replace it once the surface glazes or the Velcro backing softens, both of which show as reduced cut and grip on the pass.
Will this pad fit power floats other than the Dedra DED7767?
The DED77670 is designed for the DED7767 platform — 400 mm diameter and a four-point hook-and-loop pattern. It is not reliably compatible with the smaller DED7769 (375 mm class) or with other manufacturers' machines, so confirming the machine model before ordering avoids fitment issues and the returns that follow them.
When should the plastic disc be used rather than the polystyrene pad?
The PVC plastic disc is for the flattening stage — getting the wall straight and even. The polystyrene disc follows it, setting surface texture once flatness is established. Most professional finishing sequences use both in that order, with the plastic pass first and the texture pass second on the same machine.
Can the disc be used on freshly applied silicone or thin-coat decorative renders?
PVC plastic discs work well on plaster and basecoats during their working window. Decorative silicone and silicate thin-coat finishes are normally textured by hand-floating with a plastic trowel, since the binder chemistry is designed for hand application and power-floating is generally avoided for those systems.
Does the plastic disc replace the grit-disc stage on rougher substrates?
No. For rough or contaminated surfaces the stripping and grit stages come first. The PVC plastic pad works after coarse preparation is complete, taking the surface from flat-but-rough to flat-and-smooth before texture-setting begins — it flattens a cleared surface rather than removing bonded material.