An aluminum door is not just a profile and a glass unit. In the premium segment, a door has long since become part of the architectural statement: concealed hinges, recessed handles, and a monolithic facade surface with no visible fasteners at all. That is exactly where ADECO panels come in — a German development that makes it possible to turn a standard aluminum door into a product in which the aluminum infill becomes part of a single design object.
I have been following this technology for a long time. The first time I saw these panels was at some exhibition, and even then it was clear: this is not just decoration, it is a fundamentally different approach to assembling a door leaf. Recently we produced our first doors with glued-in ADECO panels and worked out the technology together with specialists in industrial adhesives and sealants for translucent structures.
In this article, everything you need to know about ADECO panels and their bonding technology: what they are, how the panel is built from the inside, which materials are used, where mistakes can happen, and how to avoid them. I will also break down the door hardware we assembled: a concealed closer, a GU motorized lock, EK biometrics, and a contact unit without cable ducts.
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What ADECO Panels Are and Why They Are Needed
ADECO is a German manufacturer of decorative infills for aluminum doors. The panel is a sandwich construction: a 3 mm aluminum sheet on the outside and a 2 mm sheet on the inside. Between the sheets is polyurethane foam insulation. Around the perimeter is a rubber buffer that compensates for thermal deformation and keeps the panel from warping when heated.
Why is this particular construction needed? Aluminum has a high coefficient of thermal expansion. A large door leaf under sunlight can heat up to 60–80 degrees. If the panel is glued rigidly, without compensation, then with repeated cycles of expansion and contraction the adhesive joint will start to delaminate and the leaf itself may deform. The buffer is not a decorative detail — it is an engineered solution built into the product.
The outer surface of the panel is available in a wide range of finishes and textures. We worked with RAL 7021 in a muar finish — a rough, matte surface that looks much more expensive than a smooth powder coating and is practically not marked during use. One important point: the panels are packaged by the manufacturer with special care — the coating is delicate, while each panel is quite expensive. This is not a product to handle roughly.
What ADECO Contributes Architecturally
Before these panels appeared, a designer aluminum door either had a visible frame around the leaf or required complex custom solutions. The ADECO panel makes it possible to achieve a perfectly flat face of the door — with no visible fasteners, no joints between the frame and the infill, and no relief.
Add a concealed handle, concealed hinges, and a concealed closer, and you get a door that, when closed, is hard to distinguish from a solid wall panel. That is exactly what is currently in demand in minimalist architecture and in projects with a continuous facade.
Two Approaches to Aligning Surfaces: Alutech and Schuco
Here it is important to clarify a fundamental structural difference that affects the appearance of the finished door.
When the panel is bonded into the sash, the question arises: what should be done with the frame? The frame and the sash are in different planes — the frame has no recess into which the panel can “drop.” If nothing is done, the joint between the panel and the frame will have a step, which visually looks like a ledge.
The solution for the Alutech system is metal overlay strips. Strips about 50 mm wide and 3 mm thick, painted in the same color as the entire structure, are glued around the perimeter of the frame. In our case, that is also RAL 7021 muar. After that, the frame and the panel end up in the same plane. It looks clean if done carefully.
The solution for the Schuco system is more elegant. Schuco has a special sash profile with a recess into which the panel “drops” during bonding and automatically ends up flush with the frame. No additional strips, no glue on the frame — everything is solved at the level of profile geometry.
If you need the cleanest possible solution with no extra elements, look at Schuco. If you work with Alutech, the strip technology is perfectly workable — it simply requires precision during installation.
Materials for Bonding: What Really Works
Bonding technology is not a case of “smear it on and stick it.” There is a chain of materials here, and each one has its role. We work with a chemistry products — they have specialized in industrial adhesives for translucent structures for almost 10 years, and everything listed below is not advertising but a proven practical set.
Primer Puraker 6204
Primer is the first and mandatory step. Its job is twofold: degreasing the surface and increasing adhesion. Powder coating by itself has relatively low surface energy, and without primer the adhesive will hold much worse.
The primer is applied in circular motions to both surfaces — to the sash profile and to the inner side of the ADECO panel. After application, the activation time must be observed — about 20–30 minutes. There is no need to rush here.
One important point about the surface: you can additionally pass sandpaper over the profile — adhesion will be even better. Visually the profile will look scratched afterwards, but that is not a problem — everything will be covered by the panel. We checked it: with proper priming, adhesion without sanding is also excellent. The adhesive tears itself before it comes off the surface — that is the quality criterion.
Two-component adhesive Furoflex 9280
The main adhesive is Furoflex 9280. It is a two-component IMS polymer adhesive specifically for bonding aluminum structures and leaves to powder-coated surfaces. The two components — component A (black) and component B (beige) — are mixed directly during application through a special mixing nozzle.
The adhesive starts setting quickly — after 20–30 minutes it begins to firm up, and after 2 hours it reaches sufficient strength for working with the structure. Full vulcanization takes longer, but for practical purposes two hours is enough.
You need to work with a pneumatic gun — it is hard to dispense a two-component adhesive by hand, and once mixed it will not wait. That is why application speed matters: move the gun quickly and apply in a zigzag pattern. The layer should not be overly thick — otherwise, when the panel is pressed in, adhesive will squeeze out and look messy, and later it is hard to smooth it out.
A properly chosen nozzle — a thin tip — makes it possible to control the thickness of the bead. We first tried a wider tip and got a layer that was too heavy. After switching to a thin one, the result became noticeably neater.
3M tape, 1 mm thick
Before applying the adhesive, a 1 mm 3M tape is applied around the perimeter of the sash. It serves two purposes: it creates an even gap between the panel and the profile (so the adhesive layer has the same thickness all the way around) and acts as a barrier that prevents adhesive from coming out. Without this tape, the adhesive will squeeze out at the edges during pressing and smear where it should not be.
The tape must be applied carefully, with no bubbles or overlaps. It is not fast work, but the cleanliness of the final result depends on it.
Elastic foam for filling the gap
Another material is used to fill the space between the leaf and the sash frame after the outer panel has been bonded. One thing is critical here: the foam must be elastic, with low expansion. No regular construction foam.
Why this matters: if you use rigid foam with a high expansion coefficient, as it expands it will create pressure on the bonded leaf. That will cause deformation, which will show up as a wave or bend on the front surface. Everything we carefully glued will be ruined by the wrong foam inside.
Proper elastic foam performs three functions: it fills voids (you cannot leave air pockets — they create a hollow feel and worsen thermal insulation), dampens vibration and sound, and compensates for internal stresses when the door deforms.
Step-by-step bonding technology
Step 1: Surface preparation
Both contact surfaces — the sash profile and the inner side of the panel — are treated with Puraker 6204 primer. If you want to further increase adhesion, the profile can additionally be lightly abraded with a sanding belt. After applying the primer, wait 20–30 minutes.
Step 2: Applying the 3M tape
Apply 1 mm 3M tape around the perimeter of the sash profile. Carefully, with no gaps or overlaps. It will keep the adhesive inside and provide an even gap.
Step 3: Applying Furoflex 9280 adhesive
Install the cartridge in the pneumatic gun and attach the mixing nozzle. First dispense a small amount of adhesive without the nozzle to make sure both components are flowing evenly. Then attach the nozzle and start applying.
Move in a zigzag pattern across the sash area — not around the perimeter, but over the entire surface — so the adhesive is distributed evenly. The layer should be moderate: the adhesive must spread when pressed, but not squeeze past the tape.
Step 4: Panel positioning
Place wooden spacers under the panel — several pieces of equal thickness. Lower the panel onto the spacers and gently move it into position, centering it on the sash. Make sure the corners match the profile corners.
Only after final positioning do we remove the protective film from the 3M tape — it holds the panel in place when we remove the spacers and press the leaf down for good.
Step 5: Pressing and waiting
Press the panel evenly across the entire surface. The assembly is then left in a horizontal position for two hours. By that time the adhesive reaches working strength.
Step 6: Turn over and fill with foam
After two hours, turn the door over. Fill the space between the leaf and the sash frame on the back side with elastic low-expansion foam. Let the foam rise and stabilize.
Step 7: Bond the inner panel
Repeat the entire cycle for the inner panel: primer, tape, adhesive, positioning, pressing. Before applying adhesive, be sure to wipe the infill surface with a damp cloth to remove production dust. Adhesion to a dusty surface will be worse.
What Is Inside the Door: What We Installed on These Constructions
Alongside the bonding technology, it is worth talking about the hardware we used on these doors. This is a complete smart entry system.
GU motorized lock
GU is a German manufacturer of hardware for aluminum structures. A motorized lock is not just a lock with electric control. A motor inside the body mechanically extends and retracts the bolts on command. It runs on mains power and is controlled by a signal from the access control system. No manual effort is needed for locking or unlocking.
The advantage of a motor over a solenoid lock: the motor keeps the bolts in the locked position mechanically, not electrically. That means if the power goes out, the lock stays in the position it was in — closed stays closed. That is important for security.
EK fingerprint scanner
EK specializes in biometric access control systems. The fingerprint scanner is installed into a pre-milled opening in the ADECO panel — we ordered the panel with the opening already made according to the manufacturer’s drawings. The scanner sits on the sash and is connected to the motorized lock.
The principle is simple: place a finger, the scanner reads it, sends a command to the lock, and the motor opens the bolts. The door can be opened. A wrong finger — no command, the door stays locked.
Concealed closer
The closer is milled directly into the body of the sash. It is completely invisible from the outside and from the inside — only if you specifically look for it. This is fundamentally different from standard surface-mounted closers, which protrude from the top of the door and ruin the whole aesthetic.
Concealed hinges
Three concealed hinges along the height of the sash. In the closed position of the door, the hinges are not visible from the outside — they disappear completely inside the profile. Three hinges are the right solution for heavy doors with panels: the load is distributed more evenly and the adjustment range is wider.
GU contact unit — a solution without cable ducts
This is an engineering solution that I want to discuss separately — it really is elegant.
The problem with the standard approach is that the sash carries the lock and scanner, and they need power and signal wires. Those wires must be routed from the moving sash to the fixed frame. Cable ducts are usually used for this — flexible conduits that run from the frame to the sash. They work, but they are visible. When the door opens, the wire bends. With repeated cycles, it rubs and can eventually break.
The GU contact unit solves this in a fundamentally different way. One part of the unit is on the frame, the other on the sash. When the door is closed, the contacts close and the circuit works. When the door is open, the contacts separate. No wires in sight, no bending cable.
In addition, the contact unit is also a power-supply block. The frame side receives 220 V from the mains. The block converts it to 24 V and sends it to the sash. From the sash side, the wires then go to the lock and scanner. One device performs three functions: a power bridge, safe current transfer, and a power supply block.
The handle lighting is an LED strip with a separate power supply. A touch button lets you change color and brightness. On our doors, the handle is recessed into the panel — a concealed form — and the LED contour around it creates a very striking effect in the dark.
Typical Mistakes When Bonding Panels
During the development of the technology we identified several points where mistakes can happen. I will list them honestly.
Wrong foam selection. This is the most common potential mistake, which we were able to prevent in advance thanks to the experience of our partners. Regular construction foam with high expansion is a direct path to leaf deformation. Only elastic, low-expansion foam. This is not the kind of savings where you should look for the cheapest option.
Too thick a layer of adhesive. If you apply the adhesive too generously, when pressed it will squeeze out past the 3M tape, spread over the edges — it looks messy and is hard to clean up. The correct layer is moderate, applied in a zigzag.
Wrong nozzle on the gun. A wide tip produces a thick layer that is hard to control. A thin tip is neater. It is chosen according to the specific cartridge and working speed.
Positioning without spacers. If you lower the panel directly onto the adhesive, it cannot be repositioned without losses. Wooden spacers give you time to center the assembly. They should be removed only after you have made sure the corners match exactly.
Dusty surface when bonding the second panel. After foaming, production dust settles on the horizontal surface. Before applying adhesive for the second panel, the surface must be wiped with a damp cloth. Adhesion to dust is poor — that is an axiom.
Rushing to turn the assembly over. Two hours is the minimum. If you turn the door earlier, the adhesive has not yet reached sufficient strength and the panel may shift under its own weight. Better to spend the time than to redo the job.
Economics and Applicability
ADECO panels are not a product for every door. They have their own niche, and there is no point in going beyond it.
Where to use them: entrance groups in premium cottages, entrance doors in apartments, designer entrance doors in public spaces — offices, lobbies, restaurants with a strong architectural concept.
Where not to use them: doors in standard construction, where the price per square meter matters more than the aesthetics of the infill. Also not for places without protection from direct mechanical impact — parking areas, entrances without awnings, where the door will regularly be hit by carts or other objects.
The cost of an ADECO panel itself is not budget-friendly. It is a German product with a high-quality powder coating, packaged with factory-level care. On top of that, the bonding technology requires special materials (primer, two-component adhesive, proper foam), special equipment (a pneumatic gun), and time — at least a full working day for one door with two panels.
For Alutech, you also need to add the cost of overlay strips on the frame and the labor to apply them. For Schuco, it is only the technology itself, but the recess-profile variant is correspondingly more expensive.
Bottom line on cost: a door with an ADECO panel, a GU motorized lock, EK biometrics, concealed hinges, and a closer is in a different price category from a standard aluminum door. But the result is also on a different level. When a customer opens such a door for the first time, the reaction speaks for itself.
Summary
The ADECO panel bonding technology is not complicated, but it does require care and the right materials. Three things make it successful: a quality two-component adhesive with primer, the correct elastic foam, and patience — do not rush at any stage.
For manufacturers working in the premium segment, this is a technology worth mastering. The market for designer entrance doors is growing, and customers with budgets increasingly want exactly this result: a monolithic surface, concealed mechanics, and no visible hardware. ADECO is one of the few tools that make this possible in serial production.
If you have questions about the materials or the process, write to me. I’ll be happy to share the details.
