Are Your IG Units “Slipping” While the Sealant Cures?

The most critical hour for an Insulated Glass Unit (IGU) is the first hour after sealing. The silicone or polysulfide secondary seal is still wet and pliable. If you lean these fresh units against a traditional 5-degree tilt A-frame, gravity pulls the outer pane down, causing “glass stepping” or misalignment. Quality control isn’t just about the seal; it’s about the geometry. Discover how switching to vertical glass harp racks for your curing stage eliminates shear forces, ensuring your units remain perfectly aligned while optimizing airflow for faster drying. Talk With An Expert

The Science of Vertical Curing

In a standard IGU production line, space is tight. Operators are tempted to stack units densely. However, when fresh units are stacked against each other on a slanted cart, the weight of the stack presses on the wet sealant of the bottom unit. This pressure can squeeze the sealant out or deform the spacer bar.

Glass Harp Racks hold each unit at a strict 90-degree vertical angle. By isolating each unit in its own slot, you remove the compressive load. The glass stands on its own weight, supported evenly by the slotted base. This “zero-shear” storage environment guarantees that the unit cures exactly as it was assembled, with zero chance of slippage.

Accelerating Turnaround with Better Airflow

Time is money. The sooner the sealant cures, the sooner you can ship. Units stacked tightly on an L-buck or A-frame have very little air circulation between them, trapping humidity and extending the chemical curing time of the silicone.

Individual spacing allows air to circulate freely around the sealant, speeding up the curing process.

The open-wire design of our harp racks ensures maximum exposure to ambient air. Each unit is separated by a consistent gap (customizable from 10mm to 20mm), creating a chimney effect that pulls air past the sealant edges. This can significantly reduce the “WIP time” (Work In Progress) on your floor, allowing you to clear the curing area faster for the next batch.

Batch Management Strategy

Managing the “Dry Time” clock is easier with visual tools.

Handling Triple Glazing and Heavy Units

As energy codes get stricter, Triple Glazing is becoming the new standard. These units are heavy and expensive. A 50kg triple-glazed unit puts immense stress on a standard cart’s dividers.

Our racks are engineered for this new reality. We use Q235A carbon steel reinforced dividers that resist bending even under the load of heavy triple units. The base is equipped with heavy-duty nylon rollers or a low-friction HDPE slide, allowing operators to glide these heavy units into place smoothly without the jerking motion that could compromise the wet seal.

Frequently Asked Questions

1. Will the wet sealant stick to the dividers?
No. The dividers are positioned to support the glass face, not the edge where the sealant is applied. Additionally, the PVC coating on the dividers is non-stick, ensuring that any accidental contact doesn’t ruin the seal.

2. Can we use these racks for “Gas Filling” staging?
Yes. They are perfect for staging units before and after Argon gas filling. The vertical orientation makes it easy to access the filling ports if you are using manual filling equipment.

3. What is the weight limit per slot?
Our heavy-duty curing racks are designed to hold up to 100kg per slot, making them suitable for oversized residential units and commercial storefront glass.

4. How do I prevent the units from rocking?
We offer a “Full Base” option with a grooved floor. The unit sits in a groove that matches its thickness range, providing lateral support at the bottom edge, preventing any pendulum motion during transport.

5. Can these racks go into a heated curing oven?
Standard models are safe for ambient curing. If you use a heated curing chamber (up to 80°C), please inform us, and we will use high-temperature resistant coating and wheels to ensure durability.