Anyone who has worked with polyurethane foam (PUR) knows that it is not only the foam itself that can cause problems when cleaning. Its components can be just as troublesome – especially hardeners, known as isocyanates (ISO). They are responsible for the foam’s binding process and durability, but also for hard, difficult-to-remove residues that can stick to almost anything. In this guide, we show you how to effectively deal with this problem using Tedgar ISO.
What are hardeners (ISO) and why are they so difficult to remove?
Foam hardeners are chemicals that react with moisture in the air and polyol compounds. This results in a foamy, durable material – PUR foam. However, when the hardener dries in a place where it should not, it becomes extremely difficult to remove. Unlike the foam itself, isocyanates form strong chemical bonds that do not dissolve under the influence of ordinary cleaning agents.
Common mistakes when working with hardeners include leaving foam residue in the gun, on the assembly tips, on tools, or on the surface of walls, frames, and window sills. After a few minutes, such residues are virtually impossible to remove without the help of a specialized agent.
Why use Tedgar ISO?
Tedgar ISO is a product specially developed for removing polyurethane foam hardeners and isocyanate residues. Unlike traditional solvents, its formula breaks down the chemical bonds of the hardener, softening the foam and ISO so that they can be easily removed without damaging the surface. The product works quickly, leaves no greasy residue, and is safe for PVC, glass, metal, aluminum, and painted surfaces.
Importantly, the product can be used to clean both surfaces and the internal parts of tools, such as foam guns. This prevents the equipment from clogging and keeps it working efficiently for longer.
How to use Tedgar ISO step by step
- Remove excess hardener mechanically, if possible (e.g., with a plastic spatula).
- Apply Tedgar ISO to the stained area – directly or using a cloth.
- Leave for 2–3 minutes to allow the agent to dissolve the ISO structure.
- Gently wipe and repeat the application if necessary.
Finally, wash the surface with a neutral cleaning agent and dry it.
Thanks to its reactive action, the product penetrates hard residues and breaks down their structure from the inside. Unlike aggressive solvents, it does not require long scrubbing and does not damage the surface.
Cleaning guns and tools
A foam gun is a tool that suffers most from ISO residue. Leaving foam inside just once is enough to block the needle or nozzle. Regular cleaning with Tedgar ISO keeps your equipment in perfect condition:
- Pour a small amount of the product into the spray gun.
- Leave for 1–2 minutes to dissolve any residue.
- Rinse the product with air or flush with a clean agent.
- Dry and protect the spray gun before the next use.
This allows the tool to remain smooth-running and does not require dismantling or costly servicing.
Where else is it worth using Tedgar ISO?
- Cleaning of molds and production equipment in the PUR industry.
- Removal of hardeners from metal and steel components.
- Cleaning surfaces contaminated with polyurethane foam after installation or insulation.
- Unblocking spray guns, nozzles, and valves.
Frequently asked questions and user errors
Does Tedgar ISO dissolve only the foam or also the substrate?
No—it acts selectively on the hardener without affecting the surface structure.
Can I mix Tedgar ISO with other cleaning agents?
No. The product has a precisely selected chemical composition. Mixing may reduce its effectiveness or cause a chemical reaction.
Is the product safe?
Yes, provided that basic health and safety rules are followed (gloves, ventilation). It does not contain aggressive solvents that could damage the surface.
Comparison with popular methods
| Method | Effectiveness | Risk of damage | Operating time |
|---|---|---|---|
| Acetone / extraction gasoline | low | tall | rapid pairing |
| Mechanical cleaning | average | very high (scratches) | depends on strength |
| Tedgar ISO | very high | low | 2–3 minutes |
As you can see, Tedgar ISO combines efficiency with safety and saves you time and tools.
Summary
PUR foam hardeners are among the most difficult stains to remove. Ordinary chemicals are powerless against them, so it is worth using specialized preparations such as Tedgar ISO. With it, you will get rid of foam residues, restore the efficiency of your tools, and avoid