How to Bond Confidently with Primerless Adhesives.

by Zachary Shaw September 18, 2025

Fore note: Primerless ≠ 'Cleaner-Less'

Let’s clear up a dangerous myth: primerless does not mean cleaner-less. Any supplier who tells you otherwise is being irresponsible, and that advice could cost you thousands in rework, repairs, and warranty claims. Every adhesive bond is only as good as the surface it’s applied to. If you skip proper cleaning and preparation, you’re gambling with your production quality.

An Adhesive Bond Is Only as Good as the Surface you are Bonding to

The strength of your bond depends not only on the adhesive you choose but also on the quality of your surface preparation. Some adhesives compensate for poor prep, but the most robust approach is always to use a system.

That system starts with the basics:

● If the panel is visibly dirty, clean it.

● How clean is clean? It depends on the dirt.

○ Airborne dust may only require a dry wipe.

○ Grease or oils need a solvent wipe first.

Skipping this step risks weak or inconsistent bonding, a risk no production line can afford.

Knowing the Bond Strength You Need

In the commercial vehicle and motorhome markets, structural bonding typically applies to external components such as windows, cant rails, solar panels, and wind deflectors. These parts are designed for bonding and provide enough surface area to achieve bond strengths of 1–5 MPa.

To reliably hit up to 5 MPa with a primerless adhesive like Formoa 017FE, the process is simple:

Clean: Remove visible dirt from the substrate.
Activate: With a lint-free cloth, apply surface activator liberally. Wipe in one direction, turning to a clean edge every metre.

Surface activator opens up more bonding area and is especially effective on:

● Metals, including aluminium and steel

● Powder-coated finishes

● Painted finishes

● Certain plastics like ABS and PVC

When You Don’t Need Activation

Some materials, such as flooring in trucks and trailers, don’t require an activator if the surface is clean. In these cases, the wood itself will delaminate before the adhesive bond fails, proving how strong the system can be.

The Bottom Line

Bonding confidently with primerless adhesives isn’t about skipping steps; it’s about using the right system. Clean, activate, and then bond. Do that consistently, and you’ll achieve reliable, high-strength bonds without the pitfalls of primers.

If you’re struggling to bond components with confidence in your commercial vehicle or caravan production, reach out for a free consultation. Together, we’ll build a robust bonding process for your factory.

Book your Free Consultation Here