PROTECTION BEYOND THE SURFACE
Getting inside the sills and chassis
Some of the most damaging corrosion develops where you cannot see it. Moisture collects inside sills and chassis sections, particularly around seams and overlapping steel. Rust can work from the inside out long before it becomes obvious on the exterior.
I treat these internal spaces with Bilt Hamber Dynax S50, using a flexible lance with a 360-degree misting nozzle. Access bungs are removed where needed, allowing the lance to distribute wax around the internal walls of each accessible section.
S50’s high-creep formula penetrates narrow seams and folded edges by capillary action. It displaces surface moisture and leaves a soft, corrosion-inhibiting film that can reseal small disturbances in its surface. About Dynax S50
Treating the rust before applying protection
Loose scale, failed coatings and accessible surface corrosion are mechanically removed, then the area is cleaned. Remaining rust is treated with Bilt Hamber Hydrate 80.
Hydrate 80 chemically converts the remaining rust into a more stable, dark layer, while its polymer binder forms a protective barrier. This prepares the surface for further protection. Particularly exposed areas may also receive Epoxy Mastic before the final wax coating.
READ ABOUT HYDRATE 80
Clear wax so you can see the condition underneath
I use Dynax UC on exposed underside surfaces because it provides corrosion protection without burying the vehicle beneath a thick black finish.
Its almost-transparent wax film contains corrosion inhibitors and cures to a firm, touch-dry finish that resists dirt pick-up. The treated surfaces remain visible, making it easier to check their condition and spot areas needing attention.
READ ABOUT DYNAX UC
Why I do not simply cover everything in underseal
A fresh coating can make a rusty underside look reassuringly tidy. But covering loose rust, mud or damp material does not deal with what is underneath. Where coatings crack or lift, moisture can remain trapped against the steel and corrosion can continue unnoticed.
The preparation and access are a substantial part of the work. I want the finished treatment to protect the vehicle, not just improve how it looks in an after photograph
Why I use Bilt Hamber
Bilt Hamber publishes comparative corrosion testing for Dynax S50, including testing carried out at the University of Hertfordshire. Hydrate 80 has also received a Practical Classics Best Buy award. That testing supports my choice of products alongside their suitability for the work.
The aim is to slow existing corrosion, protect vulnerable metal from further moisture and salt exposure, and help keep an otherwise sound vehicle in use. An annual check and local touch-ups where protection has worn away help maintain that work.