Bilt Hamber Dynax UC | Transparent Anti-Corrosion Film
Protection you can't see
Dynax UB and S50 both leave a brown film. On a chassis or inside a box section, nobody cares. On a painted underside, a restored bay, a visible subframe or a show car, that brown film is the problem — you've protected the metal and ruined the look.
Dynax UC is Bilt Hamber's answer: a firm, touch-dry, virtually transparent protective film at around 50µm. It goes on bare metal or over paint, it's safe on the majority of paint coatings, and it leaves the finish visible.
Multi-metal inhibitors
Bilt Hamber describe UC's film as rich in multi-metal corrosion inhibitors — a deliberate distinction from S50 and UB, which are aimed squarely at ferrous metal. If you're protecting aluminium subframes, mixed-metal assemblies or galvanic junctions, that's the reason to reach for UC.
As with the rest of the Dynax range, the wax and the inhibitor chemistry are undisclosed. Bilt Hamber name the carrier solvents in the SDS and nothing more, and we're not going to fill the gap with speculation.
Where it belongs
Painted or visible undersides. Restored engine bays. Inner arches on a car you actually look at. Anywhere a dark underseal or a brown cavity wax would detract from a finish you've paid for.
How to use it
Degrease with Surfex-HD, rinse, dry thoroughly, then wipe down with white spirit. Apply in fine coats — this is a low-build product and it is not trying to be UB. The aerosol valve works upside down, which matters more than you'd think when you're under a car.
It's removable later with solvent or an alkaline degreaser, which makes it a sane choice for anything you might need to work on again.
UB or UC?
UB where it takes stone strike and abrasion, and where nobody sees it — outer chassis, floorpans, wheel arches. UC where appearance matters or where you're protecting mixed metals. Plenty of restorers run both: UB on the hidden structure, UC on everything visible.
Handle it properly
Aerosol: Danger — H220, H280, H304, H315, H336, H411. Ventilation and respiratory protection.
Safety Data Sheets (Australia)
Download the Dynax UC SDS – bulk (PDF)
Download the Dynax UC SDS – 750ml aerosol (PDF)