A painted frame system can quote 15–20% below hot-dip galvanized. Over five years of rental rotation, that saving reverses — usually twice. Here is the arithmetic procurement teams should run.
What Each Finish Actually Is
- Hot-dip galvanizing: components are dipped in molten zinc at ~450°C after fabrication. Zinc bonds metallurgically inside and out, including node interiors where rust starts first. Coating life outdoors: 10–25 years depending on climate.
- Painted: one or two coats over bare or pre-galvanized tube. Chips during transport and erection; rust follows from every scratch and weld point.
5-Year Cost Model (per ton, indicative)
| Cost item | Painted | Hot-dip galvanized | |---|---|---| | Purchase price | 100 | 118 | | Re-coating cycles (year 2, 4) | 18 | 0 | | Component losses to rust/seizing | 10 | 2 | | Sorting and repair labor | 8 | 3 | | Resale value at year 5 | −30 | −55 | | Net 5-year cost | 106 | 68 |
The Hidden Factor: Inventory Reliability
Seized, rusted fittings do not just cost money — they cost erection hours and inspection failures. Galvanized systems sort, stack and re-issue faster, which matters when crews bill by the day.
When Painted Still Makes Sense
Dry inland climates, single short projects, or systems you plan to re-paint in-house anyway. For everything else — coastal sites, rental fleets, repeat rotation — hot-dip galvanizing wins on total cost.
All PJSCAFFOLD ringlock, cuplock and frame systems are hot-dip galvanized to ISO 1461 with coating thickness ≥ 70 μm, verified per batch. Request sample components and a coating report with your quote: WhatsApp +86 18955015380.