Finish
Galvanizing is priced by the pound. Paint is priced by the square foot. Miss that one difference and the same finish spec gets over-bid on heavy steel and under-bid on light steel, job after job.
Two different units, two different winners
A hot-dip galvanizer weighs the load; the invoice is dollars per hundredweight of steel. A paint line covers surface; whatever the quote says on its face, the cost tracks square footage of prepared, coated steel.
Now look at how members differ. A heavy column carries very little surface per pound. A picket railing is nearly all surface and hardly any pounds. So the ratio of surface area to weight, square feet per ton, decides which coating is expensive on which steel:
| Steel | Surface vs weight | Tendency |
|---|---|---|
| Heavy W shapes, built-up members | Low sqft/ton | Galvanizing costs relatively more, paint relatively less |
| Typical commercial framing | Middle | Either can win; the shop's logistics usually decide |
| Rails, pickets, light angles, grating | High sqft/ton | Paint labor explodes; galvanizing by weight often wins |
This is why a takeoff that tracks surface area per section, not just tonnage, is the difference between pricing a finish and guessing it. The rule of thumb fails exactly where the money is: on misc metals.
What galvanizing quotes hide
- Trucking both ways. The kettle is at the galvanizer's plant, not yours. Freight to and from is real money and real schedule.
- Venting and drainage. Hollow sections need vent and drain holes before dipping. That's shop labor, and on HSS-heavy jobs it adds up.
- Kettle limits and double dipping. Pieces longer than the kettle get double-dipped at a premium, or redesigned. Check the longest member early.
- Touch-up and field repairs. Welded field connections get cold-galv repair. Small line, but it belongs in the bid.
- Minimum lot charges. A handful of small pieces can cost the minimum, not the per-pound rate.
What paint quotes hide
- Surface prep is the cost. The spec's blast standard drives more of the price than the coating itself. An SSPC-SP6 blast and a wire-brush clean are different bids.
- System, not coat. A primer-only shop coat and a three-coat high-performance system differ by several times, per square foot, in both material and handling.
- Handling between coats. Every coat means moving, racking, drying, and touching the piece again. Multi-coat systems on big weldments eat crane and floor time.
- Overspray reality. Complex shapes with lattice or perforations use far more paint than their net area suggests.
How to bid it cleanly
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Carry surface area in the takeoff
Every structural section has a known surface area per foot; carry it on the row, alongside weight. Then both coating models price from the same takeoff without a second measuring pass.
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Price the spec, not the word
"Galvanized" and "painted" aren't prices. Get the blast standard, the system, and the mil thickness out of the spec section before putting a number to it.
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Split the misc from the structural
Coating a rail package and coating a frame are different problems. Price them separately, with the misc priced from its real (high) surface area.
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Carry the side costs as lines
Freight to the galvanizer, vent and drain, touch-up, masking of faying surfaces: name them in the estimate so scope review can see them, instead of padding a rate and hoping.
Coating markets move with zinc prices, fuel, and local competition; get current quotes from your galvanizer and coater rather than relying on any published rate. The structural point here is the unit mismatch, and that doesn't change.
Steel Estimator Pro prices finish from real surface area
Every takeoff row carries surface area per foot, and the finish tab prices paint systems by the square foot and galvanizing by weight, per scope, so rails and frames each get the right math.
See how it works →