Mobile Photography Studio Cove and Light Seal Repair

Light tight and rigid are both achievable and they push a builder in opposite directions. Light tightness rewards a body assembled with continuous seals, thick linings and as few penetrations as possible. Rigidity rewards structure, and structure means fasteners, joints and members, each of which is a potential path for a thin line of daylight.

The builds that work well solved both deliberately. The builds we see most solved one and hoped about the other, which is why a studio arriving here usually has either a cracked cove or a light leak, and occasionally both. Diagnosing which problem you actually have decides the whole shape of the repair.

• Light tight is a smaller tolerance than water tight
• A rigid cove needs a wall that does not dish
• Every fastener head is a potential pinhole of daylight
• A sealed dark interior gains heat faster than a white one

A cove exists to present a curve with no visible transition, which means it has to be rigid. It is bonded to a wall panel that is fastened at its edges and free in the middle, and that panel dishes very slightly whenever the unit is towed. The bond line is the stiffest part of the assembly, so that is where the strain concentrates.

The crack therefore follows the curve rather than crossing it, which is the quickest way to tell a fatigue crack from an impact crack. Filling and refinishing a fatigue crack without stiffening the panel behind it gives you the same line back within a season. We stiffen first, then rebuild the cove surface, then refinish.

A pipe grid is the most useful thing in a studio vehicle and the least anticipated by whoever built the body. Three hundred pounds of strobes, modifiers and booms hangs from a handful of hanger points fastened into roof bows that were sized to hold a roof panel up, not to span between sidewalls as loaded beams.

Each hanger point deflects the bow a little, the grid stops being level, and the roof panel above develops a waviness that is visible in a raking light. We add a hanger rail spanning between the sidewall posts, transfer the grid loads onto it and leave the bows carrying only the roof, which is the job they were given originally.

This is the acceptance test unique to a studio. A repair that passes a water test can still fail a light test, because water needs a path with volume and light only needs a line. A fastener that seals against rain can pass light around its head, and a lap joint sealed on the outside can transmit a thin bright line along its length.

So we test differently. The unit gets closed up in a bright bay and inspected from inside after five minutes of dark adaptation, which finds leaks a torch survey never will. Anything found gets sealed from the inside face as well as the outside, and the test is repeated before the unit is called finished.

1. Close the unit in full daylight and wait five minutes inside
2. Sight every reworked seam, fastener line and penetration
3. Seal from the inside face as well as the outside
4. Repeat the dark adaptation test before release

A blacked out body absorbs heat rather than reflecting it, and then you put people, modelling lamps and strobe packs inside and close the door. The rooftop unit runs close to continuously through an afternoon shoot, which works its curb flange, and the ceiling below is a sealed finished surface with no space above it to inspect from.

So the first symptom is a stain appearing on the very wall clients are photographed against. We reseal the curb properly, but we also look at whether the cooling capacity matches the load, because a unit cycling continuously is both the cause of the flange movement and a sign the build is short on capacity.

The rear doors are the loading route for backdrops, stands, cases and everything else, so they get opened and shut constantly and often with a knee or an elbow. Studio builds add a second compression seal to make them light tight, and a compression seal only works while the door still sits centrally in its aperture.

A few millimetres of hinge wear puts a line of daylight down one edge, and no amount of extra seal fixes a door that is no longer centred. We replace the hinge components, shim the door back to the aperture, and only then fit new seal so the compression is even along all four edges.

We do not offer mobile repair and there is no roadside option, and on a studio that restriction is doing real work. A coved surface refinished outdoors picks up dust that shows under a strobe, and a dark adaptation light test needs a controlled bay. Photographers reach the Yorba Linda building from Rancho Santa Margarita on the 241 to the 91.

Cove, panel, grid and refinish hours bill at $210 with paint supplies at $55 per paint hour. Shore power and strobe circuit work bills at $260. Interior cleaning before a coved surface is refinished bills from the detail department at $95. A written estimate is $150 and credits in full against an authorized repair.

Studio bodies are undemanding for size and unusually demanding for cleanliness. A 26 foot box or trailer takes a standard bay and paints whole in the booth. What we plan around is dust: a coved surface refinished in a dirty bay shows every particle under a strobe, so cove work is staged after any grinding is finished and the interior gets a detail level clean before refinishing. Grid, backdrops, stands and all camera and lighting equipment leave with the owner.