Graco TrueCoat 360 DS: Spray Finish on 40 Panel Doors Without Roller Marks

Overlap, distance, and the order across a six-panel door

Hold the Graco TrueCoat 360 DS between 25 and 30 centimetres from the door face and keep that spacing steady through the pass. The tool is a handheld airless sprayer. Airless fans have a sharper edge than HVLP fans, so a drifting hand shows up quickly in the film. On a six-panel door the raised mouldings sit roughly 6 millimetres proud of the stile face, and a wrist that chases the profile changes the gun-to-surface distance. Keep the wrist fixed and move the arm parallel to the door plane.

Use 50 percent overlap from pass to pass. An airless fan puts more paint on the centreline than at the edges, and half-lapping places the thinner edge of one fan over the thinner edge of the next. At 30 percent overlap, the centre-heavy bands can appear as faint stripes after the enamel flashes off. Across 40 doors, that small variation becomes visible because doors in the same corridor are judged against one another.

The door sequence should protect the longest wet edge. Spray the panels and inner mouldings first. Rails can follow while the panel work is still open. Stiles work best at the end, with the last wet edge running the full height of the door.

The TrueCoat 360 DS ships with reversible tips. The orifice controls fan width and flow, which is why trim enamel and door coatings usually land in the 0.011 to 0.013 inch range. A 0.011 tip gives a narrower fan with less material per pass, useful around panel mouldings where heavy spray pools in corners. A 0.013 tip covers the wider stile faces faster.

Changing tips during the same door is practical on this unit. A clog can be cleared by rotating the reversible tip 180 degrees and pulling the trigger into a waste rag. That makes the smaller tip on detailed mouldings less of a delay when the run involves many repeat doors.

Viscosity sets the limit for the pump. Water-based trim enamels from ranges such as Dulux or Sherwin-Williams usually spray unthinned through a 0.011 tip on a handheld airless. Oil-based enamels can run thicker and may pull the motor down, showing as a spitting or pulsing fan. Fan tails, with heavy spray at the top and light spray at the bottom of the pattern, point to a worn tip or pressure below the coating’s atomisation threshold. A tip beyond its rated litres will keep atomising poorly even with careful hand speed.

Brushwork at hinge edges and latch edges

A sprayer cannot mask a hinge edge cleanly, so the door edges and hinge mortices need hand cutting before or after the spray pass. An angled cutting-in brush, often sold as a sash brush, holds a chisel edge that lays a straight line beside the hinge without overloading the barrel. A 38 millimetre angled brush suits a standard 44 millimetre door edge; load only the bottom third of the bristles and draw the long point along the arris.

The brush remains useful on a 40-door spray job because the edge has to register with the sprayed face. Spray builds the film on the broad face, while an overbuilt brushed edge can shift the sheen and leave a lip. Thin the brush coat slightly, or lay it so the brush marks run the length of the edge where they read like grain. On the latch edge, excess film can bind against the strike after rehanging, once the enamel has hardened.

Reveals before spray day

Where doors meet new plasterboard reveals, the wall side gets a mist coat and the plaster side needs proper sealing. Overspray from door and frame spraying settles as fine dry dust on surfaces within a couple of metres, including fresh plaster. If sealing waits until after that dust has landed, the sealer bonds to the dust layer instead of the plaster beneath.

Mist coat, Gardz, and plaster that is ready to take paint

New plaster and fresh skim behave badly under undiluted emulsion because the surface is dense, slightly alkaline, and non-absorbent once fully dry. A mist coat deals with adhesion. Dilute a standard matt emulsion with clean water, roughly 20 to 30 percent water by volume, and apply it thin so it soaks in and gives later full-strength coats a key. Skipping that coat leaves the top coat as a skin on the surface, and tape pulled from a reveal later can peel it away in sheets.

Zinsser Gardz is a thin, penetrating sealer for friable or dusty surfaces, curing to a hard film after it soaks in. Sound new plaster usually wants a mist coat, with Gardz unnecessary. Old distemper, powdery bound plaster, and torn paper face on plasterboard are different substrates; they can reject a water-based mist coat unless Gardz locks them down first. Applied by brush or roller, Gardz dries clear to slightly amber and accepts most water-based and oil-based finishes once fully hard.

Plaster has to dry through its full thickness before either treatment. A 13 millimetre skim over board can take a week in poor drying conditions. A mist coat over plaster that is still holding moisture traps that moisture and blows later. Gardz over damp plaster behaves the same way. Reveals around a freshly hung door often dry more slowly than open wall faces because they sit in a draught-free rebate.

Lining paper where frame cracks keep returning

Cracks from the top corners of a door frame usually come from movement: door slamming, seasonal frame movement, and the stress concentrated at the opening. Filler alone tends to reopen along the same line within a season. Lining paper bridges the crack with a continuous surface that can carry minor movement.

Cross-lining, where the lining paper is hung horizontally, keeps the paper joints away from the vertical wall joints and the crack lines below. A 1200 grade lining paper is heavy enough for hairline and moderate cracks. Rougher surfaces call for 1400 or 2000 grade.

Paste-the-wall paper changes the work around door surrounds. Traditional lining paper is pasted, folded, and left to soak, expanding before it is hung and risking bubbles over a repaired crack. Paste-the-wall papers use a substrate that stays dimensionally stable when wet, so the paste goes on the wall and the dry paper goes straight into position. Around a frame, the sheet can be worked tight into the corner and trimmed against the architrave without waiting for a soaked edge to settle.

Roll the paper out from a wall-mounted plumb line, brush it into the frame corners, and cut against the architrave with a sharp blade backed by a broad knife. The filled crack must be sound and fully dry before papering, because paste moisture can soften green filler and move the paper with it. A flexible decorator’s caulk in the frame-to-plaster junction absorbs the movement that rigid filler would pass into the paper.

Cob walls, breathable paint, and the frame margin

Cob walls and older solid walls built from earth or lime move moisture through the wall fabric by design. Modern acrylic or vinyl emulsion forms a film that blocks that moisture path. Trapped water then looks for a weak point, often blistering paint or decaying timber embedded in the wall, including door lintels and frame fixings. Breathable paint, typically lime-based, mineral silicate, or a specialist clay paint, lets water vapour pass through so the wall can dry inward and outward.

The sprayed-door job meets that issue at the frame. A frame set into a cob wall depends on the surrounding earth staying at a stable moisture content. Seal the wall around it with a non-breathable coating and moisture concentrates at the frame margin, swelling the timber and disturbing the fit of the sprayed door. Silicate paints from ranges such as Keim or Beeck bond chemically to a mineral substrate and remain vapour-open, though they require a compatible mineral surface. Existing acrylic film prevents that bond and can leave the surface already committed.

On a period property, the sharpest sprayed finish may still depend on material hidden beside the frame. That margin is easy to miss because the paint film makes the frame look complete before the surrounding wall has finished exchanging moisture with the rebate.