0812 Long-Run Neon: 8×12mm Body, 10W/m, Centring Guide

The tell is asymmetric. One edge of the lit line is crisp, the other has a soft halo that fades into the channel. Nothing has failed; the body is simply sitting 2 mm off centre in a 12 mm slot, and the diffuser is now closer to one side wall than the other.

An 8 × 12 mm profile is the narrow-body option that sits between the 6 mm line and the 12 mm standard. It is frequently specified into a 12 mm architectural reveal because that is the slot width the detail already uses. The fit is not automatic. A 2 mm clearance each side is enough to let the body drift, and drift is what the eye sees first.

1. Where an 8 mm body goes wrong in a 12 mm slot

All four are mechanical. None of them require a different LED or a different driver.

2. Optical behaviour: 8 mm face, 8.33 mm pitch

120 × SMD 2835 per metre means the emitter pitch is 8.33 mm, and the diffused face is 8 mm wide. The face is slightly narrower than the pitch, which is why this body reads as a line rather than a wash.

• Viewing distance. At 250 mm and beyond the line is continuous. At 150 mm, a faint ripple is still readable on white.
• Off-centre penalty. A 2 mm offset changes the effective diffusion distance on one side. On a 3000 K white run this shows as a warmer, softer edge on one side of the line — not a colour shift in the LEDs.
• Wall wash. This is not a wall-washing profile. It delineates an edge. The 8 mm face puts too little flux sideways to graze a surface.

Colour range is 1800 / 2700 / 3000 / 4000 / 6000 K, CRI >90. For adjacent rolls on one elevation, keep the same bin lot; the narrow face hides less of a bin step than a 12 mm body.

3. Electrical: 10 W/m and the 5 m rule

• 10 W/m × 5 m = 50 W
• 50 W ÷ 24 V = 2.08 A per segment
• Driver with 20 % headroom = 60 W per 5 m segment

The electrical behaviour is identical to the 0612 at the same wattage. The difference is mechanical: the 8 × 12 section has about 17 % less surface area per metre than a 12 × 12 section, so it runs warmer in a closed slot. Mount it against a metal channel or vent the slot; do not assume that because it is 2 mm wider than the 0612 it can be buried without a heat path.

Cut only at the marked points: 50 mm intervals, six LEDs at 120 LEDs/m on 24 V.

Feed drop at the segment current (5 m out + 5 m back):

Use 0.75 mm² as the floor; step up to 1.00 mm² where the driver sits more than 5 m from the first tap.

4. The centring detail that fixes the halo

The body must be held on the centre line of the slot, not against one wall. Three ways to do it, in order of reliability:

1. A channel sized to the body. Use a channel that holds the 8 mm body by its sides, not a 12 mm generic reveal. The channel becomes the datum.

2. Centring clips. Clips that bear on both sides of the body at the same time. Standard one-sided clips will push the body to the opposite wall.

3. A spacer at the clip. Where a 12 mm channel is fixed by the architecture, a two-sided spacer at each clip position keeps the body on centre without changing the detail.

Clip spacing: 200 mm on straight runs, 100 mm through a bend, plus a clip at each tangent point. A clip over an emitter will create a bright band; offset by half a pitch (about 4 mm).

5. Bending and sealing

Bend in the plane the body was designed for, on a formed template. The 8 mm wall accepts a tighter radius than a 12 mm body but not the radius a 5 mm COB strip would take; confirm the batch datasheet before forming a corner below the published minimum.

Every outdoor cut end gets a moulded cap and a potted joint. On a 12 mm reveal the cap is smaller than the slot, so water can sit around it — keep the joint off the horizontal plane and, where possible, at the high end of the run.

6. Commissioning checks

7. Engineering FAQ

Can I use the same 12 mm channel and clips as the 1212?

You can use the channel if it is only a reveal, but not the clips. A one-sided clip sized for 12 mm will push an 8 mm body against the opposite wall. Use a centring clip or a spacer.

Is 8 mm brighter than 6 mm at the same 10 W/m?

It is the same flux over a wider face. Per metre of run the output is identical; the 8 mm face reads softer and slightly less sharp, and the line is wider. Choose it for a fuller line in a 12 mm detail, not for more light.

Does the 2 mm clearance need to be sealed?

No. The clearance is deliberate — it allows thermal expansion and keeps the body off the wall. Sealing the slot around the body traps heat and can push the surface temperature up. Seal the body ends, not the slot.

8. Specification summary

Fitting an 8 mm body into an existing 12 mm reveal? Send the slot detail and the viewing distance. We will return a centring clip schedule and a channel recommendation for this profile.