This is something i developed when creating my HNSA.
What You Need:
When the glue soaks into the filter and rock, it may release a small puff of white vapor and generate mild heat. This is normal — it's the glue curing rapidly through a chemical reaction (polymerisation).
Don't breathe it in directly and always work in a ventilated area. The vapor is harmless in small amounts but irritating to mucous membranes.
If it smokes visibly, you're doing it right — just let it flash off and proceed.
What You Need:
- Clean cigarette filters (unused, unflavoured)
- Cyanoacrylate (CA) glue (thin type works best — it wicks fast!)
- Marco rock or similar porous reef-safe rock
- Rock dust or crushed aragonite
- Shaping tool (e.g., blunt probe, forceps, or skewer)
- Gloves (you'll thank me)
- Dry Fit Your Rocks:
Line up the rocks the way you want them. Think LEGO but cooler. - Insert the Filter (Core):
Tuck the filter into a crevice or gap between the rocks. Push it in so it makes contact with both sides. This acts as a structural core. - Shape and Splay (Optional):
Use a blunt tool to force filter bits deeper into cracks, or to splay the filter ends into rock texture. This improves contact and surface area. - Add the Thin CA Glue:
Soak the filter with thin glue. Let it wick through — don’t smear it. The glue flows deep into the filter and surrounding rock pores, fusing them like rebar.
When the glue soaks into the filter and rock, it may release a small puff of white vapor and generate mild heat. This is normal — it's the glue curing rapidly through a chemical reaction (polymerisation).
Don't breathe it in directly and always work in a ventilated area. The vapor is harmless in small amounts but irritating to mucous membranes.
If it smokes visibly, you're doing it right — just let it flash off and proceed.
- Hold or Brace:
Hold the rocks in place for 30–60 seconds, or use gravity/bracing. Once set, it's rock-solid. - Gap Infill (Mortar Mode):
Use trimmed filter bits to fill any seams or voids. Soak again with thin CA to lock everything in — this acts as structural mortar. - Dust Covering:
Immediately after applying glue, sprinkle dry rock dust or crushed aragonite over the bond. This masks the join visually and improves textural blending with surrounding rock. - Cure & Check:
After a few minutes it’ll set like stone. Let it cure fully (15–30 minutes) before stacking more.
- The glue penetrates the filter and the rock
- The filter acts as both core and mortar
- Break tests show rock fractures before the bond fails
- Only use dry rock
- Excellent for vertical joins, cantilevers, floating shelves
- Filters can be trimmed or layered for custom fits
- Dust makes your joins nearly invisible — pro-level finish
- Shaping tools give you control and precision for cleaner fits

