Keeping Molten Aluminium Off Launders, Ladles, Dies And Crucibles
Everything molten aluminium touches in a casthouse either dissolves into it, sticks to it or wears it away: launders and troughs grow dross, ladles and skimmers build up, thermocouple sheaths fail, permanent moulds and gravity dies need release. A boron nitride coating gives every one of those surfaces a film that aluminium will not wet, which is why BN has become the standard protective coating in casthouses worldwide. Pyroflux India makes water-based and solvent-based h-BN coatings and concentrates for this duty in Noida, alongside Alucoat launder coating and ladle coats, so the full casthouse routine can be sourced from one supplier with local stock. This page covers which product goes where, how to apply it and how often.
Product By Duty
| Surface | Problem | Product | How |
|---|---|---|---|
| Launders and troughs | Dross build-up, metal attack on refractory, relining downtime | Pyrolube BN 5026 diluted on site, or Alucoat launder coating | Brush or spray warm; two thin coats; touch up between casts |
| Ladles, skimmers, pouring tools | Aluminium and dross sticking, iron pickup | BN suspension at a thicker dilution, or ladle coat | Dip or brush; dry before first use |
| Permanent moulds, gravity and low-pressure dies | Release, surface finish, soldering | Pyrolube 25S for cold coating; BN suspension for warm coating | Spray thin; preheat improves adhesion |
| Crucibles and furnace hardware | Wetting, cracking at the melt line | BN suspension or paste; solid BN parts where a coating would wear through | Brush; cure gradually on the first heat |
| Thermocouple sheaths, probes | Attack by molten metal | BN aerosol or suspension | Two light coats; recoat each campaign |
| Filters, spouts, transition plates | Wetting and dross adhesion | BN suspension or paste | Brush or dip |
A Launder Coating Routine That Lasts
- Scrape the old dross and loose coating off; the new film needs a sound surface.
- Warm the launder (60–100 °C is enough) so the water-based coating dries evenly.
- Dilute the concentrate to the barrier ratio on the data sheet and brush or spray two thin coats, letting the first dry.
- Bring the launder up to temperature gradually on the first heat; thereafter touch up high-wear sections between casts instead of recoating everything.
- Keep a separate thinner dilution for release duties (moulds, dies) and the thicker one for barrier duties (launders, ladles).
What Pyroflux Supplies For The Casthouse
Pyrolube BN 5026
Water-based h-BN concentrate for launders, troughs, ladles and dies; dilute on site.
BN 5026 →Alucoat Launder Coating
Protective coating for launders and moulds in extrusion, DC and continuous casting plants.
High-temperature coatings →BN Ceramics
Crucibles, nozzles, break rings and plates in solid boron nitride where a coating is not enough.
Ceramics →Covering And Refining Fluxes, Grain Refiners
Fluxes for aluminium, brass and copper, and grain-refiner tubes for copper alloys, from the same works.
Fluxes →Refcote And Ladlecote For Launders And Ladles
| Refcote | Launder coating and paste for aluminium extrusion billet casting, DC and continuous casting |
|---|---|
| Ladlecote 100 | Zircon-based coating for ladles and launders |
| Toolcote | Refractory coating for ladles and tools |
| Pyrolube BN 5026 | Water-based boron nitride concentrate where nothing must wet the surface |
Refcote and Ladlecote are the refractory washes; the Pyrolube BN grades go on top where a non-wetting film is needed.
Common Questions
How often do I recoat a launder?
Touch up high-wear sections between casts and recoat fully when the refractory is exposed; most casthouses settle on a weekly full coat with daily touch-ups. A thicker barrier dilution lasts longer; a thin release dilution is for moulds.
Water-based or solvent-based for the casthouse?
Water-based for launders, ladles and anything that can be coated warm. Solvent-based (Pyrolube 25S) for moulds and dies coated cold and used straight away.
Does the coating affect metal quality?
No. Boron nitride is inert and not wetted by aluminium; it reduces dross and iron pickup rather than adding anything to the melt.
Can you match the imported casthouse coating I use?
Usually. Send the product name and the duty; Pyrolube BN 5026 and the suspension range were developed as functional equivalents to common imported grades, and a trial pack on your own launder settles it.
Tell Us The Process; We Will Recommend The Grade
Substrate, process temperature, atmosphere and how you prefer to apply it. That is everything we need to point you at the right product, send a sample, or quote.
- Phone
- +91 98181 87838
- sales@pyroflux.in
- Office
- G-5, Sector 63, Noida 201301, Uttar Pradesh, India
- Factory
- G-15, Sector 63, Noida 201301, Uttar Pradesh, India
- Hours
- Monday to Saturday, 9 am to 6 pm IST