The spell
Superglass Make is a Lunar spell that turns every bucket of sand and alkali in your inventory into molten glass in one cast, with no furnace. It is faster than a furnace and makes more glass per bucket of sand, which is where the profit comes from.
| Detail | Value |
|---|---|
| Magic level | 77 |
| Spellbook and quest | Lunar, after Lunar Diplomacy |
| Runes per cast | 10 air, 6 fire, 2 astral |
| Experience | 78 Magic per cast, 10 Crafting per bucket of sand |
| Cast time | 3 ticks |
| Accepts | Bucket of sand with soda ash, seaweed, giant seaweed or swamp weed |
A smoke battlestaff covers both the air and fire runes, leaving only the two astral runes per cast to pay for. The OSRS magic spells list shows the same rune maths for every other spell.
Glass per cast
A furnace gives one molten glass per bucket of sand. Superglass Make gives more, on average:
| Inventory | Molten glass per sand | Notes |
|---|---|---|
| 13 sand + 13 seaweed or soda ash | About 1.3 | Cheapest inputs, smallest output |
| 18 sand + 3 giant seaweed | About 1.45, up to 1.6 | Standard setup; higher figure if you pick up spilled glass |
With 18 buckets of sand and 3 giant seaweed, the inventory fills up and some glass lands on the floor. Picking it up raises your average but costs time, and the fastest players ignore it. Plan on the lower figure unless you stop to collect it.
Where the bottleneck is
At about 600 casts an hour with 18 sand each, you use roughly 10,800 buckets of sand an hour. Buckets of sand are capped at 13,000 every four hours, so one limit lasts a little over an hour of attentive casting. Giant seaweed (limit 11,000) and astral runes (limit 25,000) last much longer. In practice, Superglass Make is something you do for an hour or so, then come back to after the limit resets.
That is why many players supply themselves. Giant seaweed grows in the underwater seaweed patches on Fossil Island, and Bert in Yanille gives 84 buckets of sand per day after The Hand in the Sand, delivered straight to your bank once you finish the elite Ardougne diary. Self-supplied inputs cost nothing at the Grand Exchange and are not affected by buy limits, which turns a modest margin into a good one.
Is it actually profitable?
Often, but not by a lot when you buy everything. The margin is the extra glass the spell creates, minus the astral runes. When molten glass is cheap, that gap shrinks; when it is in demand, the method looks much better. Molten glass sells well because Crafting trainers turn it into lantern lenses and unpowered orbs, and the Crafting money making list shows whether blowing the glass yourself adds anything. The Magic xp is a bonus: 78 per cast at 600 casts is a solid rate for a method that pays for itself.
Reading the numbers
Profit per cast is the value of the expected molten glass after Grand Exchange tax, minus the sand, seaweed or soda ash and the astral runes. Profit per hour multiplies that by a realistic number of casts. Very fast players reach far more than 600 casts an hour, and more casts means the sand limit runs out sooner, not more money per limit. For the level side, the Magic calculator counts casts to your target and the Magic training guide shows where Superglass Make fits next to other Lunar spells. The Lunar spells money making list compares it with Tan Leather and Plank Make. Check the molten glass price chart before buying a full sand limit.