OSRS Sailing Furnace Guide | Double Cannonballs Explained
© gamerblurb.com | Published on 11/27/2025 at 12:55 AM CST (USA)
The Ancient Furnace on Grimstone is one of the biggest Sailing updates yet, letting players smelt cannonballs twice as fast. It’s powerful, but not as simple as it sounds.
How to Reach the Ancient Furnace
You’ll need level 87 Sailing to moor at Grimstone. Once you’ve docked there for the first time, the nearby fairy ring code DLP becomes usable for quick travel. There’s no bank on the island, so you’ll rely on teleports or the fairy ring for banking trips.
How the Furnace Works
The Ancient Furnace smelts cannonballs at double speed, meaning you get twice the production rate per smelting cycle. However, it doesn’t double the number of cannonballs produced. Each steel bar still gives 4 balls, just at a faster rate.
It also works with the ancient mould found nearby. Using both together stacks their effects, letting you smelt twice as fast while still producing 4 per bar. The process is efficient, but travel time cuts into the total benefit.
Efficiency Breakdown
Players report around 230k Smithing XP per hour and roughly 9k cannonballs per hour with optimal banking and teleports. The fairy ring and Greater Focus teleport can reduce downtime, though most prefer fast-bank furnaces like Edgeville, Prifddinas, or Shilo for convenience.
The lack of a bank and the need for teleport loops make this method less AFK, and as of now you notably cannot smelt burbs. It’s best for players who already have the requirements and teleport setup to minimize travel time.
How to Bank Faster
Use a Farming Cape teleport to your POH, then the fairy ring back to Grimstone.
The Sailors’ Amulet offers a bank teleport close enough for quick runs.
A Crafting Cape or Seers’ Village teleport also works as a mid-tier option.
Using these routes, you can make Grimstone more practical, but it’s still a niche method compared to standard furnaces.
Final Blurb
The Ancient Furnace is a cool high-level unlock, but not a must-have. It’s fast in theory but limited by the lack of a nearby bank. If you want pure XP or efficiency, Shilo and Prif remain the best. Still, the double-speed smelting looks great for prestige and flexing that 87 Sailing milestone.
FAQ
Where is the Ancient Furnace in OSRS
It’s inside Grimstone Dungeon, unlocked after mooring on Grimstone with 87 Sailing.
Does it double cannonball output
No, it doubles smelting speed only. Each steel bar still gives 4 cannonballs.
Is there a bank nearby
No, but the fairy ring code DLP and teleport setups make banking manageable.
What XP and rates can you expect
Roughly 230k XP and 9k cannonballs per hour with efficient teleports.
Is it better than Prifddinas or Shilo
Not really. It’s faster per smelt but slower overall due to travel time.
© 2025 GamerBlurb. Linking is welcome with credit to GamerBlurb.com. Copying or reproduction without permission is prohibited.
More Old School RuneScape
