Anyone else using old washing machine drums as log burner heat stores?

Ran one behind the stove in the shepherd's hut for two winters and honestly it's the best £0 investment I've ever made — neighbour was skipping it anyway.

The thermal mass is surprisingly decent once it's up to temperature, and the drum holes mean convection does its thing without you having to engineer anything clever. Mine's packed with old engineering bricks inside for extra mass, which took the heat retention from "alright" to "still warm at 6am without a midnight stoke."

Few things worth knowing though:

• Check the drum material — some older machines used zinc coatings that you absolutely do not want heating up indoors
• Stainless steel drums only, full stop (most post-2000 machines are fine)
• Positioning matters — too close and you're just blocking radiant heat, too far and you lose the convective loop

On the boat I use a completely different setup so can't directly compare, but the hut results have been genuinely impressive for something that was destined for landfill.

Anyone experimented with filling them with different materials? I've heard sand gets mentioned but the weight becomes ludicrous pretty quickly. Also curious whether anyone's tried two drums stacked — my gut says the geometry gets awkward but I'd love to be wrong about that.

@LochLover snap! Got one sat behind the Hobbit stove in my hut right now. Picked it up from Facebook Marketplace for a fiver.

Few things I'd add:

• Painting it matt black makes a noticeable difference to radiant heat output
• Mine took a full winter before the enamel inside fully burnt off — smells a bit until it does
• Stack a couple of house bricks inside to add more thermal mass

Only downside is they're a pain to position once the stove's in — learned that the hard way. Get it placed before you commission the flue.

Stainless steel drums are brilliant for this — high thermal mass and they don't rust when the condensation hits them overnight.

Worth noting for anyone tempted: position matters more than you'd think. Flat against the back wall loses you airflow. Prop it up on a couple of bricks so heat can circulate underneath and you'll notice the difference by morning. Learned that the hard way in my static van — had mine butted right up against the flue bracket, nearly cooked the wall cladding before I had a proper look at what was happening.

Also, the drum bearing housing on the back can get properly hot. If yours still has the plastic bits attached, strip them off first unless you fancy explaining that smell to your neighbours.

@LochLover mine's been doubling as a drying rack for wet socks — multitasking thermal mass, can't argue with that.

Serious note though: worth checking the drum spin bearing is removed before mounting near anything flammable, and make sure there's adequate clearance from the flue. Some of the older plastic-lined drums can off-gas nastily if they get too close to a Hobbit or similar. Stainless-only as @FormerMechanic says. Had a near-miss in the motorhome days with a "definitely metal" component that very much wasn't.

@ValleyWanderer the sock drying is genuinely underrated — mine does the same in the static caravan.

One thing worth mentioning that nobody's touched on yet: position matters a lot. I wasted the first season having mine too far back and it was basically just decorating. Got it within about 15–20cm of the flue pipe and the difference was night and day — charges up properly within the first hour of burning and keeps the van noticeably warmer well past midnight even on a low burn.

Also worth checking the bearings haven't seized if you're picking up an old drum — a seized drum can restrict airflow around it in a tight space. Not a massive deal but worth knowing before you commit to a layout.