Cushions for the rocket bench

Hello everyone,

We have the typical j-tube rocket mass heater, with a barrel for a bell and a bench. It works really well and we heat our home exclusively with it

So, the reason I'm writing!: the bench is really comfortable during the warmer seasons and during the day, when the fire died out early the previous evening. But it's too hot to sit on when the fire is lit in the evening, when we really want to sit on it. So, quite a number of years ago, we salvaged couch cushions to put some distance between us and the bench. And then we realized that we were melting the foam in the cushions. So I folded up a couple of wool blankets to put a bit more distance between the foam and the rocket. We still think the foam gets a bit too hot, but it doesn't smell like it's melting.

Anyway, the couch cushions are ugly and don't match, so they were always going to be temporary and I got a cotton canvas tissue to recover them initially. That they were melting eliminated the recovering them idea.

So I think I really need to come up with my own cushion material idea. Sometimes I think maybe wool, but that seems like too much work and I'd have to find wool. So I looked at the wood wool insulation and wonder about that, because I think it had to be fireproofed somehow to be on the market. Or rock wool? But would that be comfortable to sit on.

And this has been a thought for a few years, at least, already. So I've come to you all to see what you think, because I really don't think keeping the foam cushions on the rocket is a healthy thing to be doing.

What heat resistant material would be the most comfy, while not being too hard to fill a cushion cover?

Hi Tiffaney,

I looked into the builders guide, as I remembered this topic was covered there as well, but it seems you've pretty much covered their suggestions.

Not sure of what materials you made your bench out of but could you add more mass to the top of your bench? Something that would take longer to heat up in the short term but also prolong the heat storage capacity for the long term.
Or, instead of adding more mass, perhaps go the opposite route and incorporate some insulation like rock wool, perlite etc right into the mix?
Perhaps this would then make it too high to sit on unless you excavated down a bit before adding the mass/insulation?

if I were you I'd go to a place that sells used clothing and blankets and see if you can find old wool blankets. My old Salvation Army had them. Lots of people have those old sledding blankets in their basements (we used to keep one in our car a million years ago). They don't sell well because people don't like to buy used bedding, but I got a few old full wool blankets at Salvie's.
If you can't find wool blankets, get wool clothing, maybe even felt it down if you need to. either way, use wool to stuff cushions (use the melt test to check fiber). I'd make cushions out of canvas (I'm envisioning old duffel bags, but also useful would be old canvas tents, canvas dropcloths, etc. Yes I'm incapable of moving away from things I buy at the army-navy or salvation army stores. I'm okay with that. )

This is very important - the fire risk is genuine! There's a good chance that if the old cushions were commercial, they have fire retardants in them, and those chemicals aren't nice.

I like Gerry's ideas, but would like to add some thoughts of my own in a different direction.

Think "cookie cooling rack"? But human sized? Wood also becomes a fire risk if it goes through cycles of high heat, so I'm thinking metal upcycled from old furniture.
A)
- our old sofa bed had a spring system inside its frame that the mattress laid on.
- my sister's day-bed had something similar but different
Both of these had a fairly flat profile, so could be adding about an inch of height between the bench and the wool blankets.
My idea is that you would make a couple of frames up that were the right size, and you would use them when the bench was hot, but remove them when it was cooler.

B) These may be harder to find, but some of our antique furniture had cone shaped coiled springs. These need a layered system to cover them so that there wasn't anything pokey. I don't know how to get some of those layers new and still get natural, but I'm pretty sure they're out there, possibly in your own environment.
This page will give you the idea I'm suggesting: https://thedesignersmarketplace.com/blogs/blogs/what-is-8-way-hand-tied-furniture-and-its-benefits?

Modern foams don't last, are expensive, and turn to 'dust' when they age. I would absolutely look for alternatives. For the top padding, if you can find someone with a backyard flock, feathers might be an option? They would need to be sewn into pockets if you want them to stay put.

Good luck with hunting up options. Please report on your progress and the outcome and how well things work. If you have a way to take before and after temperatures easily, other people who visit this site could benefit from your experimentation.

Thanks everyone for the replies. Gerry, height is a problem and excavating isn't an option. So we can't add more mass, except for a thin, finish layer. But perhaps we could put something insulating in the finish and that would help it? If we put marble powder in the finish layer, do you think that might provide a little bit of insulation?

We have old bed springs, just because we like the look of rust and they're easy structures for vines to climb on. But using them would give too much height. I like the idea of a human sized cookie cooling rack, Jay, but I don't think I'd be capable of making them out of metal and my husband always has way too much to do already.

I love used, also, and the wool blankets separating the foam couch cushions from the rocket mass are old army blankets. If I was careful about folding them, Teresa, do you think I could actually use them as cushion cover filling?