Lightweight heat riser idea

Hey all,

One of my favorite wacky youtubers recently came out with a video where he attempted to use 3d printing to create a pulejet jet engine.  Naturally, most of the things he tried wound up bursting into flames in fairly short order. (Which is why he's one of my favorites. ;) ) In the end, however, (fast-forward to 12:09 in the video below) he came up with a means of using his design to form carbon-fiber and fireplace adhesive.  According to specs the arrangement should withstand temperatures of 1500C (aka 2700F).



Bringing the experiment back home to something relevant, people around here ask from time to time about portable rocket heaters in trailers, tiny homes, yurts, etc.  Usually the problem comes down to weight.  The technique above could be just the solution they've been waiting for!

Furthermore, the flexibility of carbon fiber could allow people to experiment with shapes, sizes, and geometries simply not possible with stacked fire bricks.

What do you think?  Would it work?
Does the technique give you any new ideas you'd want to try?

Hi K,    Carbon fiber and fire cement sounds promising but it would be interesting to hear if anyone has any experience using it to line a firebox and see how well it holds up over time.

I only had time to watch the part you recommended but had to laugh when he said (and printed it out on screen with spelling error) :  "One needs to learn a new word : Refratory".  

Hi K;   Pretty cool idea.  As Gerry suggested making flat sheets to line a batchbox or a J tube burn tunnel might be a great idea.
For risers , using Morgan super wool to make a 5 minute riser is the light weight, long term way to go.

I have seen a guy on another forum making a riser with woven ceramic fibre soaked in water glass and backed with ceramic fibre matting so you get a smooth bore 5 minute riser.

Scots John wrote:I have seen a guy on another forum making a riser with woven ceramic fibre soaked in water glass and backed with ceramic fibre matting so you get a smooth bore 5 minute riser.

Link, please?

Hi I am really sorry but I just spent 10 minutes searching but it was on one of the Facebook rocket stove threads and I can’t find it now however I am sure I have seen the same chap making post this forum.
I can remember pretty much how he did it though, he used a 6” cardboard tube and wound two thicknesses of woven ceramic fibre around it and then coated it in water glass. Then wrapped it in ceramic matting and put that is a 8’’ metal tube. Then burnt out the cardboard in place .
I will keep searching for the pictures.

At the beginning of Stove Chat 27, Matt Walker was asked whether he has used carbon fiber in any of his builds. Being a surfer, he was well acquainted with composites and gave quite a verbose response. Go check it out if you are interested.

Just to be clear, the guy I was talking about used ceramic woven cloth and not carbon cloth and he subsidised epoxy resin for a water glass product all supplied
by victas U.K.
The idea was to line a riser bore with a smooth finish and stop any partials escaping... all I can say was it looked very professional and tidy.