Another lightweight fiber blanket furnace

Fire it fully, or just partly? Thanks, I've been trying to follow your method.

Jeff

 

Ok, I was thinking air drying would be enough, but I am happy to spend more time playing with fire.

Jeff

 

But you said you don't fire to red heat until the last layer is on... Did I misunderstand?

Jeff

 

Thanks Andy,

I've got about 4 hours to go before I can do anything at all with it today, so meanwhile I'm just trying to get it clear in my head what Bonz has been doing with his satanite, which he's had some great success with.

Jeff

 

Makes sense now, thanks.

Edit - turns out I actually do have a pic of coat 1, unfired:



Jeff

 

I was only planning on using the weed burner torch to fire the rims of lid and bore where they touch when the furnace is closed so I could fire the rest of it with my usual burner, but I got carried away and did the whole furnace.

Managed to get it all dried out and even glowing a little red. Haven't got a second coat on it yet, but it's ready. Did see a few cracks appear in the first coat, but it's not unexpected; that's why we do more than one coat!



Jeff

 

That's coming along nicely Jeff. For curing the rims, I've just left a gap between the two, plug the perimeter with a little wool, and then fired the whole thing....in your case through the Tuyere?

Best,
Kelly

 

I started out just trying to to dry the rims so they would be hard enough to prop the lid up a bit with a couple pieces of rebar (copying fishbonz' video), then I was going to use my normal burner in propane mode in through the tuyere to finish up. But it was working so well I just kept going. Only took about 8 minutes and I'd had the whole thing as red as the part of the lid that's under the torch in the pic above.

Jeff

 

Ouch...

Jeff

 

Funny you should say that, I found the same thing to be true!

I was just trying to dry out the mating surfaces where the lid meets the wall and maybe try to get them glowing a little so I could fire the rest of the Satanite with the usual burner, but I wound up just doing the whole furnace with the weed burner for the first couple coats. Got it to glow red pretty quick!



Last night I got what may be the final coat on, and fired up the furnace to temper the apparently unused #6 clay graphite crucible I got with my used kiln several months ago. I guess the other one I just got from Josh the blacksmith is a #6 too as it is pretty much the same size. Which is good, it means my 3 finger fireplace tongs will work really well as crucible tongs and pouring shank for both, and now I have one for bronze and one for aluminum that are small enough I can use my oil burner with them in the new furnace.

I think I'll actually try a melt using just propane. The crucible I tempered was red hot at its base and orange at its rim within 5 minutes using my Hot Shot running propane at just ~5psi with a hair dryer for a blower.


(Pic makes it look brighter/hotter in there than it actually was.)

If I can melt that #6 of aluminum as fast as I think I can using just so little propane, that might become my go to for smaller aluminum melts from now on, since I can avoid using the much noisier shop vac. The oil burner does also seem to be taking a toll on the plinth I cast for the big furnace, I think it just sits a little too close to the wall where the burner comes in.



I'll probably give it a coat of Satanite too, let that stuff take the brunt of the punishment rather than the dense castable.

We'll see. I definitely do plan to find how the Satanite holds up with the diesel drip actually turned on in the near future as well...

Jeff

 

I used up most of what I have already, but I've got more on the way for patching and repairs, or if I think I need to build it up a bit thicker or anything...

Jeff