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This looks like it could have potential


It is just this porcelain slip straight from the bottle


Whipped up with a kitchen blender with a few drops of Drexel.

However, it did not seem to want to foam up with just a few drops of Drexel. Adding a few more did not help. I thought the slip was a little too soupy so I thought maybe I could dry it up by adding some cellulose so put some sheets of toilet paper right into the bowl as it was being blended. A foamed paper clay would potentially be even more lightweight than just foamed porcelain clay and would add some strength to the mixture.

As I added a few sheets, the clay began to foam up. A few more and it started foaming up and thickening even more.

I would say the clay slip probably "expanded" about 3X from its original liquid state.

If it will dry and hold together well enough to get into the kiln it might be fired to make a foamed ceramic.

Anyway, so far the foam seems pretty stable.

The foamed paper clay has held together so far, fully dried in the oven.

The foamed lime with the water glass not so much.

The foamed porcelain cement that has been continuing to cure on the kitchen counter over the past several days is looking better and better. I may try subjecting it to another torch test and see if it comes through any better.

What I mainly wanted to report though, is the foamed paper clay has held together well enough to transfer to the kiln.

At this point it seems like it may be a little TOO light and fragile. I'm not handling it particularly gently, but I haven't poked at it or tried smashing it with a hammer. There are a few surface cracks, but overall, if it holds together in the kiln, it might just turn out to be useful.

So far, with all my experimenting, the paper clay (actually hemp hurd fiber clay) is the only thing that has resulted in a useable end product I could actually install in an engine.

In this case I just threw some toilet paper into the blender with the porcelain slip, but the Hemp has these long wiry fibers that seem to result in a stronger harder porcelain when fired, though it appears to burn away cleanly in the kiln. The paper fiber seems to weaken the fired porcelain.


https://youtu.be/F7OKe4w1dUk

I'm about to put this in the microwave kiln.

But first, I thought I would weigh it.

This rather large blob of foamed paper clay is just 45 grams. And that is before burning out the cellulose fibers in the kiln.

This is rather disappointing.

The foamed paper clay came out of the kiln looking the same as it went in.

However, though seeming kind of "crunchy" it was much too fragile to be useful for anything.


On a positive note, the weight is fabulous, leaving room for making it stronger in some way, perhaps


By volume, that is about 3X the size of the 31 grams displacer, but only weighs 1 gram. So,... As an actual displacer it would weigh just about 1/3 of a gram.

Considering it is probably 90% air, it is actually stronger than a lot of the other things I've tried.

I decided to mix up a more clay dense batch of foamed fiber clay. Since I only incorporated a relatively small amount of foam, again, I had a lot left over.

Not knowing what to do with it I had another idea.

From what I've been reading, almost any non-flammable material can be turned into a refractory by using water glass as a "glue" to hold it together, Perlite, vermiculite, limestone etc.

What about just the waterglass by itself?

So I have all this left over Drexel foam, so I just poured in some water glass straight out of the bottle and kept blending it with the mixer.

The foam seemed to just get kind of thicker and dense or gummy but otherwise just continued to look like thick shaving cream

As far as proportions I really have no idea, but probably there was maybe 1/4 cup water, maybe 5 drops of Drexel and 1/4 cup water glass. That's just an estimate based on how much water there was to start with and how much foam was left over, after getting finished with making the paper clay foam.

I had used a lot of Drexel, relatively speaking. 5 drops probably doesn't sound like a lot but I usually only use 2 or 3 or 4 for double the amount of foam.

This time however, with only the usual few drops, after making the foam I noticed I could hear bubbles popping.

I thought that was not good, so I kept adding drops of Drexel a few drops at a time until I could no longer hear bubbles popping when I stopped the mixer.

I don't know what exactly will be the result. Will this stuff set up hard like that foamed insulation in a can, or will it just stay wet foam, eventually go flat or what?

I don't know but I guess we will find out.

I'm wondering if I should put it straight into the oven to help cure it.

That waterglass foam did eventually set, but the end result is about the same as if it were actual shaving cream that sat around to dry out. A wispy, almost nothing that can't be touched without it practically disappearing.

However, I've have had this foamed Portland cement sitting on the kitchen counter for, how long has it been?

Once in a while when I think of it I'll wet it down, like should be done with any cement until it fully cures, which is actually never.

Anyway, the longer it cures, the better it gets.

It has set so well now that I was able to pick up one of the larger pieces and carve it down into a disk with just a utility knife

Then sand it down flat on both sides with some very coarse sandpaper, then finish sand it with some finer grit sandpaper

I rinsed it off under the faucet to wash off the dust. It is just 33 grams soaking wet.


I still have doubts about it holding up for long under extremely high heat conditions as is, but maybe soaked in sodium silicate or something.

I had originally thought that aircrete was just not a suitable material for making a high temperature displacer, but with a lot of patience to allow it to cure, eventually, it might just work.

Just a moment ago, I thought giving it a good soak in some hot water might speed up the curing.

In the process I found that even soaking wet, the thing can still float on water.


https://youtu.be/lltgAyrEIuU

Earlier: viewtopic.php?f=1&t=5415&start=135#p19120

I had mentioned I needed silicon powder to try a mineral foam formula I found in a patent.

I went over the patent, mixed all the materials in the proportions specified, then added the silicon powder "activator' that is supposed to cause the mixture to foam up like elephant toothpaste then turn into a hard mineral foam almost instantly (according to the patent)

Unfortunately, there was no reaction whatsoever. Nothing.

The "silicon" powder I received does not look at all like the silicon powder pictured in the eBay listing.

Infact, the very light gray lumpy powder looks identical to another listing by the same supplier for powdered tungsten (which is actually more expensive).

I suspect there was a mixup in the order.

I thought a mineral foam with, whatever it is, possibly tungsten, might still be interesting, so I made up some more Drexel foam and blended it into the mixture.

I also thought it is a rather unusually cold day, maybe the reaction requires a higher temperature, so I put the sample in the oven on warm, partly to see if it would "rise' but also so maybe it would set fast.

A similar porcelain clay mixture I tried with Drexel foam took days to dry, but did not hold its shape and collapsed before it fully set.

It has not collapsed so far.


If anything, I think it may have puffed up a little, like a muffin.

It is already pretty well dry. I think I'll turn up the heat a little.

Anyway, I had high hopes for that mineral foam. I actually hope that maybe the powder I received is not actual silicon but tungsten and that is the reason for the lack of any reaction.

If it is tungsten, that could be fortuitous in itself.

Looking into, is there any such thing as foamed tungsten,...

Foamed tungsten is commonly used to filter molten metals. Could there be anything better for making a high temperature displacer?

Well I've got 99 grams of tungsten powder left over to experiment with. Maybe. If it is tungsten, I think I'll keep it rather than try to send it back or exchange it for silicon powder.

A tungsten muffin. LOL

Well, upon firing, the "muffin", though looking great straight out of the kiln, crumbled when handled.

The supplier of the silicon assures me it is not tungsten, that he would not make that mistake as tungsten is more expensive. Looking at other sites/companies selling silicon the stuff does resemble very high purity silicon.

I tried, however, putting some in a very strong sodium hydroxide solution and it did nothing. No reaction. It is supposed to release hydrogen gas. Other online references confirm this.

To make sure the drain cleaner was not to blame, I dropped in a small bit of aluminium foil, which should have a similar reaction. That "boiled" like crazy and the reaction went on and on and on and on until the aluminium was totally dissolved.

The patent does mention something about silicon normally requiring some kind of acid wash to remove oxidation but his formula supposedly does not require that.

The patent also mentions he used impure silicon.

The silicon I got is an extremely fine powder. Perhaps it is easily oxidized. Don't know.

But, if silicon is less than 100% reliable at making hydrogen bubbles, why not use aluminium if that is the only purpose of the silicon; to make hydrogen bubbles?

Re-reading the patent, that would appear to be the case:

When mineral foam compositions are made according to the process set forth above, expansion of the mineral foam is believed to result from the reaction of silicon with the aqueous solution of alkali metal hydroxide, thereby generating hydrogen gas. Because this reaction is exothermic, the temperature of the expanding foam composition is significantly increased, and water vapor or steam is driven from the composition together with some escaping hydrogen gas.

While it is well known that hydrogen can be highly explosive when combined with oxygen or air, the wet gas liberated from the compositions produced according to the formulations and process disclosed herein is not believed to present an explosion hazard, and in fact burns with a low flame when ignited.

The aqueous sodium silicate, as used in the disclosed process, aids in retaining the gas bubbles generated within the composition without overly limiting expansion. Then, once expansion is complete, the bonding properties of the sodium silicate are believed to contribute substantially in achieving a preliminary "set" that will, for example, permit forms to be stripped away from the expanded material.

Where the mineral foam compositions have, either through overexpansion or through excessive application, exceeded the boundaries of the forms or containers into which they are poured, excess material can be easily trimmed away by means of a common hand saw or the like.

Luckily, I think, hydrogen dissipates rapidly and is virtually impossible to contain, so I don't think exploding displacers would be a problem.

I think, though, I might give the general methodology another go, but substituting aluminium powder in place of the silicon.

I've got a new (but old) plan.

I've had these expanded "Orbeez" in a sealed jar with water for maybe six months.


I had thought they could be used to make a lightweight fireproof displacer, but really they are just too big.

I thought, maybe for a very large displacer in a big engine... Someday. So they've been on the shelf, metaphorically and literally.

I've tried to find smaller versions of these things, but without success.

So now what I'm thinking is, they could be frozen, then crushed. They are like little rubber balls and can be sliced with a knife, but that's too tedious, so, I thought I'd just freeze them solid and put them in a blender or something to make crushed Orbeez ice.

I could then incorporate this "crushed ice" into ceramics clay while the chopped Orbeez substance is still good and hard and frozen. Then shape this Orbeez impregnated clay into the desired displacer size and shape.

It should then just be a matter of waiting. The clay will dry, the water will get drawn out of the Orbeez pieces leaving almost nothing behind. Voids in the clay.

Maybe it could work just using actual crushed ice but I think the Orbeez substance might maintain the shape longer so the clay has more of a chance to dry, though maybe it wouldn't make any difference.

Anyway, I'm putting some in the freezer to try it out.

An earlier experiment using Portland cement worked pretty good, but the cement didn't actually take the heat as well as it seemed at first, cracking and falling apart soon after making this video


https://youtu.be/ED3LQfK75z0

So far so good. Frozen Orbeez:


Now, the second part of the plan. Make clay using alcohol instead of water. Not sure if that can work but I'll soon find out.

The problem, or one of the problems I had previously trying this process with plaster of Paris anyway, was the plaster soaked up water from the Orbeez (actually not Orbeez, but the stuff they are made from, I think). The plaster didn't cure properly and came out very fragile like soft chalk. The "Orbeez" stuff just kind of disappeared without leaving much in the way of voids.

Anyway, If I wet some dry powdered clay with alcohol, then mix the alcohol clay with the frozen crushed Orbeez, (Or crushed ice, I'll try that as well) then the alcohol should evaporate first, the evaporation acting as a refrigerant keeping the ice cold so it doesn't melt until the clay is "dry", the alcohol having evaporated.

Theoretically this should leave a matrix of pure (strong) clay with voids, to make it lighter weight.

My impression is, so far, that the various additives, foaming agents, chemicals etc. used to make foamed ceramic adulterate the clay and weaken it to the point where the result is just crumbs, or a very weak and fragile unusable product.

I think if I can produce a pure clay matrix and get it fired it should be very light and very strong.

Well that didn't really work

Same problem.

Water and alcohol combine easily. Starting with relatively dry clay, the clay draws the water out of the Orbeez, even frozen. The results is a sloppy mess of wet lumpy clay.

Adding more dry clay powder doesn't help. It just keeps picking up more and more water.

I did learn, I think, clay is inherently quite heavy.

I tried measuring out 3 grams of clay powder, mixed it with alcohol wet, it didn't amount to hardly anything. I could hardly mix it in the bowl as it barely covered the bottom of the bowl.

Clay (dry powdered porcelain kaolin) and alcohol do work up into a normal clay putty that can be worked easily, just like normal clay. That might actually prove useful. But you need alot more than 3 grams

I did try something else while I was at it. Clay mixed with ordinary sawdust from under the sawhorse where I cut wood sometimes. Sifted through a screen to get out the bigger chunks.

The mixture became rather crumbly, so I added some dilute sodium silicate.

BTW, the waterglass I have was really concentrated

Using the hydrometer, I had to add almost a quart of water to just 1/4 cup of the "labrotory grade" waterglass to get it down to the dilution recommended in the patent.

What I have is apparently not the stuff sold by ceramic supply outlets that is already diluted with 60% or 70% water.

I had completely forgotten about the Drexel foamed sodium silicate "shaving cream"-like substance I put up on a high shelf.


Still as fragile as a newly fallen snowflake, but dry.

Taking it down to see what it was I had put up there on the shelf I discovered something interesting.

The paper bag under the foam drew a lot of liquid out of the foam, mostly that highly concentrated sodium silicate, I assume.

Looking at the underside of the paper bag. Though this looks like it is still soaking wet it is completely dry.


What is interesting is that the brown paper, now that it is dry, has hardened into a very rigid, yet somewhat pliable sheet. It seems to have the qualities of a very hard thin sheet of plastic.

I tried breaking off a piece but it only bent, then went back to its flat shape, almost like a thin sheet of spring steel. Or again, a very thin, rigid plastic.

I'm now curious what would remain if this water glass paper were subject to high temperatures. Would the paper completely burn away, or deprived of oxygen, encapsulated in glass, perhaps carbonize? Fuse together with the sodium silicate? Silicon carbide?

I may try and soak a piece of corrugated cardboard in waterglass and let it dry, depending on if the results look promising.

Anyway, out of curiosity, most likely I'll be subjecting this glass-paper to some heating in the kiln and direct flame tests sometime tomorrow... Outside.

I meant to say pyrolyze, rather than carbonize.

This seems to have happened with the spaghetti noodle displacer experiment.

Rather than burning away, the noodles seem to have transformed into carbon rods

Perhaps it might be possible to get a similar result using paper/cellulose fibers.