waterglass: experimented with it?

Hi All; I am wondering about using a mixture of waterglass ,fireclay,fiberglass & perlite, as a patch inside my cast core. Has anybody done this before? I am wondering what quanity of waterglass i would mix with my dry ingrediants ?How much plain water? I purchased a 16 oz bottle of 40% solution and i'm not sure how much to add. My inclination is to dump the whole bottle in but.....thought i would see if anybody else has tried this first before i blunder ahead. Thanks, Tom

Thomas Rubino : By now I am sure that you have looked at the 'Similar Threads' listing at the bottom of the page, it looks like a poor crop THIS Time, Because when I went to the
Permies Toolbox at the Top of this Thread and clickedon> Search I was allowed to type in Waterglass into the Google search engine and do a search just within our own ''pCloud''
and retrieved 10 previous 'Waterglass' Threads !

Our ''pClould'' may not be as wonderful as apples 'iCloud' , but it works !

For other fellow members there is a good article on Waterglass at Wikipedia !that may be helpful, Potassium silicate has been described to me as a much less corrosive and
safer 'Waterglass' For th' craftBig AL !

Tom, I don't know ratios when using straight solution, but water glass is the hardening agent in Furnace Cement, which is why I use it in my casting mix.

Matt Walker nd the 'pCloud' : I had to go to look at my last plastic tub of 'Furnace Cement' and you are right, damn if I know how i missed it before.
Good to know, thank you for sharing ! Big AL !

HI guys; Allan,matt thanks for the responses. I guess that i will try the mix it up and see what happens method of experimentation. I will try to measure my ingredients as I go and report back my great success or my dismal failure. New deep cold front moving in , mite be waiting a week or so before making any changes. Tom

As a chemist, I have experimented a little with sodium silicate (waterglass), and all I would add to this conversation is that it is more of a surface treatment than an additive to bulk mixtures. It is the old-fashioned way of preserving eggs, because it puts a thin glass casing on the egg when it is painted on.

Big Al, it may be that in 'Furnace Cement' they use it as an extra source of silicate to balance out the proportions of the resulting calcium alumino-silicate (what normal people call "cement"), but I wouldn't expect it to migrate to the surface of the material and make a slick glassy coating. For that, you would have to cast and dry your piece of clay/pottery/adobe/cob/mud/concrete/etc, and then paint it on and heat it to get it to glassify.

John; Interesting thought about (painting) the waterglass on ! I will try that also. Thank you, Tom

ok; Success, i mixed a dry batch of fireclay, perlite and fiberglass the same mixture that i originally used. I then scooped that mixture into a smaller container (apx. 2 qt,s) added apx 1/4 bottle of waterglass(16 oz bottle) then added tap water as needed. I have done this twice now, on either side of my feed tube. Patched areas are holding up very well, bonded with original core with no problems and seems to have a tougher finish than my original core (possibly from the higher concentration of sodium silicate in my new mixture) I have not taken time yet to experiment with (painting ) waterglass on my internal core yet and will report back when i have tried,but I think that it may be worthwhile. With the current cold front nite temps are running around 0-10 degrees, stand alone greenhouse is staying 38-42 YES !!! and that is with the fire going out around 11 at nite! Daytime temps are running 10-18 degrees and we can easily keep greenhouse at 70! Yes, in these temps we keep the stove lit from morning (6-10) till later evening but hey, its a greenhouse what do you expect! My old wood gobbler (victorian coal & wood burner)would have required getting up in the wee hours to add more wood!!! LOVE my rocket stove !!!

Fellow Members, 'pCloud'-ians, and Rocketeers : In the movie 'Glory' and other Civil war Epics they show the soldiers bitting the bullet of the Paper cartridge bullets and tearing
the cartridge, pouring in the measured amount of powder from the cartridge, wading up the paper and then using a wooden rod to ' Drive the charge home' ( not having enough
teeth to Bite the bullet and tear the cartridge was a disqualification from serving ! -or a note from a dentist that you had bad/soft teeth! )

The Point here is the original paper cartridge was glued together with waterglass ! A major use of waterglass today is in the manufacture of Cardboard boxes, So go out there
and scrounge some waterglass from a box maker ! And experiment, and tell us how you did !

Thomas Rubino : There is a type of Automobile muffler repair kit that goes under the name Muffler Bandage, it makes good if brittle repair that will last a fairly long time if not
hit or subject to twisting forces ! It would seem if the sodium silicate can become part of the mix that its durability should improve ! Big AL !

Matt Walker wrote:Tom, I don't know ratios when using straight solution, but water glass is the hardening agent in Furnace Cement, which is why I use it in my casting mix.

I am about to start experimenting with making my own firebricks and casting some RMH parts.
Can your share your recipe?

I think Matt shared it before as 14 parts clay, 14 parts perlite, and 1 part refractory cement. But correct me if I'm wrong, because I'm not positive, but I think that's what Matt shared as a recipie before

John McDoodle wrote:I think Matt shared it before as 14 parts clay, 14 parts perlite, and 1 part refractory cement. But correct me if I'm wrong, because I'm not positive, but I think that's what Matt shared as a recipie before

That sounds pretty clay heavy. I'm going to use perlite, fireclay(with grog) lime instead of cement and a little waterglass to harden the mix.
I just need to work out the percentages.

Scott; It's been a while since I did a cast core, I now prefer the durability of heavy firebrick. As I recall I used one #50 bag of fireclay to one 4 cubic foot sack of perlite. Matt said to add all the refractory you could afford to the mix. I did not know where to get 50# sacks of refractory at the time so I bought a 1 gal tub on ebay for way to much $ and added 1/2 to the core mix and 1/2 to the riser mix... not nearly enough! Like adding a scoop of sand to a beach. Adding a bottle or 2 of waterglass to your mix should help you quite a bit. Weak or problem areas on a cast core are the feed tube and burn tunnel roof, after your initial firing i would "paint" the waterglass on the entire feed tube (bottom and sides) and as much of the burn tunnel roof as you can reach. This should help with erosion of the walls from wood feeding in. Building and using a metal "peter channel" in your feed tube will also help with protecting the burn tunnel roof from eroding. When you "pour " your cast mix save extra in a 5 gal pail to have on hand for patching any eroding spots. When it comes to casting risers , if you follow matts directions you will not need any refractory or waterglass in the mix , I used the first one I cast on 3 different cores by carefully lifting the 16 gal barrel off the old core and on to a new one ! After the third use the barrel failed, not the casting (it did crack where the barrel failed). I still build and use cast clay/perlite risers today. As far as new stuff, I am interested in the vacuum formed lite weight ceramic fiber tubes located in Pennsylvania, I am waiting to hear reports on them.

someone had also mentioned that potassium silicate may be less corrosive, better for clay, than sodium silicate... but i wouldnt know personally

I am also considering using large tile (20in x 20in) or (24in x 12in) to build the inner form. Perhaps this would solve the wear problem?
I definitely want to find something that will last pretty well for at least a few years.

Thanks for all the info..

Ceramic tile are not designed to stand thermal shock, and are likely to crack soon. They might or might not hold together in the cracked state, or the cracking might get so severe that they disintegrate. Testing before actually using on a permanent system would be a good idea.

Firebrick splits (1 1/4" thick) facing over the castable for areas subject to abrasion may be a good compromise between strength and insulation.

Heavy durable firebricks can be made with waterglass and playsand. It can be co2 cured initially and then heat cured to completion.co2 can be from the exhaust of your engine or from a fire extinguisher or from throwing sodium bicarbonate into vinegar or fermenting sugar into alcohol or spend a very long time breathing on it. Whatever.

Waterglass is not caustic. How could we eat eggs from a jar of the stuff if it were?

It is a high temp bonding agent of excellent strength, adhesion and durability.

It can be made cheaply using silica gel and sodium hydroxide. Sodium hydroxide IS VERY CAUSTIC. Silica gel is made from sodium silicate and can be converted back to a very pure form by reaction with sodium hydroxide. Silica gell is free in dessicant drier packs you find in all kinds of things. Or buy a cheap bag of silica gel kitty litter. Sodium hydroxide is drain cleaner or what you call lye, we just call it caustic. It must be the 99% pure with no additives type; usually a pearl consistency.

Once you have your waterglass you can mix it with playsand and mould it into your desired shape; case harden it with co2 then, slowly at first, heat fire it in stages up to full temp. Be patient, it's worth it.

You can experiment with pearlite and or vermiculite admixtures but the above is a domestic version of how commercial hot face firebricks are made.

Do a little research for the weights, measures and procedures. You will enjoy that more and get a broader range of opinions than if I just tell you. The utube videos convey more than words. People use this method to cast furnaces. It's industrial, cheap and easy to DIY.

Here is a link to start you off. It's straightforward and direct and he has a similar one for the waterglass.