Is 'regidizer' necessary ?

Hi theChas,

I have found that Kaowool will literally evaporate when directly exposed to an oxyacetylene torch, however Kaowool treated with Kaowool Rigidizer wont even go black.

I did an experiment with a piece of Kaowool I treated one half with Rigidizer and the other half without, and ran an oxyacetylene torch back and forth over the Kaowool. The untreated half disintegrated, the treated half was untouched.

If the wool doesn't come into direct contact with an extremely hot flame I'm sure it will be okay.

This is what I have found, others might have a different experience.

Regards Charles

theChas. wrote:

Why not put in 3000 or so degree 'cement'. It isn't like normal cement it doesn't hold water in formation. It drys and cures under heat that boils off the water both in drying and then when heated up and cured.

It is or feels so like almost solid rock but goes very high and lasts. It is hard and takes a flame without much ill. I use it as a top cover and have the super hot gas flow through a hole in it.

Martin

Mart> Hi theChas,

Maybe just a coat of the cement over the wool, although you'd still need to dry it slowly to avoid cracking.

If he's go the kaowool and the rigidiser, that should be enough for a forge, he shouldn't need to spend more money.

Regards Charles

Mart> Why not put in 3000 or so degree 'cement'. It isn't like normal cement

can be bad for you. The rigidizer helps keep the fibers cemented down so they don't get in your lungs. The main reason for using it is to make your forge a little more resistant to breaking, especially if you move it around at all.

Definitely bad to get the stuff in your lungs, the fibres need to be secured, even if its with a thixotic zirconium paint ;-)

Regards Charles

hi all, When talking about "rigidizer" I think it's important that everyone be on the same page. In the ceramic insulation industry, rigidizer refers to an agent used to solidify the fibers of blanket type insulation. This agent is usually "colodial silica"(CS). It is a watery suspension of silica particles and acts like a hi temp binder. It stabilizes the blanket so it keeps it shape at hi temp but on it's own it does NOT protect blanket from flame impingement. ITC 100 is a mixture of colodial silica and zirconium flour. This mix not only stabilizes the blanket but the zirconium is highly refractory and so protects the blanket. Satanite and similar products are hi temp refractory cements and will prevent the blanket from deteriorating but it was not designed to bond well to blanket insulation. It will work for a while but you will be frequently patching areas that spall off. The best solution i have ever seen comes from the expierences of glass blowers. Their tank furnaces run at 2400? 24-7! They use straight colodial silica as a prep coat on interior blanket surfaces followed by a mix of CS and zirconium flour. After force drying a 1/8" skim coat of Satanite, or such, is applied followed by a final coat of CS/zirc. This leaves a durable hard shell interior for your forge. The gains far outweigh the miniscule loss of insulation value. As long as you don't punch holes in the surfaces it will be maintainence free for months of long hard usage. If you are a "weekender" expect YEARS of service. If an area does spall off just patch it with with the same ingredients. Works for me.

Glen G.

Chilla wrote:

When I say rigidizer (the wrong spelling for this country) I'm referring to the proprietry Kaowool Rigidizer, I forget that people aren't used to these terms.

I think I will try the glass blower trick, sounds like it would work a treat.

Is the 2400 you quoted, farenheight or celcius?

Regards Charles

GSG wrote:

:-)) Just for a fun experiment, I took two inches of wool rolled into a tube and bound with wire mesh from the hardware store, formed caps for the ends out of same and painted it inside and out with Satanite. Figured it would be a "disposable" forge chamber. Been using it for a long time now and it's still servicable. You don't want to bang it around too much but weighing in at a couple of pounds max it has a lot to recommend it. Useless if you get flux in it, but if you just want to heat metal it works fine.

GA