Rev. Mike

On 5/10/2017 at 2:50 PM, Frosty said:

I just Googled "Red Devil 3000* F" and didn't dig deep enough to find the analysis so I don't know if it's silicate bonded or not. If it's a high silica refractory welding flux will erode it rather quickly. The closest Meeco product to the description is a refractory cement not a lining material. It's for cementing bricks and patching small flaws not a material designed to line furnaces. 

Frosty The Lucky I have a question for you or Mikey98118 has either of you tried ebay link removed. This Alumina-Reactive, ceramic & glass supplies it is 99.5 percent aluminum oxide to see if it is good for a Flame face ?

On 11/1/2016 at 9:31 PM, Mikey98118 said:

Michael.

You place the pliable blanket where desired, push it into shape, and spritz the rigidizer into it. Then, you heat cure it in that same position; presto change-o, a stiff monolithic structure is created; either all at once, or area by area, as you see fit.

By silica based rigidizer, I mean fumed silica in water; better known as colloidal silica.

Sodium silicate (AKA water glass) melts at 1900 F and is expensive and heavy. Colloidal silica is use rated to 2300 F and doesn't melt below 3000 F; it is dirt cheap, costs very little to ship, and once the water is steamed off the blanket it adds almost no additional weight, because it flows over ceramic fibers in a very thin layer, do to its capillary action (wetting).

Why than would anyone use water glass? It makes a better binder for lite weight aggregates, like Perlite--not ceramic fiber blanket.

Where do I find Colloidal silica?

On 4/6/2017 at 1:02 PM, Mikey98118 said:

Yes, it is possible to over saturate the blanket, but all that happens then is that the excess mixture coats the inner side of your forge shell; no harm done. I think most people don't get what a small amount of glass is actually contained in colloidal silica contents; in a gallon jug of fumed silica doesn't way as much as the plastic container it comes in.Yet, glass is HEAVY; to  swim in water without settling to a container bottom the silica particles have to be very small.

The magic of colloidal silica ( fumed silica in water) comes from capillary action. The silica and water mixture isn't running down the ceramic wool fibers due to gravity, but due to whetting action; each time some of it reaches an intersection, where two or more fibers meet, some of it stays in the intersection because surface tension balances the capillary force running along each fiber, allowing a tiny glob of silica to build up until no more of the material can be supported in the joint, and all further silica and water flow on by it.

Next, you dry out the water content, and the silica powder is melted to glass by the burner  before it can drop off the fiber. The build up of material is so small it would take a micrometer to measure the increase in the diameter of individual fibers, except at the intersections where much more silica collected...fortunately.

I recommend that people making their own rgidizer add food coloring (for a temporary dye), as most suppliers do, so that they can see how far into the ceramic wool the colloidal silica has penetrated. After firing, the food coloring is burned away, and the wool appears white again. Do you need the dye to due the work? No, but it goes a long way toward quieting anxiety

I recommend doing some reading about capillary action, whetting, and surface tension by doing a little research on the web; just input "brazing" to get a reasonably quick education on the subject.

Do you recommend making your own rigidizer  if so your recipe