I'm confused. Cut out some slumping forms and took out my rigidizer for my first attempt. Instructions give every choice for application so I chose to paint it on the fiber shapes I had cut out.
Not sure how much to use, didn't saturate but coated multiple times. What is the proper way to dry it?
I put it in the kiln for 1 1/2 hours at 300 but it is still spongy( or actually more so)
what is this girl to do?
Thank you in advance
Jeri
I am used to thinking in terms of using fiber frax with rigidizer. If it is dry & crusty on the surface, then you didn't get enough to stiffen the material below the surface. This may or may not be strong enough for your slump.
If I want the whole piece saturated all the way through, I soak it in the rigidizer.
I use collodial silica, and it takes more than overnight on an inch-thick pad of fiber frax. I have played a propane torch on it to help things along.
It's generally a couple or 3 days before it is all dry.
If I'm making a mold for slumping, I saturate totally with the rigidizer, let the excess run off, then air dry. Here in humid North Carolina it takes about a week to air dry thoroughly; if you put it in a kiln to speed up the process (I don't), don't heat above around 300F. Also, you'll need to prefire and use kiln wash on the mold when it's dry. These molds will last a long time.
I've used moist pack a few times and I let it dry about 4 days. I'm about to soak some 1/2" & 1" blanket with rigidizer so I'm glad you asked this question. It's always good to get confirmation about what you are about to do. I figured I'd use an old cookie sheet I got from my wife and just soak it til it's good and soggy. As with moist pack I'm thinking it'd be good to squeaze out the excess between newspaper a couple of times, (pouring the stuff back into the bottle). Or maybe even a separate bottle if anyone thinks that would be better.
I saturate, press out as much as possible as I form the fiber to the object, & stick the object w/fiber in the kiln (lid propped somewhat) and heat at about 220 tops until it's stiff enough to remove the object. Then I finish drying it. I don't kilnwash, & have re-used many times.
For what it's worth...!
Barbara
How is it you dry it but you don't want to go higher than 300. If it is rigidizer, which is nothing more than colloidal silica, don't you want to burn it out or won't it burn out when you slump the first time?
I still haven't rigidized my fiberboard (for use as a continuous shelf in my bathtub kiln when I need that continuous surface). Same type of thing, saturate 1 side, let dry, saturate other? Or what?
Cheryl wrote:I still haven't rigidized my fiberboard (for use as a continuous shelf in my bathtub kiln when I need that continuous surface). Same type of thing, saturate 1 side, let dry, saturate other? Or what?
yes. don't forget the sides too. i did two coats on the top and bottom just to make sure. the second coat didn't sink in very much.
I have sprayed fibre shapes first then kiln dried and I have pre soaked the fibre and then wrung out the excess. For my money the second approach has worked best .
I then apply kiln wash and kiln dry again before I put the glass on top to fire. My moulds have lasted months with proper care.
I have also done this when I was desperate and out of rigidizer.
I have soaked the fibre in kiln wash and then applied it to my parent object to make a mould. I then leave it to dry in the sun ...remove parent object and then kiln fire it.
This produces a soft paper mache type mould that is re usable if looked after...kiln wash applied for every firing. this has helped me out of a few tricky spots when suppliers say its in the post and it isnt.
I'm a little confused by the replies, and I've made fibre molds, so those who are doing their first are almost certainly going to be confused.
Regardless of whether you coat the surface or soak the fibre, you need to dry it. You don't want to dry it too hot because the rigidizer is flammable until the liquid has evaporated. After drying, I sand the surface if required and then fire the form to 1350F. This makes a permanent hardened form. From the replies, I'm not sure if everyone does this or not.
There is no "burning out" of rigidizer as this is not like the binder that is in the fiber paper and board (an organic compound that burns off). The rigidizer is a refractory substance (colloidal silica) that hardens when fired.
After the form is fired (sort of like bisque firing your clay) and cooled, I always coat the form with kiln wash. I have had major sticking problems with rigidized forms where the kiln wash had broken down - way more than with clay. And that ruins your form cause chunks come away with your glass. I guess if you slump low enough it won't stick, just as it won't stick to stainless if the temperature is low enough. But it's not the same as firing on untreated fibre which won't really stick to the glass (a few particles come off the board but don't really stick to the glass). You'll take big chunks out of your rigidized form if you don't kiln wash it, or the kiln wash has broken down and you slump higher (I am usually at 1275 or so).
These forms are good in that they don't absorb heat or cause thermal shock but they are a little delicate.
Thanks Lynn. That explains things a little better for me. I thought the binder that burns off when I rigidize my fiberboard shelves was in the collodial silica not in the board itself. Still makes sense to run it up to 1350 to harden it however.
I like the rough textured look when I am using float glass. It gives the
glass a textured look and adds some needed dimension. I smooth
the fiber to the texture I want after putting on the rigidizer and again
after the kiln wash has dried.
I'm confused. Cut out some slumping forms and took out my rigidizer for my first attempt. Instructions give every choice for application so I chose to paint it on the fiber shapes I had cut out. 