Damascus Forge inside coating question
- Thread starter Ray
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Doug Lester
Well-Known Member
I've used Mizzou castable refractory over the ceramic fiber matting in my heat treating forge. It's just about impervious to flux.
Doug
Doug
I never had good luck putting Mizzou on a vertical surface and having it stick like covering fiber blanket. Its got so many pebbles and large media in it it just does not seem to stick for me like Satanite does.
I could see casting the walls of the forge using it easily though as long as you plug the center of the forge while the walls are drying.
Goodluck
CW
I could see casting the walls of the forge using it easily though as long as you plug the center of the forge while the walls are drying.
Goodluck
CW
EdCaffreyMS
"The Montana Bladesmith"
My favorite for this application is ITC-100. I put a small amount in to a paint mixing cup and add water until it's the consistency of latex paint. Spritz the interior of the ceramic wool with water (otherwise the ITC won't stick), then use a cheap paint brush to "paint" the ITC onto the ceramic wool. DON'T over do it! A very thin coat is all you need. The big key is allowing it to dry COMPLETELY before firing the forge....in Montana that requires about 3-5 days.
It creates a "shell" that prevents fibers from being dislodged, and in my forge it produces and extra 500+F in temp versus non-coated ceramic wool.
It creates a "shell" that prevents fibers from being dislodged, and in my forge it produces and extra 500+F in temp versus non-coated ceramic wool.
Mike Martinez
Well-Known Member
Ray, that should be 691 Sq. In. ( (2 PI r)*h ).
Ray is this a vertical or horizontal forge, I ask because if its a vertical forge you need some protection from the flux on the Koa wool. Flux eats Koa wool like gas eats cotton candy.
I personally use between 1/4"-1/2" of Satanite over my wool to protect it then put a wash of Itc-100 over that. I find I have to recoat the areas under the opening of my vertical forge at least once to twice a season from the flux running down the inside of the forge.
If its a horizontal forge then your good with just a ITC -100 wash on all walls but the floor of the forge.
I am probably going to next year completely gut the vertical forge and cast in a block of mizzou under the opening of my forge all the way to the floor and put koa wool everywhere else covered with Satanite.
I personally can take or leave the ITC, my blown forge can get me to any temperature I desire. I need to experiment on if the ITC wash will get me there with less fuel though.
Ed would love to hear your thoughts on if I could save propane by using ITC.
CW
I personally use between 1/4"-1/2" of Satanite over my wool to protect it then put a wash of Itc-100 over that. I find I have to recoat the areas under the opening of my vertical forge at least once to twice a season from the flux running down the inside of the forge.
If its a horizontal forge then your good with just a ITC -100 wash on all walls but the floor of the forge.
I am probably going to next year completely gut the vertical forge and cast in a block of mizzou under the opening of my forge all the way to the floor and put koa wool everywhere else covered with Satanite.
I personally can take or leave the ITC, my blown forge can get me to any temperature I desire. I need to experiment on if the ITC wash will get me there with less fuel though.
Ed would love to hear your thoughts on if I could save propane by using ITC.
CW
EdCaffreyMS
"The Montana Bladesmith"
Ray, In my test of ITC versus Plistix, it was basically not contest. I like the ITC far better than the plistix. Over the years I have tried just about every "coating" available, and they all do one thing...stiffen ceramic wool. ITC not only does that, but it will return higher temps with less fuel than the others. Cost wise, the plistix wins, but as with most things, you get what you pay for.
ITC is pricey, any way you look at it. The best prices I have found on ITC-100 is from Bailey Ceramics http://www.baileypottery.com/kilns/kilnmaterials.htm (scroll down the page until you find the ITC-100) For the average forge, a pint will do the job, provided you thin it down to a slurry as I previously mentioned.
I run my welding forge enough that it has to be relined 3-4 times a year. When I buy ITC-100, I purchase it in the 1/2 gallon tub....that's enough to last me 2-3 years.
ITC is pricey, any way you look at it. The best prices I have found on ITC-100 is from Bailey Ceramics http://www.baileypottery.com/kilns/kilnmaterials.htm (scroll down the page until you find the ITC-100) For the average forge, a pint will do the job, provided you thin it down to a slurry as I previously mentioned.
I run my welding forge enough that it has to be relined 3-4 times a year. When I buy ITC-100, I purchase it in the 1/2 gallon tub....that's enough to last me 2-3 years.
Wayne Coe
Forum Owner - Moderator
Satanite is not a castable refactory.
I suggest casting Kast-0-Lite about 1//2" thick over the ceramic blanket. Kast-0-Lite is a light weight, insolating castable refractory. Not only are you getting a lighter weight forge (compaired with Satanite or Mizzou) the casting is insolating and you get a tuff, long lasting forge. I then mix Plistix to a very soupy consistancy (like wood stain) and paint it on. I sell this in pints and paint it on until it is gone. The Plistix or ITC 100 are not strong and easily get holes poked through it. ITC 100 costs about $40.00 a pint and Plistix is $10.00 a pint. Ed did a comparison of the two and did not have good results when applying each on half of the forge. I have never had the problems that he related and believe that the problems must be due to chemical reactions between the two products. I do have a new Infrared Reflective product (Matrikote) that sells for $15.00 per pint. My source tells me that their customers like it much better than Plistix (they are selling the new product 2 to 1 over Plistix).
Several years ago I built a venturi forge for a student out of a 20# propane bottle. After the casting cured (I put it in the oven set to 500 degrees for 3 or 4 hours, do that while the wife is gone shopping) I placed a piece of 1" square in the forge, lit it and timed how long it took for the metal to come up to forging temprature. It took 11 minutes. The next day (after the forge was cooled down) I painted it with Plistix, waited for it to dry, then placed the same piece of 1" square in and fired the forge and timed it again. It took 6 minutes. Seems to me that you will use half as much gas and work twice as hard.
I built my forge this way about 5 years ago and have not have to re-cast it since, and I have had 4 teen age boys taking classes and using the forge, all at the same time. I think that is a testimony as to its tuffness.
I suggest casting Kast-0-Lite about 1//2" thick over the ceramic blanket. Kast-0-Lite is a light weight, insolating castable refractory. Not only are you getting a lighter weight forge (compaired with Satanite or Mizzou) the casting is insolating and you get a tuff, long lasting forge. I then mix Plistix to a very soupy consistancy (like wood stain) and paint it on. I sell this in pints and paint it on until it is gone. The Plistix or ITC 100 are not strong and easily get holes poked through it. ITC 100 costs about $40.00 a pint and Plistix is $10.00 a pint. Ed did a comparison of the two and did not have good results when applying each on half of the forge. I have never had the problems that he related and believe that the problems must be due to chemical reactions between the two products. I do have a new Infrared Reflective product (Matrikote) that sells for $15.00 per pint. My source tells me that their customers like it much better than Plistix (they are selling the new product 2 to 1 over Plistix).
Several years ago I built a venturi forge for a student out of a 20# propane bottle. After the casting cured (I put it in the oven set to 500 degrees for 3 or 4 hours, do that while the wife is gone shopping) I placed a piece of 1" square in the forge, lit it and timed how long it took for the metal to come up to forging temprature. It took 11 minutes. The next day (after the forge was cooled down) I painted it with Plistix, waited for it to dry, then placed the same piece of 1" square in and fired the forge and timed it again. It took 6 minutes. Seems to me that you will use half as much gas and work twice as hard.
I built my forge this way about 5 years ago and have not have to re-cast it since, and I have had 4 teen age boys taking classes and using the forge, all at the same time. I think that is a testimony as to its tuffness.
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The two versions of Kast-O-Lite with which I am most familiar are the Kast-O-Lite 26 and Kast-O-Lite 30.
In regards to dealing with flux, both will work fine for your welding forge.
The differences between the two are the densities, which affects durability (temperature rating) and thermal properties (insulation).
The 26 has a 2600 F service rating, while the 30 has a 3000 F temp rating. So the 30 is more durable under high heat because it is denser.
But the tradeoff is that density (which contributes to durability) sacrifices insulative qualities.
Lightweight refractories are better insulators, contributing to increased efficiency.
For a forge specifically set up to handle forge welding, the 26 would be my choice.
The 30 is more suitable to applications where the refractory must serve as a hotface. (A hotface is the part of the wall subjected to direct impingement by the heat source.)
So if you're sensible about your burner placement, the 26 is fine. At least it has been for me.
As the others have mentioned, I highly recommend placing some type of IR coating over your refractory.
I have nothing but wonderful things to say about ITC 100. It is the only IR coating I have used, so I can't give you a comparison.
But whichever brand you choose, the point is that they are (or should be) specifically formulated to reflect. They're not insulators per se.
If you apply an IR coating over a castable refractory, make absolutely certain that your castable is cured first.
Spalling is no fun; the possibility of a steam explosion is an even worse case scenario.
Rob
In regards to dealing with flux, both will work fine for your welding forge.
The differences between the two are the densities, which affects durability (temperature rating) and thermal properties (insulation).
The 26 has a 2600 F service rating, while the 30 has a 3000 F temp rating. So the 30 is more durable under high heat because it is denser.
But the tradeoff is that density (which contributes to durability) sacrifices insulative qualities.
Lightweight refractories are better insulators, contributing to increased efficiency.
For a forge specifically set up to handle forge welding, the 26 would be my choice.
The 30 is more suitable to applications where the refractory must serve as a hotface. (A hotface is the part of the wall subjected to direct impingement by the heat source.)
So if you're sensible about your burner placement, the 26 is fine. At least it has been for me.
As the others have mentioned, I highly recommend placing some type of IR coating over your refractory.
I have nothing but wonderful things to say about ITC 100. It is the only IR coating I have used, so I can't give you a comparison.
But whichever brand you choose, the point is that they are (or should be) specifically formulated to reflect. They're not insulators per se.
If you apply an IR coating over a castable refractory, make absolutely certain that your castable is cured first.
Spalling is no fun; the possibility of a steam explosion is an even worse case scenario.
Rob
Wayne Coe
Forum Owner - Moderator
Ray, and others, I sell the 3000 degree Kast-0-Lite in 6# bags for $15.00 and the 2600 degree in 6# bags for $12.00
Ray, I don't know where you are but if you are not close to me or going to be in the Atlanta area the third weekend of February, or at the Big Blu meeting in North Carolina the third weekend in March, or at the Batson's Blade Symposium in Alabama the second weekend in April, or at the Blade Show and need 55# look for a local source. I could ship 55# to you but probably shipping would be to much.
The main advantage in buying from me is that I re-package the products and you can buy just what you need at the time.
Ray, I don't know where you are but if you are not close to me or going to be in the Atlanta area the third weekend of February, or at the Big Blu meeting in North Carolina the third weekend in March, or at the Batson's Blade Symposium in Alabama the second weekend in April, or at the Blade Show and need 55# look for a local source. I could ship 55# to you but probably shipping would be to much.
The main advantage in buying from me is that I re-package the products and you can buy just what you need at the time.