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dtec1 09-11-2015 03:09 PM

?!?Forge Coatings?!?
Hey guys quick question i am in a lil bit of info overload. So as i have said before i recently got a new lil propane forge. Now the dimensions are 10 in deep by 8 in diameter (with out the ceramic wool blanket) once you put the blanket in it makes the diameter of the chamber roughly 5.5 in. A few days ago i was using flux and some of it came off the fire brick floor and ate a small spot of the ceramic blanket away. Its not enough to make a difference i dont think but its enough to make me want to properly coat it. I was originally planing to coat it with a refractory furnace cement i have (was purchased in home depot) but i coated a couple of bricks with this stuff to use as a "door" for the front and back of forge. I noticed first as it was heated it bubbled up and turned hard but brittle if you tap the bubble with anything hard it just shatters and then i noticed the center point of the back the coating on the brick actually melted into what looked like lightly green colored glass. I figured that cant be good now if i was going to use this on the inside of the forge i guess i would thin it out until it could be brushed on with a paint brush. On the bricks it went on thick so i dont know if that would make a difference. So i want to get a coating for it. But there are so many things out there. Just one site for example ( has satinite mortor, refractory cement, bubble aluminia refractory, ins-tuff ceramic fiber rigidizer, THEN itc-100, mizziou castable refractory, and 2 different cast-o-lite refractory. Thats just one site. Even tho i have the ceramic blanket in there now i still wanna get enough of that too (enough to cover the inside once or twice) just too have and also incase i screw up the coating somehow. I know there are some different brands but that site specifically has the "ins-wool" 1in and 2in and also 1in with a higher temp rating (2700 instead of 2400). Ok WoW i thought this would be a short question but i guess not SORRY. Basically i am just looking for people to share what they have done or have knowledge about the subject to point me in the right direction. Either way i want the top coating to be flux resistant if possible and i am not trying to spend a fortune just enough to get and help keep the forge in good condition. Also if you guys know any other websites that sells these products that i might do better with than the one mentioned above. THANKS ahed of time guys i am sure ill get good advice from everyone

dtec1 09-11-2015 03:16 PM

ohh also i have trouble getting this forge real hot. it will get hot enough to forge weld but just there and takes a bit to do it so anything that would improve heat would be great too

Ray Rogers 09-11-2015 03:33 PM

If the refractory bubbled up like that I would imagine that means you turned the forge on before the refractory had a chance to dry. Don't do that, give it a day or two to dry (depending on how thick you make it).

The hardware store stuff will work but isn't as good as what you get from hi-temp. You don't need refractory on your bricks...refractory is nothing but the same type of stuff fire bricks are made from anyway. Doesn't hurt to do that but probably doesn't help much either.

The green glassy stuff might be the refractory but it is probably the flux. My bricks don't have refractory but they do have that super hard glassy coating. Kinda makes you think twice about breathing that hot air, don't it?

Bubble Alumina is the appropriate coating for wool to make it resist flux. Note I said 'resist' and not 'flux proof'. Nothing is flux proof. If you really, really want the maximum flux resistant interior you could do as I did. I put as many fire bricks in the bottom of my forge as it took to cover the floor (3 I think - big forge). Then, I poured 30 pounds of Missou castable over the bricks - the bricks were just to take up space so I could use less castable. Smoothed that out and let it set for a week. Then I put an arch of wool over the rest of the interior. Most of the flux was on the floor so not much damage to the wool after that. But, eventually, my forge got so hot that the wool was melting and sagging so I made a 1" thick arch of castable and slipped that into the forge over the wool because the castable can take much more heat than the wool. Now, the flux puddles on the bottom where I am happy to leave it, my forge gets hotter than Hades although it takes 45 minutes to thoroughly heat that mass of castable but nothing melts except what I want to melt.

As for your forge not getting hot enough or hot fast enough, that depends on your burner and also how much mass you have to heat and the insulation. Two layers of wool take longer to heat than one layer and brick and coatings take even longer (although the ITC-100 helps hold heat for the short time it survives).

Basically, get used to the idea that welding forges need to be rebuilt periodically ...

dtec1 09-11-2015 05:17 PM

ok thanks does this sound good i have the ceramic blanket (dont know what brand it came with the forge) but i wanna get some more anyway.....on the hightemp site they had the inswool hp rated to 2400 and also inswool htz rated to 2700 (twice the money tho) the one rated 2400 good for heat treat and some forge welding or do i need the 2700 one. Would it even matter if i put the itc-100 on it ( itc-100 doesnt have a degree rating) but arent most coatings rated above most blanket's? so if i had that one top would the rating of the inswool matter. then i was thinking of getting the bubble alumina it says 2.5 pound bag can do the floor of a 12' vertical forge but basically that is a 12in diameter circle right? so i would need a lil more since my forge aint vertical and its 10in.front to back. But anyway put that on the bottom third of the forge on top of the inswool. then i figured i could cover the top 2 third's with the itc-100 to go ontop of the inswool to seal that and help with heat. the itc-100 can just go on the inswool right it doesnt need anything in between or on top of it right? I still would place a hard fire brick in as a floor. Does that sound good anything you would change?

dtec1 09-11-2015 05:56 PM

do i need satinite under the itc 100?

Ray Rogers 09-11-2015 07:39 PM

Whether or not it sounds good depends on what you expect to accomplish. If you are trying to make your forge flux proof that isn't going to happen that way (if its possible at all).

You need something to bind the wool fibers - that's what the Satanite is good for. At a minimum you need the Satanite.

If you want to increase the heat efficiency, i.e., keep more heat in your forge that's what the ITC-100 is for and it would go over the Satanite. Personally, I never felt the results from ITC-100 warranted the cost.

If you want to flux proof your forge floor that's what the Bubble Alumina is for. I used it, it works very well while it lasts but dragging heavy billets in and out of the forge destroyed it pretty quickly. With just blades and a careful touch it will last longer.

If your wool isn't melting or sagging then the 2400 is good enough. If it is sagging then the higher temp wool could help or the ITC-100 could help because it reflects the heat for as long as it lasts. Flux will destroy anything it touches including Bubble Alumina (slowly) and some things faster than others. Also, forges are hot (or should be) and that much heat softens anything you put in there so Bubble Alumina, Satanite, and even Missou are much easier to damage when hot. That means dragging billets in and out tears things up, flux tears things up, so being careful not to scrape the floor or bump the walls of your forge will do more to make the interior last longer than any coating you can put on it. This is life with horizontal forges.

You need the Satanite, painted on thin as house paint. Expect to repaint periodically depending on how much the forge is used. The rest of that stuff is optional, try it out if you have the spare cash otherwise don't worry about it ...

Except for the Satanite, none of that is essential for simple HTing. You can use it and it will help but its mostly a waste of money in my opinion. If your forge isn't hot enough a better burner is probably a better solution than any kind of coating.

dtec1 09-11-2015 08:02 PM

ok i think i got it....thanks ray...really thanks alot you have been great with some really good info from day one on this forum and i am sure i have asked some really simple questions that you have answered a million times but it is appreciated

dtec1 09-11-2015 08:05 PM

sorry 1 mo0re question there any rule of thumb on how much satinite covers so much area? like the ict-100 says half pint covers 6 sq. feet. but nothing like that that i can find anywhere on the satinite...also satinite goes on thin right?

Ray Rogers 09-12-2015 08:29 AM

Depends entirely on how thick you mix it. Satanite is pretty cheap though and you'll use it more often than you might think so buy 5 pounds of it. For coating the wool, mix it thin like latex paint. Later, you might want to do a hamon on a blade and Satanite is perfect for that too but mixed thicker like clay. Mixed liked clay it can be used to patch bricks if the need arises ...

dtec1 09-12-2015 12:42 PM

perfect thanks again ill try and put this knowledge to use

dtec1 09-12-2015 12:55 PM

hey you ever took a look at this site 25feet by 2 feet by 1 inch blanket for $33.44 thats crazy cheap they say "Do not be fooled by brand names. Heating Ceramic material to a liquid state and then blasting it with high pressure air makes a fiber used in various forms for insulation. We all make the same product the same way." so deffinitly a generic brand you think the quality is the same as ins wool or kaowool or think its just garbage? such a huge price difference 25ft roll of inswool is $145.

Ray Rogers 09-12-2015 02:20 PM

Never seen that before but looks good for the price. However, you generally get what you pay for and that material is rated at about 300F less working temperature than Inswool. So, for HTing you'd be OK but for forging it wouldn't hold up as well.

Also, I'd get the 1" wool (or Inswool) rather than the 2". If you're going to have that much wool laying around then sooner or later you'll likely build another forge and 1" is enough in many cases. If you need 2" then use 2 layers. If you do mess up your wool by flux or physical damage having two layers could mean you only have to replace one of them ...

Ed of all trade 09-12-2015 02:34 PM

Has a lower temp, only 1834 f , will that work? Ed

dtec1 09-12-2015 02:52 PM

ok wow i dont know how i missed that temp. difference good call. i think ill stick with the inswool one of those things i think the inswool has worked for many many more people than the cheaper stuff i pointed out like my father tells me dont fix it if it aint broken....i am actually about to order some stuff from (hope they dont take forever to ship) i think i am just going to get the 5 foot roll of 1inch inswool so ill have extra if needed and i purchased the forge i have now but i do wanna make one of my own and i can use the ins wool for that, also itc-100 1/2 pint i think ill coat the top 2/3 with that (over the satinite) and botom 1/3 with the bubble alumina to protect from flux sounds good right? i know you werent to enthusiastic about the itc-100 but as i said before my forge just barley gets to the point where steel stack goes yellow so maybe it will push it over the edge and be a lil easier to get there and if not i think i will take your suggestion on another burner or replacing the one i have but ill tackle that when i get there

Ray Rogers 09-12-2015 03:47 PM

That sounds like a reasonable approach to me ....

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