Help with first forge

[Judehey]

Im planning for my first propane forge. I plan to buy rather than build,  probably a Devil's Forge.   After reading everything I could find on the site,  and rereading it after I found Lou's thoughtfull consolidation, it seems the fumed silica is the first step,  followed by Matrikote and Plistix or something similar.  Should i just pitch the ridgidizer that comes with the forge? 

Thanks

[Mikey98118]

If they didn't think it worth using they wouldn't have included it. I wouldn't bet against the manufacturer's judgement without good reason.

[Irondragon Forge ClayWorks]

Use the supplied rigidizer then coat it with the Matrikote & Plistix.

[Judehey]

Thanks, does ridgidizer get applied to the insulation placed around the burner where it enters the forge? 

[Irondragon Forge ClayWorks]

Yes...the purpose of ridgidizer is to contain the loose air borne fibers. The supplied one will do, soak the strips and put it in around the burners and let it dry.

Ceramic Wool Insulation, Safety Alert - Insulation and Refractories - I Forge Iron

[Judehey]

I just recieved my first forge,  a Devil Forge two burner oval. I also have some Inswool, KOL 30, and Plistix from on line. My plan is to user the wool and KOL to make a floor to replace the supplied firebrick.  The forge comes with a paint on aluminum oxide ridgidizer. 

Should I use KOL on the sides and top, or just the supplied ridgidizer?   If I go with the KOL, how thick?  I read somewhere on the forum that reducing the volume might affect burner performance. 

Thanks

[Frazer]

Judehey, there is no need to post the same question twice, it just clutters things up unnecessarily... The gas forge experts will be along shortly to offer their opinions on what you should do (they have lives outside IFI too).

I don't use a gas forge, but I would say rigidize, then KOL, then Plistix. The KOL provides a hard shell that protects the lining from flux, pokes and prods from pieces going in and out of the forge etc. so I wouldn't skip that step.

While you're waiting for a more detailed response, read through the Forges 101 thread. The info you're looking for is in there.

https://www.iforgeiron.com/topic/53873-read-this-first/

[Judehey]

I'm setting up my new Devil Forge. It comes with strips of ceramic wool to insulate the burner ports.  How do I ridgidize this? I've searched and read through forges 101 and burners 101, but all I've found is that I need to, not how to.  I have fumed silica,  as well as a brush on air dry ridgidizer provided by the manufacturer. If I use the silica,  will it get hot enough to cure/set? I can use the brush on ridgidizer provided, but how do I get the burners out,  or should I not plan to? 

Thanks

[Irondragon Forge ClayWorks]

You asked this and it was answered in your other thread. You need to continue that thread instead of opening a new thread for every question. I see a moderator combined your threads, so any other questions about this forge should be placed in this thread.

[Mikey98118]

Nevertheless...

The usual (but not only) rigidizer is colloidal silica; and its usual form is fumed silica powder. When mixed into water, fumed silica will remain in solution, so long as the water doesn't freeze.The water allows the silica to be spritzed, painted, or poured onto ceramic fiber insulation.  The water, with its silica content will be dawn all over the fiber, by way of capillary action. Food coloring is added to the silica and water solution, as a visual aid, and completely burns away during heat curing. Heat curing causes the very fine silica dust to melt right into the fiber, and because that same capillary action, which draws the solution along the ceramic fibers, also causes most of it to congregate at joints, where those fibers touch together, most of that dust welds those joints permanently to each other.  So, the answer to every question people may ask about this process becomes apparent, if they only think about the nature of colloidal silica, and capillary attraction; which is the engine that drives capillary action.

Colloidal silica can partially overcome gravity, by capillary action.

Separate pieces of ceramic fiber insulation can be welded together with heated fumed silica on its surface.

Excess fumed silica can drip all over the inside of your forge, and won't matter.

 

[Judehey]

Here it is with the ridgidizer and Kast-O-Lite floor.  Just went in a trash bag with a wet towel over the ends. Comments,  critiques, or suggestions? I have a little more KOL if the floor should be higher. 

Thanks

[Mikey98118]

No higher, but you may want to level it more. I would suggest drilling a couple of very small drainage holes in the bottom of the forge shell, but with the ends open like that, steam should escape well enough During forced drying (firing) the Kast-O-lite. You are on the right track so far.

 

[Judehey]

Thanks, I'll touch it up. Already drilled three holes along the centerline on the bottom. 

[Mikey98118]

It's not always necessary, but never hurts. Even people who's forge show it isn't needed, at present, may need it later, and forget to do it then. Your forge will breath just fine during firing. Nevertheless, you will be surprised at the amount of steam and hot water that will blow out of those holes.

[Judehey]

Here it is, finally. Fired it multiple times,  no more water dripping and seems everything is hardened. I still need to clean it up and give it fresh coat of paint.   First flame is shown at about 3 psi, the rest at 7.  Chokes set per manufacturer instructions. Looks good to me,  but I don't know what I should be looking for, so expert opinions would be appreciated. 

Thanks

[Mikey98118]

Now, you want to work on a firebrick wall at both forge ends; hard against the forge shell at the back opening, and about 1" away from the shell edge on the front opening. You move the brick around to arrange an opening within the brick to pass the work you're heating in through. Employ the same finish coat on the inside faces of the brick that you are using in the forge.

[Judehey]

I'm welding up a stand which will have tracks for firebrick. Thanks for the spacing and coating info. 

Amy opinions on the flame? 

[Mikey98118]

You posted two flame photos; the first is a daylight photo at a distance, which limits the amount of useful information. However, the flame pattern looks strong, and its color is light blue, without any hint of green, which are hopeful signs.

 

the night photo simply indicates that the burners could be turned down quite a bit. Remember that you have two burners in a forge that could probably do quite well with a single burner of the same size. So get used to turning down the gas pressure; especially after you finish the brick baffle walls.

[sidesaddle queen]

so much good information!!!    i learn something every time i visit...  thanks y'all!!!!

[Judehey]

Why the 1" gap between the front of the forge and the firebrick doors? 

Thanks

[Mikey98118]

To give room for the exhaust gases to exit the forge. Remember that back-pressure is like try to drive with the emergency break on; not good. Also, that little gap does nothing to lower heat in the forge. The brick is there to bounce radiant energy back into the forge; for this, a 1/8" is no better than a 1" gap. What you can do to help keep heat in the forge is to coat the side of the brick that faces the forge with Plistix 900.

[Frosty]

The baffles are another reverberatory surface like the rest of the liner. The flame heats the baffle and it radiates Infrared radiation in the only direction available the inside of the forge. This is how propane forges work, flame heats the liner, liner heats the work with infrared radiation. 

The exhaust gasses from the flame MUST escape or the forge won't work. It doesn't matter what kind of burner if it burns fuel the exhaust has to go.

Frosty The Lucky.

[Judehey]

I guess I was thinking I wouldn't close the front completely, but thinking it in terms of reflected IR makes sense. 

I guess I should plan to close off the front when able. 

Thanks

[Mikey98118]

One of the reasons that people like to start with a wall of movable bricks is to use its variable opening to help them learn what works well and what doesn't. You don't want to be vague, or mistaken, while designing a door.

[AlexKelamis]

Fumed silica added to water is not colloidal silica. Period. It is NOT a rigidizer, either. And no, you cannot make colloidal silica from fumed silica, unless you have an extensive chemistry laboratory. 

I am not trying to start an argument with anyone. I am trying to clear up a safety issue. People using ceramic fiber blankets rely on accurate advice in order to protect themselves from the heated silicates (there are many types of silicates). I will be the first to admit that the resources available on the internet are horrible when it comes to fumed silica vs colloidal silica. I do not claim to be an expert in many things, and I am not a blacksmith expert. But I do take issue with experts giving advice that is not accurate. This needs to be cleared up, and the expert members of this forum need to make efforts to consolidate this information so others do not practice unsafe rigidizing.

Fumed silica is Silicon dioxide (one silicon atom with two oxygen atoms covalently bonded). In fumed silica, the SiO2 molecules connect randomly in an amorphous arrangement (ie: there is no repeating crystalline structure--its totally random within 3D space). The size of the overall aggregate SiO2 molecules varies. This is fumed silica. Powder form. It is hydrophilic (loves water). If you add it to water, you simply get an aqueous solution of fumed silica, also known as "fumed colloidal silica"--this is NOT the same as colloidal silica (without the "fumed"). Fumed silica added to water is not a rigidizer. And yes, I have tried it just to prove the point. One reason it isnt a rigidizer is because it is hydrophilic, versus ceramic fiber (the type we use) which is, overall, hydrophobic. If you add fumed silica to water and apply it in any manner, let it dry and heat cure it, you will end up with very little silica being bonded to the ceramic fibers. Instead, you end up with fumed silica powder on the surface of the fiber blanket. This makes the ceramic fiber blanket, if anything, even more dangerous, because now it is littered with fumed silica powder on the surface. This accomplishes us harming ourselves even more. 

Colloidal silica is made up of silicon atoms connected to two hydroxyl groups (hydroxyl is O-H, as opposed to -O, or oxygen) usually with a hydrogen atom/proton (H+) next to each -OH group connected by hydrogen bonding, suspended in water. Sometimes, instead of H+ ions, it may be sodium (Na+) ions, or even aluminum (Al+) ions, depending on the type of colloidal silica (this is irrelevant for the purpose of the discussion). These molecules of Si(OH)2 polymerize, or combine together, to form chains, in a water solution (no this is not being mistaken for water glass, or sodium silica--keep reading). This solution is unique, in that the silica (Si(OH)2) chains themselves exhibit hydrophobic properties, as well as hydrophilic properties; water surrounds the hydrophilic portions, leaving only the hydrophobic portions exposed to bond with the ceramic fiber. So, it is very good at penetrating, and binding to, ceramic fibers. When you use true colloidal silica, regardless of application method, you will have zero dust/powder on the surface of the blanket. Colloidal silica is one effective rigidizer; there are others. 

To clarify, fumed silica is not a rigidizer. Fumed silica added to water is not a rigidizer (I don't care what else you add with it--soap, jet dry, detergent--it isn't a rigidizer). Fumed silica added to water is never, ever, ever colloidal silica. You cannot make colloidal silica from fumed silica (unless you have extensive chemistry laboratory access). 

Again, I am not trying to argue, and I am not trying to embarrass anyone. This is a safety issue. Experts need to be absolutely certain of the advice they give, because when an expert speaks/writes, most people take it for face value without fact checking. It is going to be interesting how people respond to this. If you are really serious about spreading blacksmithing knowledge safely, then please help in clearing up the facts about rigidizing. If, instead, you chose to attack me over this, just know that you'll be showing others that you care more about attacking people behind a computer screen than you do helping to spread sound safe knowledge to others. 

I'll share one experience I had about 6 months ago. My "day job" is being a physician. July 2021, a 24 year old man came to see me. He had developed chest pain, recurrent infections/pneumonia, and shortness of breath that was now constant. A chest x-ray showed his lungs looking like a "white blizzard" (lungs should look dark on x-ray). He has terminal silicosis. At 24 years of age. He is now on a lung transplant waiting list. He must have lung transplant surgery to live, or he will be dead by 30 years of age. His chances of getting a lung transplant is about 20%. He started working as a blacksmith in 2017, using a gas forge/being close to a hot gas forge (with ceramic blanket) on average of about 6 hours daily, five days a week. In 4 years, he went from perfectly healthy to terminal. To be fair, he has a genetic mutation that makes him very, very susceptible to lung damage from many things, like silicates. About 12% of the population has this same mutation. Which means about 12% of the people on this forum who read this have the same mutation, and are at extremely high risk of developing a lung disease that can kill them, especially if they dont properly rigidizer ceramic fiber.

Happy new year. 

Stay alive.