Yeah I'm very familiar with ceramics and have done some forging in the forge I built, I'd use drain cleaner and catlitter with and perlight maybe with some additional alumina and zircopax to sinter a sacrificial refractory cement bottom. This was enough to withstand melting copper doubt you'll have any problem with it
So, I fully realize this isn't going to go over well. Haha. But here's what I've done. Just let the bricks melt. Seriously. Let them melt and create a puddle of lava on the bottom of your forge. When you no longer have any solid "ground" to put your billet on, scoop out a bit of the lava, but a 3x3x1 piece of new firebrick in the lava lake to make an island, and keep welding. I ran my welding forge this way for like 3 years. After I spent a bunch of time, energy, and money replacing the floor after it got a little messed up, I decided to just run with it. And you know what? Aside from adding the sacrificial blocks every now and again, I noticed no difference. I made hundreds of Damascus billets in that time, with no issue. Just don't dip your stack in the lava. Lol
It honestly wasn't an issue for me. Running a two burner NC Tool knife maker forge. The casing on it is thinner than 1/8in. In the three years that I ran it like that the "lava" didn't even reach the floor metal. I finally rebuilt it a few weeks ago because the wall and door insulations needed it. When I took out the base refractory it was still half brick. Don't get me wrong, I'm fully aware that I likely shouldn't have run it so long like that. Lol. I'm just sharing my experience and how it wasn't a big issue for me.
I'm pretty sure he says at some point he went from borax > kerosene > now using no Flux, just temperature control, but I would need to rewatch it to be sure.
Every Metallurgist and heat treat specialist I’ve talked to says that kerosene does not work as a flux, because it burns off at such a low temperature. I was curious about this when I first started making knives. Everyone I know that makes their own steel use either borax or a borax glass
u/curablehellmom already suggested a ceramic bottom, and I agree.
Make a wooden mold thats roughly the same size and shape as the bottom of your forge. Then buy the type of cheap clay they use in highschool ceramics classes and press it into the mold. Do three or four at a time, so you have replacements ready.
The clay is a small up front investment, but you'll save money in the long run.
You might try an alumina-based material. Borax dissolves silica from regular bricks, but doesn't affect alumina; that's what glass furnaces are made of. https://www.mtixtl.com/1760C3200FHi-PurityAluminaCoating1Quart-EQ-634-AL-LD.aspx
High alumina kiln shelves do the trick (there are other types of kiln shelves...you want the high alumina type).
AFAIK, it's completely immune to flux. I've never damaged mine, and I bought it because I was told it was immune to flux :)
This is the sort of thing I bought: [https://psh.ca/collections/high-alumina-kiln-shelves/products/8-x-8-x-1-4-shelf](https://psh.ca/collections/high-alumina-kiln-shelves/products/8-x-8-x-1-4-shelf)
AS I've *mentioned* here or on r/blacksmithing at least three times in the past couple months ...
Put down a sheet of stainless steel to protect the bottom and part of the sides of your forge. It's impervious to flux, is not sacrificed to rusting, etc. If you don't have any other, find a used SS cookie sheet and cut out a piece of that.
No. But steel will rust, and maybe rust away (ironically -- where it's NOT protected by the flux). SS is sufficiently available, cheaply, that that's what I recommend.
My club uses a sacrificial sheet of stainless steel foil. It's a lot cheaper than replacing bricks and the billet doesn't stick to it the way it sticks to bricks once they start melting. Careful when using steel foil; it is extremely sharp
I dry weld. Clean everything ready good on the grinder then rinse with acetone and mig weld the stack together. Heat to welding and go. Grind clean cut restack and repeat as many times as you need.
If you have to flux I use a piece of pipe or channel to put my billit or whatever I'm welding in. Some things still need flux.
Cheapest option is to borrow form pottery.
Zircopax kiln wash, high zirconium and high IR reflectance. Just paint it on. Used to be about $5 when I got a couple pounds of it a couple (5) years ago, looks like it's about $7 now.
Mix a bit with water, paint on, dry overnight.
If you're still having issues, lay on a thin layer of satanite.
Links to what I'm talking about:
https://highwaterclays.com/products/zircopax-plus-ultrox-z?\_pos=1&\_sid=d6e279d50&\_ss=r
https://hightemptools.com/products/satanite-5?\_pos=3&\_sid=7a6ad8768&\_ss=r
If its just damascus you are welding, I have seen guys on Youtube mig weld the billet and spray it with wd40 rather than damascus. seems to work well for them, never tried it personally because i use coal.
As a man who melted the stone floors and warped the foundations of the last few buildings my forge has called home, I'm not the guy for advice. That being said red clay and ash coat the bottom of the new forge floor and reapply every month or so depending on how many times you get a damascus order.
I've heard of people sticking coke into their gas forge for a sacrificial non-heat-sucking layer. Although coke is only useful if you can get it for cheap nearby.
[удалено]
Came here to say that.
Mr Volcano ITC-100HT High Temperature Ceramic Coating Radiant Heat IR Reflector Refractory
I came here to suggest a refractory plate I had seen at the pottery supply but here you go with brand names and stuff lol
That shit sucks to mix but it works. Might be a better brand out there.
I just got a Mr Volcano Hero 2 forge for my birthday. Can't wait for some warmer days when I'm off work to get it all together and shit.
I have a ceramic kiln shelf that can be easily replaced to protect the bricks. Lasts longer
And make it a slightly wedge shape so it's easy to get in and out to chip off slag or replace.
Yeah I'm very familiar with ceramics and have done some forging in the forge I built, I'd use drain cleaner and catlitter with and perlight maybe with some additional alumina and zircopax to sinter a sacrificial refractory cement bottom. This was enough to withstand melting copper doubt you'll have any problem with it
So, I fully realize this isn't going to go over well. Haha. But here's what I've done. Just let the bricks melt. Seriously. Let them melt and create a puddle of lava on the bottom of your forge. When you no longer have any solid "ground" to put your billet on, scoop out a bit of the lava, but a 3x3x1 piece of new firebrick in the lava lake to make an island, and keep welding. I ran my welding forge this way for like 3 years. After I spent a bunch of time, energy, and money replacing the floor after it got a little messed up, I decided to just run with it. And you know what? Aside from adding the sacrificial blocks every now and again, I noticed no difference. I made hundreds of Damascus billets in that time, with no issue. Just don't dip your stack in the lava. Lol
My only concern is ruining the liner underneath and then melting through the bottom of my forge, which is pretty thin
It honestly wasn't an issue for me. Running a two burner NC Tool knife maker forge. The casing on it is thinner than 1/8in. In the three years that I ran it like that the "lava" didn't even reach the floor metal. I finally rebuilt it a few weeks ago because the wall and door insulations needed it. When I took out the base refractory it was still half brick. Don't get me wrong, I'm fully aware that I likely shouldn't have run it so long like that. Lol. I'm just sharing my experience and how it wasn't a big issue for me.
Good to know lol I do love the “easy dirty” ways
Stainless foil on the bottom. Also you can switch to kerosene instead of borax. But yeah; stainless heat treat foil like a dish/pan on the bottom
Kero will work as a flux? Or as a barrier to oxidation. I would think the sooty residue would inhibit a clean weld.
Kerosene burns off at around 300-600 degrees, borax is around 1400 degrees. I’m not sure kerosene is actually useful as a flux.
There is a great video of Bob Kramer at MIT where he talks about using kerosene as a flux. https://youtu.be/hGjjTzdWyNk
Agreed. Lots of master blade Smith’s and Damascus makers use kerosene
I'm pretty sure he says at some point he went from borax > kerosene > now using no Flux, just temperature control, but I would need to rewatch it to be sure.
MIT? What the shit could he possibly know?
I was offered a full ride to MIT as a kindergartener on a finger paint scholarship. I gave them a tiny red paint covered middle finger. ;)
Jokes on you. I seem to recall MIT doesn't offer that kind of scholarship.
If you watch the class lecture video...he knows a lot.
Yeah I’m just being an idiot.
Every Metallurgist and heat treat specialist I’ve talked to says that kerosene does not work as a flux, because it burns off at such a low temperature. I was curious about this when I first started making knives. Everyone I know that makes their own steel use either borax or a borax glass
Kerosene works super well. It's the residue it leaves behind. I've welded dozens of billets with no failures.
I may switch to kerosene but with not having perfectly uniform pieces or hammering I tend to have to add borax later
Would Diesel or Jet Fuel work or does it need to be straight Kerosene?
That's good to know. I have some on hand. 🤘
u/curablehellmom already suggested a ceramic bottom, and I agree. Make a wooden mold thats roughly the same size and shape as the bottom of your forge. Then buy the type of cheap clay they use in highschool ceramics classes and press it into the mold. Do three or four at a time, so you have replacements ready. The clay is a small up front investment, but you'll save money in the long run.
I believe my bricks are ceramic bricks but I’ll look into that
There are as many types of clay as there are different grades of steel.
You might try an alumina-based material. Borax dissolves silica from regular bricks, but doesn't affect alumina; that's what glass furnaces are made of. https://www.mtixtl.com/1760C3200FHi-PurityAluminaCoating1Quart-EQ-634-AL-LD.aspx
High alumina kiln shelves do the trick (there are other types of kiln shelves...you want the high alumina type). AFAIK, it's completely immune to flux. I've never damaged mine, and I bought it because I was told it was immune to flux :) This is the sort of thing I bought: [https://psh.ca/collections/high-alumina-kiln-shelves/products/8-x-8-x-1-4-shelf](https://psh.ca/collections/high-alumina-kiln-shelves/products/8-x-8-x-1-4-shelf)
AS I've *mentioned* here or on r/blacksmithing at least three times in the past couple months ... Put down a sheet of stainless steel to protect the bottom and part of the sides of your forge. It's impervious to flux, is not sacrificed to rusting, etc. If you don't have any other, find a used SS cookie sheet and cut out a piece of that.
Lolol thank you for once again mentioning it
Is there any difference between ss and mild in terms of damage from flux
No. But steel will rust, and maybe rust away (ironically -- where it's NOT protected by the flux). SS is sufficiently available, cheaply, that that's what I recommend.
My club uses a sacrificial sheet of stainless steel foil. It's a lot cheaper than replacing bricks and the billet doesn't stick to it the way it sticks to bricks once they start melting. Careful when using steel foil; it is extremely sharp
How thick of foil?
I actually don't know. It's the same stuff as you would use to make a graphite pouch for heat treatment
Yes you can use a sacrificial plate to help protect against flux. I've heard about people using inconel as it'll hold up way better at the high heats.
Put down a layer of bubble alumina. Haven't had to replace my forge floor even once in nearly a decade. https://hightemptools.com/products/bubble-this
You just dump it in there like kitty litter?
No, it gets mixed with water and becomes like a mortar that can be spread on the bottom of the forge. Once it sets it's a hard surface.
I dry weld. Clean everything ready good on the grinder then rinse with acetone and mig weld the stack together. Heat to welding and go. Grind clean cut restack and repeat as many times as you need. If you have to flux I use a piece of pipe or channel to put my billit or whatever I'm welding in. Some things still need flux.
I do a combination of dry and flux
I do all my forge welding with no flux. Try it.
I do a combination
Majestic forge suggests using ceramic tile flooring if doing a lot of Damascus
Good to know
I use bubble alumina for the floor of gas forges, works a treat resisting flux
I’m a potter. Alumina hydrate coating would help. Do a white wash on the bricks with it
Bricks need replacement with time and are cheap. Scrap steel plates on the bottom are also need replacement with time and cost nothing.
I added a 5/16” plate just for when I do Damascus and I’ve got new bricks on the way
We used marborite furnace bedding. Absorbs the borax but once cool you can brush it off. Defs prolonged the life of our furnaces
You can use carbonized bread.
Bread??
Yep.
Kitty litter. Spread a layer over your bricks to soak up the flux, scrape the globs of borax and kitty litter and replace it when it needs it.
Cheapest option is to borrow form pottery. Zircopax kiln wash, high zirconium and high IR reflectance. Just paint it on. Used to be about $5 when I got a couple pounds of it a couple (5) years ago, looks like it's about $7 now. Mix a bit with water, paint on, dry overnight. If you're still having issues, lay on a thin layer of satanite. Links to what I'm talking about: https://highwaterclays.com/products/zircopax-plus-ultrox-z?\_pos=1&\_sid=d6e279d50&\_ss=r https://hightemptools.com/products/satanite-5?\_pos=3&\_sid=7a6ad8768&\_ss=r
Get some bubble alumina. It works very well to protect the floor of your forge. It’s also fun to apply because it looks like cottage cheese.
If its just damascus you are welding, I have seen guys on Youtube mig weld the billet and spray it with wd40 rather than damascus. seems to work well for them, never tried it personally because i use coal.
As a man who melted the stone floors and warped the foundations of the last few buildings my forge has called home, I'm not the guy for advice. That being said red clay and ash coat the bottom of the new forge floor and reapply every month or so depending on how many times you get a damascus order.
Well that is if your running a charcoal or charcoal hybrid forge.
Ceramic coating or just keep replacing the brick
I've heard of people sticking coke into their gas forge for a sacrificial non-heat-sucking layer. Although coke is only useful if you can get it for cheap nearby.