steveguilmette Posted April 17, 2014 Share Posted April 17, 2014 Greetings, My gas forge has a firebrick floor, and after what is now 4 months of solid 10-12 hrs a week use, the floor is covered in a sludge of scale that becomes molten when operating and sticks to my work like thick honey. My only thought is to forge up something like a small garden hoe and get it hot and scrape it out. Not expecting that to work. Anybody have any suggestions for dealing with this or how to prevent it? Thanks, Steve Quote Link to comment Share on other sites More sharing options...
Chinobi Posted April 17, 2014 Share Posted April 17, 2014 you do any forge welding with borax in said forge? thatl gum you up in a hurry. design your forge with a replaceable/disposable sacrificial floor layer for when you weld and remove it when you are not using it. if its actually molten scale....that's just scary hot.... Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted April 17, 2014 Share Posted April 17, 2014 hoe it :) then may have to re line Quote Link to comment Share on other sites More sharing options...
Jim Coke Posted April 17, 2014 Share Posted April 17, 2014 Greetings Steve, Sounds to me like a combination of flux and sand... If you screen out the fines and sand from your coal it might help. Forge on and make beautiful things Jim Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted April 18, 2014 Share Posted April 18, 2014 hoe it :) then may have to re line Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 18, 2014 Share Posted April 18, 2014 SS tray of cheap clay kitty litter Quote Link to comment Share on other sites More sharing options...
Frosty Posted April 18, 2014 Share Posted April 18, 2014 I have a spot about 2" dai. under the burner in the part of my forge I use most that melts after half an hour or so. It's 3,000f split hard fire brick and after a while even without flux the brick will form a vitrified spot that seems to have a lower melting temp. Add a little flux and it's sort of like a refractory fondu that sticks to anything you dip into it. Replace the fire brick, I didn't mortar mine in for exactly that reason. A good kiln wash will help it live longer, ITC-100 is getting too expensive for me but it works a treat for keeping flux from ruining high silica refractories. A wash I used before I realized what I was doing is Kaolin clay, porcelain when fired, it's a high alumina cone 12 clay and is pretty darned resistant to caustics like hot flux. Kiln shelf is good, SS pans work really well, bedding in kitty litter works pretty well. Whatever you use you have to think of it as sacrificial, heat, abrasion and fluxes will kill most anything normal folk can afford. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Neil Blythin Posted April 18, 2014 Share Posted April 18, 2014 My gasser gets the same way after a while. I flip the brick over when it gets too sticky. Once the second side gets the same, I replace the brick. I keep the old gummed up bricks to close off the back door / pass thru of my forge when I want extra heat for welding. Quote Link to comment Share on other sites More sharing options...
steveguilmette Posted April 22, 2014 Author Share Posted April 22, 2014 I wound up flipping over the bricks... Seemed easy enough. Wound up relining the roof too. I used some refractory mortar (sairmix 7) on top of kaowool for the roof because that's what I had laying around. Seems to be working well so far.... Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted April 22, 2014 Share Posted April 22, 2014 I think the important part was the idea that you have to maintain a gas forge and NOT expect it to be unchanging over time. I consider the entire forge to be a "consumable" just with a use life in the years or even decades. Quote Link to comment Share on other sites More sharing options...
Fatfudd Posted April 27, 2014 Share Posted April 27, 2014 I cut a piece of kiln shelf and put it as a floor which can be replaced. They seem to last for a really long time, like a couple of years. I used fire brick at first but wound up with a soft hole under the flame. You can get various thicknesses of kiln shelf and cut it with an angle grinder and a masonry blade from Harbor Freight. Quote Link to comment Share on other sites More sharing options...
Kailthir Posted October 30, 2019 Share Posted October 30, 2019 I have this issue, except I haven't used any flux. It's a syrupy goop on the floor. Only used the gas forge 2x. it appeared the first time about 45 minutes into it. Now it is pretty thick, about 1/8'" to 1/4". I have no clue what caused it. Yes i did forge weld in it, but again .. no flux. I did heat it up slowly. It's only in the spot i put the steel. Now i have to replace the fire brick on the floor. Which mean dismantling the whole forge. I have a magestic forge 3 burner. Not sure what to do or how to combat this. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 30, 2019 Share Posted October 30, 2019 Molten scale mixing with the top layer of whatever your forge is floored with? Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted October 30, 2019 Share Posted October 30, 2019 21 hours ago, Kailthir said: Which mean dismantling the whole forge. I have a magestic forge 3 burner. Not sure what to do or how to combat this. High alumina kiln shelf, or high alumina based castable refractory floor. Quote Link to comment Share on other sites More sharing options...
Mr Moose Posted October 30, 2019 Share Posted October 30, 2019 Mikey, what % is considered high alumina? I have this hapening with 60% alumina castable refractory. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 31, 2019 Share Posted October 31, 2019 What brand? 60% is pretty high alumina to just melt under an air, propane flame. From what I see most folk consider 35% alumina as high. You have to read the formula, check the brand name in a MSDS search. The MSDS itself only has a broad description of ingredients but you can do a little detective work and work to a company page that'll list the analysis. Most refractories seem to have silica based bonding minerals holding them together so you need to take a look. If you don't plan on doing much welding it's no worry. Phosphate bonded is really flux proof high temp, expensive as well. What is the max working temp it's rated for? There's usually a decent margin above they're good for. You may have lucked into a 3,200f burner, it happens one of mine has a decent circle of fused fire brick under it. You COULD have a golden bullet there! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mr Moose Posted October 31, 2019 Share Posted October 31, 2019 The brand is Whytheat K. 60% Alumina . Calcium bonded with a service temp of 2912F (1600C). I did probaly exceed that temp? It happened after about 3 hrs forging on a 5lb 4340 hammer billet. Was paying more attention to the metal that forge temp. Placed the metal in the forge a little rough (slid on floor of forge after it sliped) and pushed up a small bit of refractory. About 30 min later, heard a wierd noise in the forge, Split the burner in 1/2 (bad layout on the holes in my multi-port burner). The forge chamber was at an honest "white heat". Hurt to look at it much. Needless to say I pay more attention to the forge temps and went back to my vers.1 burner which works very well. But I do like to experiment. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted October 31, 2019 Share Posted October 31, 2019 Anyone can claim " blah blah blah, high alumina, blah blah blah." My understanding (from last year) was that any high alumina refractory's content of alumina started at 65% and up. Almost as important is what the rest of a refractory mixture contains. This is a case were the brand name matters; do you trust them are do you not. For instance, I buy my high alumina kiln shelves from Seattle Pottery Supply, and have never had any problems. But anyone who does a thorough Google search will find plenty of kiln shelves that are called high alumina, which turn out not to be, once you take a closer look at their contents. Quote Link to comment Share on other sites More sharing options...
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