New foundry, seeking advice

[Discordicus]

Hi all, I'm in the process of building a new foundry from a propane tank. I've already gotten the mechanical stuff out of the way, but now in the process of insulating it is where I'm trying to see if this will work. 

 

So I've purchased some 1" ceramic wool from a local pottery supply, and cut out the pieces I need. I made a mixture of Fumed silica and water in a 3:7 ratio. Dunked the pieces in the mixture and squeezed out any excess and let it air dry for 24 hours. I then fit it in my foundry and heated it up to about 500 deg F for roughly half hour to let it drive away any remaining moisture. This is where I'm currently at in my process. What I will be doing next is coating the wool with Greenpatch 421 that I ordered, let that air dry for a day, then fire it up to working temp for about half hour and then letting it cool down. Once that is done, I also want to apply a coating of Metrikote which I ordered as well, as an efficiency point of  view. 

 

I've seen so many posts end up contradicting each other in terms of these products and their order of application, so any advice would be appreciated or if this seems fine for a simple hobbyist, then let me know.

 

Thank you 

[ThomasPowers]

How many layers of the 1" did you use?

[Frosty]

Welcome aboard Discordicus, glad to have you. If you'll put your general location in the header you'll have the chance of hooking up with members living within visiting distance. 

I like your login handle but it's kind of cumbersome to write so if you don't provide an easy to remember name or nick name I'm just doing to call  you Disco.

What are you planning on melting in your melter? Al and lower temp metals and you're good to go now. If you're planning on higher temp melts I highly recommend a second layer of 8lb ceramic blanket refractory for the insulating outer layer.

Dunking the blanket in silica solution is overkill but I do overkill and it's not a deal breaker. Once it's dry IN POSITION THE FORGE, you want to heat cure it to red heat. This fuses the silica to the ceramic fibers where they touch encapsulating them so fibers can't drift into your breathable air. It also stiffens the blanket up considerably making it stronger and les susceptible to impact damage from bumps.

Once cured in place, wet the surface of the rigidized blanket with clean water BEFORE applying the hard castable refractory inner liner, the Flame Face. This is known as buttering and is a common masonry practice to ensure a good bond between the applied mortar, plaster, etc. it makes a BID difference so butter it first. 

I'm not familiar with Greenpatch products so follow THEIR procedures to attain a good cure.

Matricote or Plistex are good kiln washes and will improve your melter's life span and to some extent efficiency.

Frosty The Lucky. 

[Discordicus]

So probably the highest thing I'll melt is copper. Mainly to alloy it with Al. And I'm currently in cocoa FL, but I'll be moving to KY sometime in Oct. I read some of your posts before to cure the ceramic wool up to red temp but not quite sure what that means. I do have a IR thermometer a friend gifted me so I can check the temp of the wool surface directly. I also recall the butter thing so I'll be sure to do that. 

Anyway this is what it currently looks like.

[Discordicus]

So new question. A dumb question, for sure. If i apply the colloidal silica onto the ceramic wool, could I dry it in the oven at the lowest setting? It being florida and all, there was no rain forecasted today and it suddenly went grey now so I had to bring my wool out of the rain. I could potentially dry it out a bit inside my oven, but I'm concerned that the fibers will still cause issues inside the oven or worse the silica will screw up my oven somehow. The lowest my oven will go to is 170 F so it could potentially be used to dehydrate (and i've made jerky in it before as well) but whats the consensus here. Before i put myself in danger. Thank you.

[Frosty]

No need to soak the blanket in the silica solution and no, you don't dry it before putting it in the furnace. Drill a couple small holes in the bottom of the melter shell so liquid can drain. Install the blanket and let it dry. If the humidity is too high you can hang a light bulb in the chamber to help.

Silica rigidizer doesn't need to be completely dry to fire cure but there's no point in burning extra fuel to dry it from wet, damp doesn't matter.

I'm a little concerned about you now. How can someone with casting experience NOT know what RED HOT means? Another red flag for no hands on experience is wanting to make your own copper alloys. That is NOT a beginner's project.

I don't want to be a kill joy but I strongly doubt you know enough to safely cast metal, even low melt metals are very dangerous to handle. Even zinc can put you in the hospital with life altering burns. 10lbs. of molten copper has bout the same amount of too easily released energy as about 1/4 case of dynamite. A few drops of water can spray molten copper a good 30'. 

I strongly recommend you take some casting classes, a course would be better. Casting high melt metals can't be made completely safe and is no place to try and figure it out yourself. Asking strangers on the internet how is literally filling out applications for a Darwin Award.

Frosty The Lucky.

[ThomasPowers]

Please do not put fibrous refractories in an area that people use for cooking and eating!!!!!!!!!  Now if you have an oven out in your shop that you use just for burnout of molds then yes you could use it for drying.

[Discordicus]

18 hours ago, Frosty said:

I'm a little concerned about you now.

I appreciate the safety concern, and perhaps I should have been more specific. When you mentioned bringing it up to red hot, my question is the following: 

 

Should I bring it up to a low, dull red (~800-900 F), or up to bright/cherry red (~1500-1600 F)? I figured it would be towards the lower temps, but wanted to be sure. 

Thank you for the suggestion to take classes/courses before I start casting, however I regret to inform you its a little too late. I've made aluminum bronze and have melted copper before in an older, more jury-rigged foundry. I do understand however there's no way to make it completely safe. I do try and be as careful as possible. I don't pour over cement, make sure my tools are dry by heating it prior to grabbing the crucible, I don't cast large amounts of metals either (much less than 4 lbs total). I only have poured into simple ingot shapes (round or rectangular). 

 

Now, to get the xxxxxxxx off my chest, the "Darwin award" comment I felt was unnecessary, even if it did come from a safety standpoint. I've been reading these forums and reading your advice to other users for several months before I started trying this for myself, and I figured I was asking someone knowledgeable and respected on the subject, not a stranger.

 

But yes, it's not something for beginners, so I understand the risks I am taking in doing this. Thank you for the tips on the wool, good to know it can still be slightly damp before firing. I doubt i'd ever be able to get less than 20% humidity with this weather.

18 hours ago, ThomasPowers said:

Please do not put fibrous refractories in an area that people use for cooking and eating!!!!!!!!!  Now if you have an oven out in your shop that you use just for burnout of molds then yes you could use it for drying.

Yea I ended up calling the supplier of the wool and asking them directly, plus, it didn't end up raining much in the end so I am just letting it dry normally. 

Edited September 2, 2021 by Mod34
Edited for inappropriate language, excessive quoting

[ThomasPowers]

I also was wondering about putting a small metal try in the bottom and using some charcoal for heat.

[Frosty]

15 hours ago, Discordicus said:

to get the xxxxxxxx off my chest,

I won't take up THAT straight line, I'm not feeling particularly friendly. Another strong signal you wear like a rotating beacon is overthinking SIMPLE things by trying to figure them out instead of reading about them in the appropriate sections.

Forge or melter, just a propane furnace in a different configuration. There are thousands of posts discussing basic forge builds of many types. Had you bothered to do ANY reading, we'd be talking about fine details rather than things kindergarten basic. 

Expecting someone else to do YOUR research and answer your questions in a way that you wish is irritating to say the least. You REGRET to inform me you already know what you're doing?  

I've already told you how I'd line your melter. 

Frosty The Lucky.

Edited September 2, 2021 by Mod34
Edited for inappropriate language

[Discordicus]

Mmm. I seem to have struck a nerve. I apologize for upsetting you. I will continue reading up on this and hopefully if it comes out OK i'll post updates on it. 

 

15 hours ago, ThomasPowers said:

I also was wondering about putting a small metal try in the bottom and using some charcoal for heat.

Funny enough, I thought the same thing looking at my charcoal bag, but then thought "nahh, ill just let it air dry."

Edited September 2, 2021 by Mod34
Excessive quoting

[TWISTEDWILLOW]

Discordicus, first off hello and welcome to the forum! Glad to have you! 
 

i know absolutely nothing about gas rigs as I only forge with coal so I can’t help you with that stuff,

but I thought I’d chime in and say that Frosty means well and most of the time he’s really friendly! But he takes safety very very very seriously! 

ive seen this same conversation play out many times between him and others on here over many different subjects, 

but my main point is no one on here wants to see someone get hurt, killed or burn down a house, shop or half a neighborhood,

there are lots of people around the world that read this forum of all ages and backgrounds and it’s important that everything posted here is as safe as can possibly be, so that someone inexperienced doesn’t see something dangerous on here and then go off an attempt to do it their self and get hurt, when there are safer ways to accomplish their goal that are already posted here, 

ive never met anyone on here that wanted to discourage anyone else from learning, building or creating, they just wanna make sure everyone goes home at the end of the day with all their eyes, ears, fingers an toes! 
 

Research, learn, build, Be safe, have fun an post lots of pictures! I for one always enjoy seeing what everyone else builds! 

[Discordicus]

6 hours ago, TWISTEDWILLOW said:

Discordicus, first off hello and welcome to the forum! Glad to have you! y seeing what everyone else builds! 

Hi there, thanks for the welcome. I know full well he doesn't mean to offer insult, however harsh his words are, and I've already apologized in my previous reply to him as well, and will gladly accept any advice if he's still willing to give it. I'll try to make sure i'm as safe as possible.

[Irondragon Forge ClayWorks]

Over the years, we have saved a few folks from becoming recipients of the Darwin award. Kinda makes our day when someone reads a post by someone else and learns from the unexpected sharp reply. Just remember, don't take things personally and answers go out to all who read the thread.

[Frosty]

Discordicus: You don't have anything to apologize for, not really if at all. I gladly accept in the spirit it was given. Thank you.

I went off the rails I could've worded things differently but didn't. The Darwin Award statement was completely uncalled for, my bad. I offer you my humble apologies for my lack of restraint.

I don't offer this as an excuse, it is what is. I'm a TBI survivor, my emotions are always close to the surface and can take a long time to simmer down. Aphasia makes me lose words or thoughts in the middle of a sentence and I sidetrack at the drop of a new thought. Sometimes I find myself upset by something someone said years ago. It's something I deal with every day and something my dear friends here on Iforge put up with like my personal champions. My sign off says it all, I'm a lucky guy.

Frosty The Lucky.