11 replies to this topic

[captainbunch88]

I need some opinions on building my first forge. I bought a cheap BBQ pit that comes up to about waist height. I plan on drilling a hole through the bottom, and feeding air that way. I’d rather use a crank blower, but a hair dryer may have to do for now.

I’m having troubles figuring out what to use to protect the pit from the flames. I was thinking of putting some furnace cement on the bottom, and then putting fire bricks around that. Could I use Quikrete instead? For the bricks, do I have to use firebrick? I live in an old area, and there are numerous 150+ year old bricks laying around. Could I just put some furnace cement on those bricks instead?

I also thought about cutting the front of the pit out so that I could put my steel in straight instead of at an angle.

I plan on using charcoal for the time being. Here’s some pics of the pit. Sorry for the mess.

Thanks!

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[son_of_bluegrass]

DON"T use concrete or brick unless it is made for forge or fire. Regular bricks and concrete with decompose at forging temperatures and may spall or explode (believe me small or large chunks of sharp rock flying around isn't fun for normal people).

There are many cheap sources of lining. I use wood ash in an old weber grill (one of the round ones). My air comes in from the side not 'neath. Search for the differences between side blast and bottom blast forges.

Other linings include kitty litter (search lively style forge), dirt (clay type works best from what I hear). I'm sure others will chime in with other options.

I've found charcoal works better in a side blast. Just my experience. I've used both side and bottom blast with both charcoal and coal. Coal works well in either, I just find it easier to control a charcoal fire in a side blast.

Being able to but the steel straight into the heart of the fire is a good thing. Done it the other way and it becomes a hassle to control the heat in the piece properly.

If you give us the area you live in, there may be someone close by, or a club local to you where you can get help in person.

ron

[captainbunch88]

Thanks for your help! I thought I put my location in, but I guess it didn't go through.

I'm in New Orleans, Louisiana.

ETA: I'm liking the clay kitty litter ideas that I'm seeing. That'll keep it cheap and simple. I knew forge making could be a simple and cheap process, but I guess I was confusing myself with all sorts of ideas. Besides, I couldn't find refractory cement anywhere around here.

[captainbunch88]

Okay, I need some help. I lined the forge with a mixture of some kitty litter and water. I also added in some sand. I compacted it as much as I could. I've been leaving it in the sun for the past 2 days, and this is what it looks like so far.

I knew I would get some cracking, but this much? Also, I thought it would feel more smooth. Instead, it feels like Quikrete and small pieces are breaking off. Should I fill the cracks in with more clay mix, or should I scrap it all and start over?

But the good news is that the tuyere? works really well. The hair dryer really moves that air through.

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[divermike]

try a small fire and see if it works, looks a lot better than a hole in the ground to me!!

[Jreed]

Let it dry just a bit longer looks like it still has some moisture in it. Then try a small fire.

[Frosty]

You just made it too wet and it's shrink checking. Kitty litter is bentonite clay which will hold more water than you'd believe. When it dries the space the water took up causes the clay to shrink sometimes dramatically and there isn't a clay that will shrink as dramatically as bentonite.

So, it may not work this time. If it doesn't settle down and behave for you remove it from your forge and crush it up as fine as you can. Then add only a little water, less than 10% by weight and hammer it into the forge shell, hammer it till the hammer bounces. Then let it dry and seeing as you're in La I'd hang a lightbulb over it close to speed the drying.

It's a good thing you added sand, this will help it dry in a reasonable time and limit shrink checking. The downside is you're in La because bentonite being bentonite will draw moisture out of the air like a dog will eat hotdogs. Bentonite is hydrophilic meaning it's attracted to or attracts water. There's no getting around it and if it becomes a problem you can't control try fireclay.

You can find fireclay at almost any concrete supplier and it's reasonably priced though not as cheap as a bucket or bag of kitty litter. If you do end up using fire clay mix it with about 1/2 part in 4 portland cement, then mix it with about 2 parts sand. All toll that's 6 1/2 parts total whether you use a coffee can or a dumptruck, just be consistent and use the same thing to measure each part.

Okay, now add only enough water to moisten it to a compactible state. Guage this by squeezing a handful HARD, it should make a solid lump leaving your hand reasonably clean, the lump should break cleanly in two without crumbling. IF it crumbles it needs a LITTLE more water. If it leaves your hand dirty by sticking it's too wet, add a little sand. If you've ever done green sand casting it's the exact same test to see if the sand is tempered properly.

Once you have it the proper consistency, ram it into the shell with a hammer or mallet till the mallet or hammer bounces. To finish, use a steel strip like a scale (steel ruler) to plane the flat spots flat and smooth. Lastly use a burlap scrap to burnish it smooth. You have to work pretty fast once you've added the water because the portland cement WILL set up in an hour or so. You can leave the portland cement out of the mix if you like but the liner will take DAYS to dry enough to build a fire in, especially in La.'s humidity.

I hope this is more helpful than confusing, please feel free to ask me any questions you have.

Frosty the Lucky.

[zampilot]

captainbunch88, on 28 May 2010 - 05:00 PM, said:

Okay, I need some help. I lined the forge with a mixture of some kitty litter and water. I also added in some sand. I compacted it as much as I could. I've been leaving it in the sun for the past 2 days, and this is what it looks like so far.

I knew I would get some cracking, but this much? Also, I thought it would feel more smooth. Instead, it feels like Quikrete and small pieces are breaking off. Should I fill the cracks in with more clay mix, or should I scrap it all and start over?

But the good news is that the tuyere? works really well. The hair dryer really moves that air through.

Start a fire and work the blower, keep it hot for a while, throw in some metal and get it orange, have fun! Fill in the voids if any. Your forge looks good, the only thing I'd do is to make the firepit deeper by adding more material to the sides, maybe about three or four inches deep by three or four wide.

[ThomasPowers]

Probably too much water as mentioned. I would hammer my clay as it dried to get it to compact with fewer/smaller cracks.

OTOH they will not affect the use that much and fill in with ash/scale/clinker with use. Just try not to snag a hunk with your metal as you use it!

[Clam River Coal Forge]

captainbunch88, on 28 May 2010 - 05:00 PM, said:

Okay, I need some help. I lined the forge with a mixture of some kitty litter and water. I also added in some sand. I compacted it as much as I could. I've been leaving it in the sun for the past 2 days, and this is what it looks like so far.

I knew I would get some cracking, but this much? Also, I thought it would feel more smooth. Instead, it feels like Quikrete and small pieces are breaking off. Should I fill the cracks in with more clay mix, or should I scrap it all and start over?

But the good news is that the tuyere? works really well. The hair dryer really moves that air through.

If you have access to some clay that would work better than what you have. I used it for a home made foundry years back and had good results. You can break up some fire brick and add to the clay.

[Clam River Coal Forge]

Clam River Coal Forge, on 04 June 2010 - 10:36 AM, said:

If you have access to some clay that would work better than what you have. I used it for a home made foundry years back and had good results. You can break up some fire brick and add to the clay.

I know kiity litter should have bentonite clay for clumping, but not so much that is why I recommend clay like they use on gravel roads or found in river beds. May be you do not have that resource like we do in Michigan

[captainbunch88]

Clam River Coal Forge, on 04 June 2010 - 10:44 AM, said:

I know kiity litter should have bentonite clay for clumping, but not so much that is why I recommend clay like they use on gravel roads or found in river beds. May be you do not have that resource like we do in Michigan

Oh no, we have tons of Mississippi River clay here. I'm actually renting right now, so I don't want to dig up the yard. I actually had to redo the forge liner, because the BBQ pit stand broke, causing the liner to break into quite a few pieces. I have since made it much thicker on the sides and on the bottom. I'm just waiting for it to dry, and I will post pics when it does.

Thank you all for your help!