Self built forge instructables.

[eggwelder]

yes, the clinkers are a waste product, but i was wondering where they came from since i use charcoal, not actual coal. beautiful knives in your other post, i`m borrowing your rivet idea for a future project knife.

 

[Lin Rhea]

As long as I've been doing this stuff, I still don't have or haven't heard a definitive answer to what a clinker is. But, I have a general opinion of what is happening.

The smoke is gases that are spewing out and the flames are burning the gases. The "clean" coke, our primary fuel, is consumed and turned to ashes. I think it's the extra material that cant be turned to gases or converted to coke and consumed that settles into the clinkers. It's my belief that wood and coal have silicates in them and I think this might be where some of that extra material comes from that forms clinkers. Varying amounts of these extra, perhaps unwanted, materials are what makes some coal better or worse for particular uses.

 

[Billnpatti]

Seems simple enough. All I lack are a couple things......an arc welding machine and a fully stocked scrap yard. Well, I'd have to find a small vacuum, too. But, other than that, I'm good to go. :haha: Really, I like to see people who can take stuff at hand and make something they need from it for free or a nominal cost. They are imaginative and talented folks. :thumbsup:

 

[Billnpatti]

As long as I've been doing this stuff, I still don't have or haven't heard a definitive answer to what a clinker is.

As you know, there is not a specific answer to exactly what the composition of a clinker is. It is generally defined as the unburned and partially fused products of combustion of a generally solid fuel. But the exact composition will depend on the nature and composition of the fuel. Coal and coke will produce more clinkers than most other fuels because they contain a greater portion of non-combustable material and enough material having a very high temperature of combustion to form fusable ash. I don't know because I have never made a study of it but I'll bet that among the various types of wood, the hardwoods will produce few if any clinkers under conditions that are conducive to producing clinkers. I would expect trees of the ever green type such as pine, spruce, etc. to produce more clinkers due to their greater amount of combustable sap that would, during combustion, produce tars that would distill off the components having a lower boiling point. Ultimately, they would, under the right conditions, produce a tar having a sufficiently high boiling point that it would fuse with the ash and result in a form of clinker. I would expect this to be less common with charcoal since all of these saps and tars would already have been burned off in the charcoal formation process. Some woods contain a naturally occurring silica content. An example of such a wood is teak. I have never burned teak but, due to the naturally occurring silica, I would expect it to have a greater likelihood of producing some kind of clinker during combustion.

It's all in the composition of the fuel and the conditions under which it is burned that determines if, and what kind, of clinkers are formed.

 

[Loyalist Dave]

Just my opinion, but I don't see it as large enough, or efficient enough to do very much with. There are many shown on you tube videos that would be more useful. As mentioned, a forge does not have to be expensive.

Yeah, Wick is right. I have one made from concrete. I bought a bag of Quickcrete with sand as the aggregate, and made a mold out of cardboard, then mixed the concrete, poured it, and let it harden. As I poured it I added a few layers of galvanized finishing nails to reinforce the concrete. I also made it to accept a commercial, steel tuyere. I use it to heat treat parts, mostly rehardening frizzens, which are then tempered in an electric stove. The air is from a common electric hair drier. Charcoal or coal, works fine.

I plan on making another one very soon with a rectangular area for the forced air so that I can harden blades, prior to tempering them. The nice thing about concrete is that you can make any specific shape you want, and it's of course rather high in mass, so I set it right on the ground and it's stable for heat treating. I'm sure it would be awkward for working metal as one would do a lot of bending going back and forth to the forge.

The concrete cracked, as expected, but the nails seem to have done what was intended. Others have told me the nails were unneeded and cause hot spots.
:idunno:

My next one, the one for hardening the blades, will have a layer of refractory cement in contact with the actual fuel, as part of the experiment, to better deal with the heat.

LD