Is building a propane forge really that simple?

No Stacy, I didn't miss that part... if I can build one anybody can... lol.
I was more poking fun at the fact there are 90 ways to skin that cat, and we can go on for pages talking about it :D
If the OP waits for us all to weigh in on the best way to do x y and z he may never get started... lol.

For me though, the physics equation is much much simpler...

F+S=E

(F) Fire

(S) Steel

(E) Eric so happy he's about to pee his pants!

Cheers!
 
ok, let's say I can get hard firebrick most easily, and no other refractory materials. (at this point I think that's probably the case.) What kind of forge should I build? should I use half-thickness bricks or whole-thickness bricks?
 
Not for nothin, but click my sig... I have my forge and burner plans there for all the world to see. It ain't the sexiest thing, but its all hard brick full size and the only mortar I used was a thin bit of imperial fireplace mortar (small tub of black stuff at Lowe's near the woodstove piping $5) with hard brick dust (plenty of it from drilling and cutting bricks) mixed in. It won't get you big nasty billets goin, but blade thickness you will be fine.
Cheers.
 
All-brick forges, particularly those made from hard bricks, are notoriously fuel inefficient and hard to get very hot... they just soak up the heat, and don't reflect a lot. In my experience, ceramic blanket is much much better. It's not at all hard to get, you can probably find it locally with less than ten calls from the phonebook, and certainly it's easy and pretty cheap to get online.

I also found that castable refractory does not suit me, either. I burned a lot of propane trying to learn how to forge weld in a gasser with a castable shell.
 
Salem what are your thoughts on castable refractory with a itc100 coating? I did this and it seems to work really well. Its over 2 inches of wool. It heats up pretty quick.

For the OP this is my forge I recently built. It aint the prettiest thing but it works well. I stack bricks in front and stuff some wool in the back hole when I am not using it.


 
Quint, the castable forge I made had ITC100. Actually, it didn't to begin with, but adding it was the only way I could get to forge welding heat. It still sucked. There was no wool involved with that forge- I've never used a hybrid castable/wool shelled forge, although some folks apparently like them. The best, to me, is 2" of kaowool, satanite top coat, and something expendable for a floor (thin, cheap firebrick for my venturi, bubble alumina on for my vertical.) Neither of my forges have ITC right now, although I do think it's quite a boon to have.

BTW that forge looks great- a T Rex burner and a pyrometer! Good job there.
 
Castable refractory makes a durable and high temperature thermal body for the forge chamber. It works best with a reflective coating to be more efficient, but it has to have a sufficient insulating jacket around it to keep the heat it soaks up all on the inside. The normal setup is 2" HiZ wool wrapped around a 1" castable shell, coated with ITC-100, and a bubble alumina floor. It takes a good while for one of these to come up to full soak, about 30 minutes for a big one. Once fully soaked, they hold and maintain temperature very well. They are much more complex to build than most simple hobby knifemakers need.

I wish I could find the photo again, but years back there was a picture of a guy in Mexico who build a forge outside his shop. He started with a stack of cinderblocks to make a platform. On that he put a rolled up tube of insulating wool contained by chicken wire. He built up adobe around the wire to make an outside shell. He lined the forge with a mix he made from clay on his property, ashes, and lime. It was fired with a cobbled together blown burner. It looked more like a bread oven than a forge, but it worked well for him.
 
There are trade-offs, and hard firebrick are not as insulating as coated ceramic insulation (why I am using that on my blown forge project) but if they are easy to find it will get you up and running. The up-side is that it is bombproof. It does take a while to get up to temp, but keeps plenty of heat where it needs to be. And regardless of the availability of ceramic blanket, $1.15 a brick was hard for me to say no to.
So far I haven't had any problems forge welding with my setup...
 
LucyCustomKnives said:
There are trade-offs, and hard firebrick are not as insulating as coated ceramic insulation (why I am using that on my blown forge project) but if they are easy to find it will get you up and running. The up-side is that it is bombproof. It does take a while to get up to temp, but keeps plenty of heat where it needs to be. And regardless of the availability of ceramic blanket, $1.15 a brick was hard for me to say no to.
So far I haven't had any problems forge welding with my setup...
Click to expand...

Not to be nit-picky, having gone to your website to check out your work since you seem to be the newest expert on the block (how to put this delicately . . .) I do not see *any* damascus, pattern welding, forge welded sword hilts, SanMai, or consolidated bloom smelted work. How much actual experience do you have forgewelding (especially forgewelding in that forge?)

Not looking for an argument here, but you are presenting yourself as an expert.

-Page
 
I am not presenting myself as an expert in damascus making or anything of the sort. I have made a few tools and practice welds with that forge. I have also stated that it is far from ideal, and not good for large billets of anything, much less doing a lot of folding to any thickness. I do forge blades from it, and do my heat treatments with it... I said "it was a cheap and easy way to get up and running."
Now, I am not an expert, nor do I claim to be. I do know more then the average joe, but not as much as a well heeled maker. That is why I say "this worked for me."
Now, as for experience in other venues... well that's a different matter.
So far I have had the good fortune to have some very knowledgeable help along the way. Now, had I said "yeah with this forge you can make crazy nice stainless laminates and amazing big nasty billets of mosaic damascus," well, that would be one thing. I read the above (what if all I can get are hard firebrick) and figured I would show what works for me... for now... with hard firebrick...
This is supposed to be a community of cooperative learning. I fully expect if I say something wrong, to receive constructive criticism. If I say "this worked for me" and there is a better way of doing it, I would love to hear it. I wouldn't expect you to stack up with my team and know what you are doing from the word go, same as I am learning my way here and wouldn't be expected to step up to the forge with the big boys either.
If I was trying to be an "expert" I don't think I would waste the typing time on saying "I am fortunate to be able to keep the lights on in the shop." Sorry if I stepped on any toes.
 
If efficiency is important to you its hard to beat kaowool blankets with a refractory cement coating along with a thermal reflector such as ITC 100. I've found
cast-able or brick for that matter take to long to heat up and do not hold a stable heat. Both my blown forges have 3" blankets, satinite coated and ITC 100 surface treatment. The better the insulation and the smaller the chamber you are trying to heat, the easier it is to maintain a proper set point temp.
 
This pic shows a 12 inch cylinder with 3 inch inswool blanket the working area is 6 inches across.
fast%2520003.jpg
 
Several of the horizontals I have built used that same way, multiple layers of 1" wool with a throwaway thin brick on the floor, with wool under it. I found it worked very well for me, too. When a floor brick gets flux trashed or actually burnt up, it can be slid out and replaced pretty easy.
 
In this horizontal I put a boxed steel base under the brick and insulated the box inside with kaowool. The forge face is removable so the soft firebrick on the floor can be changed. This was my fourth forge and the experience gained from the earlier builds payed big dividends.
Dsc00544.Jpg
 
LucyCustomKnives said:
I am not presenting myself as an expert in damascus making or anything of the sort. I have made a few tools and practice welds with that forge. I have also stated that it is far from ideal, and not good for large billets of anything, much less doing a lot of folding to any thickness. I do forge blades from it, and do my heat treatments with it... I said "it was a cheap and easy way to get up and running."
Now, I am not an expert, nor do I claim to be. I do know more then the average joe, but not as much as a well heeled maker. That is why I say "this worked for me."
Now, as for experience in other venues... well that's a different matter.
So far I have had the good fortune to have some very knowledgeable help along the way. Now, had I said "yeah with this forge you can make crazy nice stainless laminates and amazing big nasty billets of mosaic damascus," well, that would be one thing. I read the above (what if all I can get are hard firebrick) and figured I would show what works for me... for now... with hard firebrick...
This is supposed to be a community of cooperative learning. I fully expect if I say something wrong, to receive constructive criticism. If I say "this worked for me" and there is a better way of doing it, I would love to hear it. I wouldn't expect you to stack up with my team and know what you are doing from the word go, same as I am learning my way here and wouldn't be expected to step up to the forge with the big boys either.
If I was trying to be an "expert" I don't think I would waste the typing time on saying "I am fortunate to be able to keep the lights on in the shop." Sorry if I stepped on any toes.
Click to expand...

No foul. I just saw that you have been posting up a storm, and when you claimed that you didn't have any problems welding with your forge, the implication is that you have done a lot and it world great each time. I went to your website to see if my initial impression was wrong, and didn't see anything there that would show any experience with forge welding. The problem with giving advice on this forum that is not backed up with experience is that there are 20 guys out there that will go out and try to build one just like that because it is easy and cheap, then there will be a whole rash of "hey I built a Lucy design forge, why won't it heat a 15 layer billet of O-1/L6 up to welding temps". Most of the stuff you have posted that I have seen seems reasonably good, you have obviously read a lot and paid attention, I just wanted to make sure that the information being communicated will not cause anyone trouble.

BTW my forges are typically blown propane, lined with 2 inches of 2800 degree kaowool with a hard brick floor, the kaowool is coated with satanite, then ITC 100, the floor is covered with bubble alumina then satanite with a drainage channel for the flux to run out the front rather than puddle

-Page
 
sunshadow said:
BTW my forges are typically blown propane, lined with 2 inches of 2800 degree kaowool with a hard brick floor, the kaowool is coated with satanite, then ITC 100, the floor is covered with bubble alumina then satanite with a drainage channel for the flux to run out the front rather than puddle

-Page
Click to expand...
I like the drainage idea, for that did you simply slope the satanite under the bubble alumina toward the front or did you cast a small channel to direct it into a receptacle? I am assuming this is under the soft firebrick?
I had not looked into the bubble alumina until Stacy mentioned it honestly but it seems to be an ideal setup. I would prefer not to have to build this thing again or tear it apart if I can help it. I am going with a vaulted roof looking shape with a ribbon burner gleaned from some place on the web. It uses castable refractory around a box of crayons. The crayons are then melted out to leave the burner face behind... My $$ is tight so its slow going. But like I said above, hard brick is far from ideal and yes, it is inefficient. Tired of filling propane bottles...
 
sunshadow said:
....the floor is covered with bubble alumina then satanite with a drainage channel for the flux to run out the front rather than puddle

-Page
Click to expand...

Hello Page - The photo below offers a fine visual of what you were describing above, I believe. The plate shown is a removable, sacrificial floor from my Chili Habenero forge. I need to re-line my forge fairly soon and I'd like to start doing a bit of welding without the same results, so your above design sounds intriguing. Could you possibly post a photo of your forge showing how you constructed the floor/channel?

edit to add: Also, will the use of kerosene, rather than standard anhydrous borax flux, alleviate this problem?

Thank you,

-Peter

 
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LucyCustomKnives said:
I like the drainage idea, for that did you simply slope the satanite under the bubble alumina toward the front or did you cast a small channel to direct it into a receptacle? I am assuming this is under the soft firebrick?
I had not looked into the bubble alumina until Stacy mentioned it honestly but it seems to be an ideal setup. I would prefer not to have to build this thing again or tear it apart if I can help it. I am going with a vaulted roof looking shape with a ribbon burner gleaned from some place on the web. It uses castable refractory around a box of crayons. The crayons are then melted out to leave the burner face behind... My $$ is tight so its slow going. But like I said above, hard brick is far from ideal and yes, it is inefficient. Tired of filling propane bottles...
Click to expand...

If you want to save your forge floor you might consider switching to hydrocarbon solvent and away from borax.
 
Kind of hard to shoot the drainage trough as it is full of flux which slowly oozes out the front with glacial alacrity. I just kind of squished the channel into the wet bubble alumina with a piece of dampened 1 1/12 inch round stock. (wetting it didn't do much to keep the bubble alumina from sticking to the round stock, next one I will use a layer of damp newspaper and just burn it out once everything is dry) Fred I haven't experimented with hydrocarbon flux yet. I would imagine you have to be much more careful to have the surfaces clean with it than you do with borax since there is nothing to bring the oxides into solution and carry them out of the weld zone

-Page
 
Actually Page, from what I've been reading, when welding with hydrocarbons in a reducing atmosphere, the carbon wants to burn but needs oxygen to burn- which is not readily available, so it seeks out the oxygen present even in rust or scale on steel, eating that and leaving only Fe and carbon dust. Apparently you can get away with not grinding the scale of your steel when welding reducing with kero or diesel, although Steve Culver and other recommend still cleaning your steel well for the best possible results.

I can't wait to try it myself. Especially since John White's method he posted at ABS Forum is welded up and drawn entirely with his power hammer (LG like mine I think.) I had been waiting until I finished my press build, but not anymore...
 
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