Questions regarding first forge. Experts abound?

[mikeatarms]

Good day!

 

While I normally don't barge into an established online community and ask for help without first attempting to contribute to said community, I find myself lacking specific knowledge that I hope you seasoned pros can help with.  So I hope you'll forgive me and I thank you for your time in advance!  I'm attempting to build my first forge but I'm not sure exactly what materials, burner, and fuel I should be using.  

 

Design and Considerations:

 

I want to build a small, safe, and hopefully somewhat efficient forge, to anneal mild steel sheet (low carbon) pieces.  These would range from 10 gauge to 18 gauge.  But this is where it gets interesting.  The forge would be used in the backyard of my apartment/townhouse, which means proper coal forges and oxy-acetelyne torches w/ rosebud tips are out.  You know...don't wanna scare the neighbors (or landlord).  Most importantly, these pieces will be of various sizes and shapes so I can't stick the piece in the forge's chamber without making a huge forge.  So the forge's mouth would need to be vertical and the pieces resting on top of the mouth, moving the piece around until it has been heated all over.  And after built has to cost less than $100.  

 

My uninformed idea:

 

My initial idea is stacking several soft fire bricks and carving a bowl shape into it.  The carved out bowl shape would be maybe 8 inches in diameter and maybe 6 inches deep. The forge would rest in a metal support with legs to stabilize and contain it.  The torch's flame inserts into a hole in the bottom, while the workpiece rests over the bowl-shaped mouth.  A hard fire brick acts as a door, resting on top of the piece, sandwiching it.  

 

 

Begin Newbie Questions:

 

- I'm thinking Propane or MAP gas for fuel.  I don't have experience with either for metalwork: is MAP worth the extra money per bottle because it will heat faster or is propane sufficient?  I just have to anneal to dull-red or cherry-red color.

- I'm looking at the Bernzomatic torches.  Some are "pencil" tipped, some appear larger.  Does the tip matter much in this use?

- Since the forge is facing skyward, can the torch's flame enter from the bottom?  Are there safety considerations regarding where the torch is positioned?

- Because the piece is receiving heat from below, and is not sitting in a forge's chamber, can the chamber be shallow like I mentioned?

 

I really appreciate your time and any information you're able to give!  I'm normally stubborn and go solo on my ideas but I'm plainly just lacking expertise here.  And I'd rather not blow something up!

-Mike 

[Larry H]

mild steel needs no annealing 

[mikeatarms]

Thanks for your reply!  However, I'm using hammers to form the piece into the desired shape (some very deep forms) so the workpiece has become work-hardened.  I definitely need to soften the metal before work progresses...its very difficult to move and the extra force used leaves unsatisfactory hammer marks.  Most professionals I've seen who do the work I'm doing use an oxy-acetylene torch with a rosebud tip directly to the workpiece to spot-anneal, but this is out of my ability.

[Chinobi]

what about a weed burner? it sounds like you want to make a fixed vertical flame thrower with a bit of a refractory underneath it.  put your fabrication effort into some kind of moveable third-hand stand and blast it with the weed burner.  might be a little dramatic for a dense community like an apartment complex though.

 

for what it sounds like you are trying to accomplish you can probably get away with just a propane bottle, search the site for MAPP (it wont accept 3 letter word searches) and you can find more specifics regarding the temperatures involved, but dull red does not a MAPP torch necessitate.

 

how about a regular plumbers propane torch? if you are planning to heat and move to the next zone anyway you might as well go hand held. i have forged (small stuff) with a bernzomatic TS4000T on a propane bottle holding the piece freehand and laid on a firebrick with no enclosure, so it will get you there.  a BZ8250 will save your elbow some lifting with the remote line.

 

a burner mounted vertically should not be placed underneath an awning or second floor patio, or the dry old oak tree in the backyard etc.  waste heat travels upward, point the source upward and it travels faster.

 

how large and awkwardly shaped are the pieces that you are trying to anneal?  without a sense of scale its hard to visualize how it needs to go together.  have you tested to see if your process of heating an area and moving on to the next zone will allow for a slow enough cool to actually anneal?

 

at any rate, flip through the gas forge section and see what other people have put together, and take a look at the designs at zoellerforge.com and see if something in that vein wont fit your criteria.

 

Good luck!

[mikeatarms]

Thank you Chinobi!  I think I'll try the propane, it's heartening to hear that you've used it with some success.  I was looking at the standard plumber's propane bottle and the "fancier" burner fitted with a hose and wasn't sure, but since it worked for you that's enough for me to try.  The pieces will be at largest 2 ft x 1 1/2 ft with a considerable curvature (almost a complete semi-circle) but 90% of the other pieces would be much smaller, around 8in x 6in with slight to extreme curves.  

 

No testing so far because I lack all of this equipment; I was hoping to run into someone like you that could at least help me make some informed purchases, instead of emptying my wallet on solutions that don't work.  I value trial and error but in this case I just don't have the funds, or time!  I know that a proper anneal like a professional establishment offers won't be even closely achieved, but I'm hoping this spot-anneal will suffice.  I could also always work it on black heat if annealing doesn't work I suppose...it's better than in it's work-hardened state!  And that's good enough for me to try.  

 

I really appreciate your response and time Chinobi!  I'll be sure to upload a photo after I get this thing built!

[Chinobi]

no problem mike, i just want to make sure there is enough salt applied to my recommendations :) im still pretty new here myself so you would not be hurting your cause if you stall until some of the more seasoned members can add their thoughts.

 

check with where ever you end up buying the torch kit from and see what their return policy is, that way if you mind out that it isnt working for you, you are not out the 40 something bucks for the torch (you may have to eat the propane tank though).  do you have any friends, associates, or coworkers that are 'handy' and may have a torch already that you can borrow to test?

 

make sure if you end up working it at black heat that you dont forget its hot :)

 

good luck!

[Drewed]

You can buy an very small PO set-up from HomeDepot these days for about 60$  I use one when forging when I need to heat a small rod for wrapping.  The work good and will be able to heat what you need.  I have used mine to make a 1/4" rod yellow heat.

 

http://www.homedepot.com/p/t/100092336?catalogId=10053&langId=-1&keyword=oxygen&storeId=10051&N=5yc1v&R=100092336#.UVQz6RfFVfE

[ThomasPowers]

Sounds like armour making.  What about a charcoal forge burning real charcoal not briquettes?   Deals with odd shapes well and by placing some hot coals inside the piece directly where you you want to work it will do spot heating.

 

Weed burners work especially with an insulative backdrop; but beware of excessive scaling thinning the metal.

 

May I suggest you ask this question over at the armourarchive.org a website dedicated to armour making and so well up on various ways of heating and beating sheetmetal.  (and yes we use the english spelling of armour...)

 

Also look at the article on Eric Thing raising a Norman  helmet over at Anvilfire.com to see the specialized propane forge he uses (under the armoury link in the drop down navigate anvilfire menu)

[mikeatarms]

Thanks again for the replies!  Guilty as charged Thomas, I'm making armour.  It's been a long few years conducting serious research; pouring over illuminations and starting with mail and shields, and I'm finally starting harnesses from steel sheet.  I was hoping to overcome the work hardening, but, I do need heat now.

 

A proper (and historical of course) coal or charcoal forge would be great, but my landlord definitely wouldn't allow it.  I've stumbled across Eric Thing's article before, which is excellent, and I really like his gas forge.  Pretty smart rig he built.  Unfortunately, I'll need a shop or garage to use it in and I lack either.  Using a weedburner was my first idea but that sooty flame and the loss from firescale turned me off.  Too bad though because heating a large surface area at a time from it is appealing.

 

Now that you've reminded me of Mr. Thing's article, my idea is similar to his gas forge albeit much less sophisticated.  If mine works half as well as his I think I would be satisfied.

 

One of these days I'll have to quit lurking and register over on armourarchive and myarmoury.  Thanks for the suggestions!

[Chinobi]

heat + steel + atmospheric oxygen will still generate scale, just depends on the rate.  dont think that the smaller handheld torch wont cause it, its just slower and more localized.  get a wire brush if you dont have it, shame to see so much effort go into a breastplate and then have to spend more time sanding out scale texture that got hammered in :(

 

definitely want to see some shots of the stuff you are putting together, sounds pretty interesting :)