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JB
8th May 2005, 09:28 PM
Can anyone advise me on buying or building a very simple forge, either charcoal or gas powered. I have an old portable bbq that might be a good start. Have viewed several US sites detailing making forges but they tend to be a bit elaborate, and anyway there's nothing like Aussie know-how.

echnidna
8th May 2005, 09:47 PM
I used to set an old steel car wheel up on some bricks with a bit of wire mesh inside to stop the embers falling down through the hole in the centre of the wheel.

I stuck a domestic vacuum cleaner hose between 2 of the support bricks.
Then built up a mound of sand around the bricks and outside of the wheel so the air from the vac went up through the wheel.

Light a fire in the wheel then coke it up and once burning well turn on the vac
Use the vac hose connected to blow not suck.

I used coke but its probably not easy to get these days but I have seen ordinary briquettes used very effectively and charcoal should be ok too.

Hope this helps

JB
8th May 2005, 09:58 PM
That's great Bob, just the sort of basic budget job I was after. I've got a shop vacwith blower setting so no worries there. Any problem using any old bricks do you think? (Thinks: explosions).

echnidna
8th May 2005, 10:04 PM
I think I just used old clay bricks,
I'd be wary of concrete bricks or blocks.
The bottom part of the wheel rim doesn't get red hot.

journeyman Mick
9th May 2005, 12:07 AM
I've got a couple of brake drums off a semi and a stack of those extruded bricks with the holes in them that will be my forge one day. However it's so low on the list of to dos that it's all covered in 2M high guinea grass and lost from view (there's a couple of 5M long hoop pine logs in there as well that I'll have to try and find soon :rolleyes:)

Mick-still trying to forge ahead

rodm
9th May 2005, 02:17 AM
Charcoal works fine. Find an old log that has been burnt and scrap off the charcoal with a shovel. Keep it stored dry.
I was heavily into blacksmithing twenty five years ago and fortunately for me there was a blacksmithing club in Mt Lawley - Perth.
The old blokes were all deaf and real characters and used to amuse themselves by watching their puplils bash the dickings out of a lump of iron. At the end of the night they would come over and demonstrate in five minutes what you had been trying to do all night. It was the old way of passing on the skills and you didn't forget. Once you realised they wouldn't show you twice you had their undivided attention.
Unfortunately blacksmithing at home caused too many problems with neighbours and I eventually sold the anvils, swage and tongs. I used a hand bellow as I considered it more traditional but it was much easier with an electric blower.
Thanks for reminding me of a very enjoyable part of my life.

JB
10th May 2005, 10:22 AM
All useful information, thanks fellahs. I'm about to start converting the bbq; first question is from what direction does the air need to blow from? Can it come in from the side, or do I need to drill holes in the bottom of the metal dish; does it need holes there anyway for ash to fall through; and doesn't a vacuum cleaner blow everything everywhere?!

By the way I'm not getting notification of responses to my email box. Unless some of you blokes are deliberately ignoring me (I can take it) I believe you need to use the Reply box at the bottom of the post, not the one in the poster's post (if that makes sense).

echnidna
10th May 2005, 02:17 PM
The vac blew into the side but in effect there was a large plenum chamber under the wheel centre and the air diffused as it travelled upwards through the wheel centre to the fire section.
Don't recall any ash problems.

JB
11th May 2005, 07:17 PM
For potential forge builders who may have come across this thread after doing a search for Forge:

I had one very small forging task requiring flattening the ends, and a 2" section in the middle, of a two metre long 20mm steel rod.

After extensive reading and research I figured what I needed to do was basically heat the steel to red hot then bash it flat. So:

1: Bought a 10kg bag of 'heat beads' at Target (some kind of mini briquettes I guess)

2. Chucked them in the old thin steel bbq base on top of some kindling. (Any metal container would have done, or the fire could even be on the ground, with four bricks around it to create an enclosure.)

3. Lit it up and got things moving by blowing it with the vacuum cleaner (on blow needless to say).

4. Stuck end of rod in and continued blowing with vacuum from about 2' (feet) away until rod got red hot.

5. Bashed ends flat on section of old railway sleeper clamped to solid wooden bench.

Everything was done outdoors for safety. One end of rod was supported in Triton super jaws while other end was in fire. Smartened up towards end of job by also jamming vacuum end into jaws so I didn't have to hold it.

Couple of things I learnt: standard hammer does the job, no need for anything heavier. Maximum heat seemed to result when blower was close enought to make fire glow hard, but not close enough to roar too much.

Purists will no doubt be aghast at all of the above, especially use of briquettes which are said to contain impurites that weaken the steel etc etc, but for the job I had to do i was prepared to take the chance. Flattened sections seem quite strong.

If there was one thing I gained from the exercise it was admiration/awe at the forging achievements of Ned Kelly and Co working in the bush to make their armours. What a feat! Wonder where they got their briquettes, not to mention vacuum cleaner.

johnc
11th May 2005, 09:33 PM
We used to have a forge with the hand crank blower and in that the air came from underneath and passed through something resembling a small upturned colandar. To be honest I doubt it matters much, its the air flow onto the burning embers that provides the oxygen and does the job. Your right a small hammer does the job, this forge was for chisels and punches used for stone and a ball pein hammer was the tool of choice. I wasn't the blacksmith my father was the last to use the gear properly I was more heat and shape, never quite mastered the tempering bit. The forge was sold but the rest of the gear is in the shed, one day it might be dragged out and dusted off but so far I've not been sufficiently tempted.

I've seen a few of the car rim forges, one had a hair dryer with a dud element connected up and it seemed to work OK for the bloke using it. And on the bricks clay with a low moisture content, if they have been lying on a soggy bit of ground they can explode when the moisture expands in the brick.

JohnC

JB
11th May 2005, 09:43 PM
I was more heat and shape, never quite mastered the tempering bit.
JohnC

In case there is still any doubt about my ignorance of al things metal...on future projects how would I avoid tempering the metal when I only want to heat and shape it? (I had to drill holes in the flattened rod and one end was significantly harder. I assume this was because i had inadvertently tempered it?)

echnidna
11th May 2005, 09:51 PM
Did you happen to drop 1 end into water to cool it down quick, as that would have hardened that end. Better to let it cool down in the ashes and it would be nice and soft.

JB
11th May 2005, 10:10 PM
Yeah, I did involve the hose on at least one end. Is that how you temper, by heating red hot then rapidly cooling?

I thought I heard that chisels were softened if you water cooled them when sharpening them on the grinder. Now I'm confused. :confused:

echnidna
11th May 2005, 10:17 PM
Quenching hot steel hardens it and in doing so makes the steel somewhat brittle.
Tempering is the process of reducing the hardness a little bit so that brittlemess is reduced whilst retaining sufficent hardness for the purpose in hand.

Quenching tools when grinding them is necessary to prevent them annealing from a slow cooling down.

JB
11th May 2005, 10:24 PM
Quenching tools when grinding them is necessary to prevent them annealing from a slow cooling down.

What does annealing mean here? My dictionary says toughen or temper...whay would you want to prevent that?

echnidna
11th May 2005, 10:26 PM
annealing = softening

JB
11th May 2005, 10:33 PM
Thanks Bob, that makes sense now. Though my dictionaries do define annealing as hardening.

I think the no-no I was thinking of regarding chisel sharpening was heating the edges to red hot..no doubt this would soften them. I dont think I would deliberately want to make them harder, and more brittle, by quenching them though. Best practice might be to sharpen carefully so they dont get too hot. What do you reckon?

echnidna
11th May 2005, 10:35 PM
I was taught to quench them often while grinding thus keeping them cool.

JB
11th May 2005, 10:37 PM
Yeah, spot on...now it's all coming back to me! Thanks Bob.

julianx
15th May 2005, 06:45 PM
For potential forge builders who may have come across this thread after doing a search for Forge:

I had one very small forging task requiring flattening the ends, and a 2" section in the middle, of a two metre long 20mm steel rod.

any pics - of the forge - my sons interested in blacksmithing, might be a cheap way for him to give it a go.

JB
15th May 2005, 09:02 PM
Sorry no pics, but the forge was as I've described it: just a briquette fire, in a bbq or on the ground, with me pointing a blower (vacuum cleaner on blow) at it from about 2' away.

Briquettes ae not recommended by experts, and for safety have a couple of full buckets of water on hand.

Metaphor
15th May 2005, 11:36 PM
I am new to this forum but found this thread very interesting and had to reply. I am in the process of making a small forge for myself as I wish to do some Blacksmithing. The forge I am making should be completed spending under $50. I picked up a truck brake drum for free, (370mm Dia x 150mm H) put a plate in it with slots for air to flow. Bolt the drum to 100mm dia x 400 long tube that has flange at the end. This needs to have a cap at the end to catch the ash and seal the air flow. You can attach a small car heater blower to the side of the 100mm tube, but I am going to try and use my compressor on low pressure with a small ball valve to control the air flow. Put this on a stand and away you go. Just having some problems getting my hands on a anvil or a anvil shaped object, but I am patient...

JTonks
16th May 2005, 01:03 AM
Just having some problems getting my hands on a anvil or a anvil shaped object, but I am patient...
Just spotted an anvil on ebay (6179239219). Item is in Hobart so postage may be a bit hexy

By coincidence I also saw a couple of anvils in a second hand joint today. They wanted over $400 for them. Got be dreaming I thought.

John

rodm
16th May 2005, 01:13 AM
Metaphore
You might be better with the car heater than a compressor. It is the volume of air (oxygen) that kicks it along.

Depending on what you are doing any large (heavy) chunk of metal will substitute for an anvil. I've seen railway iron locked down to a big stump and it was satisfactory. It even had a horn shaped into it. The tip is to lock it down because you do not want to be juggling with anything when you have a red hot poker in your tongs.

Traditional anvils will be expensive and in high demand but keep your eyes out for a new Asian/Indain anvil as they are reasonably priced. A bit broader and flatter in the horn but still quite usable.

Metaphor
18th May 2005, 10:46 PM
Metaphore
You might be better with the car heater than a compressor. It is the volume of air (oxygen) that kicks it along.
Thanks rodm, I will keep this in mind if the compressor doesn't work. Just trying to use what I have without going into undue expence. With the anvil I again just want something small and cheap as initially I want to make some carving tools. :)

rodm
18th May 2005, 11:34 PM
I appreciate your approach and venturing into a new area it is not wise to invest large amounts.
Do a search on ebay for anvil and you might be pleasantly surprised.
Try this for a small anvil and the freight shouldn't scare you too much either.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=20761&item=4381959972&rd=1

johnc
20th May 2005, 12:03 AM
I've seen a compressor used in a forge for air flow, which seemed to work OK, I would imagine the regulator would be set to get the air pressure as low as possible, or would you just choke off air supply a bit and let the reduced flow do the job?. Railway iron certainly works as an anvil, a bit crude but probably fine to learn on.

JohnC

goodwoody
21st May 2005, 07:49 PM
The idea of tempering is to reduce the brittleness of the steel while retaining some of the hardness. A good way to explain this is a diamond, a diamond is very hard but if you hit it with a hammer it would shatter due to fact that it is extremely brittle.
The definition of tough is being able to absorbe the shock from a force/blow.
This only happens if the steel in mention is carbon steel, ordinary mild steel wont harden after quenching.

goodwoody
21st May 2005, 07:55 PM
JB do a search fot 'the village smithy' this bloke is located at Logan/Logan village on the south side. He has a website. He also sells associated item including coke and second hand forges. Also teaches during weekend courses. www.villagesmith.com.au Allan and Hellen Ball i think their names are.