Hot Work

John Larsen · Post by **John Larsen** » Tue Jun 11, 2002 1:41 pm

I am ready to take my next big step and start doing some hot work. Since I am not ready to build a forge, and I do not want to buy a welding rig, I think I can do it with the following:

A MAPP torch
A welding glove
Some burn cream

Will the MAPP tourch really get things hot enough? What else am I missing? How much easier is it to work hot?

Thanks,
John

[edited for spelling]

[This message has been edited by John Larsen (edited 06-11-2002).]

jgalak · Post by **jgalak** » Tue Jun 11, 2002 2:12 pm

The only hot work I tried so far has been with a MAPP torch, and the results were inconclusive. The metal certainly moved easier than cold, but not much. Working 14ga mild, I could get a 1" x 1" area to a dull red, at most.

I used a Bernz-o-matic piezo-start torch with a swirl tip. In my experience the swirl tip is much hotter than the other tips, and hests metal fastest. The piezo start allowed me to turn the torch on and off one-handed, thus allowin for faster operation - I didn't have to put the work down, and didn't waste gas.

I just got some O/A gear, and want to try to use it with MAPP, instead of acetylene. The temperatures are close, MAPP has more energy density, and MAPP is much easier to store/handle, and is cheaper. With a proper rosebud tip, it should be very effective.

------------------
Yehuda ben Moshe
mka Juliean Galak
http://gerfalcon.tzo.com/medieval/armor/

CLANG · Post by **CLANG** » Tue Jun 11, 2002 11:34 pm

Two things about trying hot work with MAPP gas-it just doesn't produce enought heat to get enough of the piece hot at one time, and you'll go broke buying it for that reason.

My suggestion is to build a small forge. You can do it very inexpensively if you're thrifty, and free if you're a scrounger.

Try the blacksmith's virtual junkyard. Don't have a URL handy, but do a search and it'll come up.

I've been doing hot work of various sorts for years and the amount of metal you can move with a few hammer blows is amazing.

Think about the forge this way-if you're going to try hot work anyway, just expend the effort to get a forge together and that's all the extra work you'll need. Everything else you'll have to have anyway...

Particularly for armoring applications, you don't need a large forge, or one that produces a tremendous amount of heat. Sheetmetal heats very quickly. You can use an old brake drum as the pot and it will be sufficient for armoring needs. Hot work is awesome, but don't discourage yourself by doing it the hard, expensive way.

horsefriend · Post by **horsefriend** » Wed Jun 12, 2002 12:01 am

MAPP, no good. JGalak, IIRC you need different reg for MAPP, check first.
I can't recomend building a forge enough, I've got 3 set up,; the infamous "paint can", a firebrich bow forge, and a shower head like Eric Things. All are gas as the air quality police would have my A23 if I fired up coal here. However, I've got access to a 3' square open hearth coal forge at work so I've got it all.
A very good blacksmithing link is http://www.keenjunk.com/

You'll reconise some 'o the folks.

Alail/Scott

RalphS · Post by **RalphS** » Wed Jun 12, 2002 2:54 am

If you want to get started quickly, get either an expendable BBQ, or a solid cast iron one. You'll burn a hole in a cheap BBQ rather quickly. Charcoal + (bellows / paint stripper / hair dryer / fan / friends with good lung capacity / etc...) will give a lot of heat quickly. Beware of the radiated heat, you'll melt any plastic within 30 cm.

Iron or steel at red heat is about as soft as lead or soft aluminium. Iron (i.e. low carbon content) can be worked at yellow heat without problems, making it even softer.

The biggest advantage with hot working is IMO that raising becomes so easy. Hot steel compresses easily, and only in the hot spot. Cold steel is cold everywhere, and barely compresses, and when it moves it moves all over the place.

Have fun!

Patrick Thaden · Post by **Patrick Thaden** » Wed Jun 12, 2002 7:39 am

I am making the assumption you are speaking of mapp as in the little bottles used for brazing and soldering? These won't get you very far as was mentioned, but I have actually been using a mapp/oxygen set up for 3-4 months now and prefer it to the acetylene, I have a smaller bottle and it lasts 3 or so times longer, It actually heats a bit quicker and you can really turn up the pressure when needed versus acetylene where you can only go so high. I was also told(by the weld shop) my acetylene regulator would be fine, and has worked well, they do recomend a different grade of hose for mapp use though. Granted if you don't have the money to set up a torch never mind, but if you are looking for a torch don't rule it out too quick. I also have a gas forge and coal forge that I love to use for hot work and they were both built for under 50$ so there are several options out there for heat. Any way, Heat is good. Patrick

jgalak · Post by **jgalak** » Wed Jun 12, 2002 9:44 am

MAPP is available in alrger bottles than the little yellow hardware store ones. Oxy-MAPP burns slightly colder than Oxy-Acetylens, but actually has a higher heat density (so it heats a piece faster than OA does, but not quite to the same amount). From what I heard, it does require a different regulator, but the torches, cutters, and tips all work fine (I don't know about hoses), so you can use all the same stuff as you would in normal O/A work - welding and cutting tips, rosebud tips, etc.

MAPP has several safety/handling advantages - you can lay the cylinders on the side (unlike Acetylene), you can empty them at any rate (emptying Acetylene cylinders too fast is dangerous - I think the rule is no more than 1/7th the volume per hour) - usefull when doing heating rather than welding, and, at least around here, MAPP is cheaper that Acetylene, per amount of heat you get (Acetylenes cylinders are only about 30% fuel - the rest is acetone, buffers, and other chemicals, MAPP is almost entirely fuel).

The only real problems I am aware of with O/MAPP is that on some kinds of sheetmetal welding it can actually overheat the work compared to O/A, but since I'm not planning on welding armor with it (I want it as a heating tool, mostly), that's not an issue for me.

------------------
Yehuda ben Moshe
mka Juliean Galak
http://gerfalcon.tzo.com/medieval/armor/

Mad Matt · Post by **Mad Matt** » Wed Jun 12, 2002 10:15 am

Get yourself a tiger torch. Also known as weed burners.

They run off of propane minimum size tank is #20 that's the barbeque size.

They're cheap, propane's cheap and easy to find. They heat up a good size area of sheet metal to a nice red (probably further if I was a little more patient). And they sound like a jet engine.

I think harbour freight sells a weed burner torch for around $12.

------------------
The budding mid 14th century German Transitional guy.
Mad Matt's Armory

John Larsen · Post by **John Larsen** » Wed Jun 12, 2002 1:41 pm

Does anybody have suggestions for links to DIY forges? It seems that some of them out there are beyond what I need to do armor work.

horsefriend · Post by **horsefriend** » Wed Jun 12, 2002 1:45 pm

One of my forges uses the HF weedburner. It's actually a decent tool (made in Italy for a change) and puts out a lot of heat. Get 2 20's and manifold them together, you go through propane pretty fast. It is NOISY as hell but effiucient, I added a cone of refractory brick to mine (out of an old Nova kiln) and can get a yellow in 14 ga. pretty quick. It's sort of a twisted interpretation of a shower head.

Alail/Scott

[This message has been edited by horsefriend (edited 06-12-2002).]

Konall · Post by **Konall** » Wed Jun 12, 2002 2:36 pm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR><font face="Verdana, Arial" size="2">Originally posted by John Larsen:
Does anybody have suggestions for links to DIY forges? </font><HR></BLOCKQUOTE>

http://reil1.net/ Ron's site is packed with info, although it isn't the best layout for quick and easy reading. I suggest reading through pretty much the whole site, then taking a closer look at his EZ-Burner at http://reil1.net/design1.shtml#Reil

Destichado · Post by **Destichado** » Wed Jun 12, 2002 4:24 pm

Instructions for simple Coal Forge:
First -convince yourself that coal is not bad.

Next, Go to a junkyard nearby. Take $5.
Find, or ask someone to find, a wheel apx. 14" wide (a little wider if you plan to do any bladesmithing later) -or big enough to stick your foot in with a little room.
Find a few pieces of pipe 2"&3" wide -you don't need much lengh, but you have to have the width.
Find legs -these cen be small pipe, rod, or anything you can weld onto your wheel.

Find someone to give the $5 to -this makes you more welcome later, when you want more parts to bang on...

The 3" pipe gets welded to the center hole on the bottom of the wheel. the 2" pipe gets attatched to a hole you'll need to cut in the 3" pipe (or with a T) at a 90 degree angle, and that'll be the intake for your blower (a cheap hairdryer works well.)

the bottom of the 3" pipe will need to be closed, but in a way you can open it to dump the ashes that will collect from time to time. I suggest attaching a little plate that slides around on a pivot.
Then weld on your legs.

Find a coal supplier near you in your local Buisness-to-buisness yellow pages (they normaly are NOT listed in the consumer editions) Try the smaller guys first -the guys that supply power plants just get iritated when you ask for 150 lbs or so..

lite a wood fire in the drumb, and add coal as it gets hot (or add kerosine, as a friend does when impatient)

This ought to be perfect for your purposes, since you don't need great amounts of heat to move big metal, or forge anything.

naynix · Post by **naynix** » Wed Jun 12, 2002 4:35 pm

On the subject of working metal hot has anybody tried burners like on this page http://www.hybridburners.com/
The first burner, the 3/8 rocket hand torch, i was wondering if anyone has tried one, i saw on the page http://www.anvilfire.com/21centbs/armor/ Eric Thing is raising a helmet with a propane type burner with a big flaired nozzle and a clamp-like thing to hold the stock.
Does anybody use a torch type-thing anything like this? I know that the larger ones will melt steel and that one guy even melted chromium, but with the smaller one at lower pressures, looks like it would work better than a little propane-type torch and more economical than O\A type and a lot cleaner than coal.
Does anybody have any input on these types?