Blacksmithing and Metalworking Q&A : anvilfire Guru page : August 16

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This is an archive of posts from August 16 - 24, 2005 on the Guru's Den

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Forging Titianium-

You can forge Ti to at least 2150 F and probably hotter. If forging by hand, make sure it is as hot as you can get it. Ti that is a dull red will not move under a hand hammer, but when at a good yellow heat will forge more like copper than steel.

Patrick

Patrick Nowak - Tuesday, 08/16/05 07:28:05 EDT

Emails. . .: Our encryption system breaks when addresses have a period in the name section. . my fault but it requires rewriting and testing a complicated piece of code.

Sorry. . .

- guru - Tuesday, 08/16/05 11:42:37 EDT

Water Bellows: This uses the principal of the water seal that is also used in natural gas storage facilities. The inner drum has a check valve in the top to allow air IN and is counter weighted to rise up (taking in air). The exhust is through a stand pipe in the center of the outer drum that rises an inch or so above the water level. The exhust should also have a check valve. The inner drum can be guided on the center stand pipe but the bottom needs to be mostly open so that there is no resistance against the water.

I am sure there is some elegant way to setup the check valves but without doing a bunch of sketching I cannot think of any at this point. Common bellows use flap valves that are assisted by gravity which simplifies them. In this case the valve in the inner drum is best in the top and must open inward so it must be supported by a light spring. In the stand pipe something light like a ping pong ball that seated against the end of a ledge on the pipe and was held in place by a screen or a couple bars in the pipe.

All kinds of ways to build bellows. . .

- guru - Tuesday, 08/16/05 12:00:06 EDT

Some alloys of Ti are reported to give you "flu like symptoms" if you breath the fumes; I've never experienced any problems with CP Ti. It does become brittle after a lot of forging in thin section though.

Thomas

Thomas P - Tuesday, 08/16/05 12:38:25 EDT

Thank you guru for your input. Had considered using part of a truck tire innertube for valve on underside of inner barrel bottom. Also, considered using bicycle innertube on standpipe exiting barrel bellows. But I would like to have a reference on this if anybody knows of one. Again, thanks very much for your advice.

Rob Evans - Tuesday, 08/16/05 12:51:05 EDT

I have only been blacksmithing for a short time and recently have started making railroad spike knives. From what I have read the "HC" marking means "high carbon". Someone gave me a few spikes with the marking of "MC". I can't seem to find anything on this mark. What does this mark mean? "medium carbon"? Thank you for your help.

Ronnie - Tuesday, 08/16/05 13:12:20 EDT

I just built a new burner, and was wondering if there is a formula for figuring out propane consumption per hour using orifice size and pressure. I want to be able to figure my costs a little better.

Thanks,

Mike

Mike - Tuesday, 08/16/05 14:52:41 EDT

I found a BTU calculator. Never mind. Thanks

Mike - Tuesday, 08/16/05 15:23:38 EDT

Check Valves: Rob, Flap or check valves can be made of flexible or rigid material. In fuel pumps they are little thin disks of stainless steel. In old bellows they were simply a soft wood with fine grain. In mine I used some ruberized laminated cloth. For a Japanese style bellows I am building I am using thin brass valves on felt glued to the wood. Wood with a soft leather facing also works good. Due to the generally short life of inner tube material I would use anything else but. Flaps of plastic sheeting have also been used.

For bellows valves the seal only needs to withstand a small amount of pressure. The better the seal the more efficient the bellows. The lighter the valve the easier the bellows operation.

- guru - Tuesday, 08/16/05 17:05:51 EDT

have you ever thought about a medieval style workshop where you don't have many tools except liek a couple hammers tongs maby a chisle and for the forge you just use a big ol' honkin fire or coals

well just thought i would tell you what i work with it works fantasticly for me i like it better that a gas or electric forge

Newat-Sikis

newat_sikis - Tuesday, 08/16/05 17:36:45 EDT

I have a piece of railroad rail and i'm tring to make a anvil. I had it cut to 2' and a waist cut into it. Currently it weighs about 60 lb. I would like to build the wieght up to about 120 lb. I thought about boxing in the area between the bottom of the rail and the top of the base. then filling that area with led. What are your recomendations.

Derek - Tuesday, 08/16/05 18:44:13 EDT

Newat_sikis, how do you know if your "big ol' honkin fire" is better than a gas or electric forge if you don't have one? I have a small gas forge and it works fantastically for me. So what?

quenchcrack - Tuesday, 08/16/05 19:27:46 EDT

Guru - I like your idea of using plastic sheeting for valve material. The reason this all came up is that I have been asked to teach blacksmithing in the Congo next spring. I am trying to put together very simple forging stations that can be built with locally obtainable materials. 55 gallon oil drums are in great supply. Am planning on using railroad rails for anvils and scrap steel from derelect cars for forging materials. I have been reliably informed that in the area I will be visiting there are two local blacksmiths both of who use a charcoal fire with no blast. I felt like if I could contribute nothing else a low-tech rough and ready air source might be valuable to these people. Thanks for your assistance.

Rob Evans - Tuesday, 08/16/05 19:35:22 EDT

I'm heat treating a japanese-style sword with the clay on the back. I'm using 1080 steel and i'm quenching in oil. I heat it to bright red and then I quench it, but it curves the wrong way (toward the sharp edge instead of away from it) What am I doing wrong?

Eric Willis - Tuesday, 08/16/05 20:27:48 EDT

Would a Railroad Rail anvil be a better anvil if I were to fill the area between the rail and the base with steel welding one layer over the other rather than tring to fill it with led just to jet the weight up.

Derek - Tuesday, 08/16/05 21:15:20 EDT

Eric Willis,

I really can't give you a wonderful response, but as I understand it, most Japanese blades had about 0.60% carbon, and the bladesmiths quenched in water. In Kapp & Yoshihara's book, they discuss the methodology. When the proper heat is reached on the blade by drawing it repeatedly through a charcoal fire, the authors say that it is "plunged into water". The photo shows Yoshihara holding the blade cutting edge down and the blade point canted slightly downward before entering the long water trough. What the authors don't say is that before quenching,the water is stirred with hot piece of iron until it becomes tepid (I learned this by word of mouth, but I think it is accurate).

To judge the hardening heat better, the bladesmiths work in relative darkness, at night.

The other thing is, are you putting a thin slip of clay on the cutting edge as well as a thicker coating on the back of the blade? That might make a difference.

Derek,

In my opinion, if you're going to go to that much trouble to add weight and if you're a welder, you should take an ironwork order, finish it, get the money, and buy a real anvil.

Frank Turley - Tuesday, 08/16/05 21:41:42 EDT

don't mess around with a piece of rail.....find a big chunk of steel block from your local plate or machine shop and go from there...(it's less about rebound and more about mass)

dan - Tuesday, 08/16/05 21:57:07 EDT

Ronnie...I heard the same thing about HC on RR spikes. I made 20 or so blades from those HC spikes about 12 years ago, quenched some in oil and some in very warm water. The ones quenched in water hardened a little..a new file would cut the edge. The ones quenched in oil hardened less than with water. Good practice but not a servicable tool. I think the HC may have been a relative term as compared to other previous spikes. They didnt spark (on a grinder) like high carbon steel. In my humble opinion, I think they are .50 carbon or less.

R Guess - Tuesday, 08/16/05 22:03:43 EDT

Eric...I have made only 3 short (19-21") "Japanese style" swords, all made from coil spring from a 69 Chevy. The 3 I made curved away from the cutting edge. They went into the quench horizontaly (the blades were fairly straight) and came out with a 2 to 3" curve...a happy accident and not planned. One quenched in cool water distorded , warped and cracked...they make a terrible sound when they do that. The other 2 were quenched in 130 Deg. F Peanut oil. They curved back but didn't crack. I also used clay and heated them in a long LPG forge. I can only guess why your blade curved forward...maybe uneven heating...uneven cross section in the metal...bright red color is relative to the ambient light in your shop. I the dark corner, by my anvil, 1750 Deg. F appears bright red, yet 4 steps away at the door it appears gray in the bright sunlight. Dont give up...the next one will be better. We all learn from our mistakes. If you havent already, check out Don Foggs web site in the links on Anvilfire. Lots of info from a true Master bladesmith.

R Guess - Tuesday, 08/16/05 22:34:39 EDT

The following is from page two of www (dot) tinyurl (dot) com/cjsfo on railroad spike carbon content:

RR SPIKES

Ron Holcomb holcombron@hotmail.com Mon Nov 8 12:41:29 PST 1999

Railroad Spike Info from TheForge Archives: Analysis by U.S. Steel: Carbon - .296 % Manganese - .68 % Phosphorous -
.016 % Sulfur - .038 % Silicon - .244 % Copper - .287 % Nickel - .09 % Chrome - .13 % Tin - .001 % Aluminum -
.005 % Vanadium - .022 % Cobalt - .008 %

High carbon spikes were made exclusively starting in or around 1974 to replace the low carbon spikes that were generally just iron and carbon (with a couple trace elements thrown in for special areas).

For High-Carbon Steel Track Spikes: Steel was made by one or more of the following processes: open-hearth, acid-Bessemer, electric-furnace, basic-oxygen.

Chemical Composition: Acid-Bessemer Other Process Carbon, min. percent 0.20- 0.30 Copper, when specified: 0.20%

Tensile Properties: Tensile Strength, min. psi. 70,000. Yield Point, min. psi. 0.5. Tensile strength Elongation in 2 in., min percent 25 From: Machinery's Handbook

Ron Holcomb holcombron@hotmail.com Mon Mar 27 11:00:05 PST 2000

Note: One should not assume that these spikes are considered to be "high carbon" in the usual sense of the term. The spikes will not contain more than 40 points (.40%) of carbon and, therefore, will not (in my opinion) respond to heat treatment in such a way as to make a proper knife edge.
--------------------
The referenced site shows a number of objects made from railroad spikes.

Ken Scharabok - Wednesday, 08/17/05 05:27:38 EDT

Ken: Are yo tryin to drive down the price of rr spikes with your slanderous information? :) Actually I had wondered about the term HC applied to the spikes. Thanks.

- JLW - Wednesday, 08/17/05 07:58:49 EDT

Most of the cutting edges in the Mastermyr Find (reference to the late Viking Age toolbox for our newer visitors) were 40 point steel. 40 pts. gives an acceptable degree of hardenability and toughness without much need to temper. (As a matter of fact, the graph of hardness to carbon content starts to flatten out considerably right about at 40 pts.) You do, however, need to sharpen more often.

HC RR-spike knives make better letter openers and pry-bars than knives, but only in contrast to higher carbon steel and more sophisticated alloys. They can be adequate, but never great; but they were never meant to be (and should never be represented to be) high quality and high performance knives. Their just sort of a neat recycling of a common object with its own romantic conotations. The whole idea is: "Cool; a knife made out of a railroad spike!"

Now, a railroad spike made out of knives; that would give me problems. ;-)

Much milder on the banks of the Potomac.

Visit your National Parks: www.nps.gov

Go viking: www.longshipco.org

Bruce Blackistone (Atli) - Wednesday, 08/17/05 08:17:57 EDT

Eric may I commend the sword forum dot com to you! Particularly the bladesmith cafe forum.

Having the sori go the wrong way is a common problem quenching in oil and having the blade crack is a common problem quenching in water.

Traditional japanese swords often have a low carbon content---about .5% and are a very shallow hardening alloy---how much Mn is in the stuff you are using?---to allow them to make use of the clay hardening process.

Rob Evans; I assume you have read the 3 volumes that the UN food org put out on blacksmithing? They were written with Africa in mind and probably address the conditions there better than whet we might come up with.

Thomas

Thomas P - Wednesday, 08/17/05 10:42:24 EDT

Bob, my "149" # anvil came by Fedex ground, unboxed. Tag was on the face. I think the shipping cost was in the 60 dollar range. They do have a weight limit of 150 lbs, and will not take a pound over (officially, anyway. The local shop knew the shipper well, and fudged the scale, as it was a 151 # anvil.)

Monica - Wednesday, 08/17/05 12:49:35 EDT

I'm using plain carbon steel so I would assume the Mn would be very low. I treated one with ferric chloride and then sanded it to 400 grit and the hamon came out beautifully, but there's still the problem of the reverse curve. I treated 3 other wakazachi (20in) and the exact same thing happened. I believe that I'm pulling it out too soon. I quench it and then count to 4 and pull it out. If I'm oil quenching should I just leave it in until it cools completely? I'm using a propane forge and Heating it evenly red at dusk except for the tang which is dark red.

Eric Willis - Wednesday, 08/17/05 15:38:40 EDT

For "Atli" mainly but others are welcome:

For an upcoming SCA event I was asked to make some spearhead and be able to demo the same. Naturally I remembered the iForge demo and checked it to refresh my memory on such things.

A couple of questions:

1) When pinning the head to the shaft is it worth offsetting the shaft hole a bit from the hole in the socket to draw the two together? Or am I asking for unseen trouble in doing so? (Wedging the unwelded socket open perhaps?)

2) The demo talks about unwelded sockets ... thinking Northern Europe ... have there been welded sockets all along, the Anglo-Saxon's just didn't bother? Or in later periods with different tools and techniques did they migrate to a welded socket? (Can you tell I'm trying to anticipate the questions?)

Thanks greatly!

Timothy

Timothy Park - Wednesday, 08/17/05 16:33:31 EDT

Tempering Knives

(as long as I'm posting)

I've made a few knives and slowly doing more. To date all I've made have been either single edged or "letter openers".

I use a tempering jig cut from 1.25" sq. x 8" or so stock with a 1/4" (roughly) slot cut the long way about 1/2" deep. This works great for tempering a single edged blade: harden the blade, polish the blade, heat the block, put the blade in the block, quench when the color I want hits the edge.

On a double edged blade (which I haven't tried yet) it doesn't seem like this would work. I plan to experiment this weekend with putting the blade flat on a bar ... but will I get different enough colors and heat top to bottom that I'll have problems?

Is there a better trick?

Timothy

Timothy Park - Wednesday, 08/17/05 16:38:58 EDT

Timothy Park; they did spears *both ways*.

You can make a set of tempering tongs with blocks welded on so that you grab the blade by the midline with the heated blocks and let the heat flow.

Eric, some makers clean off a bit of the spine leaving only a thin layer of clay to help pull it in the correct curve---it does result in more of a hardened back that may need drawing though.

Thomas
Thomas

Thomas P - Wednesday, 08/17/05 18:22:27 EDT

Japanese Swords:

I've made exactly zero, so Thomas can correct me if I'm off base, but it seems to me that he temperature of the back of the sword under the clay must be critical. I'd think that if it were at a good forging heat, it would upset some when the front of the sword was quenched, and then contract and curve the sword back as it cooled. Cooler to start with, and this might not happen.

Mike B - Wednesday, 08/17/05 20:14:19 EDT

Does anyone have comments comparing power hammers? I am looking into purchasing a power hammer and the two that I have looked at are a Striker STC-55 (55#) and a 100# Little Giant (used older model but in good mechanical shape) Since I am in Central Ontario Canada there is a limited selection of hammers, the prices are comparable but the Striker is new. Appreciate some opinions, thanks in advance, David

David - Wednesday, 08/17/05 21:23:30 EDT

Timothy, You can sometimes control the color if it runs too fast and unequally by wrapping a wet rag around the end of a stick. You can touch the rag on the color that is too speedy, trying to balance the tempering.

Frank Turley - Wednesday, 08/17/05 21:53:37 EDT

The problem WAS the oil quench. I water quenched 2 wakazachi and they turned out perfectly, but I destroyed a tanto by quenching it when it was bright orange(got a little carried away) Thanks for the help!

Eric Willis - Wednesday, 08/17/05 22:50:14 EDT

..........Nothin' I enjoy more on a hot summer's day, than kickin' back an' quenchin' my ol' wakazachi. (BOG)

3dogs - Thursday, 08/18/05 03:00:45 EDT

Thomas P. -- thanks on the both ways -- that I was pretty sure of ... more double checking.

Tempering tongs I hadn't heard of until this week here, and that goes on the "things to make this weekend" list.

Frank Turley: wet rag, hunh? that I'll have to try.

Thanks to all for input so far.

Timothy Park - Thursday, 08/18/05 09:39:35 EDT

To whoever was setting up their forge in suburbia ...

For various reasons I've had to forgo a better shop the last few years and do my smithing with simpler tools in more nomadic shops. Most of the time it's been inner city back yards.

I don't have the same issues as smithing in suburbia but I've done a little there too "custom curtain rods made in your driveway!". Most of the time, in the neighborhoods I've been living in a guy making a bit of noise out back is lost in the background of sirens and other excitement.

The Forge: Gas would be better, I use charcoal in the Summer when people are outside and windows are open more. If I'm caught low on charcoal I'll light with charcoal and then shift to coal to avoid the brimstone. A little sweetgrass on the fire seems to cut the ozone smell of a coal fire too.

Hammer and anvil: keep them quiet and watch for echos. The last time anyone complained about me smithing in an urban environment was out in suburban St. Paul, I forgot to deaden the anvil, and the noise was echoing back and forth between the garage and the complainer's house. I stopped immediately (he worked 3rd shift and needed to sleep) and made him a hose holder.

Be ready to do demos. I do reenactments and demonstrate so I'm kind of used to this, but some aren't. If you're in a neighborhood and doing this, even quietly with little smoke ... you're like the smithy of old: you're a kid magnet. Grown ups too, but they're more shy. Be prepared.

I put up my rope barrier when I'm working to keep folks back. I also give into the inevitable and put the lawn chairs a safe distance from the workplace which encourages folks to watch ... and not be underfoot. I have a couple of easy things to do and make (leaves with the stem turned into a loop) that don't take long. When the neighborhood gang comes by to watch for something to do I knock one out and give it to the best behaved (or smallest) child. They have something to show off at school, and over the last year it's subtly encouraged both good relations with the neighbors and good behavior on the part of the children.

Expect to be asked for help. You've got tools. You're showing the world you know how to use them. Usually people start asking if you can fix things. I've lived in three neighborhoods in Minneapolis since I started smithing. Every spring the ritual is the same: "can you straighten this downspout?" "Mister, can you tighten my bike tire?" "The handle came off my trowel ... is it much trouble ...?"

Yes, it's hard to find concentrated time without distractions for trickier work. A ten year old with a flat tire *will* interupt a forge weld. But the trade off is that the night that I forgot to watch the time and was still hammering past midnight ... no one complained: the kids like me and I fix stuff.

Timothy Park - Thursday, 08/18/05 10:00:16 EDT

Living in the inner city I once started teaching the leader of the local kids smithing---vandalism problems with my shop and house went to *zero*

Thomas

Thomas P - Thursday, 08/18/05 10:07:41 EDT

Another thought on Urban Nomadic Blacksmithing:

Keep tabs on your scrap pile!

It means extra hauling, but try to only keep out what you'll use and put it all away. Lock it away.

36" of 1/2" square is a useful piece of stock.

If you're 11 it's a sword. I took a lesson when I spotted two kids "duelling" with pipe sections from a demolition project up the alley ... and the third who wanted to join them who asked me for a piece of stock so he could have a sword too.

Timothy Park - Thursday, 08/18/05 10:33:10 EDT

Timothy:

Pinning Spear Sockets:

A slight displacement would be a tad more secure; however, such displacements usually occurring quite by accident, especially when replacing the spear shaft. ;-)

Split vs. Closed Sockets:

As Thomas mentions, they were contemporary with each other, but the split socket was pretty much an Anglo-Saxon identifier. Viking spears, for instance, tended to have bigger shafts (over ��) and closed sockets; although I�ve noticed that some of the sockets were not welded as neatly as others.

I believe the A-S spearheads used these sockets partly for ease of forging, partly out of custom, and partly to make it easier to swap-out broken spear shafts. (Burning a chunk of broken shaft out of the head of the socket is not a good method if you have a tempered blade.) Blade styles changed, but the sockets retained the split configuration pretty much through the whole period.

Other Observations:

Lately I�ve been using ~1� X ~3/8� bar to forge spearheads without the faggot weld. The welding is cool in a demonstration, though, and is definitely the way to go with any square-bar stock you may have. The socket gets pretty puny without it.

Please let us know how the demonstration turned out, and post some pictures if you can.

Sunny and warm on the banks of the Potomac.

Visit your National Parks: www.nps.gov

Go viking: www.longshipco.org

Camp Fenby Autumn Session- 1st and 2nd weekends in November.
http://groups.yahoo.com/group/CampFenby/

Bruce Blackistone (Atli) - Thursday, 08/18/05 11:48:02 EDT

With a sphere of tensile material keeping the inside at 1.013 bar (1 atmosphere) and then pressurising the out side to 50.65 bar (50 atmosphere) knowing the tensile strength of the material what thickness should the material be.
I need the calculation in maths the different material thickness of variable out side pressures with keeping a constant 1.013bar inside. Can you help.

Andrew. - Thursday, 08/18/05 14:57:55 EDT

Bruce:

Thank you for the reply ... just enough to help me sort the snarl into a web.

1" x 3/8" stock sounds sensible for "production" ... but I intend to challenge my forge welding ability with a few out of 1/2" or 5/8"

I'll keep you posted on the demonstration. I'm working on pictures. I usually bring my camera ... and get so busy I remember I had it as I'm packing up. Really need to get a digital and offer someone entry fee and grub for working the shutter.

I'd like to have a more "period" rig at these things, but that will come.

Timothy

Timothy Park - Thursday, 08/18/05 15:50:09 EDT

Andrew.
I would guess that from the wording of the question that you have asked for help with a homework problem. We usually only help with non-school homework, ie. how do i make this item.
If this is a real design issue and not a school problem, write in with a bit more info and I suspect you will get help.

ptree - Thursday, 08/18/05 17:39:58 EDT

Spheres:

It seems to me the answer to Andrew's question is infinity. No matter how thick the sphere walls are, they will compress to some extent and increase the pressure inside the sphere.

Mike B - Thursday, 08/18/05 18:47:54 EDT

Shaping machines vices (vises)

I've just picked up a small 10" stroke shaper but it came without a vice. Will a milling machine vice suffice or do shapers use special heavy duty vices?

Bob G - Thursday, 08/18/05 20:44:54 EDT

David: On the Striker vs LG question I can't answer it as to relative performance merits. However, I do wonder about the price comparison. I was at a guy's shop today and he showed me his Kuhn (sp?) airhammer of a similar design and size. He noted he had about $15,000 USD in it. Seems high, but... I have seen 100 LB LGs go on eBay for a fraction of that price. Are you sure the LG you are looking at isn't overpriced?

Ken Scharabok - Thursday, 08/18/05 21:22:51 EDT

Bob G: Shaper vises are a little heavier than most milling machine vises, HOWEVER a 6" KURT or a reasonably well made copy of a KURT will hold better than any of the vises that came on shapers when they were new. Check with MSC or Enco.

Dave Boyer - Thursday, 08/18/05 22:35:12 EDT

I am taking a welding class and there is a lot of A6 lying around that is used in the class. What is this steel best used for? I'm thinking about a smithing magician. Is this steel good for dies? Blades, tools?

- JLW - Thursday, 08/18/05 22:59:11 EDT

Hi,
I have an old 28 pound anvil that I wish to use. The face seems softer than I would expect, and the whole thing is a bit misshapen and sway backed. It may have been in a barn that burnt down. I seem to remember from my distant childhood that a master smith could "dress an anvil' (flatten the face) and then reharden the face and ulimately temper it.
Is this practical? and should I start looking for such a smith?
Thankyou for your attention, Neville Michie

Neville Michie - Thursday, 08/18/05 23:49:55 EDT

Davids hammer question??? 55# Striker vs 100#LG

What do you want to do with them... The Striker should have more control, being a selfcontained air hammer. But the LG will have MUCH more punch. If the LG is fitted with a brake, and has an old style idler and belt clutch, it could be well mannered enough:-) The Strikers have an Ok reputation, you may have to replace oilers and electrical components, but the hammer should run, and be polite. LG's can be somewhat ill mannered and munch things while you are trying to feather your blows. But if you can get it tuned up and can keep it tuned up, the 100# LG will do more work than the striker. The LG is a more versitile hammer, but it will have a steeper learning curve most likely (lots of people never bother to learn some of the tricks, and still love them:-) With a LG you can adjust the stroke length, and the power of the blow somewhat. And being a mechanical hammer, it will hit harder than the striker anyway, ignoring the fact that it also has a heavier ram. So it will always be easier to forge heavier stock on the LG, but the striker is easier to use, and will draw, and texture, stock in the appropriate size all day long. The Striker will use more electricity by a wide margin.

The other thing to consider is what dies come with both hammers? If you have a few sets of dies for the striker, or if you have a nice big set of industrial flat dies for the LG:-) that makes a big difference. If both of them have just your basic combination die;-(

I REALLY like air hammers, mainly utility style hammers:-) (and I Love STEAM HAMMERS:-), but unless the LG had beastly manners I would be very tempted to get the bigger hammer. You can forge little stock on a little hammer, and you can forge big stock on a big hammer, and if the hammer has good manners you can also forge little stock on a big hammer:-) If you are certain you would rather work with you hammer, and not on it, then you might take a chance that you got one of the good strikers and go with the easier hammer to opperate. (LG lovers need not be offended, really;-)

Fionnbharr - Friday, 08/19/05 00:25:29 EDT

Hello
I have decided to make my own custom u-bolts for a boat trailer project and was wondering what the proper way to temper them was. I am using low carbon 3/8 steel rod.

Chuck - Friday, 08/19/05 00:47:28 EDT

Hello
I have decided to make my own custom u-bolts for a boat trailer project and was wondering what the proper way to temper them would be. I am using low carbon 3/8 steel rod. Do I temper them before or after I complete tapping the threads?

Chuck - Friday, 08/19/05 00:51:06 EDT

Chuck-- Howcum you don't just get some 3/8 allthread and bend it? Why try to temper low carbon?

Miles Undercut - Friday, 08/19/05 00:57:25 EDT

Neville M : You may have a cast iron anvil. They were made years ago for light duty use, not for forging.I got one of those from an uncle, it was old when I was a kid. If it has a hardenable steel top plate it would not be cost effective to flatten and heat treat. Unless You plan to do extremely small work, it would be be advisable to find another much larger better condition anvil, as the rule of thumb is to use a hammer about 1/50 of the anvil weight or smaller.

Dave Boyer - Friday, 08/19/05 01:11:17 EDT

JLW: A6 is a good toolsteel for dies, shear blades, punches,etc. It is tougher than A2, but not as wear resistant. Forging temp: 2025f Hardening temp:1525 to 1600f soak for 20 min plus 5 min per inch of thickness. Quench in air. Temper at 350f 1 hour for 59/60 Rc.Or at 700f for 54/55Rc[much tougher]

Dave Boyer - Friday, 08/19/05 01:32:34 EDT

Miles; I'm wondering if all those threads on allthread wouldn't constitute a bunch of little stress risers, bad enough when rolled around a round axle, but worse when bent 90 degrees, twice, if used with a square axle. I'd use cold rolled round bar, and cut the threads with a die before bending. I should think that 3/8 would bend cold easily enough. The reason I specify cold rolled is that it will be pretty much on spec as far as diameter goes. My tuppence worth.

3dogs - Friday, 08/19/05 02:14:51 EDT

Well
The bolts will be used on a 14' boat trailer springs with a 14' jon boat. I already bent them by using a homemade jig and heating with a torch. I made some prior to that using all threaded bar but was not happy with it. I suppose I could try to bend them with a press instead and they would be stronger but I really don't know how. They are 1 3/4w x 4 1/2 long.

Chuck - Friday, 08/19/05 06:39:23 EDT

I just found out that I made a mistake. The instructor said "A36" not 'A6" but in the noise of the shop i misheard. I understand that A36 is a much different beast and has very different and rather dissapointing characteristics. Like not hardening much. Bummer. I was seeing gold lying all over the shop floor.

- JLW - Friday, 08/19/05 07:30:31 EDT

Neville Michie: If the anvil was in a barn fire it will have very likely annealed and be very soft. I strongly suspect you would have more effort involved in making it serviceable again than it would be worth. If you can e-mail me some photographs (just click on name and send as attachments) I may be able to identify it for you on brand. It may have value to a collector. I have seen some very small, well-known brands sell quite high on eBay. A 14-pound Peter Wright in near mint condition went for over $1,000.

Chuck: Your low carbon rod will not harden enough to make a difference. Just shape and use. If you think strength will be a problem perhaps use two instead of one.

Ken Scharabok - Friday, 08/19/05 07:32:30 EDT

Chuck,

You don't really need to heat treat those U-bolts at all if you didn't quench them from red hot. If you did quench from red hot, they may be a bit brittle and you would be well advised to put them in the oven at 500�F for a half hour.

Assuming you made them from standard structural steel (A36), they will have a tensile strength of >35,000 psi in a normalized state, more than enough to keep the springs on your boat trailer.

vicopper - Friday, 08/19/05 08:37:27 EDT

Spring U-bolts: In general these are made of high strength steels and hardened and tempered to tight specifications (Usualy ASTM B-8 100,000 PSI). The reason is so that the nuts can be tightened enough to stretch so that the bolts do not stretch under load and the nuts work loose. They also use fine threads in this application for the same reason.

On your light duty trailer your low strength bolts may be OK but definitely NOT on motor vehicals. I would not want to be responsible for the libility in either case. Buy these bolts from a reputable supplier that knows what they are for.

- guru - Friday, 08/19/05 10:08:51 EDT

Hammer Choices: This is a hard one. Generally MORE power is better (up to a point) and the 100 lb. Little Giant is perfect IF in fine tune. However, the fast 55# Striker will have tight guides and better controlability than a worn out Little Giant. The result is that it will be easier to learn to use and probably turn out as much work as the 100# LG. However if you get above 1" square stock or are forging tool steel the 55# will be limiting.

In the recent past folks thought that a 25# LG was a big enough hammer and that a 50# was overkill. . . They did not do much forging under 100 to 200 pound hammers and nobody wanted a 100 pound LG. For this reason 25 to 100 pound hammers all sold for the same price, the 100 pounders ocassionaly for LESS! The MOST productive small shop hammers are in the range of 100 to 200 pounds (45 to 90 kilos). They will cold texture small stock and hot forge hammer size tool steel. With the right dies you can produce a 100% forged picket with details in one heat. These are serious money making sized machines.

Note that the biggest advantage to mechanical hammers is their lower HP requirements (by over half) for the same ram capacity. Where you have limited power the mechanical is the way to go.

- guru - Friday, 08/19/05 10:28:28 EDT

More about Power Hammers. . There is also nothing wrong with having two or three. Two with the Hofi combo and crown dies and a thid with flat dies for tooling work. . ;) Heaven!

If you think this is greedy or overkill you are wrong. This is a common setup in many shops. Those that put power hammers to the best advantage will use more than one during a SINGLE HEAT! This is efficiency and productivity!

- guru - Friday, 08/19/05 10:37:23 EDT

I work for a Museum in Dallas, TX. I'm looking for a company who deals in wrought iron (not mild steel) for some reproductions we need to make. Is there a manufacturer in the U.S. that still sells Wrought iron?
Thanks, Kelly

Kelly Kring - Friday, 08/19/05 11:55:52 EDT

Thought about power hammers, I assume the 55# (lbs ?) Striker is a 25 kgs ram weight - Why not go for a 40 Kgs ram Striker? - I sell the other brand of chinese hammers in the UK (the ones the Guru loves so much!!)- The price difference between the 25 & the 40 Kgs I sell is only GBP 350.00 - the 40 kgs is, in my opinion, the most usefull size. The 25 kgs seem more popular with smiths who have electric supply problems or who do blade work. The Sriker/ Anyang hammers are so compact that if you can fit a 25 kgs one in the shop you should be able to get a 40 kg one in.

Im afraid my experience with mechanical hammers such as the LG is virtually zero, so cant help with the comparison.

Guru, to date no real quality probs with the anyangs, but i give every one a proper hot work trial, and a strip / check prior to dispatch just to be sure!

John N - Friday, 08/19/05 12:14:13 EDT

John, you are right about the price difference and greater usability. Small hammers are great if all you are going to do is small work but the larger hammer will do large AND small work. The only limitation is with VERY delicate work but in this size range you are talking quite small.

Wrought Iron: Kelly, Wrought is no longer manufactured so you are stuck with recycled stuff. In GB they reforge old wrought into new bar (look up "The Real Wrought Iron Company"). In recent years pure iron has been sold that was very close in working properties to wrought but there is no longer a US dealer.

In reproductions you are much better off with mild steel or pure iron rather than wrought because it is almost impossible to tell the difference between the old work and new. If you DO have reproductions made in wrought be sure they are clearly signed and dated, deeply.

- guru - Friday, 08/19/05 13:43:04 EDT

Kelly Kring: Contact the blacksmithing group in Houston. They may be able to help you. There is also a guy on eBay now selling old scrap wrought iron.

HOUSTON AREA BLACKSMITH'S ASSOCIATION

Pres: Richard Boswell
27923 FM 2978
Magnolia , Texas 77354
281-356-5205 farm
713-562-2043 cell
281-955-2900 work
rsboswell@mindspring.com

Ed: David Bailey
116 East Mosley Lane
Huntsville, TX 77340
(409) 295-8913

www.habairon.org

Ken Scharabok - Friday, 08/19/05 14:26:00 EDT

Fionnbharr,
Done anything with the sledging anvil?

ptree - Friday, 08/19/05 19:14:08 EDT

JLW: Don't despair, the A36 is structural steel. good for all the "structural" parts of whatever You build, There are always plenty of broken axles, old files, and leaf springs to use for the tool steel parts,and except for production work they will be fine.

Dave Boyer - Friday, 08/19/05 21:28:40 EDT

Re: Power hammers
Thanks to Guru, Ken, Fionnbharr and John N for the info, all points were great and helped me verify my gut feeling. The LG comes with several sets of dies and is a work horse. It turns out that the LG is 1500.00 CAD cheaper and has a new motor as well. I think the seller is asking a bit much (4900.00 CAN) on consignment. Oh well, I hate those sale tatics when you feel you are being pushed into buying something when the market of power hammers is limited in your area. I just might have to sell my 585# or is it 699#? Peter Wright Anvil to buy a hammer, just kidding! Thanks again for the feedback!

David - Friday, 08/19/05 22:44:17 EDT