Problem with large lap welds

[Iron Poet]

I've started to make axes and hatchets the traditional way instead of cheating and just punching a thick bar. The problem I've having is that one side of the wrought iron will weld perfectly to the steel bit (5160) while the other side won't stick unless I give it a concerted effort. It takes me around 4 or 5 heats to get both sides to weld together. I used borox and I flap wheeled everything down smooth.

Now, I'm not overly attached to using wrought iron and a slug of steel for a bit. Would leaf spring be easier to weld since both sides would have the same composition? I've mostly welded smaller things together (1/4"x1" flat bar, 1x4" square, etc) So I'm not too experienced.

http://imgur.com/qj2N3d2,XRWuUm1#0

 

[Frosty]

Is the side not welding the one laid on the anvil when you first set the weld? When do you flux the join?

You might try a low alloy high carbon steel bit rather than 5160, the chrome in spring steel can cause problems with welds. Simple low alloy 1070 +/- welds more easily. Wrought may weld easily but you have to get it a LOT hotter than steel. The more carbon the lower the melting/welding temperature.

Frosty the Lucky.

[Iron Poet]

Is the side not welding the one laid on the anvil when you first set the weld? When do you flux the join?

​It was the bottom side, My forge is on the smallish side so I was only able to heat one side of the bit at a time, I flipped and heated the other side though. I bit use flux around the bit, the rest of the weld didn't need it though. I made sure to make the sides touch before I exposed them to a welding heat.

Maybe a small amount of scale was preventing it from welding? After a few failed attempts I did get a little frustrated and used a larger amount of flux and a bit more force than was probably needed.

[Frosty]

I just realized I forgot to welcome you to Iforge! With my usual welcome aboard I'd suggest you put your general location in the header, you might be surprised how many of the IFI gang live within visiting distance. Maybe someone who does a lot more welding of that type than I.

Okay, sounds like a technique problem to me though I'm sure someone who does a lot of this will be along presently. Let's see, you need uniform heat on both sides and the center. By the sound of it you're using solid fuel cover the project in fuel to insulate it from the ambient air and turn it regularly. 

When I do large lap welds I match the contact surfaces, shine them up and flux them cold before closing the joint. I've never understood heating a weld to orange before fluxing, even in the low red steel is oxidizing fast. Heck, temper colors are oxide layers. The flux being there when it heats maximizes the protection.

Just keep flipping the piece till it's bright, almost sparking yellow hot on both sides. Move QUICKLY to the anvil, do NOT lay the piece on the anvil, hold it a fraction of an inch above the face and drive it into the anvil with the hammer. Use a fairly heavy hammer but NOT a heavy blow, just a medium thump you don't really want any bounce back. Flip it and repeat. Are you using a hammering pattern? The first blow needs to be farthest from an edge so any inclusions are driven to the edges.

Lets think of the joint like the letter V with a letter I standing in the center. If you look at it from the side it'd look like a taco with a slice of cheese standing up in it. With me on the visual so far? Okay, the "bottom" of the weld is at the point of the V and looking at from the side the "Center" is the center of the taco. Your first blows needs to be bottom center, one on each side. Your next pair need to be in contact with the first blows but one hammer width to one side, say bottom left, flip it and one blow directly over the last blow or bottom right. flip it and one bottom right, flip it bottom left till you've run a pattern to the ends of the V.

Listen closely if it even begins to not thud it's time to go back to the fire. However if you go fast enough you can make a setting pattern over the entire bit in the first heat but you gotta move fast and NOT lay the axe head on the anvil, ALWAYS hold it just off the face so the anvil doesn't draw the heat.

I'm guessing 6 or fewer blows per side to complete the pattern. Brush, reflux and reheat, remember keep flipping the piece so it's equally REALLY HOT before you bring it back to the anvil. This is a refining weld so hit it moderately harder but use the pattern.

Brush, reflux reheat and hit it harder. when you've finished the pattern let it lay on the anvil till the color starts to leave and eyeball it closely. If the color is uniform throughout without a sharp color change you have a weld. IF the color changes sharply at the join it isn't welded so brush reheat and repeat the pattern.

Once you get it to heat the process takes a lot less tie than writing or reading this missive does.

Frosty the . . .

[ThomasPowers]

Build a forge that will heat the entire weld zone up to heat in one go.  Hammer firmly but not sharply along the entire weld *FAST* or as my pattern welding instructor told me 30+ years ago: "Don't look at it *HIT* *IT*!"

Trying to weld 5160 to itself will not be a happy experience for someone who is having welding issues already.

[Iron Poet]

Build a forge that will heat the entire weld zone up to heat in one go.  Hammer firmly but not sharply along the entire weld *FAST* or as my pattern welding instructor told me 30+ years ago: "Don't look at it *HIT* *IT*!"

Trying to weld 5160 to itself will not be a happy experience for someone who is having welding issues already.

​I'll try and do an asymmetrical weld with some leaf spring. I'm feeling pretty confident that I'll manage to do it eventually. Shortening the weld area to only an inch or so should help my problem I think.

[Charles R. Stevens]

Leaf sting is what TP is refering to! 

And as a side not, the historical record in scandinavia and other "viking" sites show slit and drift, as well as pole wellded (split the back of the bar, forge out the sides and weld the pole to form the eye) as well as wrap and weld. The former two are older methods. So your method is the "new method" the traditinal methid is to form a chisel like axe blade and set ithe tang threw a branch, often a fork

[Benton Frisse]

I've found that trying to forge weld carbon steel to carbon steel isn't the easiest. Doesn't seem carbon likes to stick to carbon very easily. Has a lot to do with the chromium and vanadium, correct? I've found that 5160 sure does like to stick to mild, though. 

I recently welded a billet of 3 layers, wrought with 5160 between. I was told to get the wrong almost white hot before attempting to weld. I did, too! She stuck and I didn't get any cold shunts. Gotta get it hot when working with wrought to weld, and keep er hot to work it. From my understanding, it likes to chunk off and crumble like blue cheese if you work it too cold! 

[Charles R. Stevens]

It isnt the carbon steel, its the crome aloys, wich most springs (and axles, and other automotive steels contain) you can easaly forld an old file in half (grind off the teath) and weld it, thats why you see a lot off farrier rasp hawks. If you want to use spring stock either use mild for the axe and "steel" it with a spring bit or use spring for the body and use a peice of plain carbin steel (old file) for a bit/ welding shim. Using a thin peice to assist in welding steels that do not want to stick is an old trick. 

So, your first issue is that the anvil is sucking the heat out of your stock so that only one side of the bit welds, your second is you misunderstand the metalergy (common enugh, catches most of us once in a wile). 

Further note, the wedge eye is old teck as well, I've seen hammers and axes with it from early (pre Viking era) exaples. I think that when wood was a consumable and iron was more valuable than gold, you didnt bother toting wood handles from place to place, and hen you split a peice of wood out it naturaly formes a wedge. Less work to rehandle tools if you dont fight nature.

so if you want bragging rights, split the back of your blank, rap and weld the pole and then split the front and steel your blank, wala pre Viking nordic axe. 

Now in the feild it is much easer to fit just any old stick in a round hawk eye. Than to split a sesoned billit out but the split is so much more durable

[will52100]

I've had a few issues lately, one is a hawk welded up from left over bits and pieces of some pretty rough wrought iron.  Had a few minor flaws, major enough I didn't bother filling it out and doing a proper finish, minor enough I'll leave it in my mule and use it around the place.  This is the first hawk I've tried using iron moutain flux on, thinking I may have trapped some scale while welding up, and I didn't do any grinding before hand.

I've had very good results welding high carbon steel, and even 5160 and 52100, but the steel needs to be clean and you've got to get your heat rite.  Also your hammer technique can make a big difference.  When I weld up a stack for a particular patter, most times I start with a multilayer stack of 1084 and 15n20, all pieces ground and stacked and shove it in the press.  When I'm welding up bits and bobs and making "junk yard damascus", or AKA "frontier damascus", I weld one piece at a time with the hand hammer starting from the center out.

The thing about forge welding is, your not welding with the hammer or press, your just getting clean steel in contact at the rite temperature.  All flux is doing is keeping oxygen from getting to the hot steel and keeping clean steel from touching clean steel at the rite temp.  I have surface ground a multi piece stack and used no other flux than diesel fuel.  The oil burned off leaving a layer of carbon that keep the oxygen away from the clean steel, a squeeze in the press and perfect welds.  A good flux also helps melt any scale back into the metal, or failing that lets you squeeze it out when you hammer it together.

Uneven heat, metal not at the rite heat, scaling from to much oxygen in the atmosphere of your forge, a cold anvil sucking heat away and dropping your material below welding temp before you set the weld, scale build up, trapped flux, all this can make for poor welds.

No answer except to keep at it.  After a while you'll wonder what was so hard about forge welding.  And not too long after that you'll get cocky and screw up.  Or at least I did.

[Charles R. Stevens]

Is it scale or is it slag from the wrought?

[will52100]

The slag in wrought iron make for easy welding, as long as your hot enough.  High carbon steel welds at a lot lower temp than wrought iron.  A good flux, one that acts like an acid at heat, is a must for welding high chrome steels like 5160.  The issue is scale doesn't melt back into the steel and keep metal from touching during welding, flux melts it back into the metal, or lets you squeeze it out when hammering.

[Iron Poet]

I think I figured out what I was doing wrong. The first is that I was bringing up the heat to quickly, I was a bit edgy that day and a bit impatient. The second is that I didn't do a great job of fitting the steel bit, it was a little uneven. The third is that I might have been thinking that bigger is better when it came to choosing a hammer. Lastly, I don't think my fire was quite deep enough, I can't get any coal in my area so I am quite stingy even it comes to using it.

 

So a long soak in a deep fire, a liberal amount of flux, and a few gentle hammer blows starting from the center outward should do it, right?

[easilyconfused]

Another trick from the frosty north, which I'm surprise Frosty didn't mention, is to preheat your anvil with some hot iron to help retain the heat in the piece you're welding.