Forge welding help...

[Couchsachraga]

I've been fortunately to have a local fellow show me a bit of blacksmithing before he headed south for the winter, and have had fun making an assortment of items since, mostly to have fun creating and work on my hammer skills.

At this point I'd like to try a ring, and eventually an ax head... so it's time to attempt to learn to forge weld.

 

I've tried a few times now with no success.

I'm using a 2 burner Mighty Forge, one end blocked off (there is one "door" on each end).  I'm turning down the heat a little, opening the BIG door, and once the door is open getting the item to the anvil in under 2 seconds.

 

The first time I tried i attempted to weld mild steel to itself, no flux, in a ring shape (upset each end, then made the ring (or oval in my case) so the ends overlapped, and did a slight scarf to them as well (yes, I've been watching Rowan Taylor YouTube videos...).  Not quite hot enough, so I tried again... no go.

 

Then I got some borax, and tried again, MUCH hotter (15psi vs 10), tried tapping lightly to set it, reflux and reheat, a bit more tapping, and repeat a few times, going from "tapping" to "Hammering" after a bit (I only fluxed 3 times probably).

 

Still no go.

 

Next up I tried a different piece of steel (folded over).  Let it get really hot for a while (10 min) before trying to weld, and again after "setting" it.  Some sparks this time (or at least yellow hot scale coming off).  This is an old spring, ground down to clean steel before I started, and using borax.

 

Still no go.

 

I know what I REALLY need is someone to show me or point out what I'm doing wrong in person.  But right now I don't have that, so I'll keep playing for a month or two until he returns.  I'm wondering about trying EZ Weld (or something similar), but I'm also curious / eager for any thoughts any of you might have.

 

Thank you in advance for any guidance.

[horse]

I can be of no assistance but can offer sympathy.  I could have written the same story with the same response.  I can stick about half of them in a solid fuel forge but the gasser has me baffled

[Iron Poet]

You'll get it when you get it. Flux heavily and when the metal starts to get a slight sheen it's ready for welding.

[Couchsachraga]

Thank you for the encouragement:)  I've been putting on my safety sunglasses (I made sure all my safety glasses are UV, but with forge welding it's pretty bright in there!).

I'm wondering if maybe I"m not using enough flux (understanding that the borax needs to foam up to boil away the water in it, THEN turn to a syrup of sorts).  That's one of the reasons I'm thinking of picking up some EZ Weld or something.

 

NO not sunglasses, and UV isnt the issue read the posted thread before you go blind from retna burn

 

[Andrew Martin]

Couchsachraga, I'm no expert on forge welding, but I might be able to give a few pointers. The two most common causes of a weld not taking are 1) oxidation between contact surfaces and 2) not enough heat.

To correct No.1, vigorously wire brush the scarves, or even file/grind them down to shiny metal before you attempt the weld. Also, remember to flux sparingly, too much flux creates as much of a barrier as scale does. I sprinkle on the borax at a red heat till the steel looks 'wet', then I stop sprinkling. In addition, fluxing does no good if your fire is oxidizing, make sure it is adjusted to as close to neutral as you can get it!

No.2 is corrected by careful observation/repetition. For mild steel: First, watch for the flame to turn yellowish as the fluxed steel approaches light yellow. Then wait for the flux to bubble and sizzle. Carefully watch for the sparkler effect to begin. When sparks start flying, get it out and tap it a few times. Some welds weld all the way in one heat; most need more than one.

Do all that, and remember that confidence is EVERYTHING , and you'll have it.

I should mention I've never welded with a gas forge, only in coal forges.

horse, same to you, either the forge is not hot enough, or the atmosphere is not neutral. I've frequently heard both complaints from smiths who use homebuilt gassers, that's one of the reasons I use coal. But others see it the opposite way, I just know what works for me!

Edit: it's possible you aren't using enough, but quite unlikely. Some do without fluxing at all, the real trick is a neutral fire. Flux just allows us more room for error.

Edited March 7, 2017 by Andrew Martin
Addition

[ThomasPowers]

Note that forges don't produce much UV at all; you need safety glasses that block infrared for staring into a forge.

I bet there's a smith fairly close to you; try to get to an ABANA Affiliate meeting and ask around about folks in your neck of the woods.

How do you have your forge tuned for forge welding---not gas pressure but atmosphere?

[Couchsachraga]

I'll have to check my older safety glasses... the newer ones are IR too as I recall (one of the things I looked for was both...).

 

I know another fellow, but he's not done much welding yet either.  When summer gets here there will be folks around (much bigger community here in the summer as with many recreational areas).  I will look for others though, as you are probably right.

 

For "tuning", All I've done is block off the other door and made sure there is enough gas going in to be pushing some out.  When cold I have some blue flame, when really going it is orange.  I've heard folks weld with it, but being newer haven't messed with it much (one of my reasons for purchasing vs. building was to hopefully have something that would work so I could remove one more variable).

 

I'll try brushing more next time - that may be in, as I've been wire brushing it, closing the pieces up, then a bit of reheat (as it's cool), THEN flux.

 

With gas it doesn't get quite so hot necessarily, and the amount of heat is more easily controllable.

[Irondragon Forge ClayWorks]

I can't help with the gas fired forge because all I ever used is a coal fired one. For me the "secret" is in the flux and I found out with Borax if I dried it in the oven at 200degrees for several hours it worked better. I just posted a reply in another thread about flux.

 

[Frosty]

Not to take away from all the advice you're getting from guys who don't know how but forge welding isn't hard just follow the steps. I make a forge weld a first session lesson to get the mystique out of the way. Forget UV there isn't any unless it's a cloudy day and you have a window open. Do NOT stare into the forge IR can cause cataracts. 

By tuning the atmosphere Thomas means you want a SLIGHTLY reducing fire. An oxidizing flame will scale the stock and prevent welds. Read through the gas forge section of Iforge about tuning burners. I've written that enough times already.

For your first goal do something easier than LITTLE stock. Punch and drift your rings and try welding fire or garden tools. Small stock is much harder to weld it cools very fast you almost have to squeeze weld things like rings with a pair of specially made tongs. That's an advanced technique.

Go for the low hanging fruit till you get a handle on the process, I like 3/8" x 3/4" flat stock and a simple fold and lap weld. Cut about 1/2 way through about 3/4" back from the end. Scarf the the end on the opposite side. Don't get carried away or try to make a perfect scarf, just put a steep bevel to the edge to avoid shearing forces. Brush it aggressively, make it shine. Fold it over but barely warm enough to bend without breaking if it's red flux it first. No need to wait for orange heat, what you want is a thin layer of flux to prevent oxygen contact as it heats. 

If you have the joint surfaces clean and a flux oxy barrier the flux doesn't need to flush crud out of the joint. Close it and sprinkle a BIT more flux in the joint just before you close it. Remember, flux is NOT glue it's just there to prepare the joint. Laundry borax works but foams when it reaches 212f. and doesn't paint the joint as nicely as anhydrous products. There are a number of good quality "forge" welding fluxes available and they work well. A couple years ago I was scanning shelves in the local welding supply and picked up a can of commercial welding flux like you'd use brazing, gas welding aluminum, bronze, cast iron, etc. and read the label. Anhydrous borax, boric acid and something to turn it blue. I bought a can and it works a treat. Patterson #2 I believe. Good stuff and about 1/3 the price in Alaska.

Bring it to bright yellow, when it has a shimmer to it remove it and set the weld, heavy but NOT SHARP blows. You want the hammer to strike like a dead blow hammer, bounce or shearing forces are bad things. With practice you'll hear and feel the weld set. Till your skills sets learn to recognize sets flip it lap side down on the anvil face and hold it there.

As it cools you want to see an even gradation of colors from orange on top to darker on the anvil face. If there's a sharp line it isn't set. brush, reflux and repeat set weld. test again. Once it's set brush flux and refine the weld. Do at least two refinment welds.

That's the story it takes longer to read this than prep and make a weld.

Frosty The Lucky.

[Couchsachraga]

Thank you for the great help!!  After my last post I realized those glasses are not labeled IR (at least that I can find online; the package may have been).  I'm not in the habit of staring at hot stuff, but do need to look in at times; I may see if the glasses I have for my plasma cutter will do the trick (I know they are UV, not sure on the IR side yet).

 

On the actually welding front I'll try some other stock I have - the ring was out of 3/8 stock, so I'll step up to something larger and practice there first.  From your description I suspect the faces were not clean enough first (I brushed them off good, but they were not shiny metal; I'll try filing next).  I may also try my LWS (Local Welding Supply).

I've read a few other posts on knowing what sort of fire you have, i'm headed for yours next Frosty - Thanks for taking the time to respond to yet another newbie post:)