View Full Version : Forge weld no go. Forge Newbe

Alex Cole
10-29-2004, 02:13 PM
Hello to all

I built a 1 brick forge and have been trying to forge weld just two bars to each other. No luck. I have a nicolson file and a piece of 01. Now I am not even trying to make dimascus yet...just trying to get 1 weld so I can see what it takes. Here is my setup

1 brick forge.
20 mule team borax.
bailing wire
ball pein hammer.
forging tongs.

I grind the surfaces of each peice of metal. then I wire them together using the bailing wire. then I Put them in the forge and heat up until red..not yellow, Pull them out..wire brush.....put back in quickly......heat up until red again....pull out....flux the crap out of it....put it back in.....leave in unitl I see the 20 mule melt and turn to honey like consistancy....and it starts to bubble on the surface of the metal....which is about a nice red-orange color now. I then pull it out of the forge quickly and smack it with the hammer. Now I have tried pounding the S#$! out of it and all that did was sprey me with hot I tried a lighter approach and just kinda tapped it lightly. and nothing happeded.

I have tried this manny times now and I just can't seem to get it to do anything. any it possible I'm not getting the meteral hot enough in my small 1 brick forge?

Thnaks for any input

10-29-2004, 04:56 PM
Sounds to me like it's too cool. I weld at 2300F, which to me is yellow. 20 Mule Team will start bubbling around 1900F, so you want it a bit warmer than that; when it's right it will be bubbling vigorously. Personally, I'd say 2000F minimum. When you get your conditions right, it'll weld without problem as long as you are in a reducing atmosphere. You should have a fuel-rich environment to keep the oxygen out. This is usually known by the fact that orangish flames are exiting the forge. Don't beat the crap out of it when welding. All you're trying to do is make sure the two faces of metal come in good contact. Overhammering causes it to slide on itself and it won't stick.

Hope this helps a bit.

10-29-2004, 05:04 PM
Let's see a couple of ideas here. First you are using 20 mule team borax. This has chemical water in it. Anhydros Borax works best. Melt your borax to drive all the water out. Then pour it over a glass or metal sheet. Allow it to cool and then powder the result.

Next you may not be at the right temp. Color is a very poor way to tell temp. I watch the action of the flux. Once it is boiling, I wait till it's at a rolling boil, or when the bubbles are "dancing" over your steel surface. Then I wait at least 30 secounds more (in my forge and when starting with a 1"x1" billet) for the heat to "soak" thru the billet.

You are right to try changing how hard you hit. Depending on how thick you joint is, you may not need hit hard at all. Hit too hard and the sticky layers of metal you need to fuse togather, shoot out with the flux spray.

Rather then try to weld two layers, first do something simple. I have my students forge weld simple rings made of 1/4" rod at first.

Last your one brick forge may not get hot enough. I have heard of folks welding cable in one, but not pattern weld. Cable takes a lot fewer BTU's to reach welding heat because of the small cross section of each strand.

10-29-2004, 05:11 PM
I would recomend raising your temps a little. If you cant get your torch to go much hotter try switching to MAPP fuel, it is a little pricey but will get you a few hundred degrees higher. I have never welded two bars in a one brick but I have welded some small cable. One thing that helped me get better welds is to use a HEAVY hammer and move it slow. I did my most sucessful welds with an eight pound sledge hammer choked way up next to the head and kind of just set it down on the piece. That way I wasn't worried about shearing welds, it is the bounce of a fast moving hammer that makes them pop apart.

10-29-2004, 05:51 PM
I looked up the dehydration temp of borax. It can be as high as 780F. It can also regain water as rapidly as it loses it (hygroscopic). At forge-welding temps, the water will be long, long gone. To be honest, I've never understood how the water could cause any weld problems.

I have never noticed any difference in welding with 20 Mule Team versus anhydrous borax. What I do find is that the anhydrous material sticks better and doesn't tend to fluff up and fall off into the forge. After using a bucket of very expensive pharma-grade anhydrous powder which wanted to constantly cake up in my shaker (indicates water absorption, back to the same old stuff), I returned to 20 Mule Team. I haven't noticed a bad weld yet. If it fluffs up a lot, I just hold it in the flame at the mouth of the forge until it melts. Saves the bottom of my vertical forge from getting trashed quite as quickly.

Different makers have highly varied opinions about the efficacy of anhydrous borax over the Mule Team. Scott obviously feels it's better, while I feel it's not necessary to go to all that trouble. You should try both eventually and decide for yourself. Just be sure to smash it up on a very dry day and keep it very tightly sealed so it doesn't rehydrate immediately. My sincere opinion is that you can get fine welds without dehydrating it for now. I'm not saying this to argue with Scott at all, just to say that I think your problem is temperature related and that's where I think you should concentrate.

10-29-2004, 06:13 PM
And I agree his problem is most likely temp related. If nothing else from his discription of the way the flux is moving and the color of his steel. Plus as I and another said, I would be surpirsed if a one brick forge can turn out enough BTU's

As for Anhydros Borax, maybe I just have better luck because I'm in what amounts to a Southern California desert (except you could not prove that the last two weeks, thank you El Nino.......not!).

I have just found the Anhydros stuff doesn't make as much mess in my forge as twenty mule team. It doesn't foam up as much on its way up the temp scale. Other then that it should in therory weld the same.

I have found flux is a very personnal thing. What one person swears by another swears at. Right now I using the welding flux from K&G. It is mostly anhydros borax. But it has a few other things. I think Sal Amoniac(sp?) and I don't know what else. I seem to use less and it flows over surfaces much better. But as I said it's what works for me. What works for you could be very different.

10-29-2004, 06:45 PM
There would have to be universal agreement that 20 Mule Team is far messier to use than the anhydrous borax. :) That's why I don't like to stuff a billet caked with the stuff right back in the forge, but melt it in the external flame. It eats Satanite and Kaowool like there's no tomorrow.

I've been doing some searching and reading, and find that my original statement about hygroscopicity to not be totally accurate. While anhydrous WILL pick water back up if left exposed to a lot of moisture (like an open container), it will not rehydrate as rapidly as I anticipated if stored with some precaution. In our humid conditions in the Midwest, however, it does tend to cake up if left in a shaker.

What I am having a hard time finding out is just what the chemistry of welding-temp borax actually is. I'm wondering if it's sodium borate still at all or if it's degraded into boric acid or boric oxide. Interesting question, keeps my chemistry chops working. Thanks for making me think, Scott! It's easy to fall into ennui when one retires!!

10-29-2004, 10:02 PM
Normal temperature for forging O1 is 1800-1950F but forge welding temperature would be higher than that.

Chuck Burrows
10-29-2004, 10:30 PM
Jim Hrisoulas swears by this flux formula

Flux mix is as follows:
5 parts anhydrous borax
2 parts powdered boric acid
1 part powdered iron oxide (the real STUFF NOT the concrete dyes)
1/2 part fluorspar
1/4 part sal ammoniac

This stuff sticks most anything together

10-30-2004, 09:34 AM
I have been using the welding flux from K&G and it works a lot better than 20 Mule Team.
Only problem is the the puddle of flux in the forge, I had to put in a new floor. New project is a welding forge. Gib

10-30-2004, 07:54 PM
i have welded cable in a one brick forge and had to use mapp gas in order to get it hot enough,i also used 20 mule teem no problems.if your planning on doing more welding or damascus you can build a larger hotter forge for little money,the only high cost will be the propane tank,hoses,regulator and opptional fan,there is tons of information here on theses forums and at ron reils web site on how to build burners and forges,i built my burner for less than 8 bucks and the forge for about 15,you should be able to get a propane tank for less than 5 bucks at garage sales,i had my hoses made for 15 dollars at a welding shop and my regulator(a nice one but doesnt have to be so nice)for 60$,so less than a hundread dollars and i can do so much more with it than a one brick.well anyways hope this helps

10-30-2004, 08:09 PM
I have been using the welding flux from K&G and it works a lot better than 20 Mule Team.
Only problem is the the puddle of flux in the forge, I had to put in a new floor. New project is a welding forge. Gib

Gib, do mean it works better in terms of sticking to the billet and such, or do you actually notice some difference in it's welding characteristics? If there's some decided advantage I can't figure out with the old brainbox here, I'd be quite willing to buy a bucket to try, provided it doesn't contain flourides like Dr. Jim's stuff does.

DiamondG Knives
10-30-2004, 10:28 PM
I would agree that it sounds like you need to get hotter. I had to really work on letting the billet soak. Once I thought it was ready, I looked at the clock and made myself wait another 10 min.

As far as flux goes, I started using annhydrouse from Kelly Cupples, and it works great, but does it work BETTER than regular 20 mule team? Not that Ive noticed. Somthing I have started doing is to add a few spoon fulls of brake turnings to about 1.5 cups of anhydrous, kind of has a rock salt look when mixed. I dont know if it makes a diffrence, but my welds have been consistantly solid, may be Ive learned how to do it, or it may be the flux. Dont know for sure, but its what works for me.

As I said above, the biggest problem I had was not being hot enough.

Good luck, and happy hammering!!

God Bless


10-31-2004, 08:00 AM
Mike, It always seemed to me that the Borax I was using (I just went to the grocery store and bought a box of borax soap, it wasn't 20 mule team) would eat up a lot of the steel that I was working with and sometimes I couldn't get it to stick, I was welding cable.
When I started welding Hawks I was surprised at how strong the welds were. I over drifted one on purpose and I could not get it to split.
I am welding 1050 and it works great, after the first series of light hammering it never gives any induction of coming apart. I would mention that I don't do any arc welding in the eye till it is almost finished so all the strength of the eye is tested.
As far as what it has in it I don't know. Gib

10-31-2004, 09:01 AM
Thanks, Gib! The possibility it will eat less steel is good enough for me to want to try it. I don't seem to have any problems with my welds using the press to form them, but I begrudge every last flake of steel I lose! :) I'll call Ken and see if he'll tell me what's in it, or at least if he can confirm whether it has fluorspar or not. Thanks, again!

Alex Cole
11-01-2004, 08:54 AM
wow! thanks for all the feed back guys! Over the wkend I tried to get the pieces to weld up again and .... well no luck....I think you are all right in saying that my 1 brick forge isn't hot enough to do the job. I tried turning up the gass and well it only resulted in a huge crack in my brick that eventually broke in half. I think I had the walls too It looks like i'm going to be building a real forge if I plan on doing this again. I have two of the 3 books that are "The Master Bladesmith" series and I have read both of them cover to cover more times than I can remember but I just didn't know what was going on. I wondered if I was not getting hot enough but I was afraid to get too hot for fear of burning the carbon out of the steel.

Thanks again for all your help. I will be posting again once I can get some sort of real forge put together.



11-01-2004, 10:46 AM
I would agree that it sounds like you need to get hotter. I had to really work on letting the billet soak. Once I thought it was ready, I looked at the clock and made myself wait another 10 min.


What are you trying to weld? A brick sized billet? Maybe it's just me, however last night I welded two billets, patterned one of them and did the draw down work on the other inside of two hours. First heat takes a while (maybe 5 whole min) but after that it's less then two min to get the bilet back up to welding heat and after each weld and re-fluxing. I then let the billet soak for 30 sec more.

Size wise I'm welding a 1"x1" stack of shim stock or an 8 layer stack of 1/8" by 1" wide material. I weld a six inch long billet in four heats. I then flip it over and make another welding pass in two or three heats on the other side (just to be sure). So all in all it's about 25-30 min to weld the whole bar.

So your 10 min sounds extremely long to me. Either you are welding a great big peice of steel, or else your forge puts out a lot fewer BTU's then mine.

DiamondG Knives
11-01-2004, 04:11 PM
Good point! I was not very clear here. I was refering to the initial heat. :o

After the billet is at heat, it takes much less time.

God Bless


Alex Cole
11-02-2004, 08:42 AM
I was trying to weld a 4" long x 1.5 wide peice of O1 and a 1" wide x 4" long piece of file I had ground down. For me to get the peice up to where the flux would slightly bublble would take me about 20 min for the 1st heat and after that it would take like 10-15 min to get it back.....and it lost its heat fast.

I wasn't trying to make a billet per say but just trying to get the two pices to weld together. I think you are all right that this setup is just not hot enough.

So far all my experience is with stock removal and I am just trying to get some of the forging techniques down and understood so I can hopefully grow into a versed knifemaker, like all of you!



11-06-2004, 02:42 PM
Isnt hot enough . I dont recomend any thing but plain borax. At 1200f any chemically bound water leaves. The minute you set your special dry borax down in the shop uncovered it begins to take on water from the air. Iron or high carbon steel powder will aid in welding but it will also add a bunch of unwanted junk in your pattern. Keep you steel clean and hot and it will weld you dont need flux if you can keep the air off the weld. Flux is not glue. It just keeps the oxygen off the area to be welded. It also lowers the melt temp of any oxide that forms. It is a very simple process. no oxygen and a little pressure and it will weld. remember the higher the carbon content of the parent metal the lower the required welding temp.

11-11-2004, 06:42 PM

If I read you right and you are saying your walls of your one brick forge are too thin, that could explain a lot. The forge is more then just a box to pour fire into. The forge walls need to keep every BTU in that they possibly can. I'm using simple propane burners. And without a well lined forge chamber they could not put out enough BTU's to bend thick iron. Let alone forge weld.

I'm using two Ron Reil brunners to heat a 4"x7"x9" (252 cubic inches) chamber. But it's lined with two inches of kaowool on the top and sides, with a two inch fire brick and one inc of kaowool on the floor. Plus I use ITC-100 to make my linning even more effective.

So looking at your one bick forge, here are some options. Make a new forge and watch your wall thickness. If you set a two inch fire brick on edge, figure on only a one inch wide chamber, leaving 1/2" of wall thickness on the sides. Also don't run your chamber all the way thru the brick, Stop about 2 inches from the far end (giving you a 7" long chamber). Now if you need more space you can make your chamber oval and make it no more then 2 inches high. So the resulting 14 cubic inch chamber should take very little to get up to heat (much less then my toaster over sized forge). The only weak point is the 1/2" side walls (the 2" thick top and bottom are fine).

Next make sure the hole for your torch head is a very close fit. Don't let any more hot gasses escape then you have to. The two square inch opening on the front is more then enough to allow your small forge to breath.

Also see if there is someone local you can get a small amount of ITC-100 from (it won't take very much at all. Maybe a couple of ounces at most). ITC-100 reflects something like 90% of the IR radiation that hits it. So it will make your forge much, much more effective.

Last try the mapp gas. It's expessive. so this is a last option. But if you are only doing small jobs it's not too bad.

For your first forge weld I suggest starting small. I have a my students forge weld a ring closed, made from 1/4" bar sock for the first weld. Next if you want to go bigger, still think small. My first forge welded billet was made from 3/4" cable. 1/2" to 3/4" cable will make a very nice spoon, or small knife. Pretty much how thick your cabel is, is how wide your welded cable blade will end up being.

Your 1.5" wide and 1" wide two layer piece is a no go in this forge. But you can have a lot of fun with welded cable. And if you are very lucky you just might be able to get a 1/2" x 1/2" stack of shim stock to weld up in the one brick forge. But surely no more then that.

So play with the welded cable a while. You will be glad you did. My web site and (as well as several others) has some fun welded cable tutorials. Plus there are a few simple welded cable projects in my gallery. Stop on by and look around.

Hope this gives you something to go on. Let us know how it goes from here.