looked around hardware store and found a box of borax....but question...is 20 mule team borax the same thing as i read about on hear??? its marketed as a cleaner at the store...just trying to get things right in my mind.

That's the stuff.
Try and keep it as dry as you can - it will work a little better that way.

20 mule team is a mix of acid and alkaline salts. I think the alkaline have the upper hand.

When molten, the corrosive nature of the alkaline attacks the scale on your work and dissolves it into a liquid form. This allows the scale and crud to exit the weld site when you start lightly hammering the two pieces together.

The borax also make a glass covering around your steel preventing further oxidation for a while.

I don't know what is going on chemically, but from experience, flux degrades over time in the forge environment.

Put it on at a near welding heat and don't let it sit too long in the forge when the bar is ready to weld.

If the bar looks crusty when you go to weld, don't bother. Brush the crud off - re-flux and re-heat and try again.

The problem I see with 20 mule team is it has chemical water in it. It can be bone dry and still have water in it so it foams up and falls off when you put it on the hot steel.
Anhydrous borax has no water even in humid minnesota summers. When you put it on hot steel it sticks. Turn the bar to put more on the other sides and when you get back to the oridinal side it is still stuck there not laying on the forge table.
The problem with anhydrous borax is it comes in 50# bags at the chemical supply house.

http://ull.chemistry.uakron.edu/erd/ for information on Borax. Type in borax and click on search. It brings up the MSDS on it. Actually brings up two different but similar chemicals, I think the top one is the one we are interested in "Sodium Tetraboarte".

Edited December 10, 200817 yr by Woody
fix a bad lik

The first we know as Anhydrous Borax.

The second one, we get when we buy 20 Mule team. notice the 10 units of water, this is why some cook 20 mule team to get anhydrous, to remove the water

One more thing to remember about borax is the 'after' effect, there is a residue that will leach out later. It does work but the afore mentioned 'problems' are there, it just if you are willing to deal with them. I am starting to use silica mixed with dirt-dobber nests. Goodness knows I have plenty of them! Also plan to get a can of E-Z Weld!

Thomas is quite right. There will be some residue post welding. You will see this as a white powder around the area of the weld. It can take a few weeks to materialize, but materialize it will - sooner or later..

Where possible I like to pickle my welds by submerging them in white vinegar for a day or so. That normally does the trick. No more residue.

Even though many problems are mentioned with regular old 20 Mule Team Borax, there are an awful lot of blacksmiths that get use to using it and swear by it. It is fairly inexpensive. Mark has a good idea in the pickling. I usually soaking the weld in water for a day or two and it seems to eliminate the white. I just watched a video where an older blacksmith originally from Germany was using hydrated lime. Seemed to work fine. He was forge welding with it using a actlyene torch, rather than a forge, though. If you want to spend the money, the purchased forge welding compounds such as EZ Weld and Crescent work good and are not as slick as borax. EZ Weld has metal filings which are hard to get off the finished work. Some smiths use combinations of borax and the purchased products, particularly using the borax to melt into the fine cracks etc.

looked around hardware store and found a box of borax....but question...is 20 mule team borax the same thing as i read about on hear??? its marketed as a cleaner at the store...just trying to get things right in my mind.

The hardware stores here sell Boraxo Hand Soap says 20 mule team also ...its not the same a reqular borax..comes in a white box with a red or pink stripe.
makes wonder what you have?

I watched the old german's DVD also.
He had some amazing stories about escaping from east germany after the war.
Besides the forge welding with a roasebud torch he showed flame straighning bar and talked about straightning plate
DVD can be ordered from UMBA Online
It is #RD135.
He said they used to grind up bricks to use for flux in Germany which is why he used lacked lime. (hydrated lime)
He said a bag of unlacked lime and a 55 gal barrel of water had enough strength to eat a human body in case you have monther in law problems.
Actually he did not mention anything about mother in laws.

As for the white remains from Borax Tal Harris talked about leaving the piece in the water slack tup overnight and the residue will be washed away.

I believe ez weld will also leave a white residue.