Forge Welding for Novice

R

reader_06

Joined
Jul 25, 2011
Messages
12
I have been making knives for a few years. I have my own coal forge and avils. I recently received some saw blades from a gentleman at my church whose grandfather ran a sawmill for years. I curently have a stack of the blades cut in 6 in sections with chainsaw blades between each piece of saw blade. I have welded the pieces together along with a stick on the end to help control it.

I am looking for advice on which flux would work well and the best way to forge weld the blades.

I would appreciate any help to be offered. I don't have a hydralic hammer or gas forge so I have to do everything by hand and want to make sure I do it right the first time.
 
First let me say welcome to the forum. Where bouts do you live?? It helps with the possibility to get a shop invite. It's much easier to show rather than tell.

But to answer the best I can here I need to know how large a stack you have? You use a coal forge, how large is that and it is home made or commercial? Are you actually using coal or buying coke? Have you done any testing on your steel to try and determine what it is?? All these things are important to steer you in the right direction.

Simple explanation, Borax is the most common flux. Some add iron, boric acid, or other chemicals to try and improve the weld. I prefer anhydrous borax when I wet weld. It melts at a lower temp and works better for me. The fire is very important. Need a good bed of coals UNDER your billet with a good layer on top also. A beehive mound works best but can be difficult to maintain. Heat slow and even, flux, heat some more, when it looks wet take it out an hammer it lightly to set the layers. Repeat, after the second heat you can go to town and draw it out, fold, and to it all over again.

Good luck. If you fill out your profile a bit more completely you will probably get more responses. Also read all the stickies on the top of this page that pertain to forge welding.
 
If those blades had carbide tips, they are worthless for knife steel. By "chainsaw blade" do you mean the chain or the bar? Fill out your profile so we know a little about you.

-Page
 
Welcome to the forums. I see you have been around for a while, so I would recommend filling out the profile info. It will help us help you.

Forge welding takes practice. Starting out on a complex billet from unknown materials is not a good idea.

Get some 1.5" wide 15V20 in .070" and some 1084 in .125". Cut these to 6" strips and stack four 1084 strips with a piece of 15N20 between each. Weld the ends together, and weld on a 24" rebar handle. You now have a starter billet. Borax is the most common flux used, and twenty mule team is good enough ( but anhydrous is best). Many smiths have moved to hydrocarbon flux with very good results. They use a bucket of kerosene and soak the billet in it between heats. Drain the excess off, and stick the billet in the forge.

There is a lot more than this, but from here, you bring the billet to welding heat and weld from one end to the other. Repeat several times to assure the billet is solid. Draw out to twice the length, then fold in half and re-weld. Repeat until the layer count is about 250-500....... five folds = 224 layers, six folds = 448 layers.
 
Last edited:
rerader, try to avoid stacking the sawblade next to each other. Sometimes the chrome/nickle can be difficult to weld.
 
Thanks for the responses. I did add mor einformation to my profile. I usually never post I just like reading the threads. I live in Hempstead Texas about 20 miles west of Houston.

I usually don't like purchasing billets because I like being able to take something from its original form and make it into a knife. I started with old railroad spikes and rasps.

I have coke and coal. I usually use coal to start my forge with because it starts a little quicker than coke and then add coke as I begin working the metal. The forge is homemade. I have four fire bricks in the bottom packed with wood ashes to fill in the gaps. The forge is about 1 1/2 ft. in diameter. The open area is about 6in. in diameter.

I have plenty of the band saw blade and so plan to test it, but I have been looking for a place close to me to have it tested.
 
Have you done any forge welding in your forge yet?? This will give you a feel for how to accomplish your task. You can use scrap steel to play with. I learned from a farrier/blacksmith who was not a knifemaker. I used 1/4x1 mild and folded it on itself and forge welded it. Folded and did it again. Taught me what to look for, fire control, how to stack the coal/coke. Making a beehive is easier with coal. Keep the top wet and add more coal as you go. It will coke out in the middle and provide additional coke for the fire. Plus it will hold the heat in better and you can see what's going on. Kind of like a gas forge.

Do a quench test on your badsaw and chainsaw bar. Heat to about 1500 quench in water and it should snap like glass if it did not crack in the quench. Then make a 3 layer billet, 2 of your chainsaw bar and one bandsaw in the middle. Forge weld it the etch to see if you get a good color difference. If not you will need a different combination. Might even want to try an oil quench after you weld the 3 layer billet. Some combinations of steel will literally tear themselves apart in the quench. Also of you are having difficulties getting the weld to set you may also need a different combination. Good luck and have fun
 
You must log in or register to reply here.
Back
Top