I am attempting to forge a tomahawk from 1095 leaf spring. I heated the steel and wrapped it around a 1" round bar for the eye. I don't wish to use my arc welder to weld it. I hope to forge weld it. How difficult is it to forge weld high carbon steel. Other than some borax what do I need to do? What color does me steel need to be? What can I put in my propane forge to keep the borax from eating my lining? This would be my first forge welding attempt.

BP0093 Forge Welding hosuld give you the basics. More pertinantly, zis small hand or camp axe

Edited May 19, 200818 yr by matt87

If this is your first attempt, I would try it on some mild stock first. I always warm up and forge-weld a couple of other items before I attempt a critical piece.

As far as that goes, the two pieces that will be welded together need to be clean (no scale, clinker, or rust) and forged to shape prior to brining up to welding heat. Depending on the metal used, the metal is fluxed and then brought up to a pale yellow/white heat. a few small sparks are okay but if it's the 4th of July, cut off the burned end and start over.

If using Borax, there may be some green flames just before it reaches the proper temp. I take the metal out of the fire, give a quick downward flick to remove the excess molten flux, place the two item together, and give the middle of the join a medium strike (not trying to crush them together, as the metal will move quickly at this temp). I then work my hammerout from the middle towards the ends to feather them together.

This sometimes takes 2 or 3 heats, depending on the size and composition of the metal...as I said, practice a few time with mild steel (some of my old toongs were built from scraps forge-welded together as practice), then tackle the eye....

Certainly check the blueprint section, any reference books you have, and any local smiths for additional help...

you might try the old way of doing a tommahawk and go mild steel with a hi carbon insert...it is a easyer weld and less chance of completely decarburizeing the steel. wrap for eye put a piece of steel in between the two halves of mild (in middle of the U) it protects the steel from overheating and the steel welds at lower temp than mild ... good luck!

1: does your propane forge get to welding heat? Many do not.
2: high carbon steel welds at a lower temp than low carbon steels
3: Practice before trying to make an important weld
4: can you control the atmosphere in your forge for welding?

I don't know if my forge will get that hot. I will take a piece of steel and see what color I could get. I have a fuel valve for my forge and an air restrictor. Forgemaster blacksmith model.

If your forge scales steel it's burning lean, oxidizing flame. You can correct this in the short term by tossing a piece of charcoal into it to absorb excess oxy. Pick it out of a camp fire, not a briquette.

Welding temp is as much a matter of skill as actual temp.

Frosty

a forgemaster blacksmith model will get to welding temp no problem. This is the forge that was once and for all I know may still be the most popular in the farrier competions when useing propane. Bar shoes are a pretty common shoe to forge.

I am getting a lot of scale from steel that looks clean when I put it in.

It's running lean.

What psi are you running? Too high can cause an oxidizing flame.

If necessary choking the air intake down will correct the problem.

Lastly tossing a piece of charcoal in the forge will absorb excess oxy. Use campfire, stove, etc. charcoal, not a briquette.

Frosty

I generally run about 10psi. I have a flapper over one of my burner intakes. I close it when I light it. Should I leave it shut when I am using it?

Using the choke plate to restrict the intake air will work. However it may not solve the underlaying problem. You may get a reducing fire but not enough heat. A properly tuned burner is the REAL answer.

What kind of burner are you using? It'll be easier to make suggestions if I know what kind of beast we're talking about. Can you post a pic or two? the burner at least and your whole setup would be more helpful. Occasionally problems are external to the burner itself.

Still, some other things that will effect it regardless of type are:

Over pressuring, try less pressure and see what happens. You might find you have to run at high pressure to get the forge hot and start heating the steel, then turn it down and partially close the door to bring it to final welding heat.

Alignment of the jet, if it's hitting the side of the tube it'll hurt air induction. If that happens you can have both unburned fuel exiting the forge making CO AND an oxidizing flame in the forge scaling the steel.

This occurs because propane and air do not mix naturally nor easily so if there's some segregation in the burner tube the gasses will enter as discrete units and not mix. Incomplete combustion AND excess oxy. It's counter intuitive but exists in almost all forges to one degree or another.

Another really common problem is crud in the jet. Pull it and clean it out, clean the supply line back to the hose too. If you have a little bit of something in the jet you may be getting the volume but not enough velocity for proper induction.

Those are the generic problems that apply to any naturally aspirated burner. At least the ones that come to mind at the moment and I'm trouble shooting a new adaptation of one of my basic designs right now so it's on my mental front burner right now.

Frosty

Thanks Frosty
Lots of good info I wasn't aware of. Maybe this should be a sticky.
Mark

My pleasure Mark.

I don't know about a sticky, many more and we'll have to go straight to the second page.

There are a number of other guys here who're as good or better at trouble shooting burners. Perhaps we should get together and write a burner trouble shooting blueprint.

Maybe even a trouble shooting blueprint section.

Hmmmm.

Frosty

Frosty, please do. (get together and make a BP)

Will do.

Frosty

Another possibility is that your liner is not in good shape.