problems making damascus

[neil1967]

I have taken a couple of classes in damascus steel making, one at the ABS school and another in Boston. I am now trying it for the first time solo and I have some questions about it and also have run into a couple of problems.

I have been through the forums and my questions are SORT of answered SOMETIMES but don't really get at the meat of things.

Here's what I'm doing.

I'm layering .049" 15n20, two pieces to approximate the thickness of the 1/8" thick 1095 I'm using. I have it up to "9" layers (five 1095 layers alternated with four (really 8, as I'm using two pieces together) of 15n20). Now, I was reading in a thread on Ed Caffrey's forum that getting 15n20 to weld to itself can be tricky, so is it best to only go with one layer, and if I do, will it show up right if I take it up to like 100 - 200 layers, or should I go higher in my layer count to get the layers to look evenly widthed?

I'm forging in a propane forge. I can get it up to a really bright orange, and sometimes to a yellow, but the forge isn't mine, and it's a bit inefficient, so I'm wondering just how to tell if it's hot enough to weld? I've learned that it should be REALLY yellow, and I've heard that if the flux (I'm using 20 mule team borax) is running over the surfaces like melted better then it's good to go. Is this true?

How can I put the billet together cold. Is it best to use a welder to tack it together? And if so, should I keep the weld to the ends so it doesn't get worked into the billet itself?

I HAVE been tacking it with a welder, and sometimes in the heating up, an outside layer will buckle away from the stack. Does this affect the forge weld of that layer to the next one in if I flux it really well anyway?

I've been getting some not great welds so I have some questions.

In setting the forge weld, is it best to use a power hammer, hydraulic press or just hammer it on an anvil. In my class at the ABS school, we used a power hammer, but used a sort of handheld curved dye, putting it on top of the billet when we first hit it with the power hammer to set the weld in the centerline of the billet first, then put the die aside and then hit with the flat dies on the power hammer. This seemed to help mostly, but I still got a couple of small cold shuts in my steel there.

How hard do I hit the steel to set the weld? In using the power hammer, I only have so much control, so tend to hit it a bit harder, but am wondering if lighter is better, or really where on the continuum of light to hard you should hit it to set the welds.

In the steel I've been making on my own recently, I still see some not great welds in spots. Would this be helped by setting the welds on an anvil, and then just using the power hammer to draw and shape?

In terms of borax, I've heard some say not to use too much, and others say to really soak it down. Any thoughts there?

Finally, on a billet I was working on today, I cut the steel to set up the billet with a lubricated bandsaw, the lubricant being an oil based liquid. Now, while I wiped down the steel with a rag before assembling and forge welding, I didn't really use soap or windex to cut the grease completely, and when I went to weld, I had some really funny big bubbles in the layers that REALLY didn't want to weld. I didn't experience this the other day when I cut them with a chop saw and was wondering if the bubbling could be an effect of residual lubricant?

Sorry so much, but these are the first two times doing damascus on my own and I'm just trying to learn as much as I can, and since I've made 4 or 5 billets in my life, and they've always had at least some flaws, and you all seem to have figured out how not to have any, I'm hoping you can help with any or all of my questions.

Thanks again for your always informative replies.

Neil

[Bob Warner]

Your thickness of the 15N20 mqay not matter depending on what your pattern is. A thinner layer can look just fine on some but not others. If you do a twist, even with equally thisck layers, your pattern may not look exactly evenly spaced. If you are doing a ladder pattern and you don't keep everything straight and square and flat, your pattern will look wrong anyway. I would just use one layer and see how it works out.


Judging welding temp for me is just looking for the boiling or bubbling of the borax on the steel. If the borax is moveing it is cleaning. Weld when it is bubbling. The main problem I see people have with this is taking too long from the forge to the weld. You want to increase the tem of the steel and continue increasing until you weld. This means that if your steel is ready to weld and you take it out and wait just a few seconds before hitting it to weld, it will start to cool. Even if it cools very little is is a falling heat, you can weld better on a rising heat in my experience. You should remove the steel, turn to the anvil and hit it within about 2-3 seconds.




I stack them up and run a weld bead across the layers on one end. Some people weld both ends but since the steels will expand at different rates, you will get bowing and seperations in the billet and that can cause problems. I weld one end and then go to the forge. Get it all hot and then close it all up with the hammer when hot. This will not only square things up but it will also break off the scale. Then flux and reheat. when the flux is boiling take it out and TAP the welded end together. It will weld, then reflux and reheat. Work your way to the other end. This way you chase any garbage to the far end and out instead of forcing it to be included in the billet due to a closed far end.


The buskling and seperating of the layers prior to welding is not a problem as long as you have flux on it.

If your steel is clean, it will stick together without hitting it at all. If the temp is right and the steel is clean, all you have to do it touch them together to weld them. If you are using a hammer or power hammer to weld, just tap it. If you really wail on it, it will not want to weld.




Once it is all welded (or appears to be), reflux and then vbring to welding heat again. Forge it doiwn to about 3/4 the thickness of the original piece one both the top and the sides. After you are sure it welded and you have reduced it in thickness, turn it one edge. One corner on the anvil and the other is struck with the hammer, if it did not weld, you will find out here. Then just let it cool and watch it. If you can see dark layers and bright layers, it is not welded. If it is all the same color and the entire thing changes color together, it is welded.

Borax or flux, is there to keep the steel clean by preventing oxygen from contacting the surface of the steel. It also cleans the steel and removes the garbage. It does not take much to accomplish this. however many people do not get the flux where they need it and therefore it does not do the job. If you flux the heck out of it, you probably have a better chance of getting all the areas. However, too much flux just falls off and eats up your forge.

The lubrication used on your bandsaw should not affect anything. The heat burns the oil off and the flux cleans it.

[neil1967]

Thanks, Bob, that's a tremendous help. I'll try out your suggestions and see how it goes.

Neil