Reheating and forging Damascus after steel has cooled.

[EOD Trunk Monkey]

My youngest tasked me with trying to make a folding knife for him. I have never made damascus and have a question. 
 

i started lengthening out some spring steel but had to stop before I had a chance to start folding to make the layers. I turned off the forge and set the steel next it to cool.
Can I reheat the steel and start folding it to make the layers or have I missed my chance since I let it cool?  This was an old leaf spring and I have a lot left over but I do not want to waste it. From what I see, my worst case is to use to make a knife shaped object and work on my hammer skill and use another piece to try damascus when I know I will have time to complete all of the layers.

[Daswulf]

Damascus is made of different types/grades of steel. If you just forge weld one type of steel together the chances of a pattern are slim if done right. Only exception I know of might be cable Damascus and that may have different reasons behind it like decarb, but that Is a different animal than what I think I understand you talking about. 

Spring steel can make a fine knife. What you let cool slowly will make for a usable knife. If you want Damascus, you need to clean it up and forge weld it with a different type of steel. 

I think you might have some misconceptions or misunderstanding about Damascus. A single steel type, if pure would make a better blade just shaped and ground/finished. You would be fine finishing it out if it has enough mass. If you need more mass for a blade forge welding is possible but starting with a mono steel that is beefy enough is more recommended. 

I have heard that forge welding spring steel to itself can be tricky. I have not tried it. 

In all, to answer the last question, make a Knife from it if you can to work on the skills and harden, temper and finish it out. 

[Chad J.]

Ok, I'll hop in here.  First off welcome.  I'm located in south central Cheeseheadistan. You don't need to fold and forgeweld leaf spring if that is the only steal you're using.   It won't show anything and just introduces potential problems.  So I'll save you time on that.   Most times you're using a high carbon vs mild steel or carbon steel vs a nickle alloy to get the patterns.  

You can reheat the steel that you're working.  There is the process of annealing that is actually that in a controlled method to make hardened steel easier to work for machining and some say forging but I've never noticed a difference. 

Now let's get to the main questions.  Have you forged any knives before?  How much homework did you do before you lit the forge?  If you haven't I don't recommend trying damascus or pattern welded.   I also would suggest  starting with a fixed blade. 

There are tens if thousands of smiths.  This sight is probably one of the most complete repositories of information on blacksmithing, but not the easiest to navigate.  There are several posts under the knife making threads that can help guide you, and a section on heat treating. 

Don't let this stop you,  I want you to have good info and stay in on the craziness that is smithing.  There is way to much bad info out there on the internet, on TV, and in movies.   I'd also suggest finding a local group and getting some one on one time.