Weird Gun Kote/Etch problem

Chris Railey

Chris Railey

Well-Known Member
Its hard to tell but under this brown coating is an extremely cool 1080/15N20 Go-Mai blade I made up last weekend. I etched it as normal then neutralized with glass cleaner (with ammonia). After neutralizing I blew it dry with compressed air then immediately coated with Gun Kote. Before I put it in the oven the Gun Kote was nice and clear and the 15N20 line was very bright against the 1080. After a little over two hours I pull out this brown coated blade you see below. The only difference to my process was when I pulled it out of the oven I noticed my temp (on the inside thermometer) had crept up closer to 350 rather than the normal 320. Any ideas as to why I got brown?38E9377B-25C5-42DC-BD9A-F8AE1FED1DF9.jpeg90333C54-26EA-4513-A898-32A3970AC5F2.jpeg59DA738D-652E-47AD-A7DC-1D4FC2242A27.jpeg
 
sir. Had/have the same problem and the gun kote tech that answered my email suggested it was caused by the higher temp. I didn't ask if it effected longivity of finish. I'm still playing with it to see if its affected the durability of the gun kote. I will say it does cause some interesting gold/bronze colors to 15n20 in damascus
 
vlegski said:
sir. Had/have the same problem and the gun kote tech that answered my email suggested it was caused by the higher temp. I didn't ask if it effected longivity of finish. I'm still playing with it to see if its affected the durability of the gun kote. I will say it does cause some interesting gold/bronze colors to 15n20 in damascus
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Thanks for letting me know. The temp was my main suspect for sure. I also think I got a little carried away with the thickness of my coats generally I keep the entire coat very thin. I am going to sand it all away and try again this weekend. I bet I make sure to watch the temp better this time...Stupid toaster oven.
 
I got into this after reading Ed Caffreys comments on protecting blades, especially damascus. I to try to keep coats thin but sometimes the trigger finger gets carried away. I've tried sanding back to original blade surface and taking it to a smooth surface 600 grit. I'm not sure if either makes a difference. The Kote seems to take care of sanding marks. Of course im not going to complain if Ed comments. I'm still a beginner in this
 
For anyone reading this I figured out part of the problem. Personal stupidity. The curing time for Gun Kote is 1 hour at 325. For some reason I had it in my head as two hours. I guess I cooked it.
 
I just now saw this thread! That is simply a temperature issue. Gun-Kote, and especially the clear, calls for 300F for 1 hour AFTER the entire part has reached temp.

Part of the reason for that curing specific curing temp, is that at 300F, the steel will NOT change color..... I've found through mistakes, that even at 315-320F, I will get a pale straw color. I've also found that too high a curing temp can not only affect colored varieties of Gun-Kote, often times changing the color(s) slightly, but too high temp when curing degrades the finish, many times giving it a hazy and/or a super fine textured look.

I can't say for certain, but I also suspect that curing a too high a temp degrades the durability/longevity....but that's just an educated guess.
 
Just out of curiosity, how bad of a smell does curing the gun-kote create? Just wondering if my wife would kill me if I cured it in the kitchen oven?
 
I sanded off the original and re-did it curing at the 325 recommended on the can and guess what...Just like you said pale straw color. I think I will sand again and try 300. Thanks.
 
Casey Brown said:
Just out of curiosity, how bad of a smell does curing the gun-kote create? Just wondering if my wife would kill me if I cured it in the kitchen oven?
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It really does not smell to me. Now my curing oven has a lot of old crusty stabilizing resin in it and that is what I smell.
 
Casey Brown said:
Just out of curiosity, how bad of a smell does curing the gun-kote create? Just wondering if my wife would kill me if I cured it in the kitchen oven?
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I suspect you would be sleeping in the shop if you did it in the house..... and might even be buying a new kitchen range. Just my opinion....but I don't think it smells horribly strong when baking on, but my Mrs. ....... won't even come in the shop when I'm baking Gun-Koted blades, and asks me.... "You got any brain cells left??!" ;)
 
That is strange! The curing temp. Before I wrote my last post, I actually checked the label on my can of Satin clear Gun-Kote..... it says "cure at 300F, for one hour AFTER parts reach temperature" Then I read what you wrote.....about 325F, went and checked the Gun-Kote site/data sheets, and sure enough.....it says "325F" there. Hmmmm. Anyway, give it a go at 300F..... but give about 1 1/2-2 hours, and see where that takes you. Typically what I do is place a blade in the oven, and not really knowing how long it takes for the entire blade to reach temp..... I just err on the side of caution, and give it closer to 2hrs.
 
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