When to coat the blade ? Gunkote ???

[RDT]

Okay so I'm gonna coat a bunch of blades. Now, this is how I plan on doing it, I need you guys to tell me if it sounds like the right thing to do:
Heat treat the blades and bead blast them. Then dip them in the Gunkote and cook them in the oven. Does that sound right ? Questions 1: As well, must I always bead blast them in order to coat them ???? Questions 2:Can I leave them satin finish and coat them ? Question 3:Also, can I coat them and blast them or satin them before heat treat ????
Thanks brothers......RDT

 

[Greg Covington]

First, I want to make sure you are referring to Gunkote as the bake on spray finish. I have used Kalgard for quite a few years and I spray it on with an airbrush. Here is my process.

After heat treat, do whatever finish work you need on the blade and then sandblast it. It is necessary to sandblast because the coating needs a good surface to hang onto, and times that I have tried on satin finished metal, it doesnt stay put well....it is subject to scuffing or peeling.

After sandblast I degrease with acetone and then heat the blade to around 150F or so and the airbrush on the Kalgard (I am pretty sure it is the same as Gunkote, correct me if I am wrong) and once I am satisfied with the cover I bake the blade at 275-300F for one hr.

You cannot coat them before HT because it will bake right off. They recommend that you dont bake at too high of heat because it will discolor the coating.

Brownell's sells a moly coat in a spray can that looks promising. I have also used their baking lacquer but it doesnt seem as tough.

Also, I wanted to mention that this process depends on the type of knife you are making. All steel knives or wrapped handles it is great....but you want to do all your guard work, etc before applying the coating. Remember that many epoxies and handle material wont stand up to 300F for an hour. I have sucessfully done micarta handled knives with this though.