How well finished before blasting and Cerakote?

My 1911 build is coming along well and I’m getting to the point of thinking about the finishing. I plan to have a local gunsmith blast and Cerakote it (black on black on black – everything black).

Right now, I’ve stopped the preparation with 320 grit sandpaper thinking the blasting will take it the rest of the way for a semi-matte black Cerakote finish.

Is that true? Or do I need to get the surfaces up to a 600 grit sandpaper finish?

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Paging @RogueGunnWorks

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He probably doesn’t use a pager anymore. :flushed:

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Well, I am sure he will respond eventually. This is a holiday season after all and lots of people are spending time with family, etc.

In my limited experience, what you have already done (320 grit sanding) is plenty. Especially since you are sandblasting. As long as there aren’t deep scratches, you are good @BobRock

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Sorry all, I am in the process of moving back to Washington State. Like 1/2 the shop is now in storage.

Ok, so for Cerakote there is no “sanding” to speak of. You do need to use 120 grit Aluminum oxide at about 60 to 80 psi (all depends on the blaster) to clean and prep the surface.
Once that is done, then you need to off gas all parts at 300 degrees for at least 20 minutes. If it is polymer, 150 to 180 degrees for 1/2 hour.

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Yep, all scratches will be seen…
Cerakote is sprayed at .0015 to .002 thickness unless you are spraying Elite Series Cerakote. That is .000875 or so… just under a .001 of an inch.
It shows EVERYTHING… it is NOT a filler.

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I figured you be along to explain it to him eventually

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So this really depends on the condition of the parts. There have been some parts, like a slide… that I have had to polish. Like to 3000K to remove abrasions, dents, deep scratches, etc. But that is fairly uncommon.
Usually after the parts are degreased, they are blasted as stated above, then off gassed.
This is really all you need to do. But! 1911s… are a LOT different!
Do not blast to much in any of the trigger mechanism holes, do not Cerakote the sear or disconnect unless you are using elite Series and do a very think coat. Also… do not spray the inside of the slide where the rails ride, or the frame in the same area. Extremely touchy tolerances there. I will do a light over spray there and that is IT.
you have to tape off the hammer… do not blast the sear catch at all… while you can coat that area… do it very lightly.
There is a lot to know about how much and where to spray Cerakote and it all depends on the firearm. So do some test runs on small screws and see if you can thread them into a nut or what ever. You really are looking for 2 coats that add up to .001 of an inch give it take.
If you screw up, wash it all off in acetone and blast it again. Do NOT spray over old Cerakote! And… remove all old Cerakote unless you are after a battle worn distressed look…

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Yeah, just crazy busy… hahhahahhaa

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So what you have is what you get for surface prep. The blasting will not cover tooling marks at all in the surface. Anything done with a dremel will show. While it is a pain in the ass… you basically have to 100% prep the surface. On any flat surface like the side of the frame and slide, I use a machined flat surface with wet dry sandpaper… use water and do a random pattern. Usually going to 1200 grit is enough if you are after a super smooth finish.
If you are after battle worn, then do as you please. That makes it look cool… but I assume you are not after that!
Oh… make sure you have your pistol 100% test fired. Like 100 rounds… to make sure there are no issues. Once it is coated, then you know it is just the thickness of the coating, not the firearm. If that makes sense.

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The “swirl” marks from 320 grit sandpaper will show, if I understand correctly. My aim to to get the pistol ready to pass to my gunsmith for the blast and Cerakote work and I want it to be in good enough shape that he needs to do nothing more.

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Here is what my only experience with Cerakote is:

This was sanded with 220, then 320 or 400 (whichever I had on hand), but just to clean them up. I didn’t go for pristine here because it was being blasted.

Results of Cerakote






Before cerakote

I parkerized the frame and parts at home. This was after intitial sandblasting.


Before Sandblasting

Here is what it looked like before blasting (yes, some parts I didn’t bother sanding all the way)





Hope these help.

Also, in this video, you can see detail on how the pistol looked before initial sandblasting (pre-parkerizing)

Can you guys let me know if the video above works? If not, I will post a link to youtube.

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@BobRock hopefully you can see the swirls in my parts and if you watch the video you will get to see even more and close enough. I only used 400 grit on a few areas, namely grip safety (because of pictures I was taking).

And you can see how cerakote came out after the parts have been blasted. Granted they were blasted twice -before parkerizing and before cerakote.

If you want me to take close up pics of any areas on this pistol, let me know.

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The video played just fine. And I think your swirl marks are somewhat “smoother” than mine. I’ll clean that all up a bit better on mine.

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