Anyone else using Cerakote? Tips?

I have the same gun and shoot at 50psi. do you set the psi while you are pulling the trigger on the gun? do you get a buildup of paint on the atomizers on the nozzle? and what type of pattern do you set the gun for, tall or round?
 
The guy who coats my knives, cleans his gun like there is no tomorrow. He shoots his guns and my knives around 10psi. One coat.
 
That first pic of the three blade pics sure looks like trash is still on the surface of the blade before you spray.

I seriously doubt a paint brush, new or otherwise, is capable of removing all the trash from the blade. You ought to try a tack rag instead. With a rough surface you'll most likely need to "daub" with the tack rag instead of rubbing with the tack rag.

If it's not trash on the blade it could be trash in the mixing container, trash on the stirring stick, trash in the spray gun , etc. Paint filters won't necessarily filter out such things.
 
I don't want to add to your confusion, but here ya go.:) Do you start your spray off of the blade? A gun will give that spatter if you are on the part when you pull the trigger. Im also with J-Siah try 50 to 60 with your paint volume turned down and back off to 5-6 inches. I don't use a HVLP gun anymore, I like an air brush much better but I don't do high volume either.
 
I think you are not seeing those defects before the baking because of the solvent content in the paint film prebake. I suggest you sand the defects and look at them with a magnifier to see what color they are, it could be many different things. The plumbing on the compressor looks nice, if you do it again it will be beneficial to have 15 to twenty feet of hard line before your filtration. The air coming out of the compressor will hold contaminants in vapor because it is still warm longer lines give the vapor time to condense. The dirt nibs do not look like a moisture/oil in the air issue those contaminants look either like a crater if it was oil or a blister if it was water. Make sure you are using nylon mesh paint strainers not cloth, you could see about getting a 3m PPS system with waterborne cups (these have a much finer filter built into the lid. Waterborne strainers also have the fine mesh but the glue used to hold them together would dissolve in the solventborne paint. After you strain your paint into the cup look closely at the strainer and see if it has small clumps, this is referred to as seediness and could be a result of some old material. Your filter at the gun looks good and the pressure recommended by the maker is good, air pressure will only affect texture (orange peel) if it is too low or excessive overspray if its too high. The environment you are spraying in could be to blame, dust in the air can accumulate paint mist like the forming of a raindrop. I still would sand into the finish and look at the nib color, and check the strainer, your material could be bad or old when you buy it I have seen this with toners on a mixing machine several times.
 
A tack rag will contaminate the steel. It is a good idea for wood, but not for this application. Sorry.
 
centennial said:
A tack rag will contaminate the steel. It is a good idea for wood, but not for this application. Sorry.
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Really???

In that case you should go down to the local auto body shop and tell the guys that work there the same thing. They use hundreds of 'em.
 
Automotive paint and ceracote are not the same. A fingerprint or any trace of oil, grease or any other contaminant will ruin the finish. A tack rag would leave behind some residue.
 
J-siah said:
I have the same gun and shoot at 50psi. do you set the psi while you are pulling the trigger on the gun? do you get a buildup of paint on the atomizers on the nozzle? and what type of pattern do you set the gun for, tall or round?
Click to expand...

I set the pressure while gently blowing with an air nozzle, I hadn't thought about setting it while using the gun but that is a good suggestion! I get a very small amount of paint showing around the nozzle on the spray gun, not much at all though. I set the gun for a round pattern.

TheWeatherman said:
The guy who coats my knives, cleans his gun like there is no tomorrow. He shoots his guns and my knives around 10psi. One coat.
Click to expand...

I've been cleaning my gun really well too, but perhaps there's something I'm missing? I disassemble the entire thing after each use and wash all the parts in acetone until there's no visible trace of the paint.

woodwrkr221 said:
That first pic of the three blade pics sure looks like trash is still on the surface of the blade before you spray.

I seriously doubt a paint brush, new or otherwise, is capable of removing all the trash from the blade. You ought to try a tack rag instead. With a rough surface you'll most likely need to "daub" with the tack rag instead of rubbing with the tack rag.

If it's not trash on the blade it could be trash in the mixing container, trash on the stirring stick, trash in the spray gun , etc. Paint filters won't necessarily filter out such things.
Click to expand...

I've hesitated to use a tack rage because I'm worried that the rough sand-blasted surfaces of the blade will pick up wax from the rag. I'm going to talk to Cerakote themselves today and see what they recommend.

I agree that it looks like some sort of grit or something contaminating the blade or the paint. My mixing cups, filters and stir sticks are all disposables. They're kept in a clean drawer until I use them and I only use them once so I don't think it's coming from there... I think it's either leftovers from the blasting (like small pieces of grit actually wedged into the blade or something?) or it's in the paint itself or environmental. I really wish I had a separate clean-room for finishing!

Theiskell said:
I don't want to add to your confusion, but here ya go.:) Do you start your spray off of the blade? A gun will give that spatter if you are on the part when you pull the trigger. Im also with J-Siah try 50 to 60 with your paint volume turned down and back off to 5-6 inches. I don't use a HVLP gun anymore, I like an air brush much better but I don't do high volume either.
Click to expand...

I'm definitely starting the spray well away from the blades... I have done some spraying in the past, but every other lacquer I've sprayed seems very forgiving in comparison to the Cerakote!

I might look into an airbrush at some point actually, as the volume of paint I'm using is tiny. 5 knives need much less than 30ml, probably more like 18ml of paint.

bbuford said:
I think you are not seeing those defects before the baking because of the solvent content in the paint film prebake. I suggest you sand the defects and look at them with a magnifier to see what color they are, it could be many different things. The plumbing on the compressor looks nice, if you do it again it will be beneficial to have 15 to twenty feet of hard line before your filtration. The air coming out of the compressor will hold contaminants in vapor because it is still warm longer lines give the vapor time to condense. The dirt nibs do not look like a moisture/oil in the air issue those contaminants look either like a crater if it was oil or a blister if it was water. Make sure you are using nylon mesh paint strainers not cloth, you could see about getting a 3m PPS system with waterborne cups (these have a much finer filter built into the lid. Waterborne strainers also have the fine mesh but the glue used to hold them together would dissolve in the solventborne paint. After you strain your paint into the cup look closely at the strainer and see if it has small clumps, this is referred to as seediness and could be a result of some old material. Your filter at the gun looks good and the pressure recommended by the maker is good, air pressure will only affect texture (orange peel) if it is too low or excessive overspray if its too high. The environment you are spraying in could be to blame, dust in the air can accumulate paint mist like the forming of a raindrop. I still would sand into the finish and look at the nib color, and check the strainer, your material could be bad or old when you buy it I have seen this with toners on a mixing machine several times.
Click to expand...

Thanks for the great info! Next time I put together a compressor system I will definitely do that!

I think getting a finer strainer is a good idea. I'm using 190 micron nylon strainers now, but I have a 145 micron reusable strainer on the way from eastwood.

I think I'm going to try spraying/baking some of the same paint onto a piece of polished bar stock (as oppose to a sandblasted piece) as that way I can make sure the piece is totally free of contamination before I begin, then I can at least tell whether te contamination is a residual from the sandblasting or if it's happening afterward...

Sanding back the nibs and looking inside them is a great idea. I have a cheap digital microscope at the shop, so I will take some pictures and post them up.
 
One small point about the tack rags, they don't contain any waxes, oils or stuff like that. The cheese cloth is impregnated with a rosin that won't normally transfer to the surface you're rubbing unless you rub to hard. And never touch the blade with your fingers after you've cleaned the blade with solvent.

With an abrasive blasted surface you will be bore concerned with the rough surface snagging the fibers of the cheese cloth.

But for sure if you contact Cerakote, go with what they tell you.
 
woodwrkr221 said:
One small point about the tack rags, they don't contain any waxes, oils or stuff like that. The cheese cloth is impregnated with a rosin that won't normally transfer to the surface you're rubbing unless you rub to hard. And never touch the blade with your fingers after you've cleaned the blade with solvent.

With an abrasive blasted surface you will be bore concerned with the rough surface snagging the fibers of the cheese cloth.

But for sure if you contact Cerakote, go with what they tell you.
Click to expand...

Interesting! I wasn't aware it was Rosin on the cloths, that stuff has many uses it seems.

I'm using powder-free nitrile gloves whenever I have to handle the blades after they've been de-greased.
 
Ok so I just talked to one of the guys at Cerakote. He was very helpful and they seem to be working hard to make sure that I have the support I need to get it right, they seem like nice guys to work with!

Their recommendations:

  • Use the 145 micron (100 mesh) strainer or at least double up on the cone-type strainers
  • Avoid using plastic containers to mix the Cerakote as the solvent may dissolve some of the plastic and it will come out looking like what I've been seeing (I've been using plastic containers)
  • Seeing as I'm using coarser blasting media I need to back off on the blasting pressure in order to make sure I'm not etching too deeply, otherwise corrosion resistance will be compromised, he recommended about 70-80 PSI.
  • Let the parts cool completely after gassing off and before spraying
  • Use the HVLP gun at 20-25PSI with a 2" fan from 5-6" away


Tonight I'll be sanding all the blades back to 220 grit so that I can then prep and re-spray on Tuesday or Wednesday. I'll be sure to post the results!
 
We used to use glass mixing bowls in the body shop, work great but some numb skull always broke them. The paint supply store I deal with sells mixing cups for $33 per 100 so we switched to them for a cost and time savings. I have done about 10 high end rifles with the cerakote system on the metal parts and not had any trouble with the mixing containers (made for automotive paint) or Surgical Blue brand tack rags, these are much less sticky than other brands and will not cause contamination, as long as you do not scrub with them. My final product was relatively clean but not nib free, as the weapon platforms were going to get sandy anyway. Best of luck with the respray hope you can identify the culprit when you sand into the nibs.
 
Ok, so I figured I should report back and let you guys know how I went! Since my last post I've tried 2 more times. First time was a disaster because the gun wasn't setup right, second time came out pretty well.

Here's what I did in the end:
* Degrease in ethanol
* Blast with 80 grit sand @ 60PSI
* Remove all traces of grit using a stiff paintbrush (I have discovered my shop air still has oil in it and is not to be trusted)
* Gas-out @ 300ºF for 60 minutes
* Mix Cerakote in glass beaker
* Strain through fine automotive paint cone strainer
* Setup spray gun - 35PSI - Air valve on bottom open wide - fan setup for 2" fan at 6" distance - relatively low volume of paint flow (all this gives very good atomization and creates a very nice smooth finish, doesn't look like a coating almost)
* Allow parts to cool completely before spraying (otherwise they will have a lot of texture to them)
* Spray 2 light thin coats, each coat went on wet but dried within 15 seconds or so
* Bake at 250ºF for 2 hours

I still got a few smal nibs, but they were much less noticeable than any of the other times, and some of them just scraped off with a fingernail. I'm pretty sure that's dust from the shop... I think a cleaner shop would solve the issue, but I'm spraying in a shared woodworking shop so a lab-clean shop is not really an option right now.

Here's how the coating came out:

C1uqi8Ql.jpg


^ You can see one of the tiny nibs in the middle right of this photo

ZFpeLdPl.jpg


I think next time I would spray a little lighter, I've managed coatings that were a little smoother in the past and I like the lack of texture.
 
Looking good Aaron. Since your in a shared workspace, would it be possible to corner off a small area? Before I spray, I put the plastic sheets up, blow everything off, and then about a half hour later I spray the entire area down with water to prevent any of the dust particles from floating around. In your case i would wait about 20 mins of running a dehumidifier to get the moisture out of the air, and then proceed with your spraying.
 
egally08 said:
Looking good Aaron. Since your in a shared workspace, would it be possible to corner off a small area? Before I spray, I put the plastic sheets up, blow everything off, and then about a half hour later I spray the entire area down with water to prevent any of the dust particles from floating around. In your case i would wait about 20 mins of running a dehumidifier to get the moisture out of the air, and then proceed with your spraying.
Click to expand...

Unfortunately with the way the shop is setup I don't think I'd be able to effectively wall off a corner... what I did when spraying this time was to show up at 6am before anyone would be there, and then I sprayed without touching anything in the shop, that way no dust was stirred up. Seemed to work ok.

It looks like I'm going to end up moving into my own shop by march, so I'll likely build some sort of small spraybooth. If I'm going to keep using Cerakote it's clear that I need a more serious setup/area for applying it.
 
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