1st Duracoat...texture issue

[Zartan]

Well, I sandblasted my lower, washed with solvent and hung it from a string in the garage. I mixed the Duracoat 12:1 as instructed, no thinning, and had my air brush inlet set at 40psi. Some areas came out visually smooth, and some came out visually rough, like sandpaper and they feel really rough as well. The airline had a water trap as well as a moisture/oil filter at the brush hose inlet.

Too much pressure? No thinned enough. The instructions said apply between 68-72 deg. I measured the temp at 70deg. Now how do I fix it?

[1lowluv]

I would have used a little reducer or acetone the thinner it is, the smoother it will lay down. Don't want it too thin though

[driveljay]

Have you got any pics? Sometimes the sandblasting is not even/smooth and it shows up after coating....you see this especially with aluminum parts.
If all the above does not apply...make sure you are spraying from far enough away, and you give your mixture a good shaking before spraying again between coats. Make sure you give about 20 mins between coats.

[driveljay]

oh, most likely the fix will be to let it dry for an hour and then use fine grit sandpaper over the rough spots, blow off debris and do another coat of DC.

[MingTheMerciless]

I just did two receivers this morning, doing it just like you described. They came out perfect.

I would not thin it out. There was no problem running it thru at 40 psi with even a fine tip on the airbrush. And based on what you wrote, you obviously read the 4-page directions they gave, which in part says "don't use acetone" and also says the optimal formula is 12:1.

I would suspect the airbrush or your use of it, if the issue is not the sandblasting that driveljay mentions. As I mentioned in my other thread on this, I switched to a fine tip and the difference was *huge* in controllability, and way less material went onto the receiver. Both units have a satin-like finish. They were both bead-blasted and bare, and the finish from that is what we still have. We cleaned them with Brakleen just prior to use.

[MingTheMerciless]

Something else to think of: I screwed one up and tried to fix it. the fixed parts just weren't perfect, and I wanted them to be, so I poured lacquer thinner into a tupperware pan about two inches deep and washed the receiver until it was bare metal again. then I repeated the process with clean thinner, THEN I cleaned with Brakleen again. that gave me a complete reboot on painting the thing and the second time - using a fine tip on the airbrush - it was perfect.

You can only wait so long before that stuff isn't going to come off so easy. I'm not sure how long the time period is but something to consider if its still possible.

[Zartan]

Thanks for the replies guys. Its been 48 hours. Not sure if its to cured for the lacquer thinner was, or if I should blast it again tomorrow to smooth out all the rough areas and reapply.
As for using a fine tip, its a Harbor Freight brush, no other tips available at the store.
Hope you can see the difference in the finish from the pics

[Gunsmith Dan]

Painting a firearm is no different than painting a car or any other metal object.

The 3 reasons you get a gritty texture if the entire surface is of the same smoothness is:

1) You went to fast past that area compared to the other areas. If you are hanging the receiver you should be no more than 4 to 5 inches away and going the long length of the receiver about 1 second up, 1 second down then 1 second up again. Make sure your spray goes past the receiver
end of the receiver before going the other direction.

2) Your spray gun tip was to far away in that area than compared to the other areas. You should always stay the same distance on all surfaces, approx 4 to 5 inches.

3) Your paint started to dry to fast, or took to long to paint the surface, and overspray dried onto the other surfaces than were dry enough to be tacky. Make sure you mixed it correctly and if applying 2nd or 3rd coats do not wait to long or the surface will be to dry.

If the surface was uneven it is highly recommended to lightly hand sand a surface after sand blasting. You should do a final surface sand with 320 to 400 grit sand paper to get a nice surface and have good paint adhesion.

Looking at you pictures kinda looks like a uneven surface, but hard to tell in pictures without feeling the surface.

Hopes this helps.

[Zartan]

Thanks Dan. After I blasted it, the surface was quite nice. It had tooth, but not rough. I remember I kept losing track of my airbrush orientation so that didnt help. I think Ill blast it again to even it out and respray. Or should I blast it to remove the old?

[kcstott]

Thats called orange peel and it is due to the paint drying before it hits the surface.

Too far away, to fast a travel speed, part surface to hot, paint to thick to flow and level out can all contribute to the problem

[Dakine_surf]

Looking at your pics I would say that you were too far away when you sprayed... I also know that while you can do a nice job with the cheap airbrush, a nice dual action make things way easier...

I run a Paasche VLST-Pro... I think when I got it, it was about $150 but they have since come down a bit and I have seen some for about $90. It is a seriously nice piece, and has a huge selection of needles, tips and bottles...

[Zartan]

Hey Dakine, yea, I thought to myself that I plan on doing several Duracoat projects so wtf did I get the HF brush? I have a Paasch DA VL in my Amazon cart as we speak My plan is to blast the surface even and smooth, not totally remove, and recoat.

Thanks for all the feedback guys!

[MingTheMerciless]

I used a Badger 350 with the fine tip from here

http://kustomaccessories.com/Badger-350-Airbrush-Set-with-All/M/B000BROVIY.htm

Ran me about $60 delivered. Duracoat actually supplies a generic unbranded version of that airbrush with a medium tip. Using a medium tip, its a lot easier to screw up. A fine tip, dialed down and used properly, will make it almost impossible to create runners or screw up (edit: the price you pay is the job takes about twice as long, but what you are doing is very precise and controlled).

I saw somewhere on a site offering duracoat products that this type of airbrush (external mix) is preferable given the consistency of their material (they weren't selling airbrushes).

[Zartan]

Hey Ming, have any closeup shots of your latest projects?

[BanG_Bang]

i recommend not using sand as a blast media as it's super abrasive and rough grit. if you have a blasting cabinet i suggest investing in glass beads. gives you a nice sating finish and rough enough for parkerizing or duracoating. when i first started i had the same issue