Effects of Reducing Epoxy on Color and Gloss

S

strum456

Oldtimer
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I sprayed my car in epoxy last spring as a temporary top coat. 1 really wet coat, unreduced and it came out black and semi gloss.

I just sprayed the hood today with 15% reduced epoxy (slow reducer), 1 wet coat, and it is not as dark black or as glossy. I reduced it becasue it is straight and I didn't really want to add extra mil-thickness.

Do I have to spray it unreduced to get a nice black color, or did I screw something else up? :p Coupe1.jpg
 
That is how we kill the gloss by how much and speed of reducer, you will need to shoot unreduced.
 
i wouldnt worry about those mils with unreduced epoxy. even unreduced it is still pretty thin...think barry has said before that the unreduced epoxy is still as thin as basecoat? or that it sprayed like basecoat? either way i wouldn't consider that a big deal.
 
Thanks Jeremy and Barry. I just resprayed it with unreduced epoxy and it looks like the rest of the car. I guess the reducer makes it dry faster, and the faster it drys, the flatter it gets. I remember reading that before, but I thought a little slow reducer wouldn't hurt. Live and learn...

NEXT QUESTION:

When my epoxy dries, I always get some light stripes. I set up my gun on masking paper according to Barry's instructions, and I try to keep a 75% overlap. Is this the nature of epoxy, or am I likley to have stripes in my base too if I don't figure out what I am doing wrong?
 
It is all in application and or gun adjustment, epoxy is the perfect item to practice on for shooting base.
 
Ok, now I am concerned. I measured my fan pattern on the masking paper, it is about 8 inches (the same distance between the stripes. I dont know what to do better with spray technique. I keep the gun perpendicular to the panel and at a constant distance and speed. I used to overlap 50%, but lattley I have been overlapping 75%. I used to use the HF purple gun, and I always thought that was the problem. I'm having the same problem with my Astro 9011. The only thing I can think of is my spray pattern looks a little more wet on the top, when I set it on paper hanging on the wall. I have meticulously cleaned the gun several times.
 
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I cleaned the gun using a tooth pick and q-tips. I had a little epoxy left over, so I mixed reducer with it so I would have enough liquid to spray some test patterns.

I labled each pattern with the number of turns off the seat. How does it look now? Is 1-1/4 turns my best pattern? It looks to me like 1-1/2 is heavy at the top and bottom.

28 psi


P.S. I thought I should switch back to this thread, instead of the Metal Working thread.IMG_3119.jpg
 
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After cleaning the gun really good, I thought I had my problem figured out. The picture shows my last test pattern and one test pass before spraying the hood. I checked the pattern after spraying on paper, and it looked the same.

What the heck is going on here :mad:
 
What about 2.5 turns out and like he ask how fast you moving, pattern looks restricted.
 
I try for 1 foot per second. This hood is about 40 inches long, so I count "one onethousand, two onethousand, three onethousand" for each pass.

From what I have seen, more turns out = orange peel, but I am willing to try it if you think that is my problem. I think one half of the fan pattern looks wetter than the other, but it seems uniform in shape. I don't know what else to clean on the gun, I used a tooth pick on every hole aand q-tips where I can't reach.

The wet part of the stripes on the hood are close to running.
 
Try two turns then and adjust the fine orange peel with a couple more pounds of air pressure. (2-5)
 
I resprayed it and I still have stripes. The gun definitely shoots better with your settings Barry. I am convinced that the problem is due to the uneven pattern my gun is spraying. The fan is uniform in shape now, but one half is wetter than the other. Bob suggested flipping the air cap to see if the problem flips. He was right, it does. I soaked the cap in thinner and blew out the holes several times. I still have the problem. I'll post pictures later.
 
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The hood looks better this time, but the gun is still not spraying right. I used the north, south, east, west method to hide the stripes a little becase I don't feel like respraying this thing for the 4th time.

The gun was 2 turns off the seat and 30 psi for this test. If you look carefully at the picture, the right side of the pattern is wetter than the left. What could possibly cause this?

I decided to spray air through the gun with it disassembled to see if it was coming out of all the holes in the head. In the picture I am pointing to a hole with a screw driver. This hole is blowing out 10X more air than any other! What to do?
 
i dont want to sound like a weiner but arent those cheap guns to be using on nice full size resto projects? after getting an iwata my astro evo is gather dust in the corner...
 
It almost looks like the gun is too far away, but if the pattern is bad you might need to do that.

If I am putting epoxy on suspension parts, I use my primer gun (LPH440) because it is more efficient. But if I am doing large panels with epoxy as a topcoat (inner fenders and hood undersides, etc.) I use my LPH400. I hate to do it in a way, because that is my clear gun, but the finish it lays down is noticeably better. Someday I will get another good gun for single stage and certain epoxy jobs.

Topcoating with products that are semi-gloss or have flattener in them can be very challenging, in my opinion. A good gun goes a long way toward making the process a lot less frustrating.
 
I think I had some dried epoxy in the air horn, as Bob suggested. My problem did flip with the air cap, but it doesn't now.

Now I have an even fan that is slightly wetter on one side, when I snap the trigger. If I hold the trigger for a couple seconds, the runs look pretty even. Should I worry about the slight unevenness when snapping the trigger?

I am starting to think that I am holding too close, not turning my fluid knob out enough, and going too slow. I was 6 inches off the pannel, 1.5 - 2 turns off the seat, and moving about a foot per second.

I was told today by an experienced painter that I should be 9 inches off the pannel, and closer to 3 turns off the seat. Does anyone think spray technique is my problem?
 
Try shooting it about 7 inches from the panel surface, choke the pattern down just a little bit and open the fluid knob slightly, it's all a ratio thing and experience. Find a test subject before you shoot a good panel. An old fender, a piece of sheetmetal, anything with a somewhat smooth surface so you can make a pass and see how well it's transfering. Look to achieve a smooth wet coat that is thin and that you can apply at a rate fast enough that each pass flows together. Remember air to fluid ratio is key-example:that gun will spray properly at 10psi but you would need to choke the fluid down enough to match, distance to panel will be closer, and then the rate of application goes down as well. Viscosity also factors in-thicker materials will require more air to atomize. Play around with it and you'll get the hang of it.
 
I finally fixed my Astro 9011. First I unscrewed the air fitting at the handle. Then I put some new teflon tape on it. Third, I got a new IWATA LPH400 and screwed it onto the fitting. Problem solved!

Actually, I havent tried it yet. Do you guys use high flow fittings? 3/8 hose? Has anyone noticed a difference from standard fittings?
 
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