Flow coating. What's your method?

jtfx6552;n74268 said:
Could someone explain the "urethane wave"?
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I'm sure barry will chime in with a better explanation but to me it seems like as the clear dries out it gathers up and forms a wave, it is slight not like a shoddily worked panel but it's there. The easiest way to be able to see it is to put the car/panel under a fluorescent light tube and look at the light in the reflection. When you cut at 400 and reclear and re cut it eliminates that wave giving tons of depth to your clear, like looking at your reflection in a calm pond.

I had never thought of drop coating it on jc. I wonder if that'd work with the uv since it seems any light spray leads to peel.
 
bomccorkle;n74273 said:
I'm sure barry will chime in with a better explanation but to me it seems like as the clear dries out it gathers up and forms a wave, it is slight not like a shoddily worked panel but it's there. The easiest way to be able to see it is to put the car/panel under a fluorescent light tube and look at the light in the reflection. When you cut at 400 and reclear and re cut it eliminates that wave giving tons of depth to your clear, like looking at your reflection in a calm pond.

I had never thought of drop coating it on jc. I wonder if that'd work with the uv since it seems any light spray leads to peel.
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Urethane wave is nothing but high solids, a production shop that does two coats on a car will never see the wave or have a problem with it.
You hear things like thin the clear or do lighter coats to avoid, well you are going backwards and could also just use a lower solids clear.
Custom work we need the solids.

What JC did with enamels is true but not so true with urethanes, however if a retarder is added to last coat and last coat it does help on the re-flow.
 
A urathane wave could be like a run in the clear that you tried to wetsand out and when you have it all sanded and buffed you can still see where it was. Even though you had the panel completely sanded there is a slight wave in the clear that can be kind of a pain to get rid of if you don't have any intention in reclearing. Black is real good at showing you that.
 
DATEC;n74285 said:
A urathane wave could be like a run in the clear that you tried to wetsand out and when you have it all sanded and buffed you can still see where it was. Even though you had the panel completely sanded there is a slight wave in the clear that can be kind of a pain to get rid of if you don't have any intention in reclearing. Black is real good at showing you that.
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I had forgotten about it showing up like that, good call. I had a hard on when I started painting and it was gonna be black or nothing, reading here I learned of flow coating andBAM!

I'll see if I can get it to resize some pics (posting from pbone) but I have a picture that I'm only at the second buff stage and when I show it to people they ask why I have a mirror outside. The depth and clarity are amazing and it's a black bedside!
 
what gets a lot of painters in trouble is gun adjustment . if you have your gun high on fluids - low on air you tend to get orange peel. so to get rid of it they just try to hammer on a flow coat.
thin wet coats work far better. this is why the horrible pos hf purple gun is something no one should ever use. the thicker the coat the more product to push around creating thane wave .
when using very slow acc i see no reason for reducer or retarder . unless it is extremely hot .
 
I often tell new painters or ones with not as much experiance that I would rather see it alittle dry then overly wet. They either run it trying to get that "no buff" slick shine or heavy large orange peel. I explain that it is easier to make it flat and slick as glass when it's alittle on the dry side (small peel) then overly orange peeled (large peel) when you cut and buff. Runs, well that's just another problem that can bite ya. I explain that what you are doing by getting that slick as glass shine is taking it just at the edge of a run and stopping but that comes with experiance and knowing your equipment and material you are using, but even then everyone gets one from time to time.
 
DATEC;n74346 said:
I often tell new painters or ones with not as much experiance that I would rather see it alittle dry then overly wet. They either run it trying to get that "no buff" slick shine or heavy large orange peel. I explain that it is easier to make it flat and slick as glass when it's alittle on the dry side (small peel) then overly orange peeled (large peel) when you cut and buff. Runs, well that's just another problem that can bite ya. I explain that what you are doing by getting that slick as glass shine is taking it just at the edge of a run and stopping but that comes with experiance and knowing your equipment and material you are using, but even then everyone gets one from time to time.
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Exactly right you are, please remember the painters that gave this information to me, are some of the best as one was from one of the highest dollar shops in North America (Canada)
Not for the faint of heart for sure.
 
I really struggle with gun setup. I watched a friend paint something and he controlled the product. The clear went on effortlessly and had perfect peel. I love to watch a pro.
 
Whenever the discussion turns to light coats, medium coats, wet coats I can't help but think those are undefinable terms without hands on instruction and demonstration. Whenever I try to spray clear in "light coats" it looks like layers of orange peel. My best finishes come from wet coats and by that I mean putting it on the way I want it to look when finished. I have to increase the flash times and use only 885 reducer (so far that is because retarder will be in my next order). The danger is running it but if you can be patient during the flash times the chance of running is greatly reduced.
Not saying my way is right by any means but either I don't understand what people mean by "light coats" or my technique is different because wet is the only way I can get clear to look right.
 
[QUOTE='68 Coronet R/T;n74375]Whenever the discussion turns to light coats, medium coats, wet coats I can't help but think those are undefinable terms without hands on instruction and demonstration. Whenever I try to spray clear in "light coats" it looks like layers of orange peel. My best finishes come from wet coats and by that I mean putting it on the way I want it to look when finished. I have to increase the flash times and use only 885 reducer (so far that is because retarder will be in my next order). The danger is running it but if you can be patient during the flash times the chance of running is greatly reduced.
Not saying my way is right by any means but either I don't understand what people mean by "light coats" or my technique is different because wet is the only way I can get clear to look right.[/QUOTE]

Yes sir. That is always how I took wet and it looks like huge peel directly under the gun and as soon as you pass it it just lays down.

The flash times are the key to lack of runs it seems. I always wait to blast the next round until you can see that skin forming. Sometimes in the fall and early winter before the heat comes on (I only keep the shop at 55 unless sprayimg epoxy) it can take all day to get 3 or 4 coats
 
flooding clear on is not necessary . a thin wet coat will help reduce solvent pop and die back . the most problematic painters i ever hired were one who insisted on hammering on paint to make up for poor gun skills. just because it is slick does not mean it will not have problems. i have a gun setting where i start . adjustments from there depend on air temp and bp . tuning a gun is much like tuning an engine .
 
Very true shine. I rock an iwata lph 400 silver cap, I start at 2 1/2 out on fan 3/4 in on fluid and about 27 lbs on air. I then do spray outs on my walls that are papered and adjust, sometimes just the temp or humidity will change how things flow and break up.

I also notice that the overlaps, distance and speed play a huge part in how your clear lays as well. Those things tend to be the most problematic for me as I am attempting to shuffle around corners and such.

I will admit to help with sickness I have/do reduce uv but it is in what I feel are problematic areas, the main spot being under hood and deck lod bracings. I think just do to all of the angles in there you are constantly double coating all over and a lighter coat with about a 10% reduction works wonders. But I NEVER reduce any pretty parts
 
I use an Iwata 300 with a 1.3. If I don't add a little reducer the clear doesn't look right. There is no way I can get a good finish at the 18 pounds it calls for. That "tulip"shaped fan doesn't seem to be as consistent as the angular pattern.
 
shine;n74379 said:
flooding clear on is not necessary . a thin wet coat will help reduce solvent pop and die back . the most problematic painters i ever hired were one who insisted on hammering on paint to make up for poor gun skills. just because it is slick does not mean it will not have problems. i have a gun setting where i start . adjustments from there depend on air temp and bp . tuning a gun is much like tuning an engine .
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"A thin wet coat"
Herein lies the problem with my understanding your terminology. To me thin and wet are two different things. Trust me, I am not arguing with you just trying to understand.

To me a "wet" coat is that which is heavier than a "medium" coat. Therefore, a "thin" coat would be just heavy enough to avoid dry spray but not as a heavy as a medium coat.

I think I'm getting in over my head with all this thinking. LOL
 
what i am trying to say is flooding on high solid clear to get it wet is not the best way. the thicker the coat the more wave and op. think big drops to small drops . with gun adjustment along with overlap and speed you can stack small drops on wet as opposed to big drops and trying to flow them together. ever wonder why you dont get peel in base ? smaller drops less solids. most all the majors clears will fail in heavy coats . same as over reducing. too many solvents.
to me it's better to slow down or open the gun a little than to speed up to fight runs . jmo
 
I'm with Shine's train of thought on this as well, I try my best to apply the thinnest wet coats I can. A few things can factor in though, if the base doesn't flash off nice and flat then it's going to be impossible to shoot a thin flat coat of clear- people using fast reducers in their base run into this situation. And if the gun isn't atomizing well then a person needs to put it on heavy which creates wave and runs. Back in the late 80's when high solids urethanes were being introduced in my area it was a big learning curve for me, the old siphon feed JGA80 I was using for lacquers and enamels now needed an additional 20psi to break up/atomize the high solids stuff-same basic scenerio. Clear activator selection also plays a big part, slowest possible is best-imo not for flow after application but rather so it stays wet enough to accept that dryspray around your pattern as you make your pass. With good atomization and application the clear is wet and flat as sprayed within the main contact area of your pattern and the clear that is outside the main contact area just melts in quickly without adding any texture if the right speed activator is used. You can watch the outer perimeter of your pattern's contact area as you make a pass and get a good idea of what's going on. A worst case example: spraying a hood in 100* temps with high humidity with fast activator and a person finds they have to apply 3X the amount of clear to get a slick finish but then end up with major urethane wave from pushing a puddle back and forth. Just rambling here...
 
What does properly atomized look like? I can do a squirt on a piece of paper and it seems to look fine but when on the part it looks like bowling balls. Gets to be frustrating.
 
[QUOTE='68 Coronet R/T;n74375]Whenever the discussion turns to light coats, medium coats, wet coats I can't help but think those are undefinable terms without hands on instruction and demonstration. Whenever I try to spray clear in "light coats" it looks like layers of orange peel. My best finishes come from wet coats and by that I mean putting it on the way I want it to look when finished. I have to increase the flash times and use only 885 reducer (so far that is because retarder will be in my next order). The danger is running it but if you can be patient during the flash times the chance of running is greatly reduced.
Not saying my way is right by any means but either I don't understand what people mean by "light coats" or my technique is different because wet is the only way I can get clear to look right.[/QUOTE]
It might be good to try 895, that is probably a reducer you could use quite a bit, being in hot country. Then you would be able to use smaller amounts of retarder to adjust flash time depending on the size of the job. I think it is best to have a reducer that matches temps as close as possible.
 
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