Contamination in single stage

Dan Trimbach said:
I’m using a 7hp Spl 10.3cfm@90psi 60 gal air compressor and a harbor freight 3/8” air filter. Item 68230

I’m using a 3m accuspray gun with a 1.4 tip

I drain it about once a week and usually there is very little water on there.
Click to expand...

That filter is fine to use but not as a stand alone unit. My past setup was a 5hp 60 gal 2 stage comp with a filter like the one you shown feeding into a dessicant filter from HF then finally a devilbiss whirlwind filter at the gun. On big jobs i would drain tank between coats. I never had moisture issues with that setup.
 
Dan Trimbach said:
drain it about once a week and usually there is very little water on there.
Click to expand...
Most of the moisture forms droplets as the hot air cools and condensates, dropping out right at end of the run. Those spots look like water to me. Try a better filter setup with a desiccant stage. Something like this is much better than what you have. https://www.harborfreight.com/38-in-desiccant-dryer-with-oil-removal-filter-69923.html Draining your compressor once a week is not enough. The reason you are not getting much water out of it is the air is hot and the moisture is still a vapor. It has to be cooled to separate itself from the air and drop out. If you didn't get the contamination until the last coat, my guess is the compressor was running more, getting hotter, and finally dropped the moisture on your hood.
 
Dan Trimbach said:
Well I didn’t just come up with that on my own.:)

Flow coating. What's your method?

As a preface I have been flow coating all of my personal projects and the ocassional customer project for a while now. Maybe the way I do it is just how it is but just wondering if anyone else out there has any pointers, tricks, time savers on doing it. My method is to spray base then wait...
www.spiuserforum.com



[USER=3]
Barry
[/USER]
Barry
Paint Fanatic
Staff member
Jun 12, 2015
Here is something interesting, I plan to try.
I have heard from a number of shops (7-10), now and all swear you have never seen anything like it.

They do 3 or 4 normal coats waiting 30 minutes between coats, then as soon as done with 3rd- 4th coat they mix more clear and I have been told from some they add 30% retarder and some they add 50% and right away put a 5th coat on.
Makes sense to me but have not tried it myself yet.

This is why I love the tech line, learn something everyday!

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I wasn’t brave enough to do 30%
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These guys are working in a controlled environment, with clean air and good spray booths in most instances, which seems a far cry from what you are dealing with.
 
Dan Trimbach said:
Well I didn’t just come up with that on my own.:)

Flow coating. What's your method?

As a preface I have been flow coating all of my personal projects and the ocassional customer project for a while now. Maybe the way I do it is just how it is but just wondering if anyone else out there has any pointers, tricks, time savers on doing it. My method is to spray base then wait...
www.spiuserforum.com



[USER=3]
Barry
[/USER]
Barry
Paint Fanatic
Staff member
Jun 12, 2015
Here is something interesting, I plan to try.
I have heard from a number of shops (7-10), now and all swear you have never seen anything like it.

They do 3 or 4 normal coats waiting 30 minutes between coats, then as soon as done with 3rd- 4th coat they mix more clear and I have been told from some they add 30% retarder and some they add 50% and right away put a 5th coat on.
Makes sense to me but have not tried it myself yet.

This is why I love the tech line, learn something everyday!

Like Reply
Report

“

I wasn’t brave enough to do 30%
Click to expand...

You need to forget this. Put it out of your mind completely. As a novice flow coating is not something you need to be concerned with. Doing something without understanding why you are doing it will just get you in trouble 9 times out of 10. Context of this was written for UV Clear anyways, not SS. Barry was talking about guys with years of painting experience experimenting with retarder.
Follow the directions in the SPI Tech Manual. Follow them exactly, don't improvise. I cannot emphasize that enough. Only reason for a novice to use retarder is if you are spraying in extra hot temps (85-90 and above) and even then you would only use enough to allow the product to behave like it would at 75 degrees. (2-3 ounces per 32 ounces of RTS product no more than that)

What would be more important is adjusting your gun correctly, forcusing on straight line passes with the proper overlap. 50-75% I would reccomend closer to 75%. Don't spray as heavy. Watch as you are spraying. Look for SS to "fill in" as you are spraying. You want to see it fill in and no more. Adjust your speed to acomplish that. More overlap (meaning around 75%) is better than less. As you are spraying your focus needs to be on where the product is hitting the panel. That is where you want to see it fill in. If that doesn't make sense do some practice runs on something. Once you can see it and understand that you are on your way.

Personally I was thinking water as well but since I read what you did I am not as sure.
Anyways here are some questions. What type of air piping do you have? Do you have drops? Have you set it up with at the bare minimum 50 feet between the compressor and the water trap? When your compressor has been running a lot can you connect a blow gun to your hose and let some air through the blow gun? Do you see water vapor when you do that?
 
Dan Trimbach said:
I’m using a 7hp Spl 10.3cfm@90psi 60 gal air compressor and a harbor freight 3/8” air filter. Item 68230

I’m using a 3m accuspray gun with a 1.4 tip

I drain it about once a week and usually there is very little water on there.
Click to expand...
BallsOutPerformance said:
That filter is fine to use but not as a stand alone unit. My past setup was a 5hp 60 gal 2 stage comp with a filter like the one you shown feeding into a dessicant filter from HF then finally a devilbiss whirlwind filter at the gun. On big jobs i would drain tank between coats. I never had moisture issues with that setup.
Click to expand...

Forget the Chinese made bullshit. This is American made and professional grade quality. And it's a heckuva deal. Couple this with a quality (IE not Harbor Freight) water coalescer (first stage) then an oil coalescer (2nd stage) and finally the dessicant dryer and you have a good quality system for under $500.
Cheaper than a redo.

Got a great deal on a new Arrow Desiccant Dryer

Needed a new desiccant dryer as my old one of the same make (Arrow) was corroded and leaking. I'd already "JB Welded" it one time so I figured get a new one. Looked around for the same model I had and Zoro Tools had the best deal by far, $122.66 + tax for a total of $129.16. Free Shipping. This...
www.spiuserforum.com
 
This Cam Air unit from Devillbiss is a good choice for a home shop. I'm using this setup now along with the Arrow above in my home shop. All 1 person needs really. Plenty of CFM capability for painting and even media blasting. I've hooked up a 1/2 hose to this and media blasted (pressure blaster) quite a bit with it. Combine with the Arrow above and for $500 you have a nice system that'll give you clean dry air (provided you have a well designed air piping layout) Plus the dessicant is reusable, so you are saving money right there.

Like I said before with the cost of materials now,this is cheaper than a re-do.
www.tooltopia.com

Devilbiss (DEV130523) Camair 2-Stage Filter System

DetailsAir Filtration/Regulation System Compact and effective perfect for cramped shop spaces Removes dirt, water and oil from air line to 0.01 microns-assures superior finishes Quick change bowls and air inlet valve accommodate rapid, trouble free maintenance without shutting off main shop...
www.tooltopia.com www.tooltopia.com
 
Chris_Hamilton said:
Forget the Chinese made bullshit. This is American made and professional grade quality. And it's a heckuva deal. Couple this with a quality (IE not Harbor Freight) water coalescer (first stage) then an oil coalescer (2nd stage) and finally the dessicant dryer and you have a good quality system for under $500.
Cheaper than a redo.

Got a great deal on a new Arrow Desiccant Dryer

Needed a new desiccant dryer as my old one of the same make (Arrow) was corroded and leaking. I'd already "JB Welded" it one time so I figured get a new one. Looked around for the same model I had and Zoro Tools had the best deal by far, $122.66 + tax for a total of $129.16. Free Shipping. This...
www.spiuserforum.com
Click to expand...

Im sure that that is a great setup.
But there are other ways to skin a cat. Especially for people that are hobbyist, or working on a limited budget. I had great success from using the dessicant system from HF that texasking posted a link to. Its good to give opinions and options for people but not everyone does this for a living and can get by just fine with lower end equipment. Im not a die hard HF supporter but there some of there stuff is decent. Be open minded.
 
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I blew some air on a mirror and it did leave something on the mirror. I’m going to do some work on the air filter, driers, line drops, etc. before the next try. Thank you guys for the suggestions.

for some reason I always have to learn the hard way. Barry wrote “the perfect paint job” and for some reason I decided to mess around with flow coating.

I Keep telling my wife that my lack of intelligence is offset by my boyish good looks and bubbly personality.
 
Dan Trimbach said:
Well I didn’t just come up with that on my own.:)

Flow coating. What's your method?

As a preface I have been flow coating all of my personal projects and the ocassional customer project for a while now. Maybe the way I do it is just how it is but just wondering if anyone else out there has any pointers, tricks, time savers on doing it. My method is to spray base then wait...
www.spiuserforum.com



[USER=3]
Barry
[/USER]
Barry
Paint Fanatic
Staff member
Jun 12, 2015
Here is something interesting, I plan to try.
I have heard from a number of shops (7-10), now and all swear you have never seen anything like it.

They do 3 or 4 normal coats waiting 30 minutes between coats, then as soon as done with 3rd- 4th coat they mix more clear and I have been told from some they add 30% retarder and some they add 50% and right away put a 5th coat on.
Makes sense to me but have not tried it myself yet.

This is why I love the tech line, learn something everyday!

Like Reply
Report

“

I wasn’t brave enough to do 30%
Click to expand...
I've done 50% many times, when it's hot.
 
When my refrigerated dryer died, I tried several filters and none of them gave me dry air. I painted a bunch of cars without issues, but the air definitely had moisture in it. Here, where I live, a dryer is a necessity if you need refinish quality air. I couldn't get through a single complete without desiccant getting saturated. This was after coming out of a screw compressor, through an aftercooler, into a 120 gallon tank with an automatic drain, through 30 ft. of 1" pipe to a drop with a 1" filter with a drain, back up to the roof, 20 ft., then another drop with a manual drain, back up to the roof, 20ft. to a drop with a drain, back up to the roof, then down to a moisture filter, oil coalescer filter( both Parker) and Motorguard M60. Still got enough moisture to see it coming out of the hose with a blower attached. Added a large, cheap desiccant filter before the M60, and saturated it almost daily. Finally went and bought another dryer, put the large moisture and oil coalescer filters before it, and have the M60 only before the paint hose. Not a single drop of moisture since.
 
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