3M Accuspray gun settings for Akzo

[bertschb]

I'm using the 3M Accuspray 2.0 system with Akzo epoxy primer. I watched a bunch of videos produced by 3M to try to get a feel for how I should set the gun up. I followed their recommendations.

3M recommendations:
- Set the top knob (fan) to 1-1.5 turns out.
- Set the bottom knob (fluid) to 3-4.5 turns out.
- Set the pressure at the gun to 20psi when pulling trigger.

The pressure at my air compressor was set at 90psi. When not depressing the handle on the gun the pressure at the gun is around 90psi. When pulling the trigger it drops to around 20psi.

This was my first time using a paint gun and it seemed to me that the air pressure was too high. The paint was going on really thin (maybe the fluid knob needs to be opened up further?). I think I was wasting paint with overspray. I ended up using 18oz of Akzo to prime all the parts for the -14 horizontal stabilizer and I didn't put it on thick. Just enough so the aluminum didn't show through.

In another thread I asked for priming tips and it was suggested I should use 4oz of Akzo- and even that might be too much. With two long spars, a bunch of ribs, stiffeners and two skins, there is no way 4oz would work with my gun settings so something isn't set up correctly. I ended up doing 3 spray sessions with my 6oz cups to get everything covered (with 30 minute wait each time I mixed the primer). It was a LONG day!

My questions:
Should I reduce the air pressure at the compressor? Otherwise when I first pull the tigger it's at 90psi before it drops down to 20psi. Is this where I'm wasting paint? Should I set the fluid knob to 4.5 -5 turns out?

 

[Brantel]

AKZO is one of the easiest primers to spray.

What tip size are you using?

Set you gun pressure at the point where you are about half triggered where full air is being expelled but no paint. You can feel this and see it.

It is easy to set the fan too high which waste paint and air. You want a nice cigar shape and nothing more.

It’s been a couple years since I sprayed AKZO with the 3M system so I don’t remember my knob settings.

Currently I run a regulator at 80 and set the gun for 20 when trigger is just before paint starts flowing and the fan is what I want.

If you used that much primer, most of it ended up all over the place except the parts you were priming. Keep in mind that that stuff is extremely toxic!

I recommend finding a mentor to get you started and to show you what you are missing. Even if you have to visit a local body shop.

 

[wirejock]

Accuspray

No experience with the Accuspray, but maybe some of this will help.

Is it HVLP? That's low pressure. Usually below 30psi.
You need a gun regulator. That way you can run full pressure on the hose and regulate right at the gun inlet. HF mini is ok but they tend to wander a little. I run my HF Black Widow at 22 psi at the gun regulator with trigger pulled blowing air. I recommend a really good regulator at the gun. I use a RTI 1/4" Mini. It never changes. I keep the regulator and separator right at the gun in that order. 5/8" hose plugs into the separator.

More than 2 turns out is a lot of paint. I'm suprised it doesn't splatter. Start at 1 turn out and shape the fan on a piece of cardboard so it's like a saucer viewed from the edge. The sweet spot is the fat area. The thin areas are your overlap zones. Each pass should overlap the previous. Make passes in one direction till the piece is covered. Horizontal for a vertical fan. Most paints need some flash time before the next pass. Varies by manufacturer. Kirker needs an hour so I walk away. Second goes on medium to get opaque. That's primer for a top coat. SW P60G2 can be sprayed immediately so I shoot two passes. One horiz, one vertical till I just see color and walk away.

My Black Widow settings.
1.3 tip
Pressure 22 psi
Flow 1 turn out to start and open if more paint is needed. Rarely does it open more than 1-1/2.
Fan set one turn out. I like a sharp oval fan. It will blast a big circle wide open.
The Black Widow is an HVLP HTE. High Transfer Efficiency. It really puts paint where you want it. Very little overspray or waste. I cover 2-3 ft² per ounce of mixed paint, per coat and throw away very little.

 

[bertschb]

What tip size are you using?

1.4 (recommended elsewhere)

The result look good. Just had trouble setting up the gun. I actually didn't adjust with the top knob (fan) as I didn't think that would affect primer volume but I can see now that if it was fanning out too wide, it's wasting material.

 

[bertschb]

Keep in mind that that stuff is extremely toxic!

I recommend finding a mentor to get you started and to show you what you are missing.

I'm using a 3M full face mask with 60926 filters and a Tyvec suit. I also bought an expensive explosion proof exhaust fan that really sucks the air out of my 16'x8'x9' paint booth and outside my hangar. I probably wouldn't use this primer if I was 20 years old but I start Medicare next year so I'm not as worried.

 

[wirejock]

Primer

1.4 (recommended elsewhere)

The result look good. Just had trouble setting up the gun. I actually didn't adjust with the top knob (fan) as I didn't think that would affect primer volume but I can see now that if it was fanning out too wide, it's wasting material.

1.4 should be fine
Inside is corrosion protection.
I don't see a need to be opaque. I recommend weighing some parts before and after and calculating weight gained per ft². I have numbers for mine. P60G2 weighs almost nothing but 2K and Urethane has some weight
Just my opinion. Probably not even worth $.02.

 

[bertschb]

Is it HVLP? That's low pressure. Usually below 30psi. You need a gun regulator.

The 3M Accuspray gun is HVLP and they recommend 20psi which is what I used. The gun isn't cheap but it does come with a pressure regulator.

 

[bertschb]

I think one of my problems is I'm used to spraying latex paint on a house with an airless sprayer. That always goes on really thick. One pass.

This Akzo was actually difficult for me to see initially. That's how lightly it was going on.

I'm happy with the end results - just not the process of getting there. I will continue to play with the knobs now that I have a teeny bit of experience and I'm not as stressed out.

 

[dmn056]

I've been using the Accuspray 16580 gun with 1.3mm nozzle to spray Akzo 10P4-3NF primer. It seems to work well, although I'm probably one of the world's worst spray painters.

I set pressure to 80psi at the dryer exit, then set 22psi at the gun with the trigger pulled.

Initially I set the fluid flow knob to 1 3/4 turns counterclockwise, and open the fan out to an oval shape about 150mm long when holding the gun at a stretched hand width from my test piece.

These settings work without needing to move the gun too fast across the surface. For slow movement around detail bits, I turn the flow down a bit. For faster movements over large areas, I turn it up to over 2 turns counterclockwise. It doesn't need to be applied too thickly.

Don't hold the gun too far away from the work, or you'll get lots of overspray and the primer won't flow out properly when it hits the surface, drying to a sandpaper-like finish instead of a smooth surface. High temperature and extreme humidity can have the same effect.

If you get an uneven surface, leave it a week to be sure it's fully cured, then rub it back a bit with maroon Scotch-Brite.

 

[bertschb]

I've been using the Accuspray 16580 gun with 1.3mm nozzle to spray Akzo 10P4-3NF primer.

I'm using Akzo 463-12-8. Not sure how it differs from what you're using. I got the 3M 25680 Accuspray kit but the spray guns in both those kits look the same.

Good point about gun distance. I think I was too far away from the material.

 

[lr172]

I'm using the 3M Accuspray 2.0 system with Akzo epoxy primer. I watched a bunch of videos produced by 3M to try to get a feel for how I should set the gun up. I followed their recommendations.

3M recommendations:
- Set the top knob (fan) to 1-1.5 turns out.
- Set the bottom knob (fluid) to 3-4.5 turns out.
- Set the pressure at the gun to 20psi when pulling trigger.

The pressure at my air compressor was set at 90psi. When not depressing the handle on the gun the pressure at the gun is around 90psi. When pulling the trigger it drops to around 20psi.

This was my first time using a paint gun and it seemed to me that the air pressure was too high. The paint was going on really thin (maybe the fluid knob needs to be opened up further?). I think I was wasting paint with overspray. I ended up using 18oz of Akzo to prime all the parts for the -14 horizontal stabilizer and I didn't put it on thick. Just enough so the aluminum didn't show through.

In another thread I asked for priming tips and it was suggested I should use 4oz of Akzo- and even that might be too much. With two long spars, a bunch of ribs, stiffeners and two skins, there is no way 4oz would work with my gun settings so something isn't set up correctly. I ended up doing 3 spray sessions with my 6oz cups to get everything covered (with 30 minute wait each time I mixed the primer). It was a LONG day!

My questions:
Should I reduce the air pressure at the compressor? Otherwise when I first pull the tigger it's at 90psi before it drops down to 20psi. Is this where I'm wasting paint? Should I set the fluid knob to 4.5 -5 turns out?

Pressure at the compressor should always be near max. Else you run the risk of reducing air volume via line losses. The trigger is two stage and by the time that fluid stage is open, the pressure is down. Each gun is different, so can't offer gun setting advice. You need to be able to assess how much paint is going to the surface and how much is becoming over spray. I struggle to see how 20 PSI is too high, but this is also variable and I suspect it may be too low. We care about pressure at the outlet, but no gun gives us a reading there and each gun will have a different pressure drop. You need to keep adjusting fluid until you get proper paint deposition on the surface. The manual recommendation doesn't mean much, as the adjustment is quite variable based upon tip size and paint viscosity. A common amatuer error is holding the gun too far away and this creates excessive overspray and several other issues. Experimenting with different pattern adjustments may also be helpfull, but you need to learn the technique at setting near full pattern.

If the fluid knob is not out far enough you don't deposit enough paint and therefore make up with slow gun travel speed. This is VERY inefficient as it produces A LOT of overspray. Remember that deposition rate is a combination of fluid flow AND gun travel speed. You need to strike the right balance to be efficient. I tend to do pattern tests by holding the gun steady, 6" from test area and hold the trigger for 1/2-3/4 of a second and observe deposition on test area. Keep adjusting till just right and then spray. You will eventually learn how a particular deposition rate translates to your typical travel rate. On the test, you want enough deposition to create a liquid surface that will flow out, but not so much th it runs. If your test shows ANY form of droplets or VERY thin liquid, your flow rate is too low. You must also practice moving the gun laterally while ALWAYS maintain the same distance which is around 6-8" for most guns. Letting the gun drift too far away from the surface will create many problems for you.

 

[bertschb]

A common amatuer error is holding the gun too far away and this creates excessive overspray and several other issues.

Thanks for the feedback.

Good point about the two position trigger and the first pull reducing pressure before paint arrives. Makes sense.

I'm guessing I was working about 12"-15" away from the material. The next time I prime I plan to mix a LOT more primer and experiment with the pattern and flow knobs before I spray the parts. I didn't do this the first time because I only started with 6oz of primer - for all the parts of the horizontal stabilizer.

I also need more light in the spray booth. I have a great set of lights but didn't put them in the booth until my 3rd priming session.

One more thing-
I installed a furnace filter before my exhaust fan but it didn't flow anywhere near enough air. It was super restrictive so I removed it on my third priming session. Will this ruin my expensive exhaust fan? I was thinking off getting the thinnest/cheapest furnace filter I could find which should flow better and catch some paint particles before they get to the fan motor.

 

[lr172]

Thanks for the feedback.

Good point about the two position trigger and the first pull reducing pressure before paint arrives. Makes sense.

I'm guessing I was working about 12"-15" away from the material. The next time I prime I plan to mix a LOT more primer and experiment with the pattern and flow knobs before I spray the parts. I didn't do this the first time because I only started with 6oz of primer - for all the parts of the horizontal stabilizer.

I also need more light in the spray booth. I have a great set of lights but didn't put them in the booth until my 3rd priming session.

One more thing-
I installed a furnace filter before my exhaust fan but it didn't flow anywhere near enough air. It was super restrictive so I removed it on my third priming session. Will this ruin my expensive exhaust fan? I was thinking off getting the thinnest/cheapest furnace filter I could find which should flow better and catch some paint particles before they get to the fan motor.

No guessing here. 12-15" is WAYYYY too far away and no surprise that little paint is making it to the surface.

Yes, this will ruin your fan. I use a box fan and the blades now weigh 10 or 20X what they did when new. I have to occasionally knock some paint off the blades and often need to give the blades a push to get the motor started.

 

[bertschb]

No guessing here. 12-15" is WAYYYY too far away and no surprise that little paint is making it to the surface.

So 6"??? I was very worried about creating runs which is why I was further away.

 

[wirejock]

Gun distance

So 6"??? I was very worried about creating runs which is why I was further away.

Larry has good advise. Must be something about the name.
6" That's my target distance. Any more and the paint blows everywhere.
The trick is passing at the same distance all the way across while maintaining the same rhythm or speed on every pass. Find a song with the right beat to match your paint style. Sing it while painting. Makes the job more fun too.

You can reduce the run potential by shooting a fog coat first. Allow it to flash. Shoot the final coat.

I have a bildge blower for cold weather work inside. I had to remove the filter. It's pretty well painted but still works.
I paint in my storage barn most jobs.

 

[penguin]

Look for some paint booth filter material, it is coarse bundle of fibres that is around 2 or 3" thick and traps the paint before it gets to the fan, usually on a 50ft roll, you may have to talk to your local automotive spray shop .... Also put the fan around a 90* bend from the filter, the paint is relatively heavy and will stick to the outside of the bend.

 

[lr172]

So 6"??? I was very worried about creating runs which is why I was further away.

SOrry, but runs are the cost of entry for a new painter. You will not find a painter that has not made runs while learning, especially with clear - that fun will come later for you This is all an artistic balancing act. Enough air pressure to get the paint to properly atomize but not too much to blow it everywhere or create dry spray, Enough volume to get the paint to flow out on the surface, but not too much to make it run. Once the target air pressure is found, it becomes a balance of the flow knob and travel speed. It is ALWAYS a balance between those two. You will NEVER get good paint application and coverage without keeping the gun about 6-8" away. Sorry, you just need to practice and find the balance. One more thing - if you touch the fan spray knob, you must again adjust everything else, as that is also part of the balance. There is a reason that many choose a rattle can.

 

[lr172]

You can reduce the run potential by shooting a fog coat first. Allow it to flash. Shoot the final coat.

I

While this approach seems to hang on in the industry, I have had some expert guidance that strongly recommends against it. It was the common recommended method for lacquers decades ago, as well as acceptable for acrylics and it is a common handicap for many painters, as the first coat is the easiest to create runs and fish eye on epoxy primer. Some paints like it, some tolerate it, but it creates problems for many/most in the modern world. Suggest reading the paint makers TDS. It will tell you what to do with the first coat. What Larry describes is a light or dust coat. Most makers of epoxy primer and urethane clear coats want a medium wet coat and some want a full wet coat. Few DTM (direct to metal) epoxy primer makers recommend a light or dust coat. With base coat, you can get away with most anything and adhesion is poor anyways so this doesn't really make it worse. Then again, it is pretty hard to make base coat run.

Larry, not taking shots at your approach or recommendation, just passing along some guidance I got from a paint manufacturing engineer/owner and someone that has sprayed 1000's of gallons of paint, going back to the lacquer days.

 

[CarloJ]

My Black Widow settings.
1.3 tip
Pressure 22 psi
Flow 1 turn out to start and open if more paint is needed. Rarely does it open more than 1-1/2.
Fan set one turn out. I like a sharp oval fan. It will blast a big circle wide open.
The Black Widow is an HVLP HTE. High Transfer Efficiency. It really puts paint where you want it. Very little overspray or waste. I cover 2-3 ft² per ounce of mixed paint, per coat and throw away very little.

Larry, what setting do you use for the air control knob on that gun?

 

[wirejock]

Fog coat

While this approach seems to hang on in the industry, I have had some expert guidance that strongly recommends against it. It was the common recommended method for lacquers decades ago, as well as acceptable for acrylics and it is a common handicap for many painters, as the first coat is the easiest to create runs and fish eye on epoxy primer. Some paints like it, some tolerate it, but it creates problems for many/most in the modern world. Suggest reading the paint makers TDS. It will tell you what to do with the first coat. What Larry describes is a light or dust coat. Most makers of epoxy primer and urethane clear coats want a medium wet coat and some want a full wet coat. Few DTM (direct to metal) epoxy primer makers recommend a light or dust coat. With base coat, you can get away with most anything and adhesion is poor anyways so this doesn't really make it worse. Then again, it is pretty hard to make base coat run.

Larry, not taking shots at your approach or recommendation, just passing along some guidance I got from a paint manufacturing engineer/owner and someone that has sprayed 1000's of gallons of paint, going back to the lacquer days.

No worries Mate.
In my case, it's the recommendation from Kirker Tech Support. I have called many times with my stupid questions. They actually answer. I'm sure it's specific to their product and works for me.

 

[bertschb]

UPDATE:

My second attempt at priming went MUCH better than my first! I had the parts arranged better for easier coverage and I made slight adjustments to the spray gun. I also applied the primer with the gun closer to the material. I'm very comfortable priming now whereas my first attempt was very stressful.