Why so much over spray with clear?

T

Tungsten

Promoted Users
Spraying primer and base not a lot of over spray.Considering how thin base is at 1:1 it didn't over spray much.My clear at 4:1 seamed thicker when mixing.Holy over spray,good thing I had a suit on.
Base and clear sprayed from a good quality HVLP siphon gun 1.4 tip at about 28 psi fluid turned 1.5 turns open from closed.
 
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Siphon gun? Those things waste a lot of material afaik. Transfer efficiency….No wonder you are in a fog of overspray. There’s a reason they are no longer used. :)

You likely could have paid for a new gun with the material savings… :)

Don
 
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dhutton01 said:
Siphon gun? Those things waste a lot of material afaik. Transfer efficiency….No wonder you are in a fog of overspray. There’s a reason they are no longer used. :)

You likely could have paid for a new gun with the material savings… :)

Don
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Well the gun may not be top quality but it does a good job.
Is it the viscosity of the clear or something else? Watching videos it appears clear has a lot of over spray regardless of type of gun.
Perhaps thinning it a little and reducing air psi may help?
 
Clear produces more overspray. You are compounding it using a siphon gun. Honestly, get a better gun if you want less overspray. Siphon guns waste material….

Don
 
Tungsten said:
Well the gun may not be top quality but it does a good job.
Is it the viscosity of the clear or something else? Watching videos it appears clear has a lot of over spray regardless of type of gun.
Perhaps thinning it a little and reducing air psi may help?
Click to expand...
Siphon guns require lots of pressure to create the siphon, A cheapo gravity gun will use less product and have less overspray then a high end siphon gun.

If you plan on doing any amount of body work and painting in the future, I would get a quality HVLP gravity gun, a quality DA sander, and lots of lights. The rest you can get or upgrade as you go.
 
Is this the gun you are using
www.lemmer.com

A-928S HVLP gun

LEMMER is a manufacturer and distributor of paint spray equipment and rust proofing spray equipment. Products include air & airless paint sprayer, HVLP, pressure pot, rustproofing, air assist airless, pneumatic pump, electrostatic and pipe coating.
www.lemmer.com

Don
 
Tungsten said:
Canadian brand,Lemmer A 928.HVLP.

Im really just curious why clear has more overspray then other automotive finishes?
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Part of the reason is the product itself, but a big part of it is the "color" of the clear, it reflects light as it hangs in the air and is much more noticeable then other products. If you spray black single stage and then white single stage, you will see more overspray with the white. The key there is that you SEE it.
 
RenewAP said:
Siphon guns require lots of pressure to create the siphon, A cheapo gravity gun will use less product and have less overspray then a high end siphon gun.

If you plan on doing any amount of body work and painting in the future, I would get a quality HVLP gravity gun, a quality DA sander, and lots of lights. The rest you can get or upgrade as you go.
Click to expand...
Yeah Im sure a better quality spray gun would reduce it some.
This particular gun has a regulator to supply air to the canister,recommended 2-3 psi to push paint/clear up and out.
Looking on the net you dont see this feature on siphon type guns.

Was purchased years ago to do a kitchen and a bunch of other millwork.Does a nice job with base and clear in my newbie hands. But Im no auto body expert.
 
dhutton01 said:
Is this the gun you are using
www.lemmer.com

A-928S HVLP gun

LEMMER is a manufacturer and distributor of paint spray equipment and rust proofing spray equipment. Products include air & airless paint sprayer, HVLP, pressure pot, rustproofing, air assist airless, pneumatic pump, electrostatic and pipe coating.
www.lemmer.com

Don
Click to expand...
yes.
 
RenewAP said:
Part of the reason is the product itself, but a big part of it is the "color" of the clear, it reflects light as it hangs in the air and is much more noticeable then other products. If you spray black single stage and then white single stage, you will see more overspray with the white. The key there is that you SEE it.
Click to expand...
Interesting,thanks.Makes sense.
 
dhutton01 said:
Is this the gun you are using
www.lemmer.com

A-928S HVLP gun

LEMMER is a manufacturer and distributor of paint spray equipment and rust proofing spray equipment. Products include air & airless paint sprayer, HVLP, pressure pot, rustproofing, air assist airless, pneumatic pump, electrostatic and pipe coating.
www.lemmer.com

Don
Click to expand...
Something I didn't notice before ,says air consumption 10 cfm @25psi.
Is this high or low for a spray gun ?
Thanks.
 
Over 30 years ago, that gun is similar to a Mattson Atomiser, I used everyday for over 10 years. They were one of the first HVLP guns. To be honest, they sprayed a finish better than any gun available I tried. Less overspray and fine atomized particles. Needle was .8 base to 1.0 clear. Pressurized cup was 5-6psi. The gun's biggest problem was really finicky. I had to keep a box of "consumables" and how to repair it, quickly. After I got to painting 8 cars a day, the gravity guns were more reliable and easier to clean.
 
Tungsten said:
Something I didn't notice before ,says air consumption 10 cfm @25psi.
Is this high or low for a spray gun ?
Thanks.
Click to expand...
This spray gun you reference as using is a pressure cup gun--not a siphon. I use them (HVLP pressure cup bottom mount cups of another maker) and prefer them with some painting applications over gravity feed. Large volumes of material to spray I like them---otherwise my gravity feed gun with PPS 13 oz cup or so is so convenient and a breeze to clean and switch materials to spray.


You can do very good work with the gun referenced if set up properly or you can have a real mess and frustration......I sorted my messes out for my guns but it took a lot of experimenting...... but my experience is not using a 1.4mm fluid tip on a 4:1 clear--is it some kind of "euro" clear? Try using the same air cap (or larger) for 1.4mm fluid tip and a 1.0mm fluid tip and needle. I now use a 1/2" ID air hose for HVLP and choke my fluid and maximize my air cap (with the biggest air cap that has many larger ports on it I can get away) If your clear is a MS or medium solids try a ready to spray viscosity of 14-18 seconds@ 74F measured in a DIN 4 viscosity cup or a high solids HS 15-20 seconds in same and try the next slower reducer and activator for whatever temperature or environment you are in. Personally--my HVLP stuff and me using it don't have the moxey needed to spray HS clears and with a RP gun I can do better on the smaller the surface area to be sprayed. "Production Clears" I can do quite well with lower solids volumes clears and my HVLP stuff and MS clears and my transfer efficiency is high.


I had better luck seeing where I went from being absolutely consumed in and surrounded by overspray to dialing in to where I had a very efficient column of spray with no bounce back buy turning my pattern horizontally to adjust. The sound changed slightly when the column of clear and when the point is reached with balance between the distance the gun is away from the work, volume of fluid out and atomizing air volume--it is amazing. I could clearly see no bounce back of spray coming off the edge of the pattern at about 45 degrees. My overspray went to nothing I could perceive. Remember--the numbers they list for psi and cfm consumed are minimums. Maybe good for spraying ink but higher cfm flows through the gun air cap for HVLP usually better.
 
texasking said:
Over 30 years ago, that gun is similar to a Mattson Atomiser, I used everyday for over 10 years. They were one of the first HVLP guns. To be honest, they sprayed a finish better than any gun available I tried. Less overspray and fine atomized particles. Needle was .8 base to 1.0 clear. Pressurized cup was 5-6psi. The gun's biggest problem was really finicky. I had to keep a box of "consumables" and how to repair it, quickly. After I got to painting 8 cars a day, the gravity guns were more reliable and easier to clean.
Click to expand...
Well touch wood I haven't had any issues with parts,the 1 litre pot is a pain to clean compared to a disposable cup thats for sure.
 
D.A.T. said:
This spray gun you reference as using is a pressure cup gun--not a siphon. I use them (HVLP pressure cup bottom mount cups of another maker) and prefer them with some painting applications over gravity feed. Large volumes of material to spray I like them---otherwise my gravity feed gun with PPS 13 oz cup or so is so convenient and a breeze to clean and switch materials to spray.


You can do very good work with the gun referenced if set up properly or you can have a real mess and frustration......I sorted my messes out for my guns but it took a lot of experimenting...... but my experience is not using a 1.4mm fluid tip on a 4:1 clear--is it some kind of "euro" clear? Try using the same air cap (or larger) for 1.4mm fluid tip and a 1.0mm fluid tip and needle. I now use a 1/2" ID air hose for HVLP and choke my fluid and maximize my air cap (with the biggest air cap that has many larger ports on it I can get away) If your clear is a MS or medium solids try a ready to spray viscosity of 14-18 seconds@ 74F measured in a DIN 4 viscosity cup or a high solids HS 15-20 seconds in same and try the next slower reducer and activator for whatever temperature or environment you are in. Personally--my HVLP stuff and me using it don't have the moxey needed to spray HS clears and with a RP gun I can do better on the smaller the surface area to be sprayed. "Production Clears" I can do quite well with lower solids volumes clears and my HVLP stuff and MS clears and my transfer efficiency is high.


I had better luck seeing where I went from being absolutely consumed in and surrounded by overspray to dialing in to where I had a very efficient column of spray with no bounce back buy turning my pattern horizontally to adjust. The sound changed slightly when the column of clear and when the point is reached with balance between the distance the gun is away from the work, volume of fluid out and atomizing air volume--it is amazing. I could clearly see no bounce back of spray coming off the edge of the pattern at about 45 degrees. My overspray went to nothing I could perceive. Remember--the numbers they list for psi and cfm consumed are minimums. Maybe good for spraying ink but higher cfm flows through the gun air cap for HVLP usually better.
Click to expand...
Ah yes,pressure gun.That makes sense.Clear ,yes probably a generic type.Name escapes me now.Purchased a quart in a blank can.
Currently have 3/8 ID hose and fittings.
Will read your post again about switching caps,running 1.4 and pot pressure at 4-5 psi,regulator with trigger pulled about 28psi.
 
Sounds like you have this gun
www.lemmer.com

A-928P HVLP Pressure Feed gun

LEMMER is a manufacturer and distributor of paint spray equipment and rust proofing spray equipment. Products include air & airless paint sprayer, HVLP, pressure pot, rustproofing, air assist airless, pneumatic pump, electrostatic and pipe coating.
www.lemmer.com
 
dhutton01 said:
Sounds like you have this gun
www.lemmer.com

A-928P HVLP Pressure Feed gun

LEMMER is a manufacturer and distributor of paint spray equipment and rust proofing spray equipment. Products include air & airless paint sprayer, HVLP, pressure pot, rustproofing, air assist airless, pneumatic pump, electrostatic and pipe coating.
www.lemmer.com
Click to expand...
No its the 928S,not sure what S or P mean?

edit,,,,P is for the big pressure pot that holds gallons,same gun, S is with a regulator and 1 litre cup...P is just the gun no regulator or cup.P you just hook the hose onto from the pressure pot.
 
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