My second go at spraying - looking for advice - Page 2 - Woodworking Talk - Woodworkers Forum
 3Likes
Reply
 
Thread Tools Display Modes
post #21 of 50 Old 10-03-2017, 09:30 AM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 26,356
View woodnthings's Photo Album My Photos
back to the gun ....

If your gun does require 12 CFMs then it may not work with that 1/4" hose. However, my HF purple gun runs fine on 50 ft of 3/8" flex hose, the green one, but internal openings in the quick change fittings are 1/4" ID.

Please verify that the gun is the one Rick suggested and requires 12 CFM.

If you want to try that gun, use a larger supply hose if you can. Eliminate the QC fittings if you can. I had a flow control issue until I adjusted the air volume at the base of the gun handle. Hold the trigger in until you get good atomization and a wet coat pattern while you adjust the air flow. Then raise or lower the pressure at the gun regulator in 5 lb increments to see if that helps. If not, I suspect the gun is the issue.

FWIW, I don't use a viscosity cup, but I know from experience when the mixture is thin enough ... more or less. Water like is too thin, milk is about right in my gun. :smile3:

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
Sponsored Links
Advertisement
 
post #22 of 50 Old 10-03-2017, 10:18 AM
Senior Member
 
Join Date: Sep 2011
Posts: 25,995
View Steve Neul's Photo Album My Photos
Quote:
Originally Posted by Quickstep View Post
I tried using the sprayer withou out the filter and got the same thing. The thing that seems screwy to me is that i can spray the whole panel without the compressor coming on, so it's not a case of the pump not being able to keep up. Could it be that I need larger hose even though my runs are short? I'm using 1/4" now.
No, I use a 1/4" hose, sometimes 200' of hose and don't have that issue. I can't remember ever having that issue even with the HVLP sprayers I had. They just started off not putting out enough paint and continued. My guess is there is something wrong with the regulator or sprayer. Something in your equipment has to be malfunctioning. Nobody would put up with a sprayer doing that, especially professionals that are trying to get a job done. If you keep your sprayer clean you might replace the regulator and see if that helps. If you think your sprayer may be dirty, take it apart and do a thorough cleaning.
Steve Neul is offline  
post #23 of 50 Old 10-03-2017, 11:36 AM
Advanced Color Matcher
 
ColorStylist's Avatar
 
Join Date: Jul 2016
Location: Virginia
Posts: 292
View ColorStylist's Photo Album My Photos
Are you using any "quick connectors" coming off your compressor? Those will actually reduce air flow and give you a false reading at your compressor. The only place you should have quick connectors is at the gun itself. Make sure you set the compressor at say 70-90 pounds and set the regulator at your gun to 40 pounds. It will be some drop off, mayeb down to 30 pounds, but thats ok. As said above, not many times you will be holding a trigger open for over 5 seconds at a time.

Maybe there is some type of blockage in your air line??? Look at that possibility.

Faulty air gauge?? Look at that as well.

If your spraying at 40 pounds, and have the material properly thinned to manufacturers specs, you shouldnt be getting orange peel. How close are you holding the gun to the piece when your spraying? Me guess is either you are too close to the piece when spraying or maybe you should try speeding up on the gun passes. You dont want to put alot on at 1 time. Most of the time, sealers and lacquers should be sprayed no more than 3-4 wet mils at one application.

Matching colors on different substrates is easy. All it takes is patience and beer.
ColorStylist is offline  
Sponsored Links
Advertisement
 
post #24 of 50 Old 10-03-2017, 03:54 PM
Senior Member
 
Join Date: Sep 2011
Posts: 25,995
View Steve Neul's Photo Album My Photos
Quote:
Originally Posted by ColorStylist View Post
Are you using any "quick connectors" coming off your compressor? Those will actually reduce air flow and give you a false reading at your compressor. The only place you should have quick connectors is at the gun itself. Make sure you set the compressor at say 70-90 pounds and set the regulator at your gun to 40 pounds. It will be some drop off, mayeb down to 30 pounds, but thats ok. As said above, not many times you will be holding a trigger open for over 5 seconds at a time.

Maybe there is some type of blockage in your air line??? Look at that possibility.

Faulty air gauge?? Look at that as well.

If your spraying at 40 pounds, and have the material properly thinned to manufacturers specs, you shouldnt be getting orange peel. How close are you holding the gun to the piece when your spraying? Me guess is either you are too close to the piece when spraying or maybe you should try speeding up on the gun passes. You dont want to put alot on at 1 time. Most of the time, sealers and lacquers should be sprayed no more than 3-4 wet mils at one application.
In my career I've never seen anyone that didn't have quick connectors at the compressor and every line which delivers air throughout the shop.
Steve Neul is offline  
post #25 of 50 Old 10-03-2017, 05:02 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 26,356
View woodnthings's Photo Album My Photos
Yopu will still have lots of pressure, but ....

Quote:
Originally Posted by Steve Neul View Post
In my career I've never seen anyone that didn't have quick connectors at the compressor and every line which delivers air throughout the shop.
The 1/4" ID QC fittings may reduce the flow, but still have lots of pressure. I also use them for all my air operated tools, BUT I don't have a 12 CFM gun either. I do use some 1/2" impacts that take a lot of air flow, but not very often. I don't think the commercial automotive spray booths use QC connectors, but I could be wrong. Maybe just at the gun itself, but not on the lines.... I donno?

I can't imagine 200 ft of line running anything other than a nail gun .....:frown2:

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
post #26 of 50 Old 10-03-2017, 05:11 PM
Senior Member
 
Join Date: Sep 2011
Posts: 25,995
View Steve Neul's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
The 1/4" ID QC fittings may reduce the flow, but still have lots of pressure. I also use them for all my air operated tools, BUT I don't have a 12 CFM gun either. I do use some 1/2" impacts that take a lot of air flow, but not very often. I don't think the commercial automotive spray booths use QC connectors, but I could be wrong. Maybe just at the gun itself, but not on the lines.... I donno?

I can't imagine 200 ft of line running anything other than a nail gun .....:frown2:
I sometimes have to stain a wooden fence or paint a steel one. It takes that much hose to get around the yard using a pressure pot to do the job. I have to keep the compressor close to the power source. Usually an outside outlet is wired with 14ga wire and there is barely enough power. If I ran an extension cord there certainly wouldn't be enough power.
Steve Neul is offline  
post #27 of 50 Old 10-04-2017, 10:23 AM
Advanced Color Matcher
 
ColorStylist's Avatar
 
Join Date: Jul 2016
Location: Virginia
Posts: 292
View ColorStylist's Photo Album My Photos
Quote:
Originally Posted by Steve Neul View Post
In my career I've never seen anyone that didn't have quick connectors at the compressor and every line which delivers air throughout the shop.
Alot of people dont know or dont think about it, but if you take a 50 feet hose and hook up another 50 feet hose with 1/4 fittings and quick connectors, you would be surprised at the drop off at the end vs simply using a 100 foot hose with no connectors, even though there is still a slight drop off with no connectors. All quick connectors have restrictions, that's common sense, unless you use a "high flow" quick connectors, something like this:

http://www.homedepot.com/p/Husky-Hig...138H/205184364

Alot of major shops use high flow fittings and couplers at their compressors and every line they may plug into off that air line, especially if their using multiple plug-in air stations along their shop.

As far as hoses, In the Devilbliss handbook here at work.........."for runs of 25 ft. - 50 ft., a 3/8" ID hose should be adequate for most HVLP guns. For LVLP guns putting 1/4" fittings on 3/8" hose does not yield the same result as using 1/4" hose. For your system to operate properly, your compressor should be able to supply at least 1 - 1.5x the pressure/CFM requirement of your gun. Hoses act as restrictors - the longer the hose, the bigger the diameter required to pass the same cfm."

Im not saying this is Quickstep's problem, but I also would not have a connector at my compressor. I have a 75 foot hose straight off my compressor. I keep my compressor set at 90 psi and I use air adjust valves with built in gauges to adjust air flow to whatever tool Im using, like this:
https://www.princessauto.com/en/deta...ge/A-p8108847e
woodnthings likes this.

Matching colors on different substrates is easy. All it takes is patience and beer.
ColorStylist is offline  
post #28 of 50 Old 10-04-2017, 10:28 AM
Senior Member
 
Maylar's Avatar
 
Join Date: Sep 2013
Location: South Central Connecticut
Posts: 1,151
View Maylar's Photo Album My Photos
There are high flow quick connects available that significantly reduce the pressure drop at the load. When I spray with my DeVilbiss Finishline gun (11.5 cfm) I set the compressor to about 90 psi. With the trigger pulled at the end of 25 ft of 1/4" line I can maintain the 23 psi that the gun wants at the inlet. That's a lot of loss but that's the way it is.

If the pressure keeps dropping when the trigger is pulled, something is wrong. I would suspect a regulator - either the one at the tank or the little one at the gun.

Dave in CT, USA
Maylar is offline  
post #29 of 50 Old 10-04-2017, 10:46 AM
Advanced Color Matcher
 
ColorStylist's Avatar
 
Join Date: Jul 2016
Location: Virginia
Posts: 292
View ColorStylist's Photo Album My Photos
Quote:
Originally Posted by Maylar View Post
There are high flow quick connects available that significantly reduce the pressure drop at the load. When I spray with my DeVilbiss Finishline gun (11.5 cfm) I set the compressor to about 90 psi. With the trigger pulled at the end of 25 ft of 1/4" line I can maintain the 23 psi that the gun wants at the inlet. That's a lot of loss but that's the way it is.

If the pressure keeps dropping when the trigger is pulled, something is wrong. I would suspect a regulator - either the one at the tank or the little one at the gun.
I put a link to an example of the high flow connectors above......

So you loose that much air flow on a 25 foot hose? Seems like alot, it must be the 1/4 hose. I use a 75 foot long 3/8 hose and dont loose that much. I will check when I get home and see how much I loose.

Matching colors on different substrates is easy. All it takes is patience and beer.
ColorStylist is offline  
post #30 of 50 Old 10-04-2017, 11:57 AM
Senior Member
 
Maylar's Avatar
 
Join Date: Sep 2013
Location: South Central Connecticut
Posts: 1,151
View Maylar's Photo Album My Photos
My compressor's tank has to drop to about 60 psi before the gun starts starving of air, so I set the main regulator to 90. I've also got a water separator / filter inline so there's a couple more connections.

The compressor is only 25 gallons and 1.5 HP and it won't keep up with the DeVilbiss. I need a bigger compressor.
woodnthings likes this.

Dave in CT, USA

Last edited by Maylar; 10-04-2017 at 11:59 AM.
Maylar is offline  
post #31 of 50 Old 10-04-2017, 04:34 PM
Advanced Color Matcher
 
ColorStylist's Avatar
 
Join Date: Jul 2016
Location: Virginia
Posts: 292
View ColorStylist's Photo Album My Photos
Quote:
Originally Posted by Maylar View Post
My compressor's tank has to drop to about 60 psi before the gun starts starving of air, so I set the main regulator to 90. I've also got a water separator / filter inline so there's a couple more connections.

The compressor is only 25 gallons and 1.5 HP and it won't keep up with the DeVilbiss. I need a bigger compressor.
OH, That makes sense.

Matching colors on different substrates is easy. All it takes is patience and beer.
ColorStylist is offline  
post #32 of 50 Old 10-04-2017, 05:23 PM Thread Starter
Senior Member
 
Join Date: Apr 2012
Posts: 2,716
View Quickstep's Photo Album My Photos
I'm learning a lot here.

I guess I've never sprayed anything very big before, so I never noticed it, but it looks like the airflow from my compressor can't keep up with the "big" spray guns. Even though the pump doesn't come on, it just doesn't move enough air except in short bursts to maintain pressure on the Devilbiss and Binks guns.

That is not true for the small spray gun I have. It only needs 4 CFM. But since I had been practicing with the bigger spray guns, going back to the little gun sort of puts me back to square one in terms of the learning curve. The little gun doesn't seem to move as much finish and just based on the last two coats, it's more prone to orange peel.

This is the info on the smaller gun. It's a higher quality version of the smaller Harbor Freight gun made for Homestead Finishing Products which is owned by a guy named Jeff Jewitt who has a pretty good reputation in the woodworking biz.
I like that it's smaller because I'll mostly be spraying small stuff. Now if I can just learn to use it.
Attached Images
 

Last edited by Quickstep; 10-04-2017 at 05:26 PM.
Quickstep is offline  
post #33 of 50 Old 10-04-2017, 06:02 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 26,356
View woodnthings's Photo Album My Photos
I've asked before ...

What are the CFMs required DeVilbiss and Binks guns?

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is online now  
post #34 of 50 Old 10-04-2017, 10:31 PM Thread Starter
Senior Member
 
Join Date: Apr 2012
Posts: 2,716
View Quickstep's Photo Album My Photos
Info do the Devilbiss says 9-11. I don't know about the Binks.
Quickstep is offline  
post #35 of 50 Old 10-05-2017, 12:05 AM
Senior Member
 
Join Date: Sep 2011
Posts: 25,995
View Steve Neul's Photo Album My Photos
Quote:
Originally Posted by ColorStylist View Post
Alot of people dont know or dont think about it, but if you take a 50 feet hose and hook up another 50 feet hose with 1/4 fittings and quick connectors, you would be surprised at the drop off at the end vs simply using a 100 foot hose with no connectors, even though there is still a slight drop off with no connectors. All quick connectors have restrictions, that's common sense, unless you use a "high flow" quick connectors, something like this:

http://www.homedepot.com/p/Husky-Hig...138H/205184364

Alot of major shops use high flow fittings and couplers at their compressors and every line they may plug into off that air line, especially if their using multiple plug-in air stations along their shop.

As far as hoses, In the Devilbliss handbook here at work.........."for runs of 25 ft. - 50 ft., a 3/8" ID hose should be adequate for most HVLP guns. For LVLP guns putting 1/4" fittings on 3/8" hose does not yield the same result as using 1/4" hose. For your system to operate properly, your compressor should be able to supply at least 1 - 1.5x the pressure/CFM requirement of your gun. Hoses act as restrictors - the longer the hose, the bigger the diameter required to pass the same cfm."

Im not saying this is Quickstep's problem, but I also would not have a connector at my compressor. I have a 75 foot hose straight off my compressor. I keep my compressor set at 90 psi and I use air adjust valves with built in gauges to adjust air flow to whatever tool Im using, like this:
https://www.princessauto.com/en/deta...ge/A-p8108847e
The issue though is I've never run short of air with any sprayer except when I run a couple hundred feet of air hose. I just put the regulator on the last section of hose and there is no more problem.
Steve Neul is offline  
post #36 of 50 Old 10-05-2017, 09:47 AM
Senior Member
 
Maylar's Avatar
 
Join Date: Sep 2013
Location: South Central Connecticut
Posts: 1,151
View Maylar's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
What are the CFMs required DeVilbiss and Binks guns?
Depends on the gun. They make a lot of 'em. Typical full size automotive guns need 11-15 cfm, the smaller touchup or spot repair guns are in the 4-5 cfm range.

I have a DeVilBiss Finishline II that says 12 cfm @ 23 psi inlet, A Sharpe Platinum that needs 9 cfm @50, and a Sata MiniJet 2 touchup gun that needs 4 cfm @40.

My first gun, a Binks suction feed conventional touchup, only needs 2.8 cfm @45 psi. But it's very inefficient, probably in the 25% transfer efficiency range. Makes a lot of overspray.

Dave in CT, USA
Maylar is offline  
post #37 of 50 Old 10-05-2017, 09:54 AM Thread Starter
Senior Member
 
Join Date: Apr 2012
Posts: 2,716
View Quickstep's Photo Album My Photos
Here's my latest.

I think what I was originally seeing as orange peel was actually tiny pores in the wood. They're too small to pore fill, but I think my 50/50 mix was too thin to fill them.

I switched to a 70/30 mix and things are looking better. I have some small orange peel with the thicker mixture, but it will have to be sanded and polished anyway, so maybe no harm - no foul.

This lacquer doesn't get that glassy look even when it's wet. Could that be the plasticizers in it?

Always eager for any wisdom from you guys.
Quickstep is offline  
post #38 of 50 Old 10-05-2017, 11:16 AM
Advanced Color Matcher
 
ColorStylist's Avatar
 
Join Date: Jul 2016
Location: Virginia
Posts: 292
View ColorStylist's Photo Album My Photos
Quote:
Originally Posted by Quickstep View Post
Here's my latest.

I think what I was originally seeing as orange peel was actually tiny pores in the wood. They're too small to pore fill, but I think my 50/50 mix was too thin to fill them.

I switched to a 70/30 mix and things are looking better. I have some small orange peel with the thicker mixture, but it will have to be sanded and polished anyway, so maybe no harm - no foul.

This lacquer doesn't get that glassy look even when it's wet. Could that be the plasticizers in it?

Always eager for any wisdom from you guys.
What type of wood are you spraying? Mahogany and other porous woods like that will give you "pin holes" if you do not pre-fill the wood before finishing it out. Hard woods like maple for instance should not give you any pin holes.

Most of the time, you should not have to thin a ready to spray material no more than 20% tops with the recommended thinner. What type of lacquer are you spraying? What is the sheen/gloss of the lacquer?

Matching colors on different substrates is easy. All it takes is patience and beer.
ColorStylist is offline  
post #39 of 50 Old 10-05-2017, 11:42 AM Thread Starter
Senior Member
 
Join Date: Apr 2012
Posts: 2,716
View Quickstep's Photo Album My Photos
The lacquer is Behlen's Stringed Instrument Lacquer. Reportedly contains a plasticizer to deal with expansion and contraction of musical instruments.

The wood is some kind of mystery wood plywood. It has pores, but they're really tiny. Not at all like the big pores in mahogany or oak. I tried pore filling it with Behlen's pore filler, but the pores are so tiny, the filler in the pores just sands away when sanding the excess filler off of the surface. I was wondering if there's some weird surface tension thing going on that's preventing the finish from getting into the pores.

Last edited by Quickstep; 10-05-2017 at 11:45 AM.
Quickstep is offline  
post #40 of 50 Old 10-05-2017, 05:51 PM
Senior Member
 
Join Date: Sep 2011
Posts: 25,995
View Steve Neul's Photo Album My Photos
Quote:
Originally Posted by Quickstep View Post
Here's my latest.

I think what I was originally seeing as orange peel was actually tiny pores in the wood. They're too small to pore fill, but I think my 50/50 mix was too thin to fill them.

I switched to a 70/30 mix and things are looking better. I have some small orange peel with the thicker mixture, but it will have to be sanded and polished anyway, so maybe no harm - no foul.

This lacquer doesn't get that glassy look even when it's wet. Could that be the plasticizers in it?

Always eager for any wisdom from you guys.
I don't know what brand of lacquer you are spraying. It's been a very long time since I've had one you could cut 50%. Most today you either don't thin or thin maybe 10%. You may just be thinning too much if it doesn't look glassy when wet.
Steve Neul is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
What to practice spraying on Quickstep Wood Finishing 7 09-29-2017 12:11 PM
Spraying Dye - Thanks to Steve Neul Quickstep Wood Finishing 8 04-02-2017 02:21 PM
Air siphon pressure pot setup for spraying paint Danny870 Wood Finishing 3 05-20-2016 09:23 PM
Airbrush or spray gun? And other spraying issues brutus8881 Wood Finishing 5 02-10-2016 11:14 AM
Spraying latex with an HVLP MD56 Wood Finishing 13 11-19-2015 12:39 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome