Upping My Finishing Game

[Danny in Houston]

I've finally decided to move beyond "retail" finishing approaches and purchase a spray gun and compressor system.

I was reading this thread and I'm currently considering the Qualspray HVLP gun.  

I was trying to figure out the size compressor to purchase, but the ones I'm seeing have CFM ratings at 90 psi while the Qualspray guns show minimum CFM at 40 psi.  Confusing.  Any ideas of a specific air compressor?  I'm assuming I will just get one at Lowes /Home Depot.  

I'm also going to build a finishing room in my shop.  I'm considering a spray booth with an exhaust, and a tented area for drying without dust issues. 

I was reading this article which called for an exhaust fan of 100 cfm?  Seems small.  What size fan would work for a small booth?  I would assume it would need to be explosion proof.  I like the idea of these curtains for the booth to reduce dust while drying.  

I've had great results on furniture in the past using oils with clear top coats.  I've brushed lacquer and used Deft rattle cans with nice results.  

But it's time to move to the big leagues.

Large learning curve here.  Any ideas are appreciated.

[jteneyck]

Danny, most all compressors list the output at both 90 and 40 psi.  If not, figure around 30% more at 40 psi than at 90.  IIRC, the AM-6008 HVLP gun needs 8+ CFM at 40 psi.  My 60 gal single stage Campbell Hausfield puts out around 10 cfm and has no trouble driving that gun non-stop.  This Husky at Home Depot has 13.4 cfm at 40 psi.  I'm sure Lowes has something similar.  In any case, I would only buy an oil lubed, belt drive unit.  I have mine in my garage so the noise is of no issue; sure wouldn't want it in my shop.  I don't have any special dirt/oil filters, just the stock unit, at the compressor, and a secodary regulator 20 feet from my temporary spray booth where.  I also use a little screw on filter at the inlet to the gun to catch an water or oil that gets through.  I've never had any, however, but I live in NY and you are in TX so your needs may be quite different with your humid Summers. 

To spray indoors you definitely need exhaust to carry away the over spray both so that it doesn't land on your freshly sprayed finish and so it doesn't pollute your shop and house.  For WB products and shellac you don't need anything special, just sufficient airflow, but if you want to spray solvent based products you need explosion proof exhaust and lighting and a call to your insurance agent.  I only spray shellac and WB products.

Good luck.  There is a learning curve, but it's well worth the effort. 

John

                           [url=https://www.homedepot.com/p/Husky-60-Gal-Stationary-Electric-Air-Compressor-C602H/205389936][/url]

[Bope]

I have the gravity feed version of the gun John mentioned. I use a Craftsman 10gal. hot dog compressor. My spray booth is maybe 8'x8'. I have as yet to find anything that will fit in that booth that I cannot spray with that compressor. I recently sprayed a 54" diameter octagon table top and had no problems with air.

[Mr Eddie]

I've finally decided to move beyond "retail" finishing approaches and purchase a spray gun and compressor system.

I was reading this thread and I'm currently considering the Qualspray HVLP gun.  

I was trying to figure out the size compressor to purchase, but the ones I'm seeing have CFM ratings at 90 psi while the Qualspray guns show minimum CFM at 40 psi.  Confusing.  Any ideas of a specific air compressor?  I'm assuming I will just get one at Lowes /Home Depot.  

I'm also going to build a finishing room in my shop.  I'm considering a spray booth with an exhaust, and a tented area for drying without dust issues. 

I was reading this article which called for an exhaust fan of 100 cfm?  Seems small.  What size fan would work for a small booth?  I would assume it would need to be explosion proof.  I like the idea of these curtains for the booth to reduce dust while drying.  

I've had great results on furniture in the past using oils with clear top coats.  I've brushed lacquer and used Deft rattle cans with nice results.  

But it's time to move to the big leagues.

Large learning curve here.  Any ideas are appreciated.

Danny,
I bought the Qualspray HVLP setup after seeing the great results that John was getting with his.  I am as new to spraying as it gets but I got really good results my first time out.  It's an easy gun to use and the PPG cups make it a sweet setup.  You won't be disappointed.

As noted in your link, I bought a Sanborn 60 gallon compressor from Menards.  Lowes and Home Depot appear to have the same compressor.  I bought mine at Menards because it was on sale for $400 and I had a 10% coupon from Lowes that Menards honored so my price was $360.  The compressor works fine and puts out more than enough air to run the Qualspray gun.  (Specs say 13.4 cfm @ 40 psi and 11.5 cfm @ 90 psi.)  My only complaint is it's loud.  Not as loud as an oil-less compressor but certainly not quiet.  If you can afford it I would look for a 2 stage, low rpm, compressor.  A two stage will be likely be more industrial in quality, last a long time, and not scare the daylights out of you when it kicks on!

Lonnie

[Danny in Houston]

Thanks for the replies - great info.  I'll do some shopping (compressor / spray gun) after the Thanksgiving holidays.  I have a very experienced finisher in a co-located shop to help me get set up.  I'll check with him too.

Saw some plastic wall curtains in an article for spray booths, looks like a good idea for dust control after the spray job is complete.   My shop gets dust from an adjacent metal shop, lots of grinding.

[Dave Diaman]

Danny, the qualspray is a good gun. One of my guns is the same one John has. I keep several guns in my booth with different finishes so I’m not constantly cleaning guns to change finishes. I have a good gun for shellac and my waterborne clear finishes and some more inexpensive guns for dye and paint. This is really important when I’m finishing multiple pieces which are at different stages. It isn’t uncommon for me to be spraying 3-4 different pieces at a time. My spray booth is a 2x4 frame with 6 mil plastic I picked up at Home Depot stretched over it. I added a drying rack I built with 2x4’s and pvc pipe. I also added a few pegs and hooks for hanging my spray guns mask and a few other things. For light I put all my lighting outside my booth. I use clear plastic so the light travels through and I didn’t need to worry about it being explosion proof. For ventilation I just use the cheap 20” box fans which work really well. One of the good things about using the plastics or the walls is when it gets all covered with overspray you can just pull it down and replace it without worrying about the cost. Here are a few pictures of my booth.

[Snipe Hunter]

Dave, how are you exhausting the fumes..

[Dave Diaman]

Dave, how are you exhausting the fumes..

Snipe, look for the piece of blue foam just to the left of my drying rack. That foam fill a large window that has a 20" fan mounted in it. It has a cover on the outside that lifts when it is on. I also have a large 220v heater that pumps hot air in in the winter to keep the booth around 75 degrees in the winter. I only heat the booth when I am using it but the heater will heat it to temperature in a matter of minutes and even with the exhaust fan on it is able to maintain the temperature.

[Danny in Houston]

Snipe, look for the piece of blue foam just to the left of my drying rack. That foam fill a large window that has a 20" fan mounted in it. It has a cover on the outside that lifts when it is on. I also have a large 220v heater that pumps hot air in in the winter to keep the booth around 75 degrees in the winter. I only heat the booth when I am using it but the heater will heat it to temperature in a matter of minutes and even with the exhaust fan on it is able to maintain the temperature.

I've also been wondering about the fumes, the evaporated solvents like ethanol from shellac, or other organics from lacquer.  These organics will of course pass right through the filters.  In my shop, it's huge, connected to other shops with 40 foot ceilings, and I have a large exhaust fan at the roof line.

[Dave Diaman]

I've also been wondering about the fumes, the evaporated solvents like ethanol from shellac, or other organics from lacquer.  These organics will of course pass right through the filters.  In my shop, it's huge, connected to other shops with 40 foot ceilings, and I have a large exhaust fan at the roof line.

Danny, You will probably have to avoid using solvent borne lacquers. I don't have any issues with fumes from shellac but when I have sprayed lacquer the fumes are horrible. I would guess if you spray solvent borne products unless you have a very powerful exhaust system venting directly outside the whole building will smell like lacquer If you do vent straight outside then the whole block around your shop will stink. If someone was really offended by the odor they could report you to one of many agencies which would cause all kinds of problems. Most of the shops (even auto body shops) in my area have transitioned to waterborne products. The ones that do use solvent borne send the exhaust through scrubbers so they are not releasing obnoxious fumes into the area.