My Biggest Mistake When Spraying HVLP Finishes for Woodworking - How To Clean a HVLP Spray Gun

[@13booch]

Great tutorial. Something I recommend to my customers when using a cup gun to start a job is to grab some cardboard and with the coating in the gun is to spray the cardboard. By doing this it will show you the spray pattern on the cardboard. Letting you know what adjustments are needed to be made. Ex. Tails-when the top and bottom of the spray pattern is heavier then the middle or the finish is leaving little drops of un-atomized material on the cardboard. Spraying on cardboard first will show you everything about your finish quality. Especially with spray stains.

[@rafezetter8003]

I've been spraying for years and always do this routine after each session, no-one ever told me to clean my guns this way, it just seemed the right thing to do; sure it takes a bit of time, but a hell of a lot less than trying to fix a ruined finish. Something that I was told was "backwashing", spraying with thinners but having a finger over the needle hole so the air goes into the cup and helps to agitate any residue inside. Another top tip is to have a gun for each type, water for water and solvent for solvent, and NEVER mix the two, even cleaning this thorough it's still better to have a dedicated gun for that type of finish.

[@jaykepley5238]

Very useful, Brian. Thanks!

[@paint1956]

Hey Brian, new subscriber to your channel. As a 30 year hobbyist woodworker I am impressed with the quality of your work and the content you provide. Keep it up. I've also been a professional painter for 47 years. I agree with Frank the Generalist that a soft brush is the best choice to scrub the threads, I usually just use a cheap chip brush. And I saw a wire on your bench I'm assuming for reaming pugged holes in the air cap, but use caution when doing so as the soft aluminum air horns can easily be worn distorting the spray pattern permanently. Stores that sell quality spray equipment sell a set of long, thin brushes in various sizes ( they look like a pipe cleaner ) built specifically for this purpose. A quality spray gun can easily cost $300. but nobody wants to damage even a inexpensive one. Beautiful work again, looking at your home page.

[@Benham_Design]

Thanks for the sub, and the tips!

[@realpdm]

This is much appreciated. I rarely use my sprayer as I've had such a hard time cleaning it. But honestly this effort is why I tend to prefer Osmo or Rubio. Though I am only making projects for myself no client work.

[@AssafLevyIL]

Really huge thanks for taking the time to make this. I'm having flakes on the finished piece and I now suspect it's because I don't do anything with the gun between coats and not cleaning the cup really well like you do here.

[@AssafLevyIL]

Update: There was huge chunks of pudding-like finish in the needle housing. Cleaned everything thoroughly and I just did the best coat I ever have. Thanks so much.

[@Benham_Design]

@AssafLevyIL that's awesome, glad my video helped

[@GregsGarage]

Clean gun is SOOOOOO important! Great tips Brian.

[@Benham_Design]

Thanks!

[@hakmahmed4462]

Amazing like always my dear friend.. regards.

[@mefirst4266]

THANK YOU. IF IT WAS NOT FOR VIDEO'S LIKE THIS I WOULD BE BUYING A NEW SPRAYER EVERY MONTH.

[@frankthegeneralist4752]

Great review on the cleaning process. Good detailed instructions and examples. One thing I would add to the first cleaning is a chemical resistant soft bristle brush to use with that left over cleaner and run the brush over the threads and any small parts.

[@Benham_Design]

Thanks man! That would be a good practice to add.

[@Rich-lh1kk]

Awesome

[@sivucit]

Brain. What tip size u use for primer and base coat.. an again the brand of the gun

[@Benham_Design]

It depends on what I am spraying, the tip size is determined by the viscosity of the finish you're using. In the video I show how to figure out your tip size based on the finish you use. The gun is an mpx30 by Fuji

[@oneyaker]

Use thin bristle brush bristles but never use any metal needles to poke into the tiny air holes. You do it 10 times and the precise geometry will be screwed up and with it the fan pattern. Blow the holes out with compressed air as soon as you take it out of the paint thinner.

[@Benham_Design]

The spraygun manufacturers sell metal needles that are sized to their spray guns. They are smooth so they don't wear the hole size down. I have had the same gun for several years and use it several times a week and have not noticed any change in the spray pattern. I think it would take thousands and thousands of uses to cause any problems. Just like a piston in an engine can stroke thousands of times a minute without issues. Also a new tip is $75 to replace if it does wear out. Having to sand back a bad finish because the gun wasn't cleaned well, costs a lot more in my time, sandpaper and wasted finish. Since I haven't seen anything bad happen to the tip over the last several hundred uses, I think I will stick with the manufacturers provided cleaning tools.

[@MrBerryK]

So if I’m spraying water-based finishes I can do all this but with water, right?

[@Benham_Design]

Yes, same technique. however with water base you want to be more diligent to be sure everything is cleaned well. When using solvent based finishes, the solvent can dissolve most stuff that has dried in the gun from last time. With water base, water won't dissolve any residue left over.

[@Adrian_Conradie]

Great Video, my hands are taking strain with the cleaning process as I can’t seem to find decent gloves, what gloves are you using and can I purchase them online? Thanks in advance 🫡

[@Benham_Design]

I use the viper brand gloves, and just order them on Amazon

[@branchandfoundry560]

Great info as always, Brian. Thank you for all your work producing videos!

[@joeforster5503]

Brian: First, great video and extremely useful information. But is your setup true HVLP or is it a standart spray gun system running off your compressor? I realize much of what you are saying applies to both, just question the use of HVLP.Not a complaint- just curiosity.

[@Benham_Design]

Yes, the gun I'm using is a medium pressure gun which is compressor driven. I generally don't make the distinction because when you say HVLP everyone can visualize the basic format. Getting into the nuances generally muddies the water when talking about the basics. Especially since there are so many different types of guns. To really understand them all you would have to buy them all and spray all the different types of finishes out there to get a feel for the limitations of each gun. At the end of the day, no matter what gun you use finding the right tip size, air pressure, and fluid flow for the viscosity of the finish you are using is what will make or break a good finish.

[@joeforster5503]

@@Benham_Design And that was my point. Still great video!

[@anthonymuzzillo230]

Info on the spray gun?

[@Benham_Design]

I'm using a Fuji MPX-30 amzn.to/3bjAPqC

[@reddlief]

your paint gun wood holder...plans?

[@Benham_Design]

Sorry, I don't have plans for that thing. I cobbled it together from woodscraps

[@shofarsogood7504]

Creatures of habit… like me laying out my water based stain rags LOL “………what and I doing?”

[@eitantal726]

maybe some guns are better than others, and less prone to getting clogged. The ideal gun will self-clean by just running some thinner through it

[@Benham_Design]

Yeah, I don't think the ideal spraygun is possible, a full day in the spray booth and you are bound to get build up and dry dingal-berries

[@ChrisProsserZ06]

The entire video reminds me why I spray waterborne only.

[@Benham_Design]

I have yet to find a water born that I like the look of. I'm kinda old school and like how the oils and solvents darken the wood. Which water born do you spray?

[@rafezetter8003]

why? I've never understood why so many people who use a spray gun fail to be thorough with their cleaning, solvents is no different than water, clean is clean, or it isn't and water can often gum a gun up FASTER than solvent based, so solvent is often more forgiving. You just have to be fastidious, and if you're not prepared to do that then I guess you'll get the results you deserve afterwards.

[@nateauld]

@@rafezetter8003 Water based shouldnt gum up your gun unless you run lacquer thinner after the water based without fully cleaning the gun. Then the leftovers will gum up. It's best to clean out with water/dishsoap and then spray acetone through the gun instead.

[@Benham_Design]

Thanks for the tip

[@rafezetter8003]

@@nateauld It can, but depends on pressure and ambient temps; too low pressure and high ambient temps can lead to water based drying just as it's leaving the gun, which can then gum up the tip and needle.

[@oldmanfromscenetwentyfour8164]

Any spray equipment HAS to be thoroughly cleaned after use.

[@markolmstead4709]

No, it does not.

[@oldmanfromscenetwentyfour8164]

@@markolmstead4709 Yes, it does. Tips and lines will clog, seals/gaskets will break down and fail, etc.. Also, it needs to be cleaned when changing colors or types of material. What? You don't wash your dick after using it?

[@paulhopkins1905]

Honestly, the biggest mistake was using HVLP instead of LVLP or conventional. Most people dont have the compressor for HVLP

[@Benham_Design]

Just because you don't have a compressor doesn't make it a mistake. Turbine, compressor, or any gun you choose. A dirty gun is going to have a negative affect

[@paulhopkins1905]

@@Benham_Design 99.9% of people dont have a compressor that can support HVLP, but I'm glad you are so defensive about it

[@Benham_Design]

Not defensive at all just having a conversation on KZbin. I do find it funny that 99.9% of opposing comments are because someone doesn't have the same tool I have. As a professional woodworker sharing what I do and how I do it. Why is there the expectation that I'm supposed to have hobby level tools, or that I'm not allowed to show how a professional builds things on KZbin?

[@paulhopkins1905]

@@Benham_Design I have an 80 gallon, 140 cfm @ 90 psi compressor. It will spray HVLP but my conventional guns still well outperform them. The only tool more air hungry than HVLP is a pneumatic sander. The majority of people that buy a new spray gun end up with HVLP cause they are so common and don't know better and wind up with awful results

[@Benham_Design]

I'm curious, what make and model is your go to gun?