LumberJocks

Help! I can't...... chemistry

  • Advertise with us

« back to Finishing forum

Forum topic by JonHitThingWithRock posted 319 days ago 660 views 0 times favorited 11 replies Add to Favorites Watch
View JonHitThingWithRock's profile

JonHitThingWithRock

85 posts in 320 days


319 days ago

Hello Everyone.

So I’ve been spraying “water-based poly” for a couple projects now, I was using a $15 harbor freight gun and it was ok, I would spray a coat, then take the gun apart and drop all the pieces in a bucket of water (the can said water clean-up), then i’d brush-clean with water either immediately or after a couple hours. i didn’t have any need to spray for about a month and yesterday i filled it up and started spraying. The trigger squeeze was very stiff, and i had to manually reverse the trigger to get it to stop firing. I got through the coat and took it apart, and everything was rusty inside. In my head this meant that water was no good for gleaning spray guns.

I then got on the interwebs and looked up some videos on the facetubes about gun cleaning, unfortunately 100% of them pertained to car painting, but one of them mentioned different solvents for different materials, and the guy said to use laquer thinner or acetone for “waterborne acrylics” which is (as i understand it) what water based wood finishes are. so i went and got some acetone and a new gun (a home depot husky something-or-other), brought it home, cleaned it all out with acetone, then filled it and started spraying. once done i took it apart and started dropping pieces in the acetone, i eventually realized that acetone immediately turns waterpoly into rubbery schmutz, which i’m fairly sure is caked in my new gun now, despite thorough and feverish cleaning.

My question is: What should i use to clean my hvlp gun after spraying? I’m concerned about water because it takes hours to dry and causes rust, also the shiny parts of the gun don’t look shiny anymore after cleaning with water. I scoured the internets and couldn’t find a single reference to this, apparently everyone knows something i don’t.

Jon


11 replies so far

View wbrisett's profile

wbrisett

133 posts in 946 days


#1 posted 319 days ago

Jon, for water-based polys, I use water. What I usually do is clean my canister (I have a Fuji HPLV system, but it really shouldn’t matter), then fill it or one of the extra canisters I bought with water, then spray water through the system for a couple of minutes. Once that is done, I take everything apart, clean it up with brushes, wipe it down and life is good.

I recently sprayed some non-waterbased poly after thinning it, and did the same thing with lacquer thinner. Haven’t had any issues in the past four years since I bought my system cleaning things this way.

I think the key is spraying through the system and wiping it dry instead of just soaking it.

Wayne

View Oldwest's profile

Oldwest

72 posts in 1401 days


#2 posted 319 days ago

I’ve been spraying the water based Enduro poly for 17 years.
I have one gun for poly and one for lacquer, I never mix my guns.
Like wbrisett said above the key is to spray through the system not rinse.

Here is what I do most of the time if you’re interested.

For WB Poly and WB stains I just rinse the gun thoroughly, turn the gun over
and let water run down the center tube and then turn it over and let the poly
come out. After 5 or 6 times it becomes clear and then I put some water in
my gun with dish soap and spray it for 30 seconds to get everything out and
then flush the gun again. I have an Accuspray gun and it’s made of a composite
material not metal.

-- Anyone who isn’t totally confused just doesn’t understand the situation.

View Oldwest's profile

Oldwest

72 posts in 1401 days


#3 posted 319 days ago

I’ve been spraying the water based Enduro poly for 17 years.
I have one gun for poly and one for lacquer, I never mix my guns.

Like wbrisett said above the key is to spray through the system not rinse.

Here is what I do most of the time if you’re interested.

For WB Poly and WB stains I just rinse the gun thoroughly, turn the gun over
and let water run down the center tube and then turn it over and let the poly
come out. After 5 or 6 times it becomes clear and then I put some water in
my gun with dish soap and spray it for 30 seconds to get everything out and
then flush the gun again. I have an Accuspray gun and it’s made of a composite
material not metal.

-- Anyone who isn’t totally confused just doesn’t understand the situation.

View badcrayon's profile

badcrayon

33 posts in 418 days


#4 posted 319 days ago

Try using denatured alcohol to clean your gun it dries fast and breaks down most waterborne poly.

-- Bad Crayon Studio

View Fred Hargis's profile

Fred Hargis

1643 posts in 1091 days


#5 posted 319 days ago

My experience with water borne is not as extensive as many, but I used dish detergent and water to wash the gun out. A 5 gallon bucket with lukewarm water and detergent allowed me to disassemble the gun for a soak, then a scrubbing with that same water. Another bucket for rinsing it out, the spray clear water through it. You do want to get it clean. Those acrylic resins are really a pain to remove once they harden on the gun.

-- I long for the days when Coke was a cola, and a joint was a bad place to be (Merle Haggard)

View Lifesaver2000's profile

Lifesaver2000

508 posts in 1710 days


#6 posted 319 days ago

When I spray something water-based through my metal spray gun, I clean it with soap and water. After I get get most of the water out, I put a little mineral spirits in the can, hook back up to the compressor and spray a little with it so all the inside parts get coated with the mineral spirits. This seems to work for preventing rust.

I just be sure I run a little denatured alcohol through before I use it again if what I am spraying isn’t compatible with the mineral spirits.

View JoeinGa's profile

JoeinGa

3091 posts in 605 days


#7 posted 319 days ago

And since you already have a compressor, once you disassemble and clean the gun, BLOW DRY all the pieces COMPLETELY. Dont just let them air dry.

-- Perform A Random Act Of Kindness Today ... Pay It Forward

View NiteWalker's profile

NiteWalker

2704 posts in 1174 days


#8 posted 319 days ago

I use water for cleaning my guns after spraying wb poly, followed by a bit of denatured alcohol.

Anything stubborn, lacquer thinner breaks it down with a good soak.
I doubt your new gun is toast; run some lacquer thinner through it.

-- He who dies with the most tools... dies with the emptiest wallet.

View JonHitThingWithRock's profile

JonHitThingWithRock

85 posts in 320 days


#9 posted 319 days ago

Thanks everybody! I have a lot of new things to try now. As as update, i did spray another coat last night, and thankfully, the gun still works fine, and i cleaned with water after spraying, maybe i just need to do a deep clean once a month or so, and just clean with soap and water after each use.

View NiteWalker's profile

NiteWalker

2704 posts in 1174 days


#10 posted 319 days ago

A couple other things:
I do the deep clean after I’m done spraying a particular project. The quick clean gets done changing coats of finish. I leave the finish in the gun between coats. Never a problem on conversion or turbine guns.
When you get ready for spraying, spray a bit of solvent for the finish you’ll be spraying through the gun before filling it with finish. This helps you catch any problems with solvent instead of expensive finish.

Good quality HVLP guns are pretty durable, and 99% of the time any spraying issues can be traced to a cleaning issue.

-- He who dies with the most tools... dies with the emptiest wallet.

View BArnold's profile

BArnold

170 posts in 430 days


#11 posted 319 days ago

I have several HVLP conversion guns, PC, HF, Husky. I use water with a little dish detergent to clean the gun after dumping any excess waterborne finish material out of it. After I make sure the finish is cleared from the gun, I spray clear water through it for half a minute, then put a couple of ounces of acetone in the cup and spray it through the gun. I also drizzle a little acetone on the remainder of the gun to replace any water droplets.

-- Bill, Thomasville, GA

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase