How to create dust,dirt and hair free environment to spray varnish prints

[Jglaser757]

I am at wits end! I am struggling to create a dust free environment to spray prints. I have setup paint booth and things star out ok, then when I'm done varnishing, I start to see dirt/micro hairs etc settle on prints. I was thinking about what I could do to improve situation and the only thought was doing a small section of 40x60 print at a time. Let it dry but check and remove as it settles , but this is no long term solution. I wish their was some one in south florida that did this .

[mstevensphoto]

what are you varnishing with? and onto?
I think partial coverage is a great recipe for an end result where you see each partial coat. I would not do anything other than the whole thing.

what works for me:
the spray room is only as big as I need it (less to clean)
furnace filter on the incoming air, high cfm vent fan
spray vertically oriented prints, keep them vertical (less surface for things to settle on)
use water based varnish under bright omnidirectional  lights. dry time is such that I can pick the occasional goop/hair out with no problem and the light lets me see this.

things I haven't bothered with but might try
keep the humidity higher to help settle dust (like 50-60%)
spray away from walls so that the over sprayed air isn't blowing dust off of them back into the air

honestly as clean rooms go my room is really not so clean, perhaps if you share more of what you're doing we can help more.

[Jglaser757]

I tried spraying vertically but ran into problem creating even coat. So I tried lying the photo on the ground.i get more of an even coat, but  more particles settle that way. I setup a paint booth sealed off all walls with painters plastic( then put an large fan on one side(a  filter attached to it  and ac filter taped to plastic on the other side so that it is all sealed with airflow from one side to the other. It's basically a large box with plastic to seal everything off.

[bill t.]

I bet you're blowing dust and crud off the plastic and the floor with the force of the gun blast.  Forget the floor, really bad idea.  Holding a flashlight, go through you spray pattern against whatever backing your use for a print, but with no print.  The light beam will show up what's in the air, and may help you find if and where dust is being launched.

You should coat in about 3 thin coats, letting each coat dry.  After each coat dries wipe the face of the print hard with a small, very lightly moist terry cloth painters towel like the ones at Home Depot and Lowes, or even a clean dish towel.  It's like a really light sanding.  If you remove the the dust from each coat before going on to the next, you should have no problems, you can usually just flick it away.  But dust that's under more than one dried coat is hard to remove.  Unless you see a piece of dust on a wet coat that's going to be really easy to pick up while the print is still wet, it may be best to let the coat dry before going after it, but don't forget!  I spray in an area with dust and crud and pollen and spider webs, and basically have no problems with dust using the terry cloth scheme.  Another thing to watch out for is if you try to clean off the face of the print with the air hose before spraying.  That can kick up a lot of dust, too.  Mr Flashlight will tell you if that's happening.  And for general painting purposes, Mr. Bright Overhead Light is even more helpful, and Mr. Light Coming From Behind You is the best.

[Bob_B]

use water based varnish

Interesting. Which product are you using? Almost all of the sprays specifically for prints seem to be in organic solvents. I'd much prefer water-based, if it afford good UV protection and didn't mess with the Canon dye inks I use.

[Jglaser757]

I bet you're blowing dust and crud off the plastic and the floor with the force of the gun blast.  Forget the floor, really bad idea.  Holding a flashlight, go through you spray pattern against whatever backing your use for a print, but with no print.  The light beam will show up what's in the air, and may help you find if and where dust is being launched.

You should coat in about 3 thin coats, letting each coat dry.  After each coat dries wipe the face of the print hard with a small, very lightly moist terry cloth painters towel like the ones at Home Depot and Lowes, or even a clean dish towel.  It's like a really light sanding.  If you remove the the dust from each coat before going on to the next, you should have no problems, you can usually just flick it away.  But dust that's under more than one dried coat is hard to remove.  Unless you see a piece of dust on a wet coat that's going to be really easy to pick up while the print is still wet, it may be best to let the coat dry before going after it, but don't forget!  I spray in an area with dust and crud and pollen and spider webs, and basically have no problems with dust using the terry cloth scheme.  Another thing to watch out for is if you try to clean off the face of the print with the air hose before spraying.  That can kick up a lot of dust, too.  Mr Flashlight will tell you if that's happening.  And for general painting purposes, Mr. Bright Overhead Light is even more helpful, and Mr. Light Coming From Behind You is the best.

Thanks Bill! I will follow your recommendations.

When I am spraying it seems that I the mist doesnt quite cover in one or two passes to completely cover the print and get a glossy look. I guess I need to increase the flow of the HVLP or slow my passes down.

[bill t.]

Definitely use water based sprays unless you have a good spray booth with a strong exhaust and a hose ventilated hood over your head.  It is possible to create environments that are genuinely deadly for several minutes when spraying large prints with solvent sprays.  Lacking a proper painting facility, solvent sprays should be limited to occasional small prints using canned sprays outdoors with your back to the wind and wearing a top quality mask with a 3M 6001 filter cartridge, at least.  The problem with solvent spray is, the finish is gorgeous when applied to gloss prints, it dries in minutes, coated glossies are exceedingly scratch resistant, and it is trivial to produce dust free prints even in dirty environments.  But it's so-so with matte prints and also with most micro-porous surfaces.

Moving right along, your total application of water based paint should be around 15ml for each square foot of print, at the end of all coats.  The most you should put down on a single coat on a vertical print is 5 tor 6 ml per square foot to avoid runs while also keeping the paint from landing on the print in a tacky state, which is bad.  15ml is just enough paint to bring a matte canvas or matte or gloss paper print up to a satin-going-on-gloss finish.  Around 20+ml you wind up with a very glossy and extremely scrape resistant surface, but at the expense of somewhat raising d-max and lowering the highlights.  If you decide to put down heavy coats, wait until the second coat to avoid runs on the first coat which does not have the advantage of a pre-existing coat to cling to.

I measure the amount of paint applied by weighing the gun before and after each coat with a 7kg digital scale I bought for $10 on ebay.  1 gram is darned close to 1 ml.  The model is "SF-400."  Very useful tool, also good for applying exactly the right amount of glue when applying prints to Gator.  Set the paint flow on your HVLP gun to around 200 ml per minute by spraying water into an empty bottle.  When spraying prints move the gun about 1 foot per second over the print, I use an Eno EM-11 clip-on metronome to time myself.  I am obsessively quantitative and it serves me well, sometimes.

Be sure to keep the gun from drifting further and further away during each pass, and also avoid speeding up.  Those are a strong tendencies for newbys.  A distance of 8 to 10 inches is best but feels kind of too close, get over it.   if the gun is too far back you will wind up with an ugly, bumpy surface.

[Jglaser757]

Hi Bill,

I am using clear jet semi mat on hot press natural by epson. I loved the look of it after experimenting with quite a few samples of varnish and about 40 different paper samples. I am using a mask because of the fumes and probably should get new filters for it but my spraying has been minimal the last month or so. I think I have done about ten prints so far.

My distance has probably been a little too far and would say about 12-10 inches or so.

[bill t.]

I see you are not new to this!  I also like the Epson matte papers.  I have been able to spray a high gloss surface on that stuff with water based Minwax Polycrylic after three coats cut with 12% water.  Breathing Color Pura Velvet is another outstanding matte paper that takes all kinds of coating extremely well and can be easily brought to a high gloss with water based products, if desired.  For those using Canon Lucia inks, Pura Velvet can be rolled a lot without the ink smearing or lifting.  I just wish both those papers didn't have such a regular, repetitive texture.  Of course there are smooth versions of both papers, but for many folks those appear less artistic than the textured versions, life is like that.

[Jglaser757]

I see that your using minwax polycrylic?  Interesting! It can be picked up at lowes.  I read the water soluble varnish can only be used on water resistant papers.  Tried the damp cloth and that seemed to help. Also, dusting off with soft bristle brush helps after using damp cloth. I have to resist removing any scmutz before drying because it leaves indentation in varnish from finger or tweezer.

[mstevensphoto]

drag a table in there, get an easel, anything other than spraying on the floor!

if you have trouble getting an even coat be sure to rotate 90 degrees between coats.

the nice thing about something like Timeless and an hvlp is that one coat is really all you need. make sure your sprayer is clean and spraying a fan not a cone, overlap each pass by half, move at one foot per second (I typically do my horizontal pass at 1ft/sec and an immediate second coat vertically much thinner)

Optica one and elegance velvet both take the heavy spray quite nicely. I love how elegance velvet looks and am entirely afraid to use the over-curled paper as it continually causes head strikes no matter what I do. a medium thick coat of timeless on optica one makes a lovely high gloss surface with great contrast. The biggest issue I have with optic one is accidentally guying my edges to the board with overspray. I add an extra 1-2" to the print in case I need to slice it off (helps with handling and mounting too)

[bill t.]

You don't really need heavy coats for a gloss finish, you just have to sure each coat lands on the print wet but not yet tacky.  If removing a piece of dust from a single pass leaves a mark, the coat is probably too thick.

Polycrylic is only suitable for prints that will be mounted.  It's relatively brittle compared compared to canvas varnishes, and I assume it will crack if wrapped.  Otherwise it's very transparent and dries fast.  You must wear a mask with that stuff, the smell is pretty bad when it's wet, but there is no smell as soon as it dries.  For spraying dilute 1 part water with 7 parts Polycrylic.

[dgberg]

Light,very important. I have 4 300 watt explosive proof fixtures in my spray booth.
Equipment,lots of great stuff out there I use all Binks HVLP. Many other very good units on the market.
Most important you must spray upright and angle is better.
3 light coats for me as well. They dry much faster.
Stand that print upright, learn to spray properly and the most problematic issue of dust in the print will automatically go away.

[Justan]

Long ago when I put spray finishes on pianos and cabinets, one of the standard things we did which has not been mentioned in this thread is to clean the enamel paint on the walls and ceiling in the paint area and adjacent room with a damp sponge mop and also mop the floor(s). The process eliminates and traps dust.

It is really important to start with a clean environment when spray painting. The high air flow spray and exhaust stirs up everything nearby Increasing humidity helps a lot to reduce dust from the environment, but here in the "northwet" low humidity was never an issue.

[Jglaser757]

Thanks for all the advice! I have definitely improved with my technique the last couple of days...

Coats are going on ok now without too much of an issue with dust and debris. I have reduced the number of particles to two or three now..Thank god

But, while in the middle of spraying I noticed a lone eyelash or fiber attach itself to the photograph. Would you stop what you were doing to remove it in mid spray when image is wet or wait till your done varnishing and photograph is dry?

[bill t.]

I'd finish the pass.  If a part of the eyelash was sticking up out of the paint enough to grab easily with a tweezers, I'd pull it off the wet paint.  If was entirely down in the paint, I'd wait until the paint was just barely dry.  It's too easy to mess up the print by trying to pick up something that lays entirely flat from a wet surface.  If you are using properly thin coats, on a dried but still supple coat the hair could probably be flicked away or gently rubbed loose, or for more stubborn cases, urged to leave with the tip of a sharp Xacto blade.

If I then discovered that the crud was under two or more coats, I'd lay the dry but still supple print down on my workbench under a strong light, and with a very sharp Xacto knife tip see if I could just flick the crud away.  If that fails I would make some gentle scores over the top length of the crud, and try to tease it out.  Did I say use a magnifier?  Sometimes it helps to gently rub over the scored area with a moist but not dripping towel.  There are many techniques.  For a hair or long piece of sturdy crud you might try scoring over just 1 or 2mm at one end of the hair, sometimes the rest will come along if you can get a tweezers on, or a knife-tip under, the short exposed piece.  If you can get a knife under the hair, sometimes you can press you finger tip against the flat edge of the knife to secure the the piece for removal.

But as said, I rarely have those fights anymore with good technique, in spite of my pig-sty paint booth.

The scoring thing has the advantage that a lot of the time you can reseal the cut just by pushing it down and it doesn't show, or all you need to do is put a microscopically thin strip of paint along the score with a fine brush.  Worst case is you recoat the print.

[Jglaser757]

Thanks for the great advice Bill. With every print I varnish it gets easier and learn what to do and what not to do. I forgot to test gun before spraying and got a ton of overspray. Live and learn,,,

[huguito]

I don't like to derail this conversation, but you made me very curious.
Why would you choose a matte paper to apply a high gloss treatment?
I am sure is something to be gain by this otherwise you wouldn't do it.
Is it depth?

[bill t.]

I have used matte papers with high gloss coatings because many matte papers take water based gloss coatings extremely well, and even demonstrate larger gamuts with that treatment.  It's a mechanical thing in regards to the media, and it's a visual things in regards to the gloss.  Spectacular looking glossy images sell more readily than merely beautiful and subtle matte prints.  Just ask Peter Lik.

More recently I have discovered techniques that allow a limited number of glossy papers to take water based coatings very well.  However solvent coatings create such spectacular results on glossy media that I have lost interest in water based coatings on gloss media and have committed a lot of resources to using solvent coatings on a modest production scale.  And it ain't cheap.

[huguito]

You did it again, after such a good description now I have to try it.
Premier print shield gloss lacquer would be a good one to try? Unless you have a better brand of spray in mind?