Tuesday, 19 August 2014

Quick Fix: When the Paint Just Won't Effing Stick

Apologies for the lack of posts lately.  I've got a metric ton of half-finished posts (which are on their way to full-length novels at this point) in the works at the moment, but in the meantime, here's a quick tip for anyone who's ever had problems with paint peeling off their models / terrain / bases / etc.

I've run into this issue many many times over the years, and it happens for a number of reasons.  Either I didn't clean and prep the surface properly, didn't apply the primer properly, or didn't choose the correct paint (see a trend here?  Yeah, despite knowing better, I tend to get lazy and rush things sometimes).

With metal and plastic surfaces, it's usually not too common a problem.  Most often, the project doesn't need much in the way of prep.. a well shaken can of primer (make sure you hear the metal mixing bead rattling around for at least 30 seconds) sprayed in good conditions (not too humid or cold) will do the trick.  Don't overdo the primer either.  Just a light coat, otherwise a thick build-up of primer will dry into a slick surface, giving your acrylic modelling paint very little texture to adhere to.

Resin or other materials can be a bit of a problem though.  In the case of resin, it's a fairly porous material, and it tends to sponge up the oily release fluid that they coat the insides of the mold with.  It some cases, it means that you need to soak the resin parts in a warm soapy solution for a good long time (overnight in some cases), then rinse them off thoroughly to get ride of any oil or soap residue.  This does happen to plastic and metal parts on occasion (particularly the Privateer Press version of "plastic"... that sh*t is horrible stuff to work with, for a long list of reasons), but leftover oil residue is most commonly found on resin components.  And it's worst on resin, because the oil really penetrates deep in some cases.

So what happens when you are happily chugging along, in full hobby mode, and your fully assembled model gets to the primer stage?  Oftentimes the primer just won't stick.  It'll pull up into puddles as it dries and the primer contracts.  Sometimes it won't even happen at the primer stage either... oftentimes it'll happen at the paint stage instead.

What's happening is that the liquid content of the paint or primer is evaporating as it dries, which means that the volume of the paint decreases as it becomes a solid.  Naturally, it becomes smaller, and ideally, dries to a nice super thin layer of paint.  However, if the surface it's clinging to is too slick to get purchase on, it'll lose grip and either puddle up into spots of dry paint, or it'll look fine for now, but flake or rip off later on (likely while you are handling the model, or it's rubbing against the soft foam interior of a carrying case).

This is what happened to me recently:


Here I am, desperately trying to finish off a display base for a painting competition entry that was due the next day.  The base platform was a simple picture frame that I had found at Ikea, to which I glued a thin sheet of torn up corkboard to.  I hit the whole thing with a layer of black spray primer (standard GW primer), then airbrushed and drybrushed the cork, masked off some areas and airbrushed on some quick street markings (the white diamond denotes a High Occupancy Lane, which I thought appropriate for an Armoured Personnel Carrier... the minivan of tanks).  I was just about the repaint the frame itself with some more black (to clean up all the overspray and overbrushing) when sections of the black primer just started coming off on my fingers.

The horror!

It appeared that the fake wooden frame (I think it was some sort of laminate surface) was simply too slick for the primer to get a good grip.  While it initially appeared okay, it couldn't hold on while being handled by my Spiderman-like fingertips.

Crap.  The painting contest was the very next day, and I was already working deep into the night.  Hmmm... perhaps another hit of primer would do the trick... this time I would use a Vallejo airbrush-ready paint on primer.  I could use just enough finesse with the airbrush as to avoid hitting the road bits.

Well, it worked... for a while.  Then when I tried picking it up and getting back to work on it (adding oil spots and patches of pigment for weathering), this is what happened:


At this point, the black just started peeling off faster than a stripper's clothes under a rain of large denomination bills.

Aggghhh!!!  My body and brain craved sleep in the worst possible way, and my heart was pounding under a barrage of stress.  I was ready to grab the whole thing and hurl it into the trash bin (and then take a sledgehammer to the bin as well).  But then I remembered a craft project that I had done with my then preschool age son a little while back...

We were using pieces of clear recycled plastic packaging to represent stained glass.  The problem with the stuff is that it's perfectly smooth... absolutely no tooth for paint to adhere to.  And you couldn't hit it with primer either... we wanted to retain the translucency of the clear plastic, and leave a coloured tint instead.

Paint straight up wouldn't work... the paint didn't even want to leave the brush for a quick visit to the plastic.  Watering down the paint made things even worse.  The surface was so hydrophobic that any liquid (no matter what consistency) would simply run off of it.

In the end, I ended up mixing some white glue and dish soap into the paint.  Now, you might be thinking, "Say whaaaatt???" and I would totally understand.  But hear me out before you close your browser and play more World of Warcraft instead.

Dish soap kills the surface tension of liquids.  A teeny tiny amount of the stuff stopped the paint from contracting into puddles, and instead allowed it to dry as a smooth layer instead.  The trick was not to use too much of the stuff... a fraction of a drop did the trick, so long as it was thoroughly mixed in.  Perhaps the flow release acrylic medium you find at art stores works better, but dish soap worked alright.  It works on a molecular level, and I studied English Lit instead of Science at University, so as far as I understand the principle, it works by magic.  Yup, pure magic.

The white glue, on the other hand, lends some adhesive properties to the paint.  Again, I don't know how (heck, my ancestors thought that ingesting ground up bull testicles helped old men make babies, by the same method of logic I was using, so yeah... it's all magic).  A little bit more white glue was required as compared to the dish soap, but not much more.  Again... it all required thorough mixing with the paint and soap.

The great thing about both dish soap and white glue is that they both dry completely clear.  There is little to no pigment in either (unless you're using glitter glue, of course), so the paint is the only thing that determines the colour you are laying down.

So, after raiding the kitchen sink and my 5 year old son's craft supplies, I got to work.  And you know what?  The damn thing worked.  I had to apply the paint by traditional stick brush, of course (it would have killed my airbrush), and it took damn near forever to dry properly (and a subsequent second coat as well, for good measure), but it worked like magic.

I like magic.

Anyway, finished pics:


Note that I worked the oil stains and weathering pigments over again with a soft brush and a little thinner to make them a bit more subtle.

And a pic of my finished entry, taken in my own figure case months after the painting competition:


Well, it won't win any Golden Demons (in fact, it was beaten by a very nicely weathered Leman Russ tank by Matthew Beavis... check out his blog entry regarding it here), but considering what I went through, and that it had started off looking like this:


I was happy with the final result.

In hindsight, I should have sanded the faux wooden frame a bit more aggressively.  I did make a quick pass over it with light sandpaper, but it still didn't give it enough tooth and texture.  And I've been told that GW primer is not a "true" primer, but the stuff has almost always worked for me before (I may give the latest generation of Privateer Press P3 primer a go next time, even though I had huge failures with the first generation of the stuff when it originally came out).

Most of all, I probably shouldn't have left the display base to the very last minute.  You always have to give yourself enough time for fixing mistakes and the inevitable unforeseen challenges that arise while working on a project.  In fact, I usually tell people that they should finish a competition entry at least a month ahead of time, put it away, and then look at it again a week before the competition.  By then, you might have a fresh look at the model, see any flaws that need fixing, and still have enough time to correct them before entering it.

Of course, I never take my own advice, but other people sometimes do.  Which is why I always seem to be the number one cause of my own defeat in painting competitions, but hey, nobody's perfect, right?

As for next year's rematch against Matthew and the other incredibly talented painters (more and more of them seem to be popping up all the time) in my local area, I know I have to push myself to a whole new level now.  To be frank, I think Matthew's Leman Russ is no where close to what his current painting skill level is now.  If you check out his blog, you'll see that he improves faster than anyone else I know.  At the time, he was doing his best James Wappel impression, but he's now incorporated a number of other great artists talents and techniques into his arsenal of tricks (Meg Maples was teaching a course in Vancouver recently, and Matt just gobbled up her lessons like a Hungry Hungry Hippo).  My Rhino was just as good as his Leman Russ, if not just slightly better (in my highly biased opinion), and I think part of the reason I was beat was because I entered something very similar the previous year (same judges, who are probably getting tired of seeing me enter red tanks year after year), and because Wappel's style was something new and fresh to them.  Matthew's work was a bit rough and experimental at the time, but he's getting much more refined while still experimenting more than just about any other painter I know locally.  It's a killer combination, and I'm going to have to really work to compete against it.

Bribes.  I'll probably have to resort to bribing the judges.  And maybe magic.  If only I can find some magic ground up bull testicles to mix into my paint next time, I think I have a good shot at winning.

12 comments:

  1. It's nice to see when someone posts a disaster/failure and how they dealt with it. Helps us normal folks realize we aren't alone when chunks of paint come off of things and we wonder how we screwed up.

    The soritas rhino is lovely, as are the sisters. I think you didn't win because nobody recognizes them anymore :).

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    1. Thanks Greg. I definately have more than my fair share of disasters and mishaps. The two that stick out in my mind more than the others are ones that happened during the 2002 Canadian Golden Demons, but those deserve a blog post unto themselves. While they seemed disastrous at the time, they did teach me valuable lessons that I was able to apply to my personal painting growth as an artist.

      Which is a good point. Veteran painters can make things look easy, only because they have already screwed things up the wazoo at some point earlier in their life as a painter. Every screwup a novice painter makes just brings them one step closer to being that awe-inspiring veteran painter that others will look up to later.

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    2. Oh, and just because I've been painting for awhile, doesn't mean I don't still screw up on a regular basis. Especially now that I'm trying out new tricks and techniques, I run into huge obstacles ALL the time. Thankfully now I have the vast resources of the Internet, and a good network of fellow painters to draw upon. Back in the day, I just had to figure things out by myself.

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  2. Your post reminds me of when I first used the GW Imperial Primer from a pot. The primer was peeling off as I applied paint -- didn't even make it to the carry case! (It turned out the answer was to shake that pot like it owed you money...)

    What issues did you have with P3 previously? I just picked up a can of the P3 white to spray some skinks and I'm incredibly disappointed with it. The outcome was incredibly dusty (rubbing a finger along the model left my finger white with dust) with a texture that shouldn't be there. :(

    I'm hoping the problem is (as you say) that I didn't shake the can enough before spraying.

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    1. Craig! I had the same problem. My solution was to put a lava bead in the imperial primer container and shake it until my arm hurt. Then it worked great! :)

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    2. I had the same dusty issues you did. However, I've heard later batches were much improved. If it's still the case, I would do my best to shake vigorously, and experiment with spraying from different distances than the GW stuff. Perhaps it dries faster, hence if you hold it the same distance as you do with GW primer, the atomized particles are already partially dry by the time they hit the model? If that's true, then the trick would be to hold the can closer to the project (which is scary, because that usually leads to overbuildup of spray and drips).

      As for the bead idea for brush-on primer, that reminds me of the Reaper paint pots. I'm not sure if they still do, but years ago they used to put tiny metal skulls in each paint pot to act as an agitator. Apparently it really did the trick well, and when the paint pot was empty, you could use the pewter skull for conversions or as a basing detail. So cool!

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  3. Ohhhh, I wish this had gone up a couple months ago. I went on a big terrain binge in preparation for NOVA and a lot of my stuff was repurposed kid's toys that are made of slick plastic. Primer is still flaking off some of them, and they were done with the salt-and-spraypaint method so they're not easy to touch up. Le sigh. Tried some light sanding but your dishsoap and glue trick would have worked wonders on them. Next time I'm definitely trying this out.

    Good to have you back, Kelly! Fantastic work as always.

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    1. Thanks. I think I get too caught up with trying to make each blog post "special", and should just try and bash out a nice quick easy post once in awhile. There are quite a few topics and tips that don't require entire books written about them, so I'm going to try and toss those in amongst the more lengthy dissertations.

      However, take this post for example. Somehow I managed to turn a "try mixing white glue and a drop of dish soap into your paint to help it stick" into a chapter-length article.

      Sigh.

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    2. Yeah but its a GOOD chapter length article.

      On a practical level, a post lets people know you're alive and kicking and to stay tuned. So many hobby blogs just stop and go off the grid wihout warning. Gotta stay fresh, but it's easy for me to say 'cause I have other writers at my site to keep the wheels spinning ;) And hey, if that's appealing to you we are ALWAYS looking for contributors, especially since our top painter is on mega-hiatus.

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    3. Also, if i may reply to my reply, our hobby skills are passed down by word of mouth. Stuff you or someone else may consider banal is going to blow at least one person's mind out there. I facepalmed over your simple glue-in-the-paint trick. "Why didn't I think of that?!?!?"

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  4. I had to laugh since a while back in desperation I mixed some crazy glue in with some paint and use it in my airbrush. I figured If I went heavy with acetone and extra paint thinner it would stay fluid just long enough to make it out the tip and onto the surface, I was right for about 1 minute and then I was cleaning my airbrush for even longer than I am usually. I have yet to pick up that thing and use it without taking it apart and overhauling it every time i "try" to use it!

    Sometimes it works great, not very often but I know that the time it will be working is always going to be very limited and will eventually end up clogging or spraying dust onto a perfect first coat and ruining it. My problem is I live in Phoenix, AZ and normal nightime temps during the summer are about 100 to 105 degrees F and daytime temps are 115 to 122 daily for 3 months or more with 0% humidity.

    Spray cans can be applied within a minute or 2 of last coat when I'm using candy colors in layers, 1 -3 minutes to shoot 3 or 4 colors layered and then a thick top coat of clear in 2 layers, I can finish, walk inside with it on my locking pliers, and take it off and hold it in my hands under my 10x magnifying glass and inspect it.

    3 hours of polishing 3 minutes of paint time, 3 days of looking for misplaced parts. LOL

    It's my secret combination that I seem to always use on everything.

    3-3-3

    Nice post I got a good laugh and made me remember my frustration that lead up to my glue mix in attempt. This was just a simple diecast car that would not submit to anything I tried, primer is never an option in my world. No primers can be used or you lose the look and detail of clear paints over polished metal, highly unlikely to sell if a sliver base is used. 4 colors makes an endless rainbow if layered correctly, I have found that it's very easy to make things BROWN.

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