(Review, sorta) Vallejo Gesso Primer

[Evil Eye]

(Note: No pictures at the moment as the lighting in my house is not very good.)

 

At the suggestion of a friend I acquired some Vallejo gesso primer from a local art shop- he posted his models and told me he primed them by just slopping the stuff on and letting it dry. I got black and white and did some test models...with mixed success.

 

I did 3 models- one in black, one in white and one in grey made by mixing a bit of black into some white. All 3 were metal (though the black subject had some plastic parts).

 

The black test model was a resounding success. Despite slopping the stuff on like cottage cheese, it shrank into all the recesses- in fact it shrank a bit too much in places and left areas of bare metal. Not a huge problem though and very promising.

The grey model was largely successful (barring the small uncovered bits) but curiously, in some areas it had formed a rather bubbly texture almost like the inside of an Aero chocolate bar. Annoying, but not unfixable.

 

The white test model though...oh boy. Whilst it did shrink dramatically it was still far too thick, lumpy and wrinkly, as though someone did a really crap job with a spray can. It was also very fragile, and peeled off with minimal effort (which in this case is a good thing ironically enough).

In conclusion, whilst I think gesso primer is a valid solution when spray cans or airbrushes are not available for priming, it isn't a silver bullet solution and I'd recommend sticking to the black, as the white version is for lack of a better word, dreadful. I will run further tests, with thinning as a possibility, but that's my experience so far. I will say, it is very economical, with £8 getting you enough to last a long, long time.

 

Anyone else have any luck with/hints for gesso?

[Axineton]

I've not heard of gesso before mate but I got some of the Vallejo mecha primer in white this week and used it with an airbrush and it was just terrible! worse than spraying corax white. Whereas the black Vallejo primer I have is absolutely fantastic.

[Evil Eye]

I've not heard of gesso before mate but I got some of the Vallejo mecha primer in white this week and used it with an airbrush and it was just terrible! worse than spraying corax white. Whereas the black Vallejo primer I have is absolutely fantastic.

I've used Vallejo's airbrush primer, I hated both to be honest but especially the white. I'll admit I've become a convert to lacquer-based primers (specifically Mr. Surfacer) so I may have been spoiled by that.

 

Technically, gesso is actually meant for priming canvas, but its properties (extreme shrinkage and smooth drying surface) make it in theory ideal for priming models. As mentioned I will run more tests but so far the black is definitely superior to the white.

[Firepower]

I tried the airbrush primer, and it was unimpressive.  Decent enough teeth for paint to adhere to, but it always peeled off the plastic without much more than a gentle brush of a fingernail, regardless of the many different prep and application methods I experimented with (sanding, PSI, layers, cleaning, etc.).  I too ended up using lacquer, but as a disclaimer to those who may be considering the same, the stuff comes with a lot of health issues.  You will need a respirator and good ventilation.

 

Never heard of the gesso stuff.  I imagine it would be good for those hard to reach places that sprays have issues reaching, but wouldn't spray generally be quicker and easier overall?  Barring environments unfavorable to such sprays that is, like humid areas and such.

[Naryn]

This matches with my experience with gesso as well. Liquitex white gesso stayed lumpy, was barely attached to the model, and was just generally a good way for me to waste an afternoon cleaning the gunk off again—for all that the stuff fell off raised areas if you breathed too heavily around it, it sure clogged up surface detail. Strongly recommend avoiding gesso, and going for a purpose made brush on primer if at all possible.

[Arkhanist]

There are two types of gesso. You have the traditional gesso, which is basically animal glue and white pigment that only works on a non flexible, absorbent surface such as wood panels. It is quite absorbent itself when dry, which is needed for certain types of artist paint, and is intended to provide a uniform bright white on the wood ready for the artist to start on.

 

Modern gesso is basically acrylic binder, calcium carbonate and a pigment, the acrylic binder making it more flexible when dry than classic gesso so is suitable for canvas etc. Acrylic isn't absorbent when dry, thus the calcium carbonate to try and match some of the properties of traditional gesso for those paints that need to be absorbed into the surface to produce the desired effect (such as water colours) and is also quite matte.

 

When painting a non absorbent surface with non absorbent top layers, i.e. painting plastic models with acrylics, modern gesso might as well be lumpy standard acrylic paint as a primer. It has none of the self-etching properties of a primer, which is what gives good primer its scratch resistance. It's aimed at an entirely different type of painting. Always worth testing of course, so thanks to squiqsquasher for sacrificing models and time, but I can't say I'm hugely surprised it sucks for our type of painting.

 

A good primer shrinks into detail, hides small imperfections, has good 'tooth' for the next layer, and grips strongly to provide a strong base so the rest of the paint job doesn't rub or scratch off.

 

Vallejo primer has good 'tooth' and shrinks well, but I've found its grip to be questionable - scratches off far too easily for my taste, and just peels if you try and sand/scrape it; I always seem to miss a small seam which I can only see after priming.

 

I've switched to badger stynylrez as my main primer; all the good bits of vallejo primer (paints over well, shrinks well, conceals micro imperfections), but it airbrushes easier (far less clogs even when neat) and it grips far, far better - you can sand it after 30 minutes no problem and passes the fingernail test easily, I have to use a metal tool to scratch it. Works great when brushed on too. I've heard good things about mr surfacer too, though it is lacquer based so is less suitable if you have small children (as I do); makes a great hider of imperfections on metal models though I've heard.

 

Car body acrylic primer spray cans are good too, of course, but English weather makes airbrush priming much more practical; and I get a better finish and full coverage as I have more control.

[Jackalwolf]

I've always stuck to GW Abaddon black cans and never had any issues whatsoever.

[Evil Eye]

Incidentally the black gesso model came out looking like it had been airbrush-primed, unlike the questionable grey and awful white. But then the black seemed to have a from-pot consistency much like slightly viscous acrylic, whilst the white is more of a paste (and the grey was just white with a tiny bit of black). So as an alternative black primer, it works pretty well. That said, one test is not conclusive, so I'll have to try it on some scrap parts or something.

[Evil Eye]

Update: I've talked to my friend again and he confirmed that the white Gesso seems to be fundamentally different stuff from the black for some reason we're not quite sure on. So that would explain why the black worked so well whilst the white was disastrous.

 

I'm tempted to try hand-painting Mr. Surfacer with a bit of Levelling Thinner, as that's my airbrush primer of choice and with enough Levelling Thinner it SHOULD dry very smoothly- I've seen people use that stuff to make otherwise "airbrush only" paint work wonders by hand. (It's also my preferred choice of thinner for compatible paints, as it basically turns spraying Mr. Hobby and Tamiya paints into "easy mode" due to the self-smoothing properties). Obviously it wouldn't be ideal, but in cold weather especially airbrush priming isn't always an option for those of us without indoor spaces to spray in.

[Arkhanist]

My concern with the black gesso is primarily adhesion - can you scratch it with your fingernail once it's dried, and how does it sand? It is mostly acrylic after all, so should shrink well if the pigment & carbonate is ground fine enough for our uses and it's balanced right, which it sounds like it isn't in the vallejo white (which will be aimed at canvas/wood).

 

But given modern gesso is primarily designed for preparing absorbent surfaces I'm concerned it's not going to grip that well to plastic or metal. Since that layer is what holds the rest of the paintjob (and varnish) onto the model it's important that it's a strong bond for gaming purposes. It is quite a bit cheaper so I'm definitely curious how it compares!

[Razblood]

I've been using liquitex black gesso for years, as I've run out I've added vgc dead white to make a nice midtone grey and have never had any problems, though I'd recommend a good cost of varnish after your done to avoid rubbing.