VicCina | 08 Nov 2014 11:48 a.m. PST |
I recently got turned onto using Gesso as a primer. Here's a little post about it. link
|
Joes Shop | 08 Nov 2014 1:08 p.m. PST |
|
sneakgun | 08 Nov 2014 1:44 p.m. PST |
|
TiberiusAugustus | 08 Nov 2014 3:28 p.m. PST |
I mostly use gesso as my primer. Black and grey work great I haven't been happy with using white gesso. It never seems to cover very well. |
B6GOBOS | 08 Nov 2014 3:40 p.m. PST |
I learned about using gesso as a primer a couple years ago at cold wars. One of the ladies running the university classes mentioned it. Since then it all I use. Great stuff. Bought the black gesso. Brush it on and when dry highlight white. Works great! Will never use spray primer again. |
Grumpy Monkey | 08 Nov 2014 6:36 p.m. PST |
ignorant here… why/how is it better than normal primer? |
chuck05 | 08 Nov 2014 6:48 p.m. PST |
Its better than normal primer as you never get primer fuzz due to humidity. Also you can use it indoors during the winter time without gassing yourself. |
VicCina | 08 Nov 2014 7:27 p.m. PST |
Plus it lasts longer than spray primers |
Bobgnar | 08 Nov 2014 9:20 p.m. PST |
White gesso and stain painting, invented in the 1980's by Duke Siegfried. |
pigasuspig | 08 Nov 2014 10:28 p.m. PST |
I only use black liquitex gesso. It is magical the way it shrinks down. No orange peel, no fuzz, no fumes, no mess. My first bottle has lasted 4 years of Warmaster, Flames of War, and others. Might need to replace it early next year. |
normsmith | 08 Nov 2014 10:55 p.m. PST |
Gesso itself is a superb primer and provides the perfect tooth for acrylic paint – however, I thought it needed a surface that it can lock onto, this being typically canvas or any other type of fibre / fabric. I have never understood how it can properly bond with plastic or metal – but this is perhaps because I have always used white Gesso and had poor coverage results. I will try black. Having said all of that, to avoid spray, I have been using the brush on black Vallejo surface primer, which is an acrylic-polyurethane, perhaps this and black Gesso are very closely related (or even the same?). |
Cold Steel | 09 Nov 2014 7:20 a.m. PST |
Gesso works great on metals, but I have always had problems with coverage on plastics. No matter how I wash the figures, here are always parts the Gesso won't adhere to. |
CAPTAIN BEEFHEART | 09 Nov 2014 7:52 a.m. PST |
I'm with Norm Smith. The stuff seems to rub off metal very easily. I've used Gesso for years on Canvas so I know it's not ignorance or a bad batch. That being said, I exclusively use acryllic dull coat right out of the tube (after thinning with water of course). It never lets me down like the spray stuff did and you are totally in charge of the area and depth of coverage. I may try gesso again as a primer but never on plastics as they are too slick to hold a water based paint unless primed. |
IronDuke596 | 09 Nov 2014 10:52 a.m. PST |
Has anyone had experience using black gesso as a primer and using enamel paints? A very good description of the priming method…thanks. However, I am concerned (as per normsmith) re the last part re the cleaning up. The brush was easily washed up and the remaining gesso (on the tray/dish) just pealed off and was discarded. The fact that you could peal off the gesso indicates that it did not adhere well to your tray/dish and so may not adhere well to metal figures. I suspect that after much handling under war gaming conditions the gesso may peel away with the covering coats of paint. I would be very interested to hear other comments about the adherence of gesso to metal figures. |
VicCina | 09 Nov 2014 11:24 a.m. PST |
I did a little scratch test with my finger nail on one of the figures and nothing came off of the metal figure. As my usual painting routine I will be varnishing the figures with a matt varnish, so that may help as well. I'll let you know when I'm done painting them. |
ordinarybass | 09 Nov 2014 12:31 p.m. PST |
I use gesso (white or black depending) most anytime I'm not doing a big batch in good weather (then I'll just use cheap spraypaint on the porch) or a project where I can use a colored spray prime/basecoat. Virtually our entire club uses it now. As well as the excellent painting surface it provides, the miracle of Gesso for me (as shown in your blog post) is that you really can glom it on and it will shrink down and rarely obscures detail. It really speeds things up, and it's fairy affordable to boot. It is true that it can be scratched off metal figs, but in my experience, so can almost anything other than harsh sprays and automotive products. Once it's adequately dry, painted over and varnished, I've had no issues with it being less sturdy than any other primer and I've probably used it on a Hundred figures or so at this point. Though as a caveat, I should mention that I dip most everything, so my paintjobs are nearly bombproof anyway. |
CeruLucifus | 09 Nov 2014 12:45 p.m. PST |
I use Liquitex gesso on all sorts of figures: white, black, and gray. I do find spots to touch up now and again but no worse than and usually better than most other primers I've tried, especially spray primers that when sprayed lightly enough to not obscure detail always leave unprimed spray shadows that have to be touched up with thinned paint. Yes if I try to paint over it within hours, it is somewhat delicate and for example can be easily scraped up with a fingernail. This goes away if I wait a couple days or at least overnight and then it behaves like any other primer that's been allowed to fully cure. I'm just careful when I'm in a hurry, no problem. Personally I believe it is a myth that primer has to latch onto the material to work, especially acrylic primer. Manufacturers of hobby paint sell one kind of primer for all types of figures: metal, plastic, resin. This tells me the paint has no special chemical formulation to etch or bond with the underlying material. It must be adhering just like other acrylic paint, by curing into a continuous skin. Certainly there are specialty primers that do etch surface materials (for painting outdoor furniture etc), but this is different. |
CAPTAIN BEEFHEART | 09 Nov 2014 1:46 p.m. PST |
Perhaps time was against me. I promise to try it again (metals only) because spray cans have a mind of their own. |
CeruLucifus | 09 Nov 2014 3:08 p.m. PST |
Also FWIW, I've successfully airbrushed Liquitex gesso. (So far only the white color.) So if you have an airbrush or are thinking of getting one, you can switch to gesso and still spray when you want to. |
War Monkey | 09 Nov 2014 7:48 p.m. PST |
Thank You for the information, I will have to give this a try, up here in Minnesota winters are so cold at times that most sprays freeze before it even hits the model! :o Now I may be able to paint through the winter! :D |
Sgt Slag | 09 Nov 2014 9:02 p.m. PST |
War Monkey, I, too, live (and game!) in Minnesota. I have been using White Gesso for several years. Unlike others on this forum, I have had zero issues with White Gesso rubbing off any of my figures: metal, resin, or plastic. I love Gesso, and it is my primer of choice. The only issue I've had, is that it can leave tiny pinholes which I need to touch up. It works, and it works very well. Cheers! |
pigasuspig | 09 Nov 2014 10:38 p.m. PST |
I recently tried to strip a half-painted PSC plastic tiger. It was primed with black liquitex gesso and painted with acrylics. Then it sat around for a year. I could only scrape it off with my fingernails after soaking it in hot water. And much of the beast still resisted even this. Rather than scratch up the underlying plastic, I gave up and primed over top. So gesso can bond REALLY WELL to plastic, given correct treatment. Tips on gesso rubbing: 1. Wash your plastic! The mold-release makes the plastic very hydrophobic, making the gesso not cover. 2. Use two thin coats: Even in a place which looks devoid of gesso after the first attempt, it will have received some small amount of priming, which will make the second coat stick there better. 3. Paint normal acrylic over the gesso and let it cure. This is really important: the tooth of the gesso also makes it terribly fragile: it will grab any scratching surface and flake right off. But actual paint on top covers up this micro-texture and leaves a smooth finish which resists scratching. |
Bowman | 10 Nov 2014 6:40 a.m. PST |
Pedantic Mode on: Pigasuspig and BEEFHART are correct. There is no way that gesso has the same bond to the figure as an oil based primer. Think about the chemistry. The modern day gesso is an acrylic base with fine pieces of chalk suspended in it. It is used to prepare POROUS surfaces to seal the surface and accept paint. The adherence of an oil based primer is superior, especially to metal. Having said that, the demands of paint adherence are not as heavy in this hobby, as say, the automotive industry. (Priming your car with gesso would be disasterous.) The fact that gesso works on your figure is because most wargamers seal their figures with acrylic once painting is done. (Or, in the case of Pigasuspig, before painting). This "candy shell" coating is what stops the paint from chipping, not the gesso itself. That said, for all the reasons given above, I also have used gesso for years, and it is a life saver in some situations. I handle my figures carefully when painting and seal them with either spray varnish or future wash and then hit them again with Krylon Matte or Dullcoat to finish. I have had no problems with my figures. I suspect those that also have never had troubles with their gesso priming, also take the same care. Just don't believe that a brush on acrylic gesso will adhere to metal as well as a dedicated oil based metal primer. The chemistry is against you. Pedantic mode off |
Early morning writer | 10 Nov 2014 8:58 a.m. PST |
I'm glad to hear those of you in adverse weather environments have this as an option but I'll stick with the spray primers. But I live in California and can spray almost any day of the year – maybe 10 weeks cumulative in a year I cannot spray. And rare as hen's teeth to have 2 weeks strung together without a spray allowable day. |
Mugwump | 11 Nov 2014 5:56 a.m. PST |
I used a formula of 1/3 white paint to 2/3 gesso for a primer. Thin coats or it will crack. The paint was Iron Wind Metals white. |
TheWarStoreSweetie | 11 Nov 2014 2:06 p.m. PST |
I use Gesso on large pieces and competition entries. Gesso is a canvas primer and needs something to hold on to. I mix Liquitex Gesso with Glass and Tile Medium in a 1:1 ratio. The Glass and Tile medium will hold to the metal and make the Gesso rock hard. I use Gesso when primarily in the winter when it's freezing here in NYS. |
CeruLucifus | 12 Nov 2014 12:55 a.m. PST |
Bowman, when you say "think about the chemistry" of oil based primer, what are you referring to? For example here is a link explaining how to prime various metal surfaces and what primer to use and why/how it bonds with the surface: link And here is a similar article on which primers can be used on which surfaces: link But none of these talk about choosing a primer for lead, pewter, "white metal", and other common figure metals. So do you have a link to the chemistry you refer to? I'm curious. Just don't believe that a brush on acrylic gesso will adhere to metal as well as a dedicated oil based metal primer. That doesn't describe most hobby primers. Most hobby primers are acrylic. But even the oil based primers are general purpose primers for multiple surfaces, and thus can't be specially formulated so are not "dedicated" for bonding to metal. |
Bowman | 12 Nov 2014 7:16 a.m. PST |
That doesn't describe most hobby primers. Most hobby primers are acrylic. But even the oil based primers are general purpose primers for multiple surfaces, and thus can't be specially formulated so are not "dedicated" for bonding to metal. That is true, but an oil based primer using petroleum distillates has better surface adhesion than an acrylic co-polymer. Most hobbyists use Walmart automotive primers and generic primers made by companies such as Krylon. Some hobby primers (such as GW) have used Krylon to manufacture their primers also. I believe the main distillate is 1,2,4 trimethylbenzene. This sticks to metal, amongst other things. |
CeruLucifus | 13 Nov 2014 1:03 p.m. PST |
I'm glad we agree hobby primers are not formulated to stick better to metal. Many hobbyists do use these. In fact I'd be surprised if it's true that "Most hobbyists use Walmart automotive primers and generic primers", though it may be. oil based primer using petroleum distillates has better surface adhesion than an acrylic co-polymer. Again can you point to any documentation for this? The articles I linked indicate acrylic is a better choice for some applications, though neither they nor you give a measurement of "better surface adhesion". I googled Trimethlybenzene and it is a paint additive certainly. However, since it evaporates quickly, I would think its role is solvent or medium, not binder. Once it evaporates it is no longer part of the paint, so how can it also be the adhesive? I don't know everything, just trying to apply what I do know. I suspect these properties of oil based paints are the important ones: One, on ferrous and other reactive metal surfaces, there is minimal water or salt in an oil mix so on a freshly cleaned surface the metal under the paint is prevented from corroding over time. This wouldn't apply to the metals used in figures (and not to resin or plastic). Two, because oil evaporates quickly, the paint can quickly shrink / set into a continuous skin which aids in adhesion. This is not the whole story obviously since in general oil paints are known for fully curing *more* slowly than water-based acrylics. But this may be a factor for better adhesion to figures, though I don't know why it would work better specifically on metal versus plastic or resin, unless it's because metal is more rigid in some applications (see next item). Three, most comparisons of oil paint to acrylic (and "latex" which is really acrylic) state that oil paint is more brittle, so acrylic is preferable if the underlying surface won't be perfectly rigid. I would think handling figures during gaming might cause some stress or flex, putting oil paint at a disadvantage compared to the more flexible acrylic. However, brittle surfaces are often harder than flexible surfaces, which may mean *once*cured* oil based paint is harder to damage . . . by scratching the exterior anyway. |
Bowman | 14 Nov 2014 4:27 a.m. PST |
In fact I'd be surprised if it's true that "Most hobbyists use Walmart automotive primers and generic primers", though it may be. In my experience primers such as Krylon, Rustoleum, Walmart brand etc. are used by the wargamers more than dedicated hobby primers such as GW brand, Armoury, Testor's, Army painter, etc., simply for economic reasons. Things may be different in your neck of the woods. GW, Testor's and Armoury are oil based primers. I'm not sure Army Painter is a primer in the typical sense. You are correct. 1,2,4 trimethylbenzene is a solvent that delivers toluene to the surface. Toluene is an adhesive used in oil based glues. The MSDS of Krylon just mentions "aromatic hydrocarbons". On a side note, I have a friend who never primes his figures! He doesn't seem to have any problems as he seals them when painting is done and takes good care in handling them. However, I'm not sure I'd want to follow that example. I do agree with your observations on oil versus acrylic paints. However, my comments were only directed at primers. |
Sgt Slag | 14 Nov 2014 11:35 a.m. PST |
Bowman said, "The fact that gesso works on your figure is because most wargamers seal their figures with acrylic once painting is done. (Or, in the case of Pigasuspig, before painting). This "candy shell" coating is what stops the paint from chipping, not the gesso itself." In my case, you are correct. I apply either Magic Wash (Pledge Floor Shine, full strength, a thick acrylic clear coat with paint added for shading) to my figures after painting, or I apply The Dip (solvent-based urethane varnish with stain, for shading). This is followed by a clear matte coat. The only purpose the Gesso serves, is as a base for the acrylic paints to adhere to, prior to the heavy sealants (Pledge acrylic or Minwax Polyshades urethane). I have observed some peeling of my Gesso'd figures after dropping them, on rare occasions. I do not handle them roughly, nor do I take special steps. I guess I have been lucky so far. Thanks for the insights on the chemistry. Cheers! |
Bowman | 15 Nov 2014 7:14 a.m. PST |
The only purpose the Gesso serves, is as a base for the acrylic paints to adhere to, prior to the heavy sealants …….. Totally agree. At the very least, those (few) people like my friend who never prime their figures should try gesso. And Sgt. Slag, I've read your TMP entries with great interest. With the care you take on preparing, painting and sealing your figures, I'm sure you are careful with your figures. Accidents do happen though. |
CeruLucifus | 15 Nov 2014 5:47 p.m. PST |
Bowman Toluene is an adhesive used in oil based glues. According to the Wikipedia article for Toulene, it is another solvent. The only mention of it as an adhesive is for polystyrene by dissolving and fusing the surface (i.e. as a solvent). Wikipedia: Toulene en.wikipedia.org/wiki/Toluene The MSDS of Krylon just mentions "aromatic hydrocarbons". Krylon has many products, but *this* MSDS for white ColorMaster Primer mentions Toulene specifically. Krylon ColorMaster Primer white MSDS: link I admit I'm perplexed by that MSDS though. Here are the ingredients listed: % by Weight Ingredient 17 74-98-6 Propane 8 106-97-8 Butane 3 142-82-5 Heptane 7 64742-89-8 Lt. Aliphatic Hydrocarbon Solvent 10 108-88-3 Toluene 0.1 100-41-4 Ethylbenzene 1 64742-95-6 Light Aromatic Hydrocarbons 2 95-63-6 1,2,4-Trimethylbenzene 30 67-64-1 Acetone 10 14807-96-6 Talc 2 13463-67-7 Titanium Dioxide 0.92 Barium The Titanium Dioxide is white pigment, the Talc is filler, I assume so is the Barium. The other chemicals appear to be solvents or propellants. They add up to about 91%, so I guess the missing 9% is the paint binder. If anyone else can support Bowman's statement that oil-based primer sticks better especially to figure metal versus acrylic primer, I'd like to see that documentation. I haven't found any technical description of paint that will go there yet. P.S., I think Bowman is right that most hobby spray primers are oil-based not acrylic as I said. |
Editor in Chief Bill | 15 Nov 2014 8:08 p.m. PST |
I've had some problems with gesso when drybrushing; a hard drybrush can cause the gesso primer coat to peel back. |
Bowman | 17 Nov 2014 3:27 a.m. PST |
The Titanium Dioxide is white pigment, the Talc is filler, I assume so is the Barium. The Talc is the "tooth" of the primer, just as the chalk of the gesso is. Barium is an opaquer. I suspect the "aromatic hydrocarbons" are 1,2,4 .trimethylbenzene. If anyone else can support Bowman's statement that oil-based primer sticks better especially to figure metal versus acrylic primer, I'd like to see that documentation. What is used in industry? What type of primer is used on your car? Granted oil based primers remove moisture which will oxidize the metal. Not really an issue with toy soldiers. What acrylic primer are you using on your figures? |
CeruLucifus | 18 Nov 2014 4:42 p.m. PST |
Bowman, thank you for the reply.
Barium is an opaquer. Interesting. Googling "Barium in paint", I find references to Barium Sulfate, not the pure element one would expect from these MSDS ingredients. Assuming that is what is in this paint, the first article below says it is used as a filler in paint, while the Wikipedia article says it has 3 purposes that seem somewhat contradictory: for transparency, for filler, and to enhance whiteness. ICCA Product Safety Summary of Barium sulfate: PDF link Wikipedia Barium Sulfate: link
I suspect the "aromatic hydrocarbons" are 1,2,4 .trimethylbenzene. Redundant as that's the next line item. My assumption is it's a variety of compounds that come along with the benzenes that are listed on either side, and the composition varies without adding significantly to the paint behavior. What is used in industry? Varying paint formulations depending on the surface to be treated. See my post about what primer is suitable for what surface. What type of primer is used on your car? Granted oil based primers remove moisture which will oxidize the metal. Good example that answers your question. Not really an issue with toy soldiers. Exactly why I am asking for documentation that one kind of paint formulation adheres to toy soldiers better than others. What acrylic primer are you using on your figures? See my first post under this topic. |
Bowman | 19 Nov 2014 8:06 p.m. PST |
Thank you for your reply Barium is a highly reactive metal which is never found in it's elemental form. When the MSDS says Barium, it means Barium salts. Barium sulphate is the best known: for being an opaque dye used in medicine and dentistry, among other things. I would assume Krylon uses a Barium salt as an opaquer for better coverage of its white, gray or black colours. I know you use Gesso. When I asked what acrylic primer you use I was responding to your comment of: "That doesn't describe most hobby primers. Most hobby primers are acrylic." I wonder if you have used Krylon H2O? It's a water soluble latex primer. I tried it and found it inferior to their regular primers. A quick survey on the Internet shows I'm in good company. Krylon seems to have discontinued it. |
CeruLucifus | 19 Nov 2014 10:41 p.m. PST |
Good to know about a Barium ingredient meaning Barium salts. Quick reference to the Barium Wikipedia article again says Barium salts are colorless when dissolved (which means transparent I guess) and white when solid. Sounds like an opacifier to me. When I said hobby primer I meant the same ones as you (GW, Armory, etc) and as I posted later, I was mistaken to call them acrylic. I haven't tested Krylon H2O. Based on my readings here and elsewhere, it doesn't seem like a solution for any of my needs. |
Bowman | 20 Nov 2014 7:29 p.m. PST |
No worries on the primers. In my day job I put nice tooth coloured fillings in people's teeth. They all contain barium sulphate and do not colour the filling material. But it makes the fillings radio-opaque, so I can see it on the X-Ray. My late father designed specific primers and paint strippers for the aerospace industry. One of his company's clients was Boeing. You didn't miss anything with Krylon H2O |