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mek42
04-02-2009, 08:35 PM
I haven't been on in a while as I've been playing more in the woodshop than the studio of late. As my turning ability improves, I'd like to express some ideas I have for painting some lathe work.

For the amount of painting I do, I have quite a bit of Golden acrylic product. Their factory is not too far out of my way home from work. :o I want to paint so that the grain of the wood is still visible underneath.

My usual wood finish is Bush Oil, a mixture of roughly 1/3 each boiled linseed oil, tung oil and urethanes. As much as I like the way this behaves with wood, adding just a slight amber to really pop the grain, I don't think that it would work well to put acrylic on top of this. Maybe the acrylic would adhere to the urethane though. :confused: Anyhow, I'll assume that I shouldn't use this finish when I want to play with acrylic on wood. I don't have any oil paints at the moment so can't try those over the Bush Oil.

So, if I paint directly onto the wood, there are two issues. First, how to apply the paint and still see the grain and second, what sort of protective surface treatment to apply afterward.

I'm guessing that I should use transparent colors. I'm thinking to maybe mix a bit of paint with a generous amount of media and slowly build up pigment. Maybe use some t-shirt cotton as an applicator (i.e. the brush)? I'll set the lathe to the slowest speed mine goes, 500 rpm, and hope I don't make a huge mess. As always, I'll wear my full face shield - I don't think paint in the eye would be any more pleasant than wood chips. :eek:

Does this seem like a reasonable plan?

Also, if anyone has painted on wood so as to allow the grain to remain visible, I'd love to hear what you did.

Thanks!

I posted this in Mixed Media, Alternative Materials and Other Media (http://www.wetcanvas.com/forums/showthread.php?p=7738315#post7738315) also. I remember that it was ok to post in multiple forums on occasion, and I hope this was ok. :confused:

Bright Eyes
04-02-2009, 08:56 PM
I assuming you are only doing a light painting so the grain shows through right? I'd suggest using dry pigments mixed with linseed oil at whatever ratio you want (depending on how visible you want the wood grain) and then covering it with the mixture you mentioned above. Mixing dry pigments with alcohol would work too. The alcohol sucks the pigment into the wood and dries really fast. I use this method to stain wood frames. Shows the grain really well. Keep in mind that when the alcohol dries the pigment stain will be the color of the dried pigment. The linseed mix will keep the darker wet look. Hope this helps. Good luck with your project!

Raymo
04-02-2009, 09:07 PM
Probly just something youll have to do a little trial and error on. Experiment a little bit. You seem to have a pretty good handle on it. The wood will really suck up the acrylics but that should be to your advantage. Let us see how it turns out.

mek42
04-04-2009, 06:20 PM
I've done some research on Golden's website and learned some things. Since I already have the products that Golden recommends for use on wood, I'll start with acrylics.

First, it is recommended to apply some MSA Varnish (mineral spirits acrylic) to the wood first to prevent water-based acrylics from raising the grain. The only concern I have is that for some reason, my container of MSA Varnish has lived in the unheated shop and not the studio. :crying: Guess I'll find out if it works for me as is. :confused:

Next, right before I start applying paints, I'll "slick up" my piece with an application of AGL (acrylic glazing liquid) to increase workability of the paints. I think I'll then start with some paint right out of the tube to see how it works - if I don't like it, I can try mixing with some AGL or other medium next time.

I'm shaping a test piece in the shop right now. It's going to be a handle for a tool, so if the paint process is not what I want, no big loss. I won't be getting to do any painting on it today, as my shop is unheated and it is snowing here today! If I at least get the handle shaping and sanding done today I'll post a "naked piece" pic later on.

Thanks for the interest in seeing how things turn out!

howyadoin
04-04-2009, 06:37 PM
Looking forward to pictures. This is something I'd like to try out too, at some point.

mek42
04-04-2009, 09:11 PM
Here is the naked piece.

http://www.wetcanvas.com/Community/images/04-Apr-2009/108310-halfinch01sanded.JPG

The tool (a 1/2" Thompson bowl gouge, U-profile) will be inserted to the end of the piece on the left of the picture. Just to the left of the red curtain are two grooves that are hard to see in this picture. There's a little excess wood on either side.

In between the two innermost grooves will be where I paint the piece. I'm going to apply Bush Oil after painting to either end, since I don't know what kind of grip the acrylic will yield and I am familiar with how a light coat of Bush Oil feels in my hand.

After doing as good a job as I am currently capable to get the piece smooth with a skew chisel, I power sanded with 320 grit.

Here is my current plan for painting:

First, I'll tape off a bit with low tack masking tape the ends where paint will not be applied. Then I'll apply some number of coats of MSA varnish - since it is snowing again today (happy springtime! :rolleyes:) this step will have to happen either tomorrow or later. If tomorrow isn't warm, maybe I'll pop off an email to Golden and see if they have a recommendation on how many coats of MSA Varnish to apply.

After the varnish is fully cured (not sure long I should wait - I'll probably wait at least a day to be safe) I'll coat the work with a generous amount of AGL. Then I'll put a little tiny bit of red (not sure which one yet) Heavy Body on a bit of t-shirt material and go to town.

I'll apply the AGL with the t-shirt too, and will just use the same t-shirt for painting. I'll probably just toss the MSA t-shirt bit after use.

Safety considerations - since I'll be painting on a surface spinning at 500 rpm, true cadmiums are right out. Since I'm aiming for still seeing the grain, I should probably use a more transparent pigment anyhow. Maybe naphthol red light, quinacridone crimson or quinacridone magenta. I'll need to remember to wear my full face shield and ought to setup some sort of "overspray" wall.

Assuming I get the red layer to a point that I am happy with, I'll let the red dry fully and then I'll try putting on a layer of interference blue. As long as this is a test piece, I might as well totally test the technique. :) I'm open to opinions about which red might go best with the interference blue to make a blue-red-purple shimmering effect.

After the interference blue dries will be another coat or two of MSA varnish.

Anthony Dunphy
04-05-2009, 03:48 AM
That looks like an ambitious projec! I would reaaly like to see any results you gat with it.I painton wood regualrly with acrlics but I gesso the wood first and paint over that but I don't know how you might keep the grain visible unless you urathane the wood once.paint on that and then add another coat of urathane.

mek42
04-05-2009, 04:52 PM
It warmed up a little today and I was excited about this project, so I figured I'd go try some stuff. If I don't like it I can always sand it off and try again.

I made a 1:1 mix of Golden's MSA Varnish and the mineral spirits denoted as "good" for use on their website. The mix was a bit cloudy, I was nervous to use it and came back in to read their product literature again.

Turns out, at one point in their literature they say "must be thinned" and then in another part it says "20-30% thinning is helpful for brushing, thin more for spraying" (that's more a paraphrase not a quote). So, I thought to myself, "I'm not using no stinking brush, I'll just put it on straight with a t-shirt." So that's what I did. After all, I can always sand it off if I don't like it.

My bottle of MSA is maybe 3 years old and I originally bought it for woodworking, so it has sat through some freeze-thaw cycles in the unheated shop instead of living in the studio area with my paints. Unknown if this has any impact on what I'm about to describe.

First, the MSA is very viscous. Maybe around 60,000 centipoise - this is going from memory of how the 60K centipoise viscosity standard flowed = and this memory is about five years old now. I started by putting a bit of MSA on my t-shirt material bit, turned the lathe to 500 rpm, dropped my faceshield and went to apply the MSA just like I apply Bush Oil, by gently wiping it on to the spinning piece.

Except that didn't work as expected, since the MSA is too viscous and gripped too much to the spinning piece making it rather difficult to maintain control of the cloth. So I turned off the lathe and applied a generous amount of MSA to the piece with the cloth just by hand, manually rotating the piece to get the underside, etc., etc. So now I have MSA all over my piece, but not in a uniform thickness. So what I did was then turn the lathe on again, get a very secure grip on the cloth and then wiped off the excess MSA to leave (hopefully) a uniform thickness.

The wood grain is still visible at this point and the MSA is very much just a clear coat now. The MSA has been applied to the area between the artists' tape in the below picture.

434054

I'll keep you posted on my progress with this. Again, thanks for the interest!

mek42
04-05-2009, 06:52 PM
The MSA varnish as I applied it dried really fast, so I went ahead and did the first painting coat. I put on a generous amount of AGL on the piece before applying some quinacridone red heavy body paint. I used a piece of t-shirt cloth to apply the paint, periodically also adding some more AGL.

434064

I'm not 100% happy with my first attempt, but realized that I was starting to mess around with it too much. It was difficult for me to get an even color intensity throughout the piece. This difficulty seems to have been the worst with the height differences / curves in the piece. I'm thinking to let it dry and then add a second coat. After that I might lightly sand to try and even out the "brush" marks.

Hope I'm not posting too many pics too often.

mek42
04-07-2009, 08:14 PM
That last pic was with wet paint.

Here is a pic of the paint dried. Note the opinion left by the harsh critic on the left of the piece. Apparently the bird in my shop thinks it's a crapper. :eek:

434366

I managed to do some sanding today too.

434367

I was hoping to sand down to an even color intensity, but I'm starting to think that I'll need to do multiple painting and sanding cycles to get it where I want it. I may not get to painting it again for a week or so due to weather - it is cold and snowy out and my shop is unheated. I'll provide an update when I'm able to apply a second coat, which I may try doing with a brush instead of t-shirt cloth this time.

mek42
04-10-2009, 12:02 AM
I wanted to apply lighter, more transparent coats for the second coat to be able to slowly build to a uniform red. So I thought I had a brilliant idea. I mixed a little Airbrush quin. red with a bunch of transparent airbrush extender and used a 1/2" flat brush to apply it. After doing this and having some of the paint pool at the bottom of the piece I learned that the airbrush paints are designed to be a little slower drying to avoid drying up in the airbrush needle.

Oh well, I guess this is why this is an experiment.

Here's a picture after putting on two layers of my Airbrush paint mix.

434624

I'm going to sand it down a bit again and I want to touch up the left end a bit - next try will be using a fluid, maybe with some AGL added. I'll apply with a brush again for better control.

I'm happier with this than I was before.

Heavy body on t-shirt fabric is too much pigment without much control. The Airbrush paints are too liquidy with too slow a drying time. Hopefully the fluid will be just right.

If needed I suppose I could just leave the lathe running while the paint dries, but that makes one of my safety nerves tingle.