Artist needs help with finish(es)
August 5, 2011 12:05 PM   Subscribe

What finish(es) should I use to finish my art (artist acrylic ink on cherry wood veneer)?

Hello MetaFilter,

I apologize in advance for my wordiness and appreciate any help/advise you can offer, as always!

I am an artist who needs help figuring out how to finish his work. Currently my pieces consist of the following:

Laser etched design (via lasercutter) on wood veneer mdf (usually cherry), with artist acrylic ink (on approximately 1/2 of the surface). The piece is then glued to three pieces of birch plywood to create the "frame".

I am trying to figure out the best way to finish these pieces as my tests have had less than acceptable results. Here is the process I've tried so far:

- 2 to 3 layers of Krylon's UV-Resistant Clear Acrylic Coating (for UV protection) with no sanding in-between (the coats seem too thin for sanding). 10 to 20 minutes between coats

- 2 to 3 coats of Miniwax's water-based Polycrylic applied with a quality brush; with sanding in-between coats (#220 random orbital hindsight I think this was too much & plan on dropping this down to #320 for the future). 1 to 2 hours between coats.

- I then switched to Miniwax's water-based Polycrylic spay can application (to see if it applied better than the brush); I applied another 2 coats of this. 30 to 60 minutes between coats

Initially everything looked great; the wood was looking beautiful and the ink really took on a gorgeous shine. Unfortunately, within a week of applying the first coat, some crackling (? not sure if this is the correct term) appeared in the middle of the piece. It looks as if the ink has disappeared in places though I'm not sure if this is accurate or if the finish is somehow hiding the ink. It has been a few days and I think the issue has gotten worse but I can't tell for sure; either way its not acceptable.

I'm hoping someone on here may be able to direct me to the correct steps and finish(es) to use to minimize any problems as well as providing:

- UV protection (I could forgo this if absolutely necessary but I'd really like to offer it so that customers don't have to worry about my art fading...within reason of course; my art is not intended to be in direct sun)

- A clear finish that both beautifies the wood, bringing out the natural beauty of the cherry, enhances the ink and protects the art from minor use/abuse (my pieces will predominantly be hung so I'm not expecting much "abuse").

- Hopefully without additional investment in tools (such as a professional sprayer; I'd love to have one but can't afford it at the moment). I'm also open to other low cost ideas if anyone knows of any.

Some additional issues I've run into:
- I tried to apply the brush on Polycrylic directly to the inked test pieces but the Polycrylic causes the ink to soften(?) and run, ruining the piece. I have not tried applying the Polycrylic spray directly to the inked surface, though I expect the same results.
- Unfortunately, due to the fact that I have no direct control over the specific piece of wood until after my design is etched on the surface (I currently contract out the laser etching work to a vendor and they supply the materials), I am unable to sand the surface of my pieces before applying the first coat of "finish". The laser etching is so minimal that almost any sanding would sand away the etching. Long term, the solution is to get my own laser cutter but currently that is not an option.

Thanks, Metafilter, as I said, I really appreciate any advice you care to share.
posted by ogunther to Media & Arts (18 answers total) 2 users marked this as a favorite
Can you post a photo of the crackling area? If the ink seems to be disappearing, it might be getting absorbed into the MDF. You might need to seal the wood before you put on the ink, but a photo would help with diagnosis.
posted by echo target at 12:15 PM on August 5, 2011

Response by poster: I completely forgot an important step (doh!):

After the last coat of Miniwax's Polycrylic, I wet sanded the entire piece down starting with #600, then #1000, then #1500, then finally #2000 (alternating against and then with the grain to ensure the previous scratches had been sanded out). I planned on finishing with 3M's Perfect-It Automotive Rubbing Compound but have not taken this step yet.
posted by ogunther at 12:21 PM on August 5, 2011

Response by poster: Thanks, echo target.

I snapped a couple photos (links below) but I'm not sure if they're clear enough to be helpful.
As per the sealing of the wood first, I don't know if it matters but I have pieces that have been inked for a number of months (without finishes applied) that show none of these signs. Would the act of putting on the finish somehow trigger the ink to be absorbed by the mdf?
posted by ogunther at 1:12 PM on August 5, 2011

Response by poster: Edited the pictures/links to fix my atrocious grammar (sorry):
posted by ogunther at 1:23 PM on August 5, 2011

Artist's acrylic ink is water borne, and you are finishing with solvent based varnishes, so my bet would be that's what the cracking source can be traced to as the water evacuates from your drying layers.

Acrylic ink has no substrate fix, so it is leeching into the wood, probably.

Acrylic inks, many of them, are not lightfast, and will fade out with exposure to sunlight.

You might want to choose a coloring agent made for use with wood.
posted by effluvia at 2:17 PM on August 5, 2011

The Japanese use cherry extensively in block printing, so you might look for a Japanese pigment source like Holbein or a wood specialty for your pigments.
posted by effluvia at 2:19 PM on August 5, 2011

Response by poster: Thanks, effluvia. I am using Daler-Rowney's FW Acrylic Artist Inks which they state as "an acrylic based pigmented water resistant ink (on most surfaces) in a range of 38 colours, all of which have either a 3 or 4 star rating for permanence. Such a high degree of lightfastness over such a range of fully intermixable colours makes them ideal for use by artists in the production of pictures for permanent display." which is part of the reason I used them; however I am quite the novice so maybe I'm just buying into their marketing-speak?

I'll look into the Holbein pigments as I had not heard of them before. Thanks!
posted by ogunther at 4:09 PM on August 5, 2011

- 2 to 3 layers of Krylon's UV-Resistant Clear Acrylic Coating (for UV protection) with no sanding in-between (the coats seem too thin for sanding). 10 to 20 minutes between coats

This is what I do to seal metal and plastic miniatures painted with acrylics, and I've never seen anything like what's happening here. I think effluvia and echo target have it: the wood needs to be sealed before you paint it.

You can paint over the Krylon, so that's what I would try first: seal the wood with one careful coat of the Krylon, wait for it to dry, paint, then seal again.
posted by vorfeed at 4:15 PM on August 5, 2011

I use the Daler inks myself and they are great. Inks are made to drop into paper and stain it rather than have body and stay on the surface like paints. Even though Daler says the inks are water resistant, they are a plastic resin emulsion with a water vehicle. Mineral spirit based acrylics require solvent clean up and that's what your varnishes are, resins with no pigment in a selection of surface finishes. When you apply the mineral spirit based varnish, it rewets your water borne acrylics with the solvents, and the coloring agent leeches out of the paint film and into the wood, and you see it vanish---so to speak.
posted by effluvia at 6:20 PM on August 5, 2011 [1 favorite]

Response by poster: Thanks, vorfeed...I'm not sure if what I'm doing would work over the Krylon as I'm using inks instead of paints but I honestly haven't tried so its worth a shot.

Effluvia, thanks for the follow-up. To clarify (not trying to be daft, I just want to make sure I understand and that we are talking apples to apples), I can see how mineral spirit based varnishes would cause a problem with the inks but the Polycrylic is supposed to be water based (not really sure if that matters honestly as my tests confirm that putting the Polycrylic directly on the ink does cause it to rewet as you stated)...however I put the Krylon UV-Resistant Clear Acrylic coating down over the ink first as I was thinking that would protect the ink from the Polycrylic (if that makes sense) this point I'm thinking one or more of the following happened:

1) I did not put enough coats of the Krylon over the ink and thus allowed the Polycrylic to reach the ink
2) Something in the Krylon and Polycrylic did not play nice together.
3) The Krylon itself is reacting to the inks and/or wood

#1 or 2 seem likely but my Krylon test pieces (some of which are over 6 months old at this point) don't bare out #3.

So at this point changing my medium may be my best bet, however, since I already have a number of pieces ink, if you have any suggestions on how I might salvage those, I'd be all ears. :)

Regardless I really appreciate you (and the others) taking the time to try and help me out.
posted by ogunther at 8:58 PM on August 5, 2011

Response by poster: Actually I just thought of a forth possibility:

4) The Krylon does not have the ability to protect the ink from the Polycrylic (ie. regardless of the number of coats, the Krylon may not be able to completely protect the inks from the Polycrylic)
posted by ogunther at 9:01 PM on August 5, 2011

derp, I missed the ink part! I'm not sure about that. The ink might run if you try to apply it over Krylon, and it might not... might as well try with a scrap piece of wood, if you've got one.
posted by vorfeed at 10:47 PM on August 5, 2011

I paint on doorskin(cheap wood veneers) with acrylics and years ago switched from using any acrylic varnishes available in an art store to Flecto Varathane which has proven to be far superior. It's a heavy duty waterborne wood varnish that applies thinly and evenly and dries with no yellowing. It might be useful to mess around with and test. I have never had an adverse reaction to the paints I use and it also mixes well with the acrylic paint. The interior brand is far less odorous the the exterior brand.
posted by Phlegmco(tm) at 11:40 PM on August 5, 2011 [1 favorite]

Any coating that has mineral spirit will open up a water borne media. Your experiments are spot on. You could choose a fluid mineral spirit tint or choose a water borne varnish. With water borne media, you must allow a lot of drying time to allow layers of water to escape completely. I would go for a month, and if you live in humid conditions some sort of drying process.

I used to get a lot of violin makers who were looking to tint their wood a cherry color. Their favorite thing to use was Wisnor and Newton Alizarin Crimson, madder root based. They would even go so far as to expose the pigment to black light to make sure it flouresced violet. The modern pigment in the Winsor palette called Alizarin Crimson is now quinacridone violet and is much more lightfast but not quite the same blue shade red.

At any rate, you might try tinting with gum arabic based water color, and finishing with the varnish of your choice. Holbein makes a very fine product, as does Schminke or Sennelier. I believe the Schminke has a bit of resin in the media, so that might be a nice match.

Most artist brands have color charts on their websites, but they're nothing like the experience of naked pigment contact, so you might want to check the ranges out in a store.
posted by effluvia at 6:33 AM on August 6, 2011

Response by poster: Vorfeed: Haha not a problem; I'll definitely give it a try.

Phleqmco(tm): Thanks for the tip. I'll definitely check it out. Do you do anything to the wood before you paint on it (like seal it)?

Effluvia: Thank you so very much for all the information; it sounds like you really know your stuff...something I hope to be able to say about myself some day (in the distant future). I must admit that all the options and knowledge necessary to choose between them can be a bit overwhelming so I greatly appreciate your guidance.

I will take your advice and try some of the gum arabic based water color (I had been hoping to experiment with water coloring anyway so this is a win-win going forward).

One clarification: When you stated that "With water borne media, you must allow a lot of drying time to allow layers of water to escape completely. I would go for a month, and if you live in humid conditions some sort of drying process." where you speaking about letting the ink dry for a month or the finish (or each of them in turn)? If the finish, are you suggesting I wait a month in-between coats? Sadly I do live in a high humidity area (yay Georgia) so I will have to error on the side of caution.

Thanks again to all for helping me out. :)
posted by ogunther at 8:38 AM on August 6, 2011

Best answer: You are most welcome, and I don't mind more questions so you can Memail me if you have further questions.

Acrylic media slowly locks the pigment into the layer as the water escapes and the plastic begins to make a lattice structure. In thin layers, the surface dries, but there is still some water left in the layer that needs to make its way out. Acrylics and watercolors will respond to ambient humidity, so mind that you gently dry your paint completely. Folks who live in humid environs like yours will get all sorts of interesting surprises from their art materials due to environmental factors.

Acrylics applied in thin layers with no additional media (like modeling paste) will need an absolute minimum of three days to be touch dry and a month----I am being cautious here---for the sort of sealed varnishing you are undertaking in your work. Some things you will see if the water is emergent from the interior of the paint film or the wood, which is also a water absorbent material---cracking, fogging, and foxing (mold). For example, if the surface becomes cloudy, then goes away, then comes back, that's water in your paint film trapped and fogging the paint film.

Liquitex and Golden acrylics probably both make a water based varnish for acrylics that might be successful for your application. Personally, I would choose Golden since they are domestically manufactured and they make a very fine product.

Good luck with your work!
posted by effluvia at 2:24 PM on August 6, 2011 [1 favorite]

Phleqmco(tm): Thanks for the tip. I'll definitely check it out. Do you do anything to the wood before you paint on it (like seal it)?

Nope, I just start, part of what I like about the wood is that it changes the colours of the first layers of paint I apply. Every few layers of paint I apply a layer of the Varathane and in 17 years or so of doing this I have never had a problem with it. I also use it to apply layers of coloured glaze like traditional oil painting. I can apply the next layer within 30 minutes usually with out an issue so I would try that also, just building up layers to see what happens. You can look at my website which is in my profile and see what I do, and if you have further questions please feel free to memail me and I would be happy to share whatever knowledge on the subject I have.
posted by Phlegmco(tm) at 12:30 PM on August 7, 2011

Response by poster: Thanks, Phleqmco(tm). I really appreciate your help and offer. You definitely have some amazing work. I'll let you know how it goes and definitely memail you if I have any other questions.
posted by ogunther at 3:09 PM on August 8, 2011 [1 favorite]

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