Need Spray Painting Advice

[FrankEV]

I don’t have a spray gun setup but do use a lot of Rattle-Can spray paints and lacquers for some of the work I do.  Flat items, like frames or plain backers, I do not have too much difficulty with.  However, spraying thick wood (3/4”) cuttings is another story.  When trying to get into all the cut surfaces, the paint gets too heavy on the front or back and I get runs and puddles.  I will even get runs and puddles when I use a primer.  Masking the face surfaces is not an option as the piece has many intricate cut outs.  Just wondering if anyone has spray painting tricks or advice to share?

[Bill WIlson]

One of the reasons shellac has become my go-to finish for spraying fretwork.  It is best sprayed thin and dries very fast, so if you are hitting an item from multiple angles to get into all the frets, you can pace yourself, applying multiple coats, without the runs and puddles of, thicker, slower drying finishes. 

I'm not crazy about the rattle cans, though.  I do use them occasionally, but I don't think they atomize the shellac well enough, plus you can't modify the spray pattern or fluid/air flow.  I get much better results with an HVLP spray gun.

I don't cut a lot of thick stuff, but reaching all the deep crevices can be challenging.  Usually, I'll dip in BLO first, then apply shellac as a top coat.  I get full coverage with the BLO and it isn't so obvious if the shellac doesn't cover as well in those deepest corners.  I believe somebody on the forum dips in shellac.  I've never tried that, but it might be an alternative.

[TAIrving]

When dipping in BLO or shellac or anything else for that matter, it wicks up into the crevices.  I can blow it out, but if I miss one and it dries, then that crevice is permanently filled.  What do you do about the wicking?

[LarryEA]

I do a lot of spraying mostly with a (High Volume Low Pressure) HLVP sprayer.

Much better than rattle cans. But have not found a solution getting inside of thick fret work.

The best way I found was to thin down my solution and using a very small paint brush.

Using the bristles and apply my solution (lacquer). I try to "stuff" the bristles in the cuts. I then do a top coat with my spray gun

Not perfect but better than just spray. 

Of course, do this on both sides, starting with the back.

 

Edited October 20, 2022 by LarryEA

[OCtoolguy]

Frank, have you tried an air brush. Once you get familiar with them they are very controllable and you should be able to put the paint where you want it. 

[kmmcrafts]

Coming from a auto collision repair and painter.. This is why I do not spray my items that are made from thick materials.. I've mentioned many times on here that I only dip my projects in Danish oil as it has a small amount of poly in it. 

I will sometimes dip in the Danish oil and then a few days later top coat with Poly.. can't really use Lacquer on oil base or even over acrylic paints.. Water based clears will work on most all of it.. however in spray can form I find the water based poly to not spray too well. I just was at Menards today and seen they have a Varathane brand water base poly.. I should have grabbed a can but I was short on cash.. so only got what I was after. I may give that one a try. 

Just like Shellac.. Lacquer dries quite fast.. but again.. I have that eye for spray painting and my detailed eye I pick out the uneven finish whether you make it puddled up or not.. several light coats is still getting over spray onto the surface and that stands out to my spray painting eyes like a sore thumb.. I really dislike any of the fretwork I've ever seen that was top coated or just sprayed in general. No matter what you do.. you're getting an uneven finish.. tape the surface off you get over spray in the fret areas or visa versa doesn't matter.. my trained eye sees it.. so for the most part I don't spray thick fretwork pieces.. Probably most folks don't see it.. I'm unfortunate that I do.. because I really do like the look of a nice sprayed top coat.. but more times than not I see the uneven spray coat and it's just a big turn off for me..

Something I've been meaning to try is the dipping of Shellac method. @Denny Knappen does this to his puzzles.. I believe he dilutes it quite thin 50/50? with denatured alcohol? 

[FrankEV]

2 hours ago, OCtoolguy said:

Frank, have you tried an air brush. Once you get familiar with them they are very controllable and you should be able to put the paint where you want it. 

I have one and have never used it, but seems like I may have to learn.

[FrankEV]

Just for clarification, I was questioning about applying a color type finish.

 

I recently made a sculpture cutting out of Poplar and attempted to apply a high gloss Black Laquer finish.  It was impossible to apply the finish to the many cut surfaces with out over applying spray to the face surfaces.  

I guess it is not a practical finish.

[OCtoolguy]

45 minutes ago, FrankEV said:

I have one and have never used it, but seems like I may have to learn.

I've been watching a ton of "how-to" videos on this guys channel. He has tested just about everything. I've learn quite a bit but still haven't actually done it.

 

[Scrappile]

After using my cheap HF sprayer, I can see how it would be very good for painting spoons!  No kidding, it works as advertised, I have not tried to spray small lines or anything with it.

[OCtoolguy]

58 minutes ago, Scrappile said:

After using my cheap HF sprayer, I can see how it would be very good for painting spoons!  No kidding, it works as advertised, I have not tried to spray small lines or anything with it.

I don't think it will work for that Paul. More of just a tiny syphon spray gun.

[jollyred]

Just wondering, could you do the painting before removing the pattern after cutting?  It would act as a mask to keep the paint off the surface.  Once it is removed, the surface would be painted.

Tom

[FrankEV]

7 hours ago, jollyred said:

Just wondering, could you do the painting before removing the pattern after cutting?  It would act as a mask to keep the paint off the surface.  Once it is removed, the surface would be painted.

Tom

I thought of that, after the fact, but  I would have had to apply the liner material to both sides before cutting.   I may just try re-cutting the piece this way and see if it works. 

Thanks.

 

[kmmcrafts]

1 hour ago, FrankEV said:

I thought of that, after the fact, but  I would have had to apply the liner material to both sides before cutting.   I may just try re-cutting the piece this way and see if it works. 

Thanks.

 

This would work if you taped both sides and spray the finish from both sides to get good coverage.. That said, don't use shelf liner if you're going to do this.. the solvent from the paint melts the shelf liner.. Don't ask how I know that one, LOL..

A big part of learning CNC router carving is actually painting the carved out area.. OR painting the entire board and then carving.. otherwise most carvings don't show up real well.. kinda like scroll sawing a BBply sign and then using a same colored BB backer, LOL.. So I'm having to learn wood painting techniques... certainly different that auto painting for sure.. since wood can soak up a lot of finish and soak into the gain etc. 

IF you're going to be trying this I suggest either painters tape or better yet use Oramask Just be sure you get a good Oramask, they are not all created the same.. some is less chemical resistant than others depending on the type of solvents used in your paint.. ie Lacquer is strong stuff and could melt the Oramask just as it did for the shelf liner.. an oil based paint or a Acrylic might work well with any of the Oramask.. I do not have any personal experience with Oramask, I just know there is different grades of it.. The guys in the CNC world say it's the only way to go when trying to carve a sign and paint the carved areas.. 

Also something that helps make the paint take better on wood and get that "even coat look" since different areas of wood grain take the paint differently ( ie some areas soak it up more than others which creates uneven look ) is to seal the wood first.. I use water based polyurethane ( several coats to build up the surface to a even look with that ) and then will spray the actual paint.. that helps tremendously to get a even coat on the color without getting tons of spots where the paint soaked in rather than stay on the surface.. If not using water based poly be sure to use a type of sealer that will your paint wont have a reaction too.. most spray can paints do not mix well with oil wood finishes. You may need to try test pieces to find what will work together..  I've been using the water based poly in the blue / teal color cans and so far been working well with any of the spray paints I've used.. just make sure it's had a good amount of time to fully dry and cure.. not just dry but cured.. if you smell the poly or paint it's not cured yet.. and that doesn't mean smelling it from a foot away.. put your nose right on it.. if you smell it.. it's not ready.. 

Edited October 21, 2022 by kmmcrafts

[FrankEV]

30 minutes ago, kmmcrafts said:

This would work if you taped both sides and spray the finish from both sides to get good coverage.. That said, don't use shelf liner if you're going to do this.. the solvent from the paint melts the shelf liner.. Don't ask how I know that one, LOL.. 

My normal routine is to apply shelf liner first and the paper pattern to that.  I often cut away the liner and pattern from tareas to be painted.  This allow me to lay down a primer before hand painting with acrylics.  I havn't had any problems with melting the liner doing it this way.  

In the case of the sculpture I want to apply a high gloos Black Lacquer to, I woul apply the shef liner to both sides, the pattern on on side and blank paper to the other. The Idea being to allow the spray lacquer to get onto all the vertical cut surfaces before the liner/paper is removed.

[kmmcrafts]

3 hours ago, FrankEV said:

My normal routine is to apply shelf liner first and the paper pattern to that.  I often cut away the liner and pattern from tareas to be painted.  This allow me to lay down a primer before hand painting with acrylics.  I havn't had any problems with melting the liner doing it this way.  

In the case of the sculpture I want to apply a high gloos Black Lacquer to, I woul apply the shef liner to both sides, the pattern on on side and blank paper to the other. The Idea being to allow the spray lacquer to get onto all the vertical cut surfaces before the liner/paper is removed.

Like I said.. Lacquer will melt the shelf liner.. It'll shrink it.. lacquer and most acrylics do not typically mix well with one another too..

[OCtoolguy]

Just tossing this out. Has anybody ever tried something like "Glad Cling Wrap" or similar brands? It just popped into my head.

[TAIrving]

I tried cling wrap, don't remember but it might have been Glad brand.  It did not stick well and pulled up while cutting.  Gave up on it after the first try.  

[tomsteve]

heres what i do:

 think like the surface:"if i was this surface and wanted full coverage of paint and not too thick, how would i spray it?"

first i set the piece on painters pyramids.i go for the interior cuts first. spray can from a distance and angled for the paint to 'float" into the cuts. light misting coats. as in not even heavy enough for full coverage. i typically have to go from different angles- basically move in 90 degrees- spray left to right from one side then go 90 degrees from that side... repeat/

let it tack up then repeat. theres times i have to flip the piece over and spray from the other side. i only want full coverage. with light misting coats, i can typically get full coverage on everything and dont  get any sags, drips, or runs and achieve full coverage.

[John B]

Frank, I place my items on a a lazy Susan type thing and as @tomsteve does, get down low and spray light dusting coats from the 4 compass points, Cut back the surface with 220 or 360 paper and repeat, this prevents any build up on the edges. Sometimes I will turn the piece over and do the same from the rear. When I'm happy with the coverage, using acrylic paints, I repeat the process with lacquer, for a final gloss or satin coat on the surface.

Edited October 25, 2022 by John B

[Modern Art Studios]

I have cut out over a million letters in 52 years. Letters and objects from 1/2" to 10'x 12" thick. The small letters are the hardest 

because I had to paint them, as in the photo below. The first step is to hand edge them with pigmented shellack. Yes, it is tedious. Thicker objects require light sanding and I spray the second coat. I used a Fitch brush that I purchase from a sign supply. Without hand brushing the edge, you'll waste a lot of time and paint.  Letters as small as shown, I tape the face to a stick and hold by hand as I work around the sides. I used an HVLP Croix gun with the nozzle in a circular pattern and dial down the pressure to about 25 psi. When the back is dry I turn the over and do the face. I use lacquer when at all possible. Aluminum, Plexiglas, and p v c products don't require hand priming. MDF is the most laborious of products to paint because the edge takes the most time to prepare. Pigmented shellack is great for priming. Sands easy and drys fast and hard. Sorry, but I have no easier way to share, but this what I had to do for a great finish. BTW, the Beazer sign was a 4 color match. I used a commercial lacquer from Mathews Paint. They can match any color on the planet. 12 years ago at $49.00 a quart plus reducer and catalyst. If you use a spray gun, I highly recommend a spray booth and exhaust fan and follow city codes. 

[barb.j.enders]

On 10/20/2022 at 2:13 PM, FrankEV said:

I have one and have never used it, but seems like I may have to learn.

I got one for Christmas last year - still struggling to learn how to use it.