Alternative Painting Methods.

Painting. It's the crowning touch on a job well done and it's what separates a good DIY effort from a showroom-worthy work of audio art.
The pursuit for the perfect paint job will take you down an expensive road - spraying. Compressor, sprayer, breathing protection, cleaning solvents, etc. The better quality paint isn't cheap either, not to mention top quality automotive paint. It takes practice to do well and mistakes can be costly.
You could (many do) arrange to have your creations painted by a pro at a auto refinishing shop. For one-off work this will cost a lot less than the DIY route of buying all of the equipment.

There is always the brush and roller, and good results can be had with this method. Spray cans are a possibility, but can get as expensive as a good pro paint job on larger items.

I have started this thread to present another way, one that doesn't require special equipment or much practice or painting skills. It gives excellent results and can be done anywhere (space permitting). I'd also like to hear about other ways of getting a good finish.

I have finished one thing with this method so far and I'm working on a second project now. The first is a computer case made from HDF and MDF. It was initially painted with spray can shortly after it was built last winter. During the spring, I sprayed it silver with my spray equipment but I didn't like the colour - too plain. I wanted to do something different. I wanted a kind of distressed, worn on the edges candy paint job - one that looks like it has been polished for years.
I got to thinking then about candy apples, how they are dipped in the hot candied sugar. I asked myself why not dip an object in paint and let the excess run off? That's fine for small things, but what about big things? Then it occurred to me - pour the paint on, let the excess run off. Make the paint thin enough that it goes on evenly.

Part of the above is from another thread where I mentioned this, so apologies if it sounds familiar.
In a nut shell, that's it. Pour the paint on and let it run off and dry.

Here is the computer case after it has been colour sanded and polished.



Closeup of the front:



More details next.

I didn't take any pics during the work on that, simply because I didn't think it would work. I did what I normally do - just went ahead and tried it.
There are some trouble areas when doing this: anywhere that the paint will collect and start to run such as openings or edges need to be minimized or closely watched during the painting. The paint needs to be very thin, so it will take some time and patience to build up a good layer. There needs to be a bottom, a place that will not be visible on your finished piece.
On the computer case, I had to close the power switch hole and the DVD drive hole, but paint still collected around these. Paint also collected in the "trough" in the front (as it can be seen in the photo above). It fits with the overall look of the case though.

Here's what you need: You'll need to build a drain tray, one that has a sloped bottom. It needs to be big enough for your project to fit on with room to spare. Mine, in the picture below, is just 1/2" melamine particle board with sides. It slopes to one corner that has a drain hole. I have the tray suspended on two buckets and the run off drips back into the paint can below. A jug filled with paint is used for pouring. It takes quite a lot of paint to evenly coat a good sized object, so have enough on hand and thinned to do the job.

This is a solid wood front for a new amp. It is about 6" high, 17" long and 1.75" thick, so it's small but not tiny. It is getting coated with clear polyurethane and this is how it looks after the first "pour". I will let this dry thoroughly over night and sand it smooth with fine paper tomorrow. I'll then proceed with more layers without sanding between. The idea is to produce a thick film for polishing.

Aengus said:

John

Interesting idea, and certainly impressive results.

How do you avoid runs and holidays on the sides that are vertical while you're pouring? Is is just a matter of making sure that lots of paint runs down the sides?

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Hi Aengus,
Runs are hard to avoid, but easily controlled. The paint needs to be very thin so the excess runs off quickly. Orienting the object so that it's tipped toward one corner will help. If a run developed and you could not avoid it, you can sand it down once the paint is completely dry.
Yes, you need to make sure there is plenty of paint on hand - you need to get every side covered quickly and this takes more paint than I first expected.

As big a problem as running are bubbles. You need to mix the paint slowly, pour it into the jug slowly and pour it on the work slowly to avoid creating bubbles. If they do form, blowing on them will usually burst them.

Doing this in a dust free location is good too. That holds true for all painting though.

peterbrorsson said:

Hi John,
That case look really good, bet you got tired of polishing these curved panels.
One rule of the thumb, when it comes to dipping or pouring as in this case. Viscosity around 14-15s/DIN4 Ford cup is quite ideal.
This low viscosity will bring down the solids in the lacquer so sagging will not occur so easily, but one has to dip several times to achieve desired surface. And maybe the polishing will not be too extensive

Hanging the pieces in an angle, so one has a corner at the lowest point and wipe off the excess lacquer could work, but of course dependent on the shape of object.

I assume it is water based PU you have used?

Peter

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Hi Peter, Good to hear from you again🙂
The paint is solvent based - urethane based and clear polyurethane. It should work well with the waterbased urethane paint I used before, but I don't have any left.
The drain tray is tipped itself in two ways to the corner. This tips the object too. The amp face in the pic above has 3 screws driven in the back as "feet" to hold it up off the tray.

Sanding and polishing that case was a snap. The paint was about 100% smoother than I could ever do with a sprayer, so no orange peel to cut through. That is one of the biggest advantages on this method.
My viscosity meter is my stirring stick - 2-3 seconds to turn from run to drip 😀

454Casull said:

Did you prime before you poured the paint on? If so, did you brush or also pour?

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Hi 454,
The computer case was primed with clear polyurethane that was rolled on. It was then sprayed with flat black Tremclad in a spray bomb.
If you are really asking if it can be primed by pouring then the answer is yes, of course. Primer is just paint after all.

peterbrorsson said:

Solvent born you say, must be quite slow drying then? If I use solvent born lacquers, I use fast thinners when spraying vertical panels. Easier to spray thicker layers without sagging. Thou one has to be fairly quick also with movements and finish all sides within 20-25 seconds to avoid spray dust on the surface.
I normally do so because I'm lazy, don't want to polish😎

Othervise one can do the same as your pouring technique. Just flush the vertical panels and wipe the excess lacquer off the bottom corners. Though it takes some nerves to do it the first time! But the result gets similar as this case of yours.

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I haven't seen a paint job from a sprayer yet that I'd be satisfied with on one of my speakers. What is passing for a paint job on new cars these days is a total visual assault - I can see orange peel 2 lanes over at 130kph!

Kentucky eh? That a ways from here still. Good luck with the new job.

The clear urethane I use dries in about 2 hours. I will be getting some waterbased and trying that to see how it goes. Really, it should be the same or better.

The amp face piece dried and is as smooth as silk - it could not be improved by sanding. I went ahead and poured it again. I'm thinking 6 to 7 coats will do.

Real time updates and pictorial documentation! It doesn't get any better than that on a fun-filled Saturday evening. 🙂

The third pour:




I'll do a couple more tonite, then see how it looks tomorrow. No arguing with one positive thing about this - the speed of application. It's no longer than pouring out a jug of milk. 😉