Author Topic: I got my own spray gun.... how can I improve my skills? (Read 1898 times)

Paul Taylor · « **on:** March 19, 2012, 05:41:02 PM »

I now have my very own spray gun and would like to work on my spraying skills.

What type of paint can get at home depot to spray with this gun and compressor that will spray like dope?

I am sure I will have to get paint and thinner.

Thanks

Mark Scarborough · « **Reply #1 on:** March 19, 2012, 06:38:09 PM »

First,, make sure your subscription is current to stunt news so you can follow my column,,, LOL

there is a cabinet lacquer that may be similar in viscocity enough to give you some experience. An Enamel will not work, it sprays different completely...

what kind of gun did you aquire?
and as an aside, good positive attitude to want to practice FIRST before trying to paint something that matters.....

you may also try a local hobby shop for some bizzare color of dope that they have left over from the phsycedelic 70s or something,,
a Metallic will really help you learn to spray good even overlap, and set up your gun best,,

Bill Little · « **Reply #2 on:** March 19, 2012, 07:04:17 PM »

Hi Paul,

Nothing much to add except you will learn with "doing", and practice is the key. Like Mark said, some lacquer (dope is a "lacquer type" paint) to practice with, and Ty's suggestion to have more than one gun is a good one. I have a primer gun, a couple touch up guns for different colors, and a good gun for the clear. At least a different "clear gun", since you don't want a red speck flying out into the clear!

Bill

Paul Taylor · « **Reply #3 on:** March 19, 2012, 07:33:48 PM »

Thanks guys!

It is not a high dollar gun, but is a HVLP type.
http://www.harborfreight.com/20-oz-high-volume-low-pressure-gravity-feed-spray-gun-47016.html

Mark - I am watching what you do in SN. And your VSC plane looks great! I want to be like Mark.

And yes Ty, I have some old hangar queens I can try this out on.

Mark Scarborough · « **Reply #4 on:** March 19, 2012, 07:35:40 PM »

Hey Paul, BoB Hunt told me if I help boost circulation I will gat another 100% raise in my salary for th ecolumn,,Hence the shameless plug,, LOL

Bill Little · « **Reply #5 on:** March 21, 2012, 07:35:29 PM »

Quote from: Mark Scarborough on March 19, 2012, 07:35:40 PM

Hey Paul, BoB Hunt told me if I help boost circulation I will gat another 100% raise in my salary for th ecolumn,,Hence the shameless plug,, LOL

Don't believe it Mark (Although Bob is a super honest guy). I was told that back when I was doing the Products Column for SN. Never did get the promised raise! LOL!! But then 100% increase from "$0" still is "$0" . (well, maybe I DID get the raise! LOL!! )

BIG Bear
RNMM/AMM

Randy Powell · « **Reply #6 on:** March 22, 2012, 11:57:50 AM »

Paul,

Experiment with the amount of air pressure (you did get a pressure gauge for the gun, didn't you?), fan and material screws see what happens when you change these. Use a dark paint on a light surface (or vice versa) so that you can easily see the spray pattern. I'm sure Mark will have other suggestions.

Wynn Robins · « **Reply #7 on:** March 22, 2012, 01:26:16 PM »

I'm in the same boat Paul - just got spray guns and all the required fixtures and fittings - once I get a decent mask i'll be learning to paint also - maybe we should swap notes as we go

Tim Wescott · « **Reply #8 on:** March 22, 2012, 02:11:58 PM »

Quote from: Randy Powell on March 22, 2012, 11:57:50 AM

(you did get a pressure gauge for the gun, didn't you?)

Surely you mean pressure regulator.

Paul Taylor · « **Reply #9 on:** March 22, 2012, 08:27:36 PM »

Wynn,
Here are the notes I made when painting my Vector. I had help painting the plane. My mentor would spray the top and i would get to spray the bottom. When it came to the last coat of clear he did most of the spraying. So not sure I can get full credit for painting the plane. This is the process I will follow when painting my hangar queen. My Vector turned out light and the process was simple.

I stopped after step #11.

1. Sand wood surface smooth before finishing with 220.
2. Brush on 5 coats of 60/40 dope/thinner. (no sanding between coats)
3. Final sand with 220 after last coat of 60/40 dries.
4. Lay silk span in place wet.
5. Brush a mixture of thinner with 10% dope on silk span and stick to surface. Only on the perimeter. Rub with fingers.
6. When dry brush 5 coats of 60/40 dope to surface. Do not sand between coats.
7. Spray 1 to 2 coats of filler (dope & aero 1) 1/2 Thinner + 1/2 Dope + 2 heaping tablespoons of Randy's Aero 1, thin to spraying consistency with Thinner - I mix this to give one quart.
8. Sand with 320 wet.
9. Spray 1 cost of base white and sand with 400. wet - note: all sanding after #5 is wet
10. Spray color base & add trim.
11. Mix approximately 1 qt dope. mix 50% Thinner + 50% Dope to equal 1 quart - thin to spraying consistency with Thinner. Put one coat on entire plane.
12. Sand with 1500 & buff out.

Randy Powell · « **Reply #10 on:** March 22, 2012, 08:35:47 PM »

Tim (and all other smart-asses),

The gauge and regulator are one piece. Sheesh!

john e. holliday · « **Reply #11 on:** March 23, 2012, 08:50:52 AM »

Easy on the guys Randy and don't get your shorts in a tight wad...

Its just some people are picky. But, like has been said, it takes practice and tons of patience. Lots of elbow grease and sand paper does wonders.

Mark Scarborough · « **Reply #12 on:** March 23, 2012, 09:20:44 AM »

Quote from: Randy Powell on March 22, 2012, 08:35:47 PM

Tim (and all other smart-asses),

The gauge and regulator are one piece. Sheesh!

dont forget the inline dryer/moisture trap,, a regulator on the compressor, and another at the gun,, and,,,,,,,,,

LOL,, there is a difference actually between a regulator and a gauge,, I have a gauge and volume adjustor on my gun,, but the regulator is at the compressor,, a regulator actually controls the pressure regardless of the input pressure,, the typicall gauge and valve assembly used at the gun is onlly a volume adjustor,, not a regulator,,

( just in case anyone really wants to get technical,,,,

)

Randy Powell · « **Reply #13 on:** March 23, 2012, 03:13:20 PM »

I tend to set the regulator to full blast at the compressor and use the setup at the gun to adjust the amount of pressure, but that's me and I don't always do it that way.

And yes, having some kind of de-humidifier and filter in the line cuts way down on "oh crap" moments,

Paul Taylor · « **Reply #14 on:** March 23, 2012, 09:24:27 PM »

I have one of those mid size compressors that has a built in regulator.

I have started stripping a old hangar queen. Chipmonk. Someone gave me this model. It was in real ruff shape. Globs of Ambroid glue, built some time ago.

My first thought was to just try and put a cheap paint job on this plane and maybe hang it on my office wall at work and call it art. But now that I just about got her stripped I am thinking about putting some new leadouts in it. Weight tip box and adjustable LO guide. Kind of treat it as a ARC and maybe try and fly it. Touch up some of the glue joints also.

Things I am thinking about:
Do I remove the flaps to attach new polyspan?
Getting to the bellcrank. Cut the bottom block off?

Me just thinking out loud.

john e. holliday · « **Reply #15 on:** March 24, 2012, 07:30:46 PM »

Yes, do what ever is neccessary to check the control system. Don't forget the flap and elevator horns. I have covered a lot of planes with poly-span after the flaps or elevators were hinged. It looks like you have pinned hinges, which would favor covering with flaps/eleators in place.

Bill Little · « **Reply #16 on:** March 26, 2012, 11:24:57 AM »

HI Rootbeard,

I like to cut the top and bottom blocks off to change the controls. Makes it a lot easier and quicker to get to everything. Just do it as neatly as possible. You might need to change everything out and with the top and bottom "open" it is a lot easier.

I'm getting ready to strip and rebuild a Sterling Spitfire I built around 1972 or '73. With the blocks off I can hollow them better than when I first built it. I will remove the fin/rudder, then all blocks and stab./elev. I, too, will be adding an ADJ. L.O. guide and a tip weight box.

Unfortunately all the bills that are coming in is going to really restrict my modeling budget.......

Bill

Paul Taylor · « **Reply #17 on:** April 03, 2012, 02:28:07 PM »

Well I have put this model on the back burner for now. Need to get things in order for flying season. New lines, handles ect.

Tim Wescott · « **Reply #18 on:** April 03, 2012, 02:50:04 PM »

Quote from: Paul Taylor on March 23, 2012, 09:24:27 PM

I have one of those mid size compressors that has a built in regulator.

Post a picture?

Most compressors that I know of have an automatic on/off switch to keep the pressure up (don't mistake a gauge for a regulator -- regulators set pressure, gagues report it) -- but that's not the kind of regulator that we're talking about here. You want a regulator for the line feeding your gun, or, better yet, a regulator on your gun.

I don't know of a compressor that comes with a built-in regulator, unless it's one of those itty bitty airbrush compressors.

Randy Powell · « **Reply #19 on:** April 03, 2012, 03:46:41 PM »

Tim,

My compressor has a regulator (with gauge) to adjust the output. There is a gauge to report the pressure in the tank and a second one that reports the pressure in the line (as part of the line regulator). I use that regulator when I using the airbrush since it doesn't have it's own regulator. When I use the spray gun, I open that one up to match the pressure in the tank (around 120lbs - basically it's taken out of the loop) and use the regulator (with gauge) on the gun. There is also a regulator on the inline de-humidifier/water trap, but that one is usually just wide open. It has it's own gauge, too.

Bill Little · « **Reply #20 on:** April 05, 2012, 06:08:22 PM »

Hi Tim,

Mine is like Randy P.'s. It has two gauges and a regulator. One gauge shows pressure in the tank, the other is line pressure. With a 33 gallon tank I get to spray longer than I used to!

Bill

Paul Taylor · « **Reply #21 on:** April 16, 2012, 06:30:18 PM »

Quote from: Tim Wescott on April 03, 2012, 02:50:04 PM

Post a picture?

Most compressors that I know of have an automatic on/off switch to keep the pressure up (don't mistake a gauge for a regulator -- regulators set pressure, gagues report it) -- but that's not the kind of regulator that we're talking about here. You want a regulator for the line feeding your gun, or, better yet, a regulator on your gun.

I don't know of a compressor that comes with a built-in regulator, unless it's one of those itty bitty airbrush compressors.

Here ya go Tim.

Tim Wescott · « **Reply #22 on:** April 16, 2012, 07:35:01 PM »

OK -- compressors come with gauges. I just don't hang out in the high-priced section of the compressor store, I guess.

Randy Powell · « **Reply #23 on:** April 17, 2012, 12:52:53 PM »

Hey, some people like to slum.

Mark Scarborough · « **Reply #24 on:** April 17, 2012, 01:05:32 PM »

Quote from: Paul Taylor on April 16, 2012, 06:30:18 PM

Here ya go Tim.

that kinda looks like a construction compressor,, does it have an air tank? and how big is it,,,

Dennis Moritz · « **Reply #25 on:** April 20, 2012, 08:59:01 PM »

I use a smaller gun. Ones with a 4 ounce cup and a .008 needle. A 20 ounce gun will probably spray a larger pattern than needed, wasting paint. I have found smaller guns for as little as 10 bucks. Presently I am using a 27 dollar gun, I found at Pep Boys, local automotive chain. It says Kawasaki on it. Works pretty good. With dope I found it almost always necessary to mix in a bit of retarder in order to avoid orange peel (rough spots). Temperature, humidity, all are factors that effect the way paint goes on. Dope has many useful properties. Among them the ability to fix almost any mistake. Sand out the offending area, try again, new layer of paint will melt into previous paint. Some colors are translucent, not opaque, and will clearly show any color inconsistency under the color coat. Which means. A new blocking coat, under the color coat, needs to be applied, to even out the under color. And so on. I started spray paint some years back using a 10 dollar gun and a 2 gallon sprayer. Just went for it. Even my first crude efforts were much better than the result I was getting with a brush and the current model airplane dope mixs. Wear a good mask. Force ventilate the paint area. Painting is a learn by doing skill.

Howard Rush · « **Reply #26 on:** April 21, 2012, 10:22:57 AM »

Quote from: Randy Powell on March 23, 2012, 03:13:20 PM

I tend to set the regulator to full blast at the compressor and use the setup at the gun to adjust the amount of pressure, but that's me and I don't always do it that way.

And yes, having some kind of de-humidifier and filter in the line cuts way down on "oh crap" moments,

I'd think that having the expansion at the gun could cool the air below the dew point and blow water with the paint. Having the expansion-- most of it, anyhow-- upstream might allow the air to warm back up before it gets to the gun. Better yet is if the expansion is upstream of the water trap. I don't base this on any experience; Mark would know.