jetflyer

My Feedback: (5)

Today I played around with my HVLP gun and latex paint that I had mixed up at my local Lowes store. I've read several post on spraying latex paint and since I don't have the proper equipment to spray PPG I figured I'd give latex a try. Below is a what I found worked for me.

Mixing the Paint
1) Using the spoon from some plastic ware that my wife had I spooned out 10 spoonfuls of latex paint into a 9oz plastic cup.
2) used my small scale and weight out 1 oz of water and poured that into the cup with paint.
3) added 1 spoonful of Flotrol paint conditioner and stirred everything up.
4) Then I poured the contents into my gravity feed HVLP gun.

Spraying
1) It took just a few adjustments on the gun to get the paint to spray like I liked it.
2) I proceeded to spray a light to medium coat on my part. I was careful not to spray too much and make it run. Again play with the gun adjustments.
3) I let that sit for about 3 or 4 minutes to allow the paint to settle out a bit before I used my Monokote heat gun to carefully apply a little heat to the painted section. I just wanted to heat the area until the sheen of the wet paint was gone.
4) I then sprayed another coat on the piece trying to get a little more coverage then before. I allowed some time for paint to settle out again before applying heat.
5) I repeated step 4 until I was satisfied with the coverage. One thing to note, do not apply too much heat once you have 3 or more coats down. It will cause the latex to crack and spraying too many coats will cause the orange peel effect.

I practiced on some sample pieces but plan to try this method out once more before I attempt to spray my plane. So far I am very pleased with the results and clean up was a breeze considering water is all you need. Plus latex has no fumes to worry about. When I go at this again I will take some pictures as I go long.

JR Gautreaux

jetflyer

My Feedback: (5)

This the gun I was using which can be purchased from Harbor Freight - http://www.harborfreight.com/cpi/cta...emnumber=46719

JR Gautreaux

Tmoth4

My Feedback: (1)

jetflyer,

That's good information you posted. I have the same gun from HF and I love it! I haven't tried the Fowtrol yet, just water. Another thing I found out is that a solution of Mr. Clean and water cleans the guns well with the latexes. I keep a jar on hand and a small stiff brush to keep the spraygun tip clean while I'm working too.

Jim

RCVFR

My Feedback: (7)

jettflyer,

How much air pressure are you using to get good results?

Edwin

My Feedback: (2)

Do ya'll filter the paint mix with those funnels they have at the paint stores? I'm gonna be doing this too when it comes paint time on my next project.
Edwin

jetflyer

My Feedback: (5)

Jim,

I'll have to try the Mr. Clean solution. I was using Denatured Alcohol to clean the gun and also after painting I disassemble the gun's needle and make sure to clean that too. I'm not sure the Flotrol makes any difference and I might try next time leaving it out.

JR Gautreaux

jetflyer

My Feedback: (5)

Jim,

I had my air compressor's regulator set at 60lbs but had the gun's regulator at around 40lbs. I also documented each knob setting on my gun so I can always check before each painting session.

Edwin,

I'll be honest and say that no I didn't filter the paint mix even though I have some in my garage. I did use distilled water and made sure the cup I was mixing the paint in was clean

kipperk

Hi jetflyer
I'm just getting ready to try my hand, for the first time, at spraypainting my latest build.[X(] I have just finished glassing an astro-hog and am in the sanding stage right now. I have been looking at different paints and latex seems to be the way to go. No fumes & easy clean up.[sm=thumbup.gif] How does it hold up to fuel? Do you have to use a clearcoat? Any other suggestions or help would be appreciated.
KipperK

jetflyer

My Feedback: (5)

KipperK,

From what I've read, Latex once cured is ok for gasoline, but needs to be clear coated for nitro fuel. Some people are using water based poly to clear coat with at least 2 or 3 coats and getting it resistant to nitro fuel. The other options would be to use rattle can clear coat or take it to an auto body shop and have the use PPG clear coat. I plan on trying the water based poly after my parts have cured for at least 7 days. Latex paint takes a bit longer to fully cure out.

Before painting your astro-hog be sure to practice a bit on some test parts. If you don't use the heat gun, you can just take the part out to the water hose and wash the latex off. I did that several times until I got my gun shooting they way I liked. Then I started using the heat gun. But once you start using the heat gun, you will have to scrape the latex off if you want to practice again. I did that too several times. Oh, and I had my piece almost at a 90 degree angle so I could tell if I was going to get any runs.

All in all you just need to spend some time on a test piece and practice. It's really not that hard and just like everything else the more you practice the better you get. Plus after seeing the finish come out good it makes all that sanding pay off.

JR Gautreaux

Campy

My Feedback: (1)

Here is a link to an article by Roy Vallencourt on using latex for planes http://www.modelairplanenews.com/how_to/latex1.asp

I do take exception with Mr. Vallencourt on a couple of the things he says.

My personal experience has shown that 2 sprayed coats of a water base poly is good to 10% nitro (various reports say it is good to 15% nitro ).

Mr. Vallancourt says the latex is dry in 24 hours. Again, my personal experience has shown that while it may be dry to the touch, it has not cured. It normally takes 7 - 10 days to cure. How I check to see if it is cured is to firmly press my finger on a hard spot (I use the cowl ). If a fingerprint remains, it is not cured. The fingerprint will disappear in a day or two. What MAY make the difference is that I do not use the heat gun to speed the drying. I tried that method and was not happy with the results.

The final item I disagree with Mr. Vallencourt on is the spraying pressure. He states 20 psi, give or take 5 psi. To me this means 15 - 25 psi. I have had my best results using 25 - 30 psi. Over 30 psi I tend to get some "dimpling" due to air pressure and under 25 psi I don't get the coverage per coat I like.

The article by Mr. Vallencourt is EXCELLENT and I highly recommend it to anyone interested in or considering using latex on their models. The exceptions are my own and in no way are meant to demeane or minimize Mr. Vallencourt's excellent article.

susquach

My Feedback: (1)

Jet,

thanks for taking the time to post your findings. I'll take note of your experiences for future projects.

I've been using Latex as a primer for about 15 years. Have never been disappointed. However, I've always brushed, never sprayed. With a good quality brush, the brush yields a finish very similar to spray. My shop is fairly small. and it doesn't take long for overspray to fog the place.

A couple points that I've not seem covered in the articles and pots I've read on the subject:
Latex is a rubber material. As it dries, the fillers rise to the surface while the rubber material settles to the bottom. What that means is that it doesn't sand like other materials. Sanding is limited to a slight smoothing of the surface with 360 (there 'bouts). Once the surface finds are sanded down, what's left is rubber, and sands about like rubber. So, the best way of dealing with surface flaws that might require sanding is to avoid them to begin with. If and when I get a sag, I wipe it out with a a damp rag and continue on. The layers of paint are being applied in thin coats, so chances are, the wipe-out will never show in the final result.

jetflyer

My Feedback: (5)

I sprayed my first "real" parts tonight and so far I am happy with the results. Below are pictures of tonights painting session. I used the same method of mixing the paint as describe earlier and the paint mix was right on again. As Campy mentioned above the article is a great starting point in my opinion and somewhat of a guideline. Like I said before, practicing will help yield better results and allow you to very certain steps towards your liking. I noticed Campy made a mention he does not use the heat gun. Interesting because tonight I only used the heat gun once and that was after I felt enough coverage was on the parts. And after I used the heat gun to just take the sheen off the wet paint I sprayed another 2 or 3 light coats to kind of even things out. Also, the article mentions only spraying 2 or 3 coats but I found I have to apply about 6 to 9 coats before I am happy with the coverage. Still though the process goes pretty fast because I am only waiting about 5 minutes between coats. And I'm sure I might be able to cut down a few coats if I was a little brave and tried to spray heavier coats.

I also checked my previous sprayed test parts today and they still look real good. The latex really settles out nicely and evenly. I plan to wait about 6 or 7 days and then try spraying water based poly on them to get some practice. I use Kerosene for my turbine jet and I want to see how the latex with and without poly reacts to it. Even though I plan on spraying everything with poly anyway.

Picture 1 shows my gun.
Picture 2 was taken after the first coat was sprayed.
Picture 3 was taken after 4 or 5 coats.
Picture 4 was taken once I was satisfied with the overall coverage.

The parts sprayed tonight were my Super Reaper nose piece and main hatch. The hatch will be partially yellow and blue.

JR Gautreaux

3dd

My Feedback: (6)

latex in semi and gloss colors takes two to three weeks to cure good enough to clear coat over.flats are cured in about 1 week.i like to spray minwax polycrylic on mine as it is made not to yellow over light colors like white.the flowtrol will make a smooth paint job even better.it slows the dry time down just enough to let it really settle out good

warbirdcolors

My Feedback: (5)

BETTER THAN LATEX!!! Check out www.warbirdcolors.com...water-based, fuel-proof, polyurathane, scale colors

jetflyer

My Feedback: (5)

Ok I went to the Warbirdcolor site and I'm sticking with the Latex and Poly route. Latex is very cheap $9 a quart for me and I can get any color custom mixed while I wait at my local Lowes or Home Depot. So far I like my results.

Plan on shooting my fuselage tonight.

JR Gautreaux

jetflyer

My Feedback: (5)

Tonights painting session yield better results than ever. Apparently last night I forgot to add the Flotrol to the paint (1 spoonful) and thus caused some unwanted results on my main hatch. So using my heat gun I heated up the paint a bit and began to use a scraper to carefully lift the paint. Being latex it pretty much lift like rubber. I finished getting the rest off with water and my finger nail. I than quickly wet sanded the area with 400 sand paper. Let it dry and prepared it for painting.

I sprayed the hatch again along with the canopy deck and a small touch up on the nose cone. I mix up the paint as before and added the Flotrol. Boy what a difference this made. It made the paint really flow and settle out good. I even opened up my gun a bit to flow more paint. Also I was able to get the coverage I liked with just 4 coats. The first coat I sprayed kind of medium as the paint was laying down well. I let that sit for about 5 to 10 minutes before I sprayed the second coat. This time I really put down the paint. I made my passes slow and closer to the part. Things were really looking good. I let the second coat dry again for about 5 to 10 minutes. After I was done spraying the 3rd coat it looked well covered. I sprayed the 4th coat just for good measure.

Here are some pictures.

JR Gautreaux

the-plumber

32 bucks a quart ?

And such a wide variety of colors . . .

Tmoth4

My Feedback: (1)

JR,

It sounds like you're getting everything under control! From what you said I'm going to have to try the flotrol next time. The only problem I've had with the latexes is where I want a soft edge, like a camouflage job. The feathered edge sometimes has a rough feel to it, like it dried too fast. Maybe the flotrol will help.

I've used a lot of different colors of the latexes and some colors cover better than others. Yellows seem to be the worst as far as coverage. Even some shades of brown need extra coats. I guess it depends on the pigment for cetain colors.

Jim

Campy

My Feedback: (1)

For yellow, I have had my best coverage using a thin coat of silver/aluminum as a base coat. The second best base coat is white, but it is a distant second compared to silver.

jetflyer

My Feedback: (5)

Plumber,

I agree the high price for warbird color paint is on the high side and I probably will not go that route. If I change my paint I will probably move towards PPG but for now I'm trying latex.

Tmoth4,

The Floetrol does appear to make a major difference in the way the latex settles out. Now I wouldn't think of shooting latex without mixing that in. Yeah the yellow looks pretty in the can, but try shooting it and it takes a bit to get the color on the part.

Campy,

I'll have to try shooting silver under yellow sometime. For now it just looks like I have to shoot 1 or 2 more coats then normal to make sure the color it there.

OK, I just shot my fuselage with color matched latex for Monokote Insignia Blue. I went to Lowes last weekend with a strip Insignia Blue Monokote and asked the paint guy to match it for me. With a few clicks of the mouse the color computer came up with the mixture. In the can the paint looks a lot like a baby blue color, but as it dries it matches the Monokote very, very good. A heck of a lot better the Krylon or Lusterkote and at $9 a quart not a bad investment. Here are some pictures of tonights shoot and also the steps I follow.

JR Gautreaux

jetflyer

My Feedback: (5)

More pictures.

JR Gautreaux

Edwin

My Feedback: (2)

I have heard you can get rustoleum in cans. Is that true? Would like to try a little of that just for a fuel test.
Edwin

jetflyer

My Feedback: (5)

I have a few small cans of Krylon that I used to paint with. I did not really like it all that much. Never thought about thinning it out and spraying it though. For now I will just stick to latex. Last nights shoot went really well with the blue color. And I only shot 3 coats to get the coverage I liked. Much improvement over the 4 or 5 coats of the yellow. The last picture up above was taken after the 2nd coat. I'll try and take some more pictures tonight to show how the fuse came out. I checked it this morning and it looks good. I'm happy!

JR Gautreaux

Campy

My Feedback: (1)

SOME Krylon and Rustoleum paints are fuel proof, unfortunately I do not know which ones. If you are using either of them, either do test panels first or plan on clear coating them.

FWIW - Dupli-Color Truck & Van paints are labeled on the back. If they say ACRYLIC they are fuel proof. Just be careful with compatibility. You can put enamel over lacquer, but not the other way around. They cost about $4 at Wal-Mart for an 11 oz spray can. The small cans are not labeled as to whether or not they are acrylic.

jetflyer

My Feedback: (5)

Here is a link to my website where I have done a write up on the process of spraying latex. Includes picture of my results and how I mix my paint.

http://www.houstonhobbies.com/tips/p...latex-hvlp.htm

JR Gautreaux