Base Coat / Clear Coat with Dave Jones (DSP Builders)

[Dsp Dave]

Alright Guys I will try to explain some of the high points to painting but just like covering and rolling harriers and tork rolling none of this comes without practice. I could write on here all day on exactly how to paint a cowl, but if you have never had any spraying experiance you will more than likely have some trouble your first few times. Painting takes practice to learn how to do it without getting any runs or dry spots and thats something I can't teach you. What I can help you with is proper equipment and supplies and probably eliminate some simple problems that occur during the painting process. The first pic is of the painting materials that I use. The primer I use is PPG K36 and the catalist for this primer is K201. The paint that I use is PPG DBC Base Coat. The clear that I use is PPG Concept DCU 2021 and the catalist is DCX61. The reducer I use varies with the temperature. I use DT875 in the summertime and DT870 in the wintertime. The reducer in the pic is Grows 1370 its alittle bit cheaper than PPG and I am trying it out and it seemed to work just fine. DT875 is a slower drying thinner thats why it is used in the summertime it allows the paint to flow out before it dries. DT870 is used in the winter and is a fast drying thinner which helps if its not as warm where you paint as it is in the summertime. The Dx330 is a wax and grease remover and I use it before I spray anything and also in between coats.The DBC500 is a intercoat clear and is used to help blend the paint lines before clear is applied. I will try to explain all of these as I go.

[Dsp Dave]

Okay first things first firberglass cowls suck I don't care what brand airplane your building all of them are full of pin holes. The first thing I do is wet sand all the parts with 400 grit sand paper. After that I wipe everything down with DX 330 wax and grease remover and then start filling the pin holes. I have tried everything known to man for filling pinholes and nothing worked good enough for me. I then came across BVM pinhole filler and it literally saves me about 4 hours of work that I used to have to do. I buy it from Bob Violet Models and its about $15.00 and works unbelievable! Put some gloves on dip your hand in and rub it into the fiberglass like you were waxing a car.Let it dry just like wax(to a white haze) and rub off with a dry paper towel. After that damping a rag with DX 330 and wipe down let dry and tack it off with a tack rag and you are ready to spray your first coat of primer

[Dsp Dave]

Now its time to spray primer, I mix the primer 5-1-1, 5 parts K36 primer, 1 part K201 catalist and 1 part DT870 reducer. After you mix the primer you only have about 1 1/2 - 2 hrs. before it sets up so spray your parts and get your gun cleaned out! I use a small HVLP gravity feed spray gun and I run it at about 50 psi. Make sure you use a good moisture filtering system on your aircompressor. I use one on the air compressor and a small one right before it gets to the gun. Moisture from the aircompressor is the fastest way to ruin a paint job. Tack off all the parts and spray a lite wet coat of primer on all the parts and let them dry usually about 20 minutes. Check for pinholes, if you did a good job appling the pinhole filler you will probably only have about 10 or 12 pinholes to worry about. Use the pinhole filler again only on the holes you see and wipe off again with DX330 and shoot another lite coat of primer on the parts. I know I use the DX330 wax and grease remover alot but the other thing that ruins a paint job is oily hands and using this between coats eliminates fish eyes and other blimishes. Let the primer dry 30 minutes or so check once again and make sure you got all the pinholes filled then wet sand with 600 grit sand paper and now you are ready to start spraying color.

[Dsp Dave]

Its now time to start spraying colors, The first thing I do is wipe everything down again with DX330 and tack off. After you wipe things off with DX 330 don't touch them with you hands unless you are wearing rubber gloves because again you don't want to get any oil on the parts off your hands. The next thing I do is spray all parts with a lite coat(but wet coat) of white paint even if I am not painting any white on the airplane I do this and what this does is dampen the darkness of the grey primer so it doesn't take so many coats of paint to achive the right color. Next I painted the top of the cowl because it is going to be mostly white I painted the whole thing with a couple coats until I achived the right color. Some colors take more coats than others so its a good idea to have a piece of the monokote out there to check it against to make sure you are getting the right color. I mix the paint at 1-1 ratio 1 part DBC base coat and 1 part DT870 reducer. The nice thing about base coat paint is there is no waste after you are done spraying dump whatever is left back into the can. The only thing added to it is reducer and by the time you use it again the reducer is evaporated. Let it dry about 30 minutes(depending on how warm your shop is) and you are ready to tape off for your next color.

[Dsp Dave]

I tape off for my next color with 3M vinyl fine line tape. This stuff is expensive but you will not have any tape bleed. I then cover all exposed parts that I don't want to get painted red with 3M green tape and then spray the red.

[Dsp Dave]

The same process was used for appling the blue.

[Dsp Dave]

Next anything that has tape lines I spray a coat of DBC500 over and let dry. Unlike other paint systems You CAN NOT color sand before you spray clear on base coat. So to get rid of the paint lines spray a coat of DBC500 over it then let it dry and then you can light sand the paint lines down.The DBC500 seals the colors so you are not actually sanding the colors you are sanding the clear. I usually use about 800 grit to do this. Wipe everything down and you are now ready to spray the clear coat.

[Dsp Dave]

Last but not least its time to spray the clear coat. I mix this at a ratio of 4-1-2, 4 parts DCU 2021 clear,1 part DCX61 catalist and 2 parts DT870 reducer. Make sure everything is clean and wiped down with DX330 and tacked off and you are ready to spray the clear. I spray a lite coat on the piece(kind of a tack coat) wait about 30 seconds and then spray 2 full wet coats on. The project is now complete after about 3 days of good drying if there is any dirt nubs in the paint you can now sand them out with 2000 grit sandpaper and buff them back to a glossy shine! Hope this helps but like I said before it takes alot of practice but anyone can learn to do it!

[EJB]

And the questions start, bare with us Dave.

What's the advantage of using a two part catalist type primer over the lacquer type auto primer at Walmart for $2.98 a can ?

And do you use a glove when applying the fine line tape?

[Chris Puckett]

Dave how much of the BVM filler do you use on a typical 40%plane?

[RollingHarrier]

Great thread and thanks for sharing. One thing you might want to add is to use and good organic respirator. Looks like you have a nice spray-booth but most of us garage sprayers don’t.

[Mike Bargman]

Awesome thread, Dave. Can't wait till I have to do it to mine!