[ Home ] [ Up ] [ Mission Statement ] [ News ] [ Products ] [ Meet the Team ] [ Photo Gallery ] [ Where to see us ]

Let's assume the body work--meaning the filler--is reasonably straight, having used the 16" straight line hand sanding block so much you have grown to dislike it intensely, and have blocked out the skim coat. You are now ready to switch to the process of spraying primers and sealers.

I'm not going to get really into a big safety thing with you, but what I do want to remind you is that this stuff can kill you! Be careful. PLEASE read labels and follow ventilation recommendations!

Remember to clean surfaces with MEK or RM 901-902 before each application of any substrate.

Sealers

Sealers are used to do just that, seal in between the changes from one type of substrate to another and provide adhesion to both without allowing one to penetrate the other. Sealers provide some filling for scratches, but mostly in the 320 to 240 grit area, meaning that it will fill 320 type scratches at best. Anything beyond that will swell up and show later as the paint finally shrinks up.

I recommend that you apply a light coat to the whole plane to ensure that the primer sticks to all the different substrates. You can skip this step, but I don't recommend it. I have never, never had a paint failure with this method.

Primer/Surfacer

Now we can start working on the surfacer. This may be urethane surfacer, Featherfill by Marson, or similar products. I use the Featherfill for the initial coat or two, then the K36 for final surfacer coats. These are surfacers, meaning they give some degree of filling (up to about 36 grit scratches) and have some leveling properties (from about .03 to .07 low spot).

These products are used to fill and to give consistency to the feel and/or friction. If the friction is the same when you feel across the surface, you will be feeling the holes and high spots. If you have sanded through to the filler, even though the surface may not be perfectly flat, it will feel as if that spot were high or low because of the difference in the friction. Remember, we feel it straight more than we see it straight.

Use successive coats of surfacer to fill and sand with a 16-inch hand file and 150 grit sandpaper until it feels and looks smooth. The 16-inch' hand file will become your best friend, however, you will get sick of it. Every square inch of the plane must see the face of the stick at least four times. The surface will look smooth when you sand it with the block after coating if all the material comes off at the same rate, leaving no high spots or low spots, and all the scratches are even and continued.

Guide Coat

When you think you are getting close, use a guide coat of black Krylon brand flat spray and give the plane just a very light misting. Sanding with the 16-inch block will show the low spots and high spots more easily because the black Krylon misting will sand off quickly on the high spot and will be the last thing to sand off in the low spots. When the Krylon mist all comes off evenly in one or two swipes of the file, the surface is flat. When you don’t seem to be accomplishing anything (meaning you prime and sand and have no high spots or low spots), you are probably done!

To a newcomer or if you are going for a show finish, this process will consume about three gallons of surfacer or K36 sprayed on the plane and subsequently sanded off in about 6-8 heavy coats. Almost all of this you will sweep up and throw; it may seem as if you are actually throwing your money away. Remember this product has a purpose--to help you see and feel when your plane is straight and not to add unnecessary weight.

I feel that this process, although the least fun and most time consuming, is one of, if not the most, important factor in the quality of the final appearance of your plane. You can expect this phase in the refinishing process to take at least 80 hours if you really want a great job, depending of course upon how experienced and efficient a worker you are and how good a job you did in constructing the plane.

The best way to ensure that you have the plane good enough is when you cannot make it any better. It sounds simple, but it is hard to make yourself take the extra time to get it just past good to great. But that is the difference between a just OK looking job or one that people will be looking close to find a mistake. If your job is obviously an amateur, most people will be polite and not say anything bad or pick it apart. If it's a great job, you will see people taking the time to look for some flaw.

Special Areas of Concern

Wings

Sand wings from tip to tip, then from front to rear at a 45 degree angle one way then a 45 the other. Then go back and go over it from tip to tip. Repeat this once more at a 45. Guide coat it with Krylon and sand it one more time, but this time with a slower stroke, looking to see if the low spots are showing up as a black area and the high spots are sanding away faster. Go through about 3 cycles of this with a coat of K36 in between. When you see no forward progress and it seems as though you are wasting your time doing it again, you probably would be, and this is a sign to stop.

Wing and Tail Surface Roots

I know this is the cause of most of the headaches you will have. Don't waste time making some new invention that uses things like rubber hoses or leather rolls, or whatever. I've seen boxes full of these inventions gathering dust in shops. Use the 16-inch straight stick, run from the top to the bottom at a 45 degree angle with a small amount of pressure and take your time. You will see and feel it to the shape.

Use guide coats to help you out, but most of all work slow and on about 1 to 1 1/2 feet at a time. Use the edge of the file board, about 1/4 inch is all; kind of roll it on its side. Change the paper often and remember use 80 grit to finish straightening body filler and micro and 150 to the same on K36 and feather fill. When it is straight, final block out with 180-220 and hand sand with nothing courser than 320.

How do you know if it's Ready for Paint?

Guide coat every square inch with Krylon flat black as I explained earlier. Then block sand it with 6" and 16" file boards until you are sick to death if it--and I mean sick of it. No small black spots should be left when you sand the primer off. When you hand sand with a hard rubber pad, it should be smooth with no scratches showing. Next sand across 45 degree angle cris-crossing every square inch. Then spray a guide coat and sand it lightly with 180 grit sandpaper and a hard block. All the guide coat should be sanded off and none should be left in scratches, pits, etc. Then, and only then, you will be ready to prepare for paint. If you are not sick of the whole process by now, you probably have not done it long enough or well enough.

Once the body of the plane is finished to your satisfaction, you need to spend a lot of time looking it over and over. You simply will not believe how much you can catch the third, fourth, and fifth time through. All pits, scratches, or any other imperfections must be taken care of now, before you shoot any paint on it. You must understand that if you can see it now, it will look worse with paint on it. When I talk about being able to fix problems after you shoot color, I am only speaking about painting problems, not body work problems. You must have all the surfaces as good as you can and be proud of your work. Paint will make the imperfections permanent and time consuming to fix later.

Preparing for Paint

You must mask off anything that should not be painted. I don't care if it will be covered with interior or whatever, cover it. This is a sign of a real pro. Don't over spray everything. The windows are a real challenge. I recommend using the 3M hard plastic repair product to blend the body to the window and the 3M adhesion promoter to make sure it sticks to the plastic window. This is not a place you want a paint failure. Ask for 3M Rigid Parts Repair #05899 and Polyolefin Adhesion Promoter #05907. These products work well in my experience.

After you blend the window to the glass to your satisfaction, tape it with 3M blue fine line tape. This tape will give you nice crisp lines, it follows the shape of the surface because it stretches, paint will not bleed through it, and it will come off when you want it to without causing damage to the surface underneath. I strongly recommend you don’t settle for less here.

Get a roll of 36-inch 3M masking paper. This paper has a special coating to prevent it from sticking to surfaces and will not allow the colors to seep through. Also get good quality masking tape--the body shop stuff, not the hardware stuff. All masking tapes are not equal. Cheap tapes don't use good glues, they stick too hard and pull the paint off when removed. 3M tape was meant to be pulled off and the glue is designed for this purpose. You will need good tape to mask off the areas around stripes, N-numbers, etc., to prevent over spray. It would be tragic if your new paint peeled off with the tape.