Entering into my first warbird project, I was also about to embark on my first attempt at building a glassed and painted plane. Therefore I began doing countless hours and days of research on RCU to find out what was the best/preferred method and materials for this process. Seemed like a simple thing to determine... yeah right. I soon found that this is as controversial and sometimes passioniate a topic as politics and religion! So with a year of work at stake and over two grand invested in it, I didn't want to take anybody's experiences at face value without doing some testing of my own, hence the results of this article. Here were some of the issues that I was concerned about:

• Simplicity of application / Ease of use
• Toxicity & Odors
• Durablility
• Cost
• Finish
• Gasoline Proof / Resistant
• Availability

Glassing Resins

Through my studies on RCU and conversations with many experienced builders, I soon narrowed my choices down to a few final contestants. I don't like the mess, hassle and weight of epoxy based resins, not to mention the cost. I ruled out a few others and it came down to 2 types of Poly... Lacquer-based Polyurethane and Water-based PolyCrylic.

Paints

As for paints, again I don't like the cost, odor or hassles of two-part automotive, lacquer or epoxy based paints. Therefore I decided to test Latex house paints. For primer, I tested standard automotive scratch-filling primer.

The subjects

To make things as realistic as possible, I built two test subjects that simulate a couple wing bays on a sheeted wing. Two identical samples were made to test different options and take weight comparisons along the way.

Constructing the Samples
	Each of the two samples were identical in weight and size at 7 x 7.5 inches and 1/2 ounce each. The balsa was actually 1/16" thick, which is thinner than most applications in my project. I just made a 7 x 7.5 inch frame out of 1/4 x 1/4 stick and sheeted it. I also added a 1/16 x 1/4 inch "rib at the midpoint, making it kind of like 2 rib bays of a wing. This should be very similar to the results of sheeting most wings.
Fiberglassing the Samples
	I used Deft Lacquer Poly to glass Sample A, and the Minwax WB PolyCrylic to glass Sample B. This way I could compare the characteristics, ease of application, and weight between the two, weighing them every step of the way to see how the weight is affected. Cost wasn't a big factor, since both were very inexpensive compared to epoxy resins (probably about $10-20 to do the whole plane). I used 3/4 ounce fiberglass cloth on both samples. I found that both the Lacquer and Water based materials went down very quick and easy without much hassle. However the fumes from the highly toxic lacquer option were unbearable. Extreme ventiliation is a must and even then, a good quality respirator is in order when using lacquer! Cleanup is much cheaper with the waterbased option since only "water" is needed. I also did a little spot test for compatibility with Squadron White Putty on each sample. I use it from time to time to fill and repair small low spots and smooth out dings in the balsa stage. Sample A: Lacquer application Glassing with Lacquer Poly started with 2 coats of Deft Lacquer Sanding Sealer, sanding after each coat. Dry time was about 15-20 minutes per coat. Next was 5 coats of Deft Lacquer Clear Satin Poly, without sanding between coats (sanding not recommended). I gave it an overnight dry time and weighed it. Total Coats: 7 Weight Gain: .2 ounces Sample B: WaterBased application Glassing with the WB Poly again started with 2 coats of Deft Lacquer Sanding Sealer, sanding after each coat. This is to seal the wood from the moisture in the WB Poly which can tend to warp thin balsa sheeting in some cases. Next was 3 coats of Minwax Waterbased Clear Satin Poly, this time sanding between coats (recommended). I followed it with 1 coat of WB Poly mixed with MicroBalloons. Lastly I threw on 1 more coat of WB poly for good measure. Again, I gave this one an overnight dry time and weighed it. Total Coats: 7 Weight Gain: .2 ounces Opinions & Remarks Both of these tests gained the same weight, had the same relative finish/hardness, cost about the same and were equally easy to apply (no mixing required!). However, the waterbased was less messy/sticky, easier and cheaper to clean up, and most importantly, doesn't kill every living creature in your house for the next 3 days. The fumes and toxicity of Lacquer just made it a bad candidate for me.
Primer Application
	Next I used PlastiKote Spot Filler & Primer (thick but light & sandable automotive primer) to throw down a couple coats of primer. This filled the weave and allowed me to easily sand it back off to level the surface out very flat and smooth. Nearly all the primer was sanded off and then one last coat of primer was applied.
Adding Panel Lines, Rivets and Hatches
	I didn't have any chart tape on hand, so I just used some pinstriping laying around to put down some panel lines. I shot a few coats of primer down, until the primer level came up to the thickness of the pinstriping. Next I very lightly sanded it back a little and pulled the striping up to reveal my panel line detail. After cleaning up the panel lines a little, I threw down some "sloppy" details. Access hatches were made from aluminum foil tape (HVAC tape), and I used both Titebond and Alyphatic Resin to make raised rivets. (pardon the rushed and sloppy application of rivets).

Painting & Weathering

I just used some off-brand Latex paint I had laying around to do my tests. I didn't want to get into "brand wars" at this point, I just wanted to test "latex paint" regardless of brand. I did however compare interior versus exterior versions. Sample A got the Interior Satin Latex and Sample B got the Exterior Satin Latex. I found them both to be very easy to shoot through the Porter Cable Detail Gun that I picked up at Lowe's for around $50.

I mixed each type of latex with Windshield Washer Fluid to thin it to a milk-like viscocity. This actually slows down the dry time a tad and allows the paint to settle & level better before drying. I also added a dab of Floetrol to help stabilize the paint and make it shoot through the gun a little better. I'm not convinced the Floetrol makes much difference, but that's another topic. I shot both paints at about 25 pounds of pressure, never over 30 pounds, and applied 3 light coats for good color coverage.

Lastly I through down some extensively "overdone" weathering just to test some techniques and find out what I "can't do" with latex. I also wanted to see what gasoline would do to lightly airbrushed areas.

Sample A: Interior Latex
Additional Weight Gain to Primer and
add 3 Light Latex Coats: .2 ounces

Sample B:Exterior Latex
Additional Weight Gain to Primer and
add 3 Light Latex Coats: .2 ounces

Gasoline Testing

I gave both test a good 3 weeks or so to cure well before testing them against gasoline. Not being an optimist, I anticipated a failure in this test and preceded it by adding a clear coat into the equation. I used Nelson Hobby clear for my test. I wanted a satin finish, but they only sell flat and gloss. So I mixed them 50/50 shooting for a satin mixture. Thinning it about 40% with water, I shot 4 light coats on both. On the Interior Satin version, I masked off half of it to compare the cleared vs uncleared version in terms of appearance and gasproofing. The end result was about almost unmeasurable at about .05 ounces of weight being added in the clearing process. I let the clear coats dry for a couple days or so before gas testing on them.

Next I used a little gasoline on a paper towel to moderately rub the surface of each test. The bare/raw latex immediately began softening and coming off onto the paper towel. The clearcoated areas were not affected at all. I then put a small "puddle" of gas on each sample and left it for about 24-30 hours. This had absolutely no effect on the Nelson clear coat.