Light vs Medium Finishing Tapes

[Hank Jarrett]

Sorry if it sounded like that. Didn't intend to sound like you weren't following directions, just that a few guys I have talked to did incredibly minor deviations that caused them problems. I am in SE Virginia on the Chesapeake Bay and high humidity only seems to not be a problem here when it is below freezing (which doesn't happen often). Did you finally conclude you were getting moisture through the compressor air lines or was it the humidity in the air where you were spraying?

[cbcfly]

Hank I believe it was the humidity in the air. I was running a high quality filter/moisture trap. I was weighing the paint components before mixing. I was using the Finishline 3 gun they recommended. I was very particular about following their instructions. First coat was a very light tack coat. Then subsequent coats were applied with 1/8 more turn on the fluid control of the gun. I was just getting very inconsistent results from day to day. Sometimes OK. Sometimes lots of texture or orange peel at the end of the last coat. But if you tried to lay it on any wetter at all it would look good for a few minutes and then all just slime off.

I'm not a painting novice. I've painted 3 airplanes, a tractor, and other odds and ends. I read the spec sheets for every type of paint I shoot. I don't just cavalierly throw paint in the gun and spray it "like I always have." I knew before-hand that Stewarts used a different technique and I did my best to follow it. I tried to shoot early in the day before it got super hot, but we still had humidity in the 90-plus percent range. Unless they've changed the formula in the last 6 or 7 years, Stewarts is just too finicky for me to use again. I have no doubt that it works great for lots of people. Like I said earlier - it's a great system up through primer. If I were building an experimental, I'd consider their system with a different topcoat. Since the Tcraft is not experimental, I've got to follow the applicable STC and use any one system all the way through from start to finish

[cbcfly]

The manual now mentions a refrigerated filter from harbor freight for high temp and high humidity. That blurb was not there during my timeframe.

[cbcfly]

I assume they're describing this thing.

Between my neighbor's improved success by adding hangar air conditioning, and the addition of this info in the manual regarding high temp/high humidity conditions - it tells me that there are difficulties using Stewarts paints in the conditions that are predominant where I live. Regardless, I'm not interested in experimenting further. I'll use the urethane that I'm used to, coupled with a fresh-air full face mask and paint suit.

[astjp2]

Yep, stick with polyfiber...not many issues with it...

[N96337]

Had guys shoot it successfully in South Africa, so not sure just what the deal was. Sorry you didn't have a good experience. I've been shooting and teaching this system for over 20 years, and used to own part of the system before Stewarts. The only problems I've had is too cold...it doesn't like that at all.
John

[Ragwing nut]

Here's my two cents..... I think they're called finishing tapes for a reason ie simply a means by which to seal and smooth out the surface where the underlying fabric is perforated by wires, lacing etc. The integrity comes from the reinforcing tape under the wire, lacing, rivets, screws. Light tapes are approved for this application and lay down nicely in a good wet bed of dope, polybrush or whatever equivalent, with very little sanding (especially if your system allows for smoothing with an iron). Medium tapes will be far more difficult to get to lay down nicely, so more ironing and/or sanding..... For no real benefit.

The benefit is when you accidentally run that piece of sand paper over a ribs stitch or abrasion underneath the fabric and it doesn't cut through the tape instantly. Its also harder to keep straight since its easier to pull the weave when you trying to lay one down nice and tight. If you understand how to lay tapes efficiently, its not any harder to lay a heavier tape. The #1 mistake people make is not enough dope layed on the base fabric before tapes go on. You can't force the dope through the fabric, you have to wick it through. 90% of the time I don't use a brush to lay tapes.

[Scott]

There is an inexpensive solution to moisture problems... I run a small dehumidifier in my hangar whenever the temperature is above freezing. My air compressor intake is right next to the dehumidifier outlet.

I originally did this because the floor is asphalt and moisture percolates up from the ground (which is poorly drained) and used to condense on the ceiling. Yes it would actually rain inside the hangar.

The dehumidifier provides me with a supply of distilled water (no water supply in my hangar) and keeps the relative humidity below 50%. Sweet?