NE0

My Feedback: (9)

OOPS!

Correction to my math above. Each square foot would gain .55 oz, which brings 20 sq ft area to 11 ounces. That sounds more like it, but still quite light for a whole 85" plane!

Sorry for the slip,

Neo

ProfLooney

Neo you put the rivets on just before your color coat. you have to lay down your panel lines and primer then wetsand to where you can pull your panel tape off then wetsand a fuzz hair more to clean the jagged edges then add rivets and color.

Joe

NE0

My Feedback: (9)

Of course, that makes perfect sense. How else would you sand if the rivets were already down?! Thanks for the reality check.

Neo

Juice

NEO,

Thanks for sharing the results of your test. Let us know what else you determine from them.

Can you comment on warpage? How much in each case, if at all? Did you do anything to prevent warping? How much does 1/4" thick balsa warp with plain water?

Thanks,
Juice

NE0

My Feedback: (9)

Juice,

Sure, I'm going to post a web page w/pics documenting the test when I finish. No warpage at all with either medium. 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.

I didn't do anything special to the lacquer version, but the water-based polycrylic one I did. I used Deft lacquer sanding sealer (2 coats) sanding between coats, before applying the WB poly. You can't hardly tell anything has been done to the balsa after the 2 coats, but it makes a difference.

I haven't done a test with straight water on balsa, but that's what you do when you intentionally warp sheeting for turtledecks and such, so I thjnk we all know what that would do.

Got the panel lines, rivets, etc. down now and hope to start shooting the Latex soon. I'll test with Interior Flat and Exterior Satin to see what differences that makes.

Neo

Tmoth4

My Feedback: (1)

If you don't seal the balsa with something like Deft or dope before glassing with WB poly the grain will raise up and thin balsa sheeting will buckle.

Jim

NE0

My Feedback: (9)

Well I shot exterior satin on the WB test, and interior satin on the Lacquer test. Both went down well with windshield washer fluid and Floetrol added. Shot a milk-like viscocity down for 3 light coats... covered well and lays flat. I like the finish of the exterior better. The interior satin looks nearly "flat" rather than satin.

Both tests gained an additional .2oz from the latex coats... same as from glassing. That puts me at .4oz over balsa weight. This means each square foot should gain 1.1oz going from bare balsa to glassed & latexed (no weathering yet). This includes extra primer for panel line detail and raised glue rivets.

Again, using 20sq ft as an estimate of surface area for my plane, it should only gain 22 ounces to glass and paint using either of these 2 techniques. Throw in a few extra ounces for hatches, and misc small details and you're still around 1-1/2 to 2 pounds total, which should really help keep the wing loading down. Also, 20 sq ft is probably more than I'll really have, but better to err on the high side when estimating this.

I'll do some simple weathering, give them a few days to fully cure and then do some gas testing on them. I may also do some "stress tests" to see how they hold up from a strength standpoint.

Neo

ProfLooney

Neo whats the purpose of the windshield washer fluid and Floetrol ? I have never had to add anything to mine. heck its so thin i bet it would shoot from my airbrush with an H3 tip in it.

Joe

NE0

My Feedback: (9)

The WW fluid is used to thin (instead of water). Water can cause the paint to dry faster, not letting it really fully "settle out flat".... causing "orange peeling." WW fluid slows the drying time letting it even out before drying. Floetrol is a conditioner that improves consistency in the paint flow and settling qualities of latex. I think it helps reduce clogging your gun too. Many experienced latex painters use one or both of these, but it's "whatever works for you" that matters.

Both latex paints I'm testing are VERY thick and would never run through my airbrush as is. It's like trying to spray honey if you don't thin it at least 40%.

Neo

ProfLooney

Oh I musta misunderstood I though you were thinning the Poly U with it guess i wasnt fully awake yet hehe

Joe

NE0

My Feedback: (9)

No worries mate ;-)

Neo

chuck l

My Feedback: (17)

Neo,

Can you give me a few pointers on your spraying technique. I have not be able to get a smooth flat finish using latex. I have tried exterior and interior paints, flats and glossy, high pressure, low pressure. I have to put on lots of coats to cover the surface, 8-10 coats. I have tried the windshield washer fluid, fluetrol, and DI water. The paint doesn't seem to want to flow out to a flat surface. I have been using Badger Air Brush, and have tried both Benjamin Moore and Sherwin Williams paints, both in bright yellow.

NE0

My Feedback: (9)

Chuck,

Sounds like you're doing everything right, but I think maybe the problem lies in the Badger airbrush. First off, Badger isn't a real high-end brush... more of an entry level hobby brush. My Iwata is a $200+ artist's brush and still doesn't do "that great" with latex. For base/color coats you should use an automotive detail gun, like a Devilbis, Porter Cable, Binks, etc. They are designed to spray larger patterns with more paint flow, airbrushes are not. Airbrush nozzles are much smaller too, and tend to clog easily with latex paints. When you get the mixture and pressure so it will shoot well with an airbrush, sometimes it's not right for the surface you're painting it on.

Even with the right gun, it can be a tedious dance getting the perfect viscocity to your paint, air flow rate, paint flow rate and air pressure to make it happen. A lot of variables and combinations that have to hit simultaneously... You just develop a "feel" for it after time. Each paint and each gun has different characteristics, so it's hard to say exactly what you need to do. I'd stick with the WW fluid though, it helps a lot. I would shoot between 18 and 25 psi with a detail gun, but airbrushes may be different.

I've been airbrushing for over 20 years, but never with latex until now. Just getting started with the automotive detail guns too. So, you may want to enlist the help of some of the more experienced latex shooters here in the forum besides me. You really should consider spending the $50 and picking up a detail gun though, it will make the job much easier. Besides, they hold a lot more paint than the airbrush will, so you don't have to refill the gun as often.

Neo

Tmoth4

My Feedback: (1)

Harbor Freight has touch up spray guns for only about $20. That's what I use for bigger areas. I use the airbrush (Iwata) for details and smaller areas.

I found that latexes have to be thinned out quite a bit to go through spray guns and airbrushes and I have to do several light coats rather than a couple of heavy wet coats.

ProfLooney

You can get touchup guns for abt 25 at walmart and a complete paint gun set from lowes for 50. they have touchup gun and the reg gun (which is great for clear coats or primer coats) and has hose, hose quick connects, spare pots and few other things really worth the few extra to get a complete set.

I have had the harbor freight gun before prob with them is they are cheaply made so when you need to replace parts you cant get the parts to rebuild the gun. besides at 5 bucks more might as well run to wally world as it will get to you faster hehehe and they will charge at least 5 bucks at harbor for shipping.

Joe

NE0

My Feedback: (9)

Check out the results of this test...

http://www.renderwurx.com/rc/glasstest/index.htm

Neo

ProfLooney

Good Job Neo very good testing. I was curious if the sanding sealer would keep the balsa from warping with water based. I always use laquer based but do it outside and if your plane works out fine with the waterbased using the sanding sealer let us know because i would prefer to save my self some fumes because as we all know you cant glass outside in the winter or the rain.

Joe

PS

I told ya so its a nice lightweight finish lol i just couldnt resist

dionysusbacchus

My Feedback: (25)

Neo,

One VERY important test was not mentioned. The SUN! Environment has just as much importance as gas, many times our models sit in the sun, especially in Florida! I have found that anything water based tends to blister when subjected to even short exposure to direct sun light. I would have liked to see the sun test, you have good colors to test, some dark and some light.
I'll never use anything water based on my models, anyone have similar experience?

Luke

NE0

My Feedback: (9)

Prof,

The sanding sealer seemed to work great on preventing moisture warping of the sheeting. I used 1/16 sheeting too, which is way thinner than what I'm using on my SBD.

Dion,

Not worried about the sun (we get so little of it in Ohio). My plane may sit in the sun for 4 or 5 hours, 2 or 3 times a month (it's not all I fly), 6 months out of the year. That's only 15-20 stints of 4 hours per year. At that rate, it will take a LONG time to do any damage.

Besides, we all paint our houses with WATERBASED latex and that gets more exposure to sun, wind and rain in 1 year than my plane will in 10 lifetimes. I've never had waterbased latex blister on my house (well, maybe after 10 years... which is 100 plane years!)

Neo

TTARK

Will monocote seal over the WB thane?? I have a plane I need to glass the center section of the wing, the last time I did this I used epoxy and the monocote would not stick to the glassed section. I wonder if this method would be better??

Terry

ProfLooney

Hi Terry I have had Moneycoat stick to the poly u just fine. but would use something other than poly U for glassing center section of the wing. Poy U makes a strong glassing material for covering sheeting but I would not use it in a high stress area like joining wing halves. I would use CA or epoxy or some other GLUE. Poly U is not a glue thus I wouldnt trust it. Not saying it wouldnt work just hat I have never used it that way and would be leery to try it for something like that since there is a lot of stress on it.

Joe

dionysusbacchus

My Feedback: (25)

Good points Neo, it definitely has something to do with where you live. We don't glass and then seal our hoses though, so I don't think you can make a direct comparison. Something happens to the paint when it is sealed between the glass and the clear sealer. My plane started to bubble when I lived in Texas, it gets VERY hot in the summer. I guess I could use a system like you did and give it the test. I'll do it for all the guys that have year round flying seasons like me! One guy had a U2 spy plane in Arizona that melted on the tarmac! Black or dark paint has an effect also!

Luke

NE0

My Feedback: (9)

Good points, I agree with them all. I guess the upside of having a short flying season is that our area doesn't have to contend with the blistering year-long heat that yours does.

Seldom over 90 degrees here, usually cloudy, and we fly on grass. Blacktop will amplify the heat to the nth degree. Like I said, I fly a lot of planes, this one will only come out for a few hours 2 or 3 times a month... shouldn't see a lot of sun. Sometimes I cover mine up too when not flying them (to protect them from the sun), which means they only see sun for 20-30 minutes per flying day.

Tmoth and others have used the WB techniques on planes for years, I'd defer to their experience on what long-term effects the weather has on them. If they have flown with it on planes 3+ years old with no ill effects, then I'd have to say it works... at least in our neck of the woods.

Neo