Bob,
I've heard from several different modelers that they tried this method but the finish turned out to be too heavy.  I'm referring to the Polycrlic base.  Can you explain how you are going to avoid this type of finish getting to heavy?  Thanks Bob.

DON'T DO IT!!!

I did on my SV-23.  If you insist, try it on a smaller practice ship.

Call me if you like.

Curt

Mark,

The Freelancer I gave you is finished this way. Not a dope of dope on the plane. Watch out applying polycrylic on base wood. It can cause warps.

It's pretty easy to use a no-lacquer finish if you don't have any open bays. It gets a bit dicey if there are open areas that you have to cover with silkspan. I did it with the Freelancer by attaching the silkspan wet with polycrylic and then after it was dry coating the silkspan with polycrylic and using a hairdryer to shink it. It sort of worked.

OK..

I have no issue with the basecoat/clearcoat systems.  I have been using Omni and Matrix products.  The Matrix especially is VERY user friendly.  Others up here use strato clear  and BC/CC with great success.

It is the Polycrylic that I advise against.  Not to say it doesnt do certain things as described..but it has real issues in my experience.

First, it is water-based.  EVERYTHING you put it on twists up like a pretzel.  It does get rock hard but so does epoxy and .5 oz glass.

I was able to salvage flaps after having to heat and weight them to get them flat again.  I tried doing all sides at once and laying them flat, weighted down with saran wrap.  Then the stuff wouldn't cure.

After all of the disasters on the span and Poly, I applied a standard acrylic lacquer automotive grey primer.

It looked very smooth and surface was hard etc.  But the poly had added more weight than I might have liked.

Now..here's the ultimate downer.

My plane is slightly off-white with green LE and top block.  after only a couple of hours in the sun, everywhere in the green areas (hot)  there was grain and small blisters showing through. 

The grain was a series of small blisters along grain lines.  When I say small, they were no bigger than the diameter of a pin, for the most part, but thousands of them following right along the grain lines in the LE sheeting and top blocks, etc.

Now, I have used silkspan for years, and have painted in  a variety of systems for years.  I don't believe there was a handling or surface prep proplem like contamination.  The surface was candled with 320 prior to grey primer.  The primer was done with 400 and was spotless.  The poly probably had several weeks prior to grey.

All of the BC/CC went as usual--and it looked really perfect--right up until I took it outside and let it sit on the flightline for an hour.

Subsequent dissection of several bubbles revealed that the greay had simply released from the polycrylic substrate underneath.  There was no failure to cure and I could see sanding scratches printed into the backside of the grey indicating there was tooth in that area.

Anyway,  Thats the story.

I guess I would use the stuff if I was allergic to dope or something, but it wasn't faster, I don't think it was lighter, and I don't think it is any harder than epoxy glass.  It is harder than glass/Nitrate or CF nitrate, but I don't see that as a significant advantage.

If it works for you, great, but I won't try it again, and I surely wouldn't recommend someone try it out on a big plane.

FWIW

Curt

PS:  Now you don't need to call me.

PS2:  Seems that much of what I experienced is similar to what Doug found.  Especially the sanding/prep etc. and the weight. 

Curt, and Doug,
thanks thats the information I was looking for. I have heard about this system several times, and wondered about it. I am also a professional painter by trade, 25 years, I have a serious aversion to mixing systems. However there is some motivation to mix as there is the problem of shrinking silkspan over open bays. I have a top secret super whammy system I am working on,, (ok so I dont want to say until I know it works or doesnt)
thanks again for sharing your experiences  guys.

I listened one time while Bill Wilson vented about people having trouble with his system.  In every case they had not followed the directions he gave them, but had "improved' his system. I have never used his system, so I'm just giving you some second hand information. If I were to use his system, I would follow his advice to the letter. 

I didnt say it didnt work for me.  It did, but I found no advantage for me personally.  That is all I am saying.  AND, be ready when you put a water based product on your balsa plane.  I followed it but I had to wait a while before sanding and it got rock hard to the point where it was alot of work to get it completed.

I did not have the blistering problems that Curt ran into.  That sounds like moisture under the finish and the heat activated the poly or something of some sort.  Who knows.....

And I will go one step further that if I outlined the way I do it start to finish people might try it and not like it for whatever reason.  We all have our ways of doing it.  We all refine it as we go.  Making a change to what you are doing should be calculated with a certain reason for doing so.  Then specific attention is paid to make sure that the reason you changed is accomplished or not....

Sparky going for lighter finish in this case is going to be darn hard to beat what he does now.  To get the finish lighter, dont know why that would be a concern of his at this point, just do less to the plane.  No pilot, no cockpit detail, no gear skirts, less filler on the bottom of the plane, no panel lines, no extra trim scheme paint, use dark colors that are NOT transparent (get one coat coverage, stay away from white!), no blocking color under main color, no extra colors on the bottom of the plane, go from grey primer or whatever primer color to finish trim scheme (primer becomes your main color saves weight), apply all sprayed material with the exception of clear with an airbrush (Ah la Gieseke), dont use butyrate dope colors they have gloss hardener in therm makes them heavy, apply clear with a circle pattern (not a large fan) at a low pressure (9-13lbs) from an HVLP gun and make small movements, thin clear with Urethane thinner (10% or more), only two coats applied no matter what....things like that make for a lighter finish.