Today was the first day in a while that I had actual time to work on airplanes (!) I tried @cyclone3350's formula for thinner and it works very well! I think the glycerin and larger needle is what makes it really work, as I added some glycerin to just washer fluid and it worked almost as well. The coats still come out very light and many are required but they're much less splattery and don't just run off like water. Unfortunately now that I have the gun set up to spray the paint nicely I found that the color matching was done rather poorly. It's not close enough that I'd be happy with it. Oh well, time to run back to the store and see if I can get something that fits a bit better. I think the fact that the scraps of covering I brought them were shiny might have messed with the machine so perhaps I'll go over them with fine sandpaper to dull them down.
However... just because I could I also covered a bit of scrap fiberglass with the Chinakote I used on the airframe just to see if it would be a viable alternative to paint. Usually film type materials don't work well on fiberglass because air bubbles pop up like nobody's business but somehow this material is immune to them, just like how I was able to iron the material onto itself to do the patterns on the fuse and wing. The adhesive also works incredibly well on it - it pretty much welds itself to the surface. It's more difficult to peel off fiberglass than wood!
Naturally that's the route I ended up deciding to take. Not only would the color be a guaranteed match but it would also match the shine perfectly too. If only I knew this route was right under my nose for months maybe I'd have this done a lot quicker...
I wish I still had the Saito stickers that this engine came with. They'd look quite nice slapped onto the cowl.
Unfortunately the drawback of using a film covering on fiberglass is the seams are very difficult to hide away. I tried to put them more towards the bottom of the cowl, more shielded away from prying eyes. I actually did the entire base color on the cowl with two pieces. One which covers about 75% on the top and the other just on the bottom. The engine cutout helps immensely with this as you can cut the covering right there and shrink it up on the little bit at the front so it conforms nicely with minimal additional pulling or wrinkles. One day I'll figure out a way to do it with one piece...
Unfortunately I do not have enough yellow covering left to do the gear with and plus that has metal components anyway so it's better to just paint it instead. Same with the struts.
On another front I got all the CG fiddling out of the way today. It required 6 ounces of nose weight to balance, plus mounting the battery to the back of the firewall. I expected this airplane to need nose weight anyway as the engine is very lightweight for its displacement. Total weight I couldn't check because it was over the 8 pounds that my scale is capable of measuring.
Engine was also fired up today to check if the fuel system worked, which it does just fine. I thought maybe the relatively low position of the tank would cause issues but if anything it just prevents the engine from flooding out which is nice. I forgot how nicely this engine runs. It sounds like a sewing machine at idle, it's just so quiet. To get it started all you have to do is grab the spinner and flick it backwards to bounce it off compression and it fires up every time.
Initially however totally forgot to put a piece of fuel tube on the breather nipple which resulted in a nice river of oil on the bottom of the fuselage after a few minutes of running. I wonder if I put a seperate tank just for oil in the fuselage if I could reuse it?
Holy Cow! U got covering to go over your cowl. I'll take that, even with the seams, over painting and masking that type color pattern any day of the week. Another well done classic Sig. U R correct about the gloss of covering and getting the color to match. I've tried using 600 grit to take the shine off and or spraying some Krylon satin clear. I think the Krylon works better.
You do not want to try and save the oil from the crankcase to reuse may have too many contaminates. If you have some clear monokote or any clear covering you could print out the Saito logo and cover it with the clear covering.
I have a set from Fiberglass Specialties already on order. I could build another set but buying another bag of ultracal was more money.
I got better paint today. It matches the covering a lot better, though under certain light condition it's still not exactly perfect, but I really don't care at this point. I'm pretty sure it's as good as I'm going to get as getting a paint that matches under all lighting is pretty much an impossibility. I'm going to give it another week to cure before I clearcoat it and by that point the pants should be here.
Other than that I'm pretty much done. Now to just wait for a day with decent weather to re-maiden...
At some point I'll start putting together a set of floats for it. Float flying season is mostly over now because the water is too cold to comfortably swim in and I don't have a rescue boat so it'll probably end up being a winter project.
Went pretty darn well too, at least initially. It only needed like 5 clicks of down elevator and 2 of left aileron and then it was perfect. My math for the CG seems to have checked out too as well. Gear works fine, the toe-in I put into the mains I thought I'd have to reduce a bit but it actually felt great on the ground in the taxi test. I haven't flown a plane with a free castering tailwheel in a while so that took a little getting used to, but I honestly think I prefer that setup more than an actively steered tailwheel because it helps cut tail weight out and you can usually make tighter turns on the ground too.
I say all went well initially because as soon as I went to disassemble the airplane to clean it off and go home, both of the jury strut tabs on the main struts fell off! Due to the fact that the JB weld failed at the joint and didn't itself break, the tabs had been held there by pressure only for an undetermined portion of the flight I guess it was not up to the task. It's a good thing I didn't try to test if the struts actually increased the maximum allowable G load else I might be writing a postmortem instead of a flight report...
With that, my original idea I had for struts is getting tossed out. The only reason it even had the jury struts in the first place was to keep the main struts from rotating because they've got clevises at both ends and also bear a little bit of G-load. I think what I'll do instead to replace it is crimp the strut at one end around a piece of thicker sheet aluminum which I'll then braze into place, and then just screw that into the fuselage bottom. I'm willing to bet the big hardwood block in the bottom of the fuselage which the steel bar screws into can handle the G-load just as well as the bar itself could. I will keep the clevis at the other end, but instead of the jury struts having clevises they'll either get deleted entirely or replaced with music wire brazed onto the strut, which would be much more secure.