Sopwith Batboat

[g_kandylakis]

Covering completed a couple of days ago, everything was shrunk with alcohol.

Alcohol is indeed much milder than water when it comes to shrinking, just the thing for delicate structures.

First coat of dope given on all surfaces today, tomorrow the second coat.

Quite satisfied so far.

Next comes the painting and the attempt to simulate the pioneer look of the original.

[g_kandylakis]

Final steps prior to painting of the flying surfaces.

The weather here at the moment is not ideal for spraying, much less for experimenting a new finish.

So, other small tasks are proceeding instead.

The model was put once again onto the alignment jig, in order to define the fastening position for the scale radiators to the center struts.

In my previous model the radiators were simply glued on to the struts. Due to the limited rigidity when the top wing moved a bit compared to the bottom, the radiators would get knocked loose. After losing them twice, I figured I would make a more secure fastening. IT might even add some stifness as a diagonal brace to the front and rear struts.

The engine bearers on the other hand are more than adeqately rigid. The diagonal front struts secure them well in position. The only problem? They have to be removable, to allow the top hull decking to come out.

[g_kandylakis]

The struts have carbon pins that slide into the engine bearers, so are very easy to remove - reposition.

I modified the dummy engine into a two-part affair, allowing me to finish the model for flying and add all the detail I want later (typically of me, just a day before the competition day).

And started with varnishing of the wooden parts, the tail boom got the first coat of three.

Now, if only I had a new air compressor as promised...Should be ready soon...

[Garry]

George
Your skill level is so much higher than mine, I don't have the patience.

When you shrink your tissue, do you coat it with anything while still on the frame? I usually give mine a coat of 80-20, 90-10 (thinner to nitrate) and let it sit while I built the model, nitrate mostly stops shirking in about a week and I found that it would still shrink just enough to take out the odd little wrinkle after covering and it would let me use VERY light structures without warping.   

[gravitywell]

That fuselage is absolutely gorgeous!  Well....the whole plane is actually.

[OZPAF]

Beautiful work George. I really like the detailed careful use of carbon fibre to reinforce and act as locating pegs.

Another work of art.

John

[g_kandylakis]

Thank you all...

When you shrink your tissue, do you coat it with anything while still on the frame?

Garry, no.
I pre-shrink with water.
Let it dry then remove from the frame.
Cover with dope and thinners.
Shrink with alcohol.
Then two coats 50% thinned dope and that is it.
And then paint of course.

Worth mentioning, I am using Esaki, which might make a difference compared to other covering tissues.

This has worked fine for me for years.

George

[lincoln]

You, sir, are a master of the art. The level of detail is amazing. However, I think the tappet clearance on the third cylinder on the old model is a little off. We wouldn't want to burn any valves, would we?   ;-)

[g_kandylakis]

Thanks lincoln and welcome!

I was having serious power problems with the old one, that is why I decided to build a new lighter one...

Had I checked the engine and thus found the error you spotted, and had I corrected it, I might have spared many hours spent making the new one

George

[g_kandylakis]

Varnishing of the various wooden parts is proceeding. It takes some time to apply three coats with 2 days drying in between.

Meanwhile other small items are getting done and out of the way, such as the radiators, now their fixing complete.

So, radiators and tip floats are waiting for some copper paint.

[nickhawk]

Your Quasimodo compressor  will be ready until Saturday.

[g_kandylakis]

and as evidenced from the last picture, the fabric paint covering is next.

A number of possible paints had been bought 2-3 years ago (optimism...) so now came the time to make tests.

The only color reference for the Batboat is the color plates in the Kenneth Munson booklets, "Pioneer Aircraft..." and "Flying Boats...".

Of course, their accuracy and correctness leaves very much for discussion. Not to mention the drawing itself which is unbelievably wrong.

But as far as colour goes, it is better than nothing, so that is what I will present for documentation.

The covering is described as unbleached linen.

So, the 6 candidates were brushed on a sample wing. 3rd picture shows the sample on the wing of my previous model (one of the few parts that survived intact).

The last picture shows the samples after a second coat was brushed on. Too lazy to take out the airbrush for the initial choice.

And the winner is: 3rd from the left, Vallejo 71.132 aged white. It will be given some extra shadow treatment but it will be the main base colour.

Comments and suggestions are most welcome at this stage.

George

PS. Just saw the message Nick! Great, as you can well imagine, I can hardly wait at the point we are now...

[g_kandylakis]

Hello again...

a variety of reasons has led to a significant delay in painting the flying surface parts by nearly a month.

But I did finally manage to get to it this week. Not finished yet, just the main base color.

I had some serious problems with my airbrush which was supposed to do the job, ended up using my older but eventually much more reliable one, luckily with no serious problems on the painted parts. Just a lot of frustration and fiddling around and waisting time.

One thing about using acrylic colors is that when the coat is full, the covering sags a lot and takes a lot of hours to recover to taught condition. This does look scary at first, but you get used to it and hope things will go back to normal again.

[g_kandylakis]

And here is the resulting mess after the first coat was finished...

The hull is finished, waiting for the lower wings and struts to come in place.

All control cables (threads) are in position, the only thing missing is the pilot's seat and pilot. Not really necessary for test flying, which must take place soon as time is running out at an alarming rate.

George

[g_kandylakis]

Next step is a rather crazy one. Naturally...

Each rib and wood in contact with the tissue has to be masked and a fine spray of darker color airbrushed on, to make some shading fitting to the original fabric.

17 ribs per wing panel, 2 sides, 4 wings, that is plenty of rib tape masks...