Finally, finally, the dope has arrived. It was ordered in November and promised in February, but didn’t arrive at the docks until ten days ago. By the time it had been transported to the stockholder and packaged up it was safer for Theo to go and collect it in person in Friday, which he did.
You may remember that what we were waiting for was the butyrate dope. We’d applied the first two coats of nitrate dope, which act as a sort of undercoat, binding to the fabric and giving a good keying surface for the butyrate, which is more fire-resistant.
Today, most aircraft are covered in coloured dope, and will have a coat of aluminium dope applied underneath which blocks the UV which is what did for our original linen fabric. 1264 is clear doped, so we have two unusual requirements of our butyrate dope; we need to try and block the UV, and we want to replicate the colour of 1264’s original covering.
So we were supplied two additives; clear UV blocker, which we’ve been adding at the recommended rate of one pint per 10 gallons if you’re American, and one part in 53 if you’re anyone else.
The other additive is Yellow Oxide, which was recommended to be added at the rate of 1/4 pt per eight gallons (or one part in 256). We mixed one gallon at this rate, but were horrified to find when we applied it to the underside of the fuselage that it was far to bright a colour. We decided to go by looks alone, and added a few spoonfuls of the diluted mixture to another clear gallon until we had what looked about right. We’ve calculated that the final ratio was one part in 1,400!
This came out very much better, and by midnight on Monday, we had completed the doping of the fuselage, tail surfaces and ailerons. We’d also attached the fabric discs to the wheels ready for doping.
We were up betimes today. and we’ve added the markings to the fuselage, doped the wheels, attached the tailplane to the fuselage, refitted the axle with some new pieces of rubber tube to try and limits wear, fitted the bungee suspension, re-attached the cabane, and put the fuselage back in the trailer, clearing the space in the workshop for doping the wings. The dope goes off very quickly so we are likely to be applying dope solidly all day, and we hope to have most of the wings finished tomorrow. The ailerons are a pain to reattach, and then we have to paint the cockades and finish modifying the trailer racks.
It’s a race, but we’re still hoping to have the airframe packed in the trailer by Friday night so that I can tow it back home. Then we can reinstall the engine the week after next and get her back to the Shuttleworth Collection in time for the opening show in early May. Can we do it? We’ll do our best.
In the meantime, here’s a picture of progress so far.