Wednesday, November 27, 2013

Stringers

Tonight I finished making the wooden stringers for the sides and underneath fuselage. Simply used the previous stringers as templates for the new ones. Could find matching pre cut lists in Oslo. The longest one I had to make from two pieces, joining them with a scrap metal piece from an IKEA shelf...

Gave the stringers and the floor boards a good coat of "Visir Olje-grunning". Thats what we put on outside walls for wooden houses as a first layer. Must give it 2-3 days for drying in these low temperatures, and then the first layer of OD wood paint. Will be exciting to see how well the paint shop matched the OD on this type of paint. Hope I'm not rushing this, I know I should have had a second floor board fitting at the hangar...


Tuesday, November 19, 2013

Olive Drab color

"OD". Olive Drab. The US military green camouflage color. Apparently, it's not easy to say: "This is Olive Drab green". First of all, US Army changed the standard OD several times. It really depends on which year your OD was painted. Then there were differences in batches of color. In the field, they most likely used whatever mix they had... And I guess there is no easy way to mix OD based on the old color-definitions in todays system.

Luckily we have enthusiasts who gladely spends months and even years investigating this type of details. Steve, running L-4 owners page on Facebook and Paul Smith are amongst those brave men. The rest of us can just sit back and wait for their decision: What is the correct OD color? They did not have an easy job. Most pictures from the time is B/W. The few color images are faded, and so are most samples of fabric or cowlings still with original color.

Talk about timing! As I was just starting to think about OD, the L-4 owners Facebook page was full of results from Steve's experimenting with OD. By the time I needed a color card, Steve had just produced 12 sample color cards of:
- No 613 Olive Drab
- No 612 Medium Green (for camo pattern around the wings and tail)
- No 603 Sea Gray (under wings/fuselage)
- No 614 Orange Yellow (for tail Serial Number)

Getting my hands on a set of those color cards saved me a lot of time. So, how to get my hands on some paint ? I went to see a local car painter. His laser-scanner only came up with a 90% match and he was not even willing to try and mix it "by hand". So much for "specialists". Turns out that a small car parts warehouse in Lillestrøm (BilXtra) got a 100% match with a german Autocoat BT MM Mercedes Benz Truck paint (DBT6844). I'm putting german paint on an aircraft that was built to neutralize german military 70 years ago! How about that! :-)

I decided to treat the fuselage tubes with a coat of this paint on top of the old Hansa Primer. Just to give it an additional coat. The real find of the day was when I discovered that the inside of one wing pulley fairing cup still had OD! And there is no other paint or primer under it, so I'm thinking this is the original from 1944. I think it matches Steve's color sample card damn fantastic, well done Steve! Some photos below.






The fuselage on it's way from my garage to the hangar at Kjeller airport (ENKJ). Will bring it back early spring, hopefully in March. Having it in my garage is the only way to get steady progress.

Floor boards

Norwegian winter is here and the Cub had to move to the hangar at Kjeller airport (ENKJ). My wife was happy to park in the garage again now that the car windows are frozen each night. Anyway, I still have a lot of parts up here to work with.

Floor boards: A plate of 6.5 mm thick, 5 layers plywood from Oslo Finérfabrikk was purchased. Fine finish (much better than at the local builders warehouse), and the glue is suppose to be water-resistant...  The old floor boards were naturally used as templates for the new ones. But.. since I plan to actually use the baggage-compartment behind the rear seat, I decided to put floors there as well. It was on the original L-4's, obviously for the observer who sat facing rearwards and he must have had some floor to rest his feet. I have never seen an original drawing of how these L-4 rear floor boards were cut. I'm going to try something I've never seen before: one long piece reaching from under the front seat all the way back past the baggage compartment.

Boards are now ready for fitting. I need to bring them down to the airport and try them out and make adjustments. Then, when all fitted, I will give them 3 coats of olive drab paint used for wooden houses. Type "Drygolin Extreme" was the toughest paint they could recommend. The plywood is in fact so nice in itself, that it hurts me to paint it olive drab. I really like the brown wooden finish, but it would simply not be authentic for the L-4's. I guess US Army pushed Piper pretty good regarding price (approx. 2000 USD per aircraft!) and so the whole interior were simply sprayed olive drab. All of it! Boring yes, but authentic for it's time.

The MAV came with really nice floor protection metal sheets which I will reuse, authentic or not... At some point you've got so decide where to draw the line. I'm happy with an aircraft I can say is "very close to the original". Wingtanks, 90 HP engine... there's so many things anyway that breaks with the original specs. Some L-4 enthisuasts will disagree with me (sorry...) but thats life.

I'm happy with the result of the floor boards so far. More pictures after fitting and painting. Next up: wooden stringers (side and bottom).