S7 Speedster project in Belgium

[Tombrackx]

Hi everyone,

First of all happy new year to all of you fellow builders!
Then let me introduce myself:
I'm Belgian, from the Flemish/Dutch speaking part (I know I live in a complex country ). And after a 1,5 year wait I finally received my kit at the end of November. Not only in the USA, but also in Europe Kitfox is starting to become famous again. Personally I went for a Kitfox 7 Speedster because actually it fills the gap between the ultralight(ULM) and the "certified SEP" legislation in the European market. Sadly enough we don't have the great backcountry flying like you guys have so an STI is little use in Europe. But for alot of European GA pilots the main goal is:
-to haul a reasonable load (impossible in a ultralight with the low ULM MTOW restrictions we have)
- at a cheap cost (100LL is @ 2,55€/L up here, that's roughly 10.7$/USG. Whilst UL95 is widely available at a much lower cost)

So flying a Kitfox speedster with a Rotax 912, registered as experimental seemed the way to go for me to reduce my flying bills and still have good fun at a decent speed! Next to that I simply love to build stuff, so the build part is even as exciting as flying it.

I've been reading through this forum for the last 3 years, and the great community support is for sure one of the reasons why I went for Kitfox. You're never alone!

I do already have a first question.
What are you guys thinking about the corrosion protection on the self fabricated Alu and SS parts. I know it's been discussed before for the wing spars. But for all the self fabricated brackets I don't know if I need to only alodine them or also epoxy prime them? And how about the stainless steel parts (e.g trim scissor links), altough the manual specifies it, it seems strange to epoxy prime them whilst they'll be moving parts.

Thanks for the help!

Tom

[jiott]

Welcome Tom. I epoxy primed all my bare aluminum parts including spars inside and out. I did it because it seemed like a good idea with no downside (other than time) and because I might someday install floats. The SS parts did not all get primed.

[efwd]

Hi Tom, Welcome.
I alodined the aluminum fabricated parts. Epoxy Primed the spars inside and out. Nothing to the trim links.

[jrevens]

Welcome, Tom! Stainless steel is generally very corrosion resistant and usually requires no coating or treatment to protect it.

[Tombrackx]

Making some good process, so I started on the rudder cables. I was swaging the rudder cable bushings on the adjustable rudder handles side. But as I finished both of them I started to doubt if I didnt swage them too tight. The washer supplied sits on top of the ferrule, so I would need to grind some of the washer side to get it to fit nicely. What do you guys think?

[Av8r_Sed]

It does look a bit suspect, but it's hard to tell with the heat shrink on there. There are gauges to check for proper crimps. I found a helpful article here:
https://www.kitplanes.com/the-big-squeeze/

[efwd]

I trimmed the spar off. You definitely have to be mindful of what landing light you will be using. Had I cut my fiberglass, My AeroLEDs would not have fit. Or it would have partially resided inside the spar tube.

[Delta Whisky]

I cut an accommodation in the tip - and was still able to fit the landing light. I guess it depends on your particular selection of lighting.
Right wing tip install complete small.jpg

[Tombrackx]

Hi everyone,

I started covering my wings with the polyfiber.
I have the PVC leading edge installed as its a speedster wing, so I decided to coat the leading edge with 2 coats of polybrush. I also precoated all the rib caps with Poly Tak to then reactivate and glue the fabric when shrinking is done.

But when I actually started with attaching the fabric to the leading edge I ran in to 2 issues

1) the poly tak dries so fast it looks like I sometimes have spots in the fabric where the cement isn't really soaked into the weave. I did maximum 10" of glueing at a time. Could I use a little thinned poly-tak + acetone on those areas to make sure the fabric is properly glued? (Impossible to find MEK in Europe)

2)I have loads of wrinkles in the fabric in the glued areas which I don't manage to iron out at 250F. Will you see these through the finishing tapes? What about small airbubbles?

20210903_122713.jpg20210903_122703.jpg
Thanks for your input

[Jerrytex]

I am certainly no expert and I am sure others will chime in.....The manual has you scallop the fabric on the bottom piece between the ribs. That way the fabric wraps over the leading and the gluing portion is behind the the leading edge, mostly on the spar and not on the PVC itself. Then your upper piece of fabric wraps over and is glued to the fabric on the bottom side, making a nice straight overlap that gets finishing tape. That way, there is really no glue between the PVC and the fabric. After shrinking used thinned polybrush over your pre-coated leading edge (like you do with the fuel tanks) to reactive the pre-coated polybrush, and it will be nice and smooth. I would think that you're going to have a real hard time with the fabric if you are unable to get MEK? I would beg, borrow, and plead to find some.