Little Stuff....

Ironflight · #1 03-12-2006, 06:01 PM

Well it was obvious (to anyone that has flown on the Gulf Coast for a lot of years) that it wasn't going to be a great day to get airborne. Low clouds to start, and sure, they'd lift to maybe 1500, but along with strong gusty winds...yuck! OK if you had to go somewhere, but otherwise...a good day to fix those "little things" (Besides, I flew over three hours yesterday...)

Yesterday when putting the -8 away, I noticed that one of the rivets holding the air intake "seal" fabric had pulled out of the airbox - again! This meant pulling both upper and lower cowls. Not a big deal, but not something I want to do on days I plan to fly, so this was a good one.

Well, of course when I got the cowls off, I noticed a couple of little oil drips - time to tighten up the hose clamps on the oil return lines (114.7 hours now). That wasn't too tough with the right screwdriver, and holding your tongue just right...Got all the little drips cleaned up, and she was spotless again!

Next, I noticed a little crack in the fiberglass intake "extension" - the part that you build up yourself to match the air box. I guess I didn't get enough layers of glass on there when I fab'ed it. No problem - just time. Cut an inch and a half strip of glass, mixed one squirt of West Systems, and wrapped it with two layers....

Gee, can't put that right back on...Oh yeah, I wanted to check the alternator belt! Yup, it had stretched a little since new - time to tighten it up. Of course, I had safetied the upper and lower bolts on the adjusting arm together, so I had to reach way up there under the baffling to re-do the upper one. Wouldn't have taken too long, except for three visitors (no one was flying)who wanted to kibbitz...but OK, got the belt adjusted, and the visitors approved the safety wire...

I guess I could clean the belly...I have figured that since it isn't painted yet, why clean it too much? Grady will have to do a total clean-up before paint in May...But I have already noticed some very, very tiny dots of white on the leading edges - very small corrosion sites - this salt air and high humidity can be nasty! I don't want to put any polish or wax on, since that'll make the paint job clean-up that much harder. I guess I'll just keep an eye on it. I've seen much worse!

What else...Oh, that's right, I had started out to fix that pop rivet! Well, the wide-heads I had were too short (the problem in the first place), so I used some longer pops with washers on both sides. That took five minutes - and of course, the epoxy hasn't set up yet, so close up the hangar and head home for some weekend chores.

Three hours later, another drive to the airport - cleaned up the new epoxy, buttoned up the cowl, listened to the AWOS...no, 15 gusting 28, 60 degrees to the runway is just not worth it....Gee, it's spring break week, not much on the schedule - maybe a day trip will present itself!

Paul

aadamson · #2 03-13-2006, 01:56 PM

Get your self some "peelply" and keep it handy, when you do those little parts, put ona matcihng piece of peelply after the layup, it will make "clean up" oh so easy. Other trick is if you have to sand, and it's a hand layup, you can start the sanding when the cure is "green" and save you a bunch of time on vs. doing it after the hard cure.

Anyway, peelply pulled, is what some claim to be the best surface for the "next" layer if ever needed

.... Me, I'm getting really good with 40 and 80 grit

...

If ya have one of those "food savers" around and the part will fit in a bag, you can also do a minimal weight layup. Use peelply on top and then some of that batting that you get at the wifes fabric store. Put down the layup, peelply, batting, stick it in the bad, and suck out the air... poof, poor mans vacuum bagging. You'll be amazed at how much epoxy you'll pull out of the layup doing this and *NO* air bubbles.

rv8ch · #3 03-13-2006, 02:29 PM

Guys, don't remind me that I still have my cowls to do, once it gets above 10c in my workshop. Yuck.

rvbuilder2002 · #4 04-06-2006, 06:33 PM

Paul,
If you are pulling out rivets from the airbox and the Fglass extention is cracking in only a little over 100 hours, I think you may have other issues.
Possibly you have a bit too tight of an interface between the two, need to have a dynamic prop balance done, etc.

While fixing, I would looking for the root cause.

Scott McDaniels

Ironflight · #5 04-06-2006, 09:15 PM

Finding the root cause for any failure is always important, and I'm glad you made that point! In this case, I realized that I really hadn't made the extension tube very well (it's that "I hate fiberglass" thing), and didn't get the layers right. The rear edge was too thin, and that's where the crack started. (I actually had a problem with the seal inverting right after the first engine start, becasue it wasn't cut right, and I think that started the crack.)I also felt that the airseal was a bit too tightly stretched, and could see where it was distorting a little, so I loosened up the fit a little.

One of the problmes with the "first plane" that you build, is there are a lot of little things where you aren't quite sure how much tension to put into something, or how much clearance you need. (That's one of the great things about all of these forums - how did people build an airplane before the Internet?!) I've actually been really amazed at how few of those kind of things I've found - I was expecting lots of tweaking and tinkering, and really haven't done hardly any. I think it speaks for the margins built into Van's design more than to the skill of (at least this) builder.

Paul