by uscgairdale » Thu Dec 28, 2006 7:54 am
John,
Your description of you d-cells sounds exactly how mine was. There was a small amount of movement in the skin and the ribs felt like they were still in place. As a matter of fact, every nose rib was in place, but on each one the glue had become brittle and there was no bond to the aluminum whatsoever. From what I understand, the strength of the d-cell is from the shape of the d-cell and not necessarily from the foam inside. However, it's important for the foam to help hold the correct shape. I am not trying to become the "nose rib nazi", but considering the age of most Lazairs, people should serioiusly consider opening up their d-cells if they have any concerns.
The process wasn't that bad. I first opened up the outboard section so I could see what was going on. It was at that point that I could see that the glue had failed and not the foam ribs. Of course I then removed the rest of the rivets and pulled out the ribs and cleaned everything up. Once I was satisfied with the clean up, I used some PL Premium construction adhesive to glue it back together.
A few pointers about the job:
1. If you don't have clecos, get some yesterday! You want the #30 ones that are copper in color. Take a few minutes and shop around because some places will want an arm and a leg for them. They're around 40 cents each or so, but will last a long time. I've got 100 of them that I got about five years ago through Wicks Aircraft Supply. Not only do you need them for this, but you'll see just how important for the rest of the plane (the center section and ribs on the center section especially).
2. Be sure to always use a sharp drill bit to remove the rivets. Not only will this remove rivets faster, but it will also help to minimize making all the rivet holes larger.
3. The Avex series rivets work really nice for when you put it back together. They are good because as the mandrel is pulled it also expands in the hole. Very desireable for when you are riveting up previous holes. On the Lazair II wing, there is a factory flush mount rivet about 3' from the root end so be sure to get a couple of flush rivets too.
This job looks intimitating, but it really isn't a complicated job.
Dave
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