Attaching the Wraps

Most of attaching the warps isn't so bad: it's fairly straightforward, following Tim's instructions, using thin CA and an applicator tip. But, it seems that if there's any radial stress (stress perpendicular to the surface) on the warp when the CA is applied, there's a chance the wrap will crack at that spot. Small crack, most likely, and no melting, but a crack. Cracks—tears, really—can also form from circumferential stress, along the surface, such as when you're trying to stretch the wrap to help it lay flat.

If I was pushing a piece down, the chances of a crack forming were pretty high.

So, the leading edges of the protrusions on the Second Stage Aft Skirt wrap (the LH2 Fill, fairings for the LH2 feed lines, LOX vent cover.) aren't secured yet. I'm debating whether to use some quick-set epoxy or thick CA. I'm leaning toward the epoxy, but the quickest set I have is five minute, and I want one minute. I expect I'll use the same to secure the various loose wrap ends, but I'll see just what happens after I attach the various tunnel covers.

I'm almost dreading applying the wrap covering the interstage between the S-II (second) and S-IVB (third) stages: it's a tapered wrap. Maybe Tim has a different method for attaching, or maybe I'll just go with the double-sided tape.

All Wrapped Up and No Place to Go—Yet

The wraps are in place: positioned, oriented, taped down.

It's time to apply the CA—in the morning.

The thrust structure wrap is a bit short, 1½, maybe 2mm. But, it looks like Tim designed things so a fin faring will completely cover the seam.

Practice, Practice, Practice

The Web abounds with stories of doom and gloom from people trying to attach the vacu-form wraps to the Apogee Saturn V. Rocketeers bemoan melted stringers, torn wraps, problems getting the CA to wick the way the instruction video describes—and on and on.

What to do?

Tim shows an alternative, using a particular double-sided tape. It's appealing: no risk of melting plastic. But, I remember the nerve-racking work attaching the paper wraps to the Estes Saturn V. Estes recommended using a permanent spray adhesive to attach the wraps, and I sweated proverbial bullets over getting those things lined up just right before attaching them. I'm not exactly thrilled with repeating that process using the Apogee vacu-formed wraps.

So, I thought I'd just try out the CA method, using some trimmings from the wraps and some other paper tubes. The procedure worked as advertised: the CA wicked, the wraps didn't melt, all seemed well. And the CA method has a big advantage: you can very, very carefully align and check and double-check the alignment of the wraps, tape them down, check again, and then apply the CA.