First carbon fiber tube wrap

Last night I finally mustered the energy to lay up my first carbon fiber tube. In this case I reinforced a partially built booster for a 54mm minimum diameter craft. I roughed up the phenolic tube to better take the resin, followed Dave Triano's layup schedule to the letter, and ended up with the following structure:

In this oblique shot you can just see the heat shrink tape spiral:

Finally I placed this structure in my curing oven and let it sit for 90 mins:

Here's a close-up of the cured result:

Most of the structure is smooth but I picked a varied area for the blog. The Mylar film I used to smooth out the cured surface was not treated with a release layer. As a result some spots of higher surface energy didn't want to release the film so I've got some point defects to deal with (white flecks). Also, despite saturating the structure with resin, there are still some voids down to the fabric. I'm thinking I'll fill, prime, and paint the booster fully and hopefully the payload section will turn out better.  I can then leave the beautiful carbon fabric appearance on this upper section.  Overall I'm very pleased with this first effort.

I'll reiterate here that Dave Triano is my hero 'cause he chooses to share his wealth of composite material knowledge with the high-power rocketry community. Thanks, Dave!  Please consider buying his videos.

Vacuum-bagged fin half

I was supposed to provide an update on my fin layup weeks ago.  Well I finally cut it out and here's the result:

You can see that the perforated film drew too much resin out so the texture undulates rather than being smooth.  You'll also notice the slight profile near the edges so that pretty much worked.  I'm not sure I'm going to continue with this design.

President's challenge design for 20,000+

The San Diego club has a standing "President's challenge" to reach or exceed 20,000 feet.  I've decided to take a crack at this at Plaster Blaster on October 3rd.  Here's my preliminary design:

I have many of the parts already including the bad-ass nosecone so construction will begin shortly.  I'll provide updates as I progress.