Forum

Blog

Blog Post

Welcome, Guest
Username: Password: Remember me

TOPIC: Laminating HP Body Tubes / Airframes

Laminating HP Body Tubes / Airframes 1 week 6 days ago #2767

  • Robert Bantly
  • Robert Bantly's Avatar
  • Offline
  • Junior Boarder
  • Posts: 34
  • Thank you received: 3
  • Karma: 1
Last night I got out to the shop and tried out the Giant Leap Rocketry Easy-Glass system with stretch-on sock and Aeropoxy Lamination System with PR2032 Resin and PH3660 Hardener (1 hour pot life). Supposed to be a better epoxy than West 105. I can't say since I haven't ever done epoxy lamination but it spread and wetted the layer pretty well. It also had pretty minimal odor, MUCH less than a small amount of stinky JB Weld or the standard 30 minute or less stuff at the hardware store.
The thickness of the mixed epoxy will promote sagging and I spent a lot of time brushing and moving epoxy
around, and periodically turning the tube. Did a volume-checked perfect 3:1 mix and it stayed movable well over an hour. At 2+ hours, it started to tack at 75 degrees. I would recommend 30 minute hardener next time with a kitchen timer to keep you aware of pot life. Might make it a little easier and take less time.

This job requires coveralls, a well-covered floor, and nitrile gloves - I had all of these and managed to keep
the shop 99% epoxy mess-free haha. The stuff is like Moly Grease - it gets everywhere and requires some
advanced planning to control! I didn't have butcher paper, so I had to mind the package wrap as epoxy will
soak through it after a while.

My Mini-Magg 5.5" tube got the small Easy-Glass sock, stretched over the tube and pulled tight with zip-
ties, and a piece of sacrificial or payload section 75mm LOC tube got the Kevlar reinforcement. The small
version of the sock was an easy fit over the 5.5" tube and I think they are just a little larger than specified.

The Kevlar reinforcement sock was thick, and I think if you use this, you will either have to build up a stock
nose cone or turn your own. Body tube diameter will increase, can't give an exact amount until Easy-Glass is
installed over cured and dry Kevlar and it is primed. I will be waiting until the epoxy on the tube is no longer "green," a couple days, and also for the return of warmer weather to reduce shop heating cost.

Both laminations have been setting overnight at 75 degrees and are looking pretty good. The Mini-Magg
tube looks and feels pretty well set up, the Kevlar is still a tiny bit tacky, probably due to thickness of material
and amount of epoxy absorbed. I also noticed a little tack on the coathanger used to suspend the Kevlar
test. Again, may be thicker due to mess when I brushed it up.

I can't say anything about finishing yet, but I suspect it may take a tad more work than described. The web
of the Easy-Glass sock is going to show through the epoxy post-squeegee and brush, but hopefully not much. Will post pics from google drive when I figure out the link protocols.

Cheers / Robert

Details at Link below:
giantleaprocketry.com/products/components_composites.aspx
The administrator has disabled public write access.

Laminating HP Body Tubes / Airframes 1 week 5 days ago #2768

  • Robert Bantly
  • Robert Bantly's Avatar
  • Offline
  • Junior Boarder
  • Posts: 34
  • Thank you received: 3
  • Karma: 1
After a 24 hour + setup, the Mini-Magg tube is now an airframe and very strong. I'd say: "works like they say!" You can't easily compress or distort it with hand pressure. it does add weight though. Will weigh and compare when I get access to an accurate scale. 4 ounces by volume of mixed epoxy covered the 5.5" Mini-Magg and the 3" Kevlar tubes barely. The slightly longer work time let me transport extra epoxy off of the larger tube onto the Kevlar. Going to give it another 24 hours till I untie and cut the ends off. Opening TTW slots and cleaning up the ends will be a little work, but if all else fails, I have some rotary diamond files for my Dremel.
Some notes: the Easy-Glass sock isn't fiberglass, it is some kind of stretchable fabric. The Kevlar is a mix, since 100% doesn't stretch and this does, a little. It really does look like a sock with the lengthwise raised areas. If I get a successful double lamination on the 3" tube, will consider covering my Renegade upscale, but that depends on the weight gain.
I used little plastic cups, thoroughly washed, from takeout Chinese for mixing. I measured the 3:1 volume and marked cups with a sharpie, 3 part line for Resin, 1 part line for hardener. This worked great, I got a good mix the first time with zero cost on measurement cups.

Below are some links to google drive - not sure how to get outside drive pics to display.

Tubes prepped for lamination: Mini-Magg, 3 Mega Der Red Max, and 75mm Kevlar test
drive.google.com/file/d/1y1J7hPChKuf0gmF...2qx/view?usp=sharing

Mini-Magg tube set up:
drive.google.com/file/d/1702m_VECSt-gWtO...QWt/view?usp=sharing

Kevlar tube dried:
drive.google.com/file/d/12KS5XPdWPKTg1JF...rp4/view?usp=sharing

I've found that in general, epoxy is more 'work' than fun, it takes prep time, is nasty, and you have to protect everything. It works great and is ultra-strong but I miss the water wash up Titebond II!

Cheers / Robert
The administrator has disabled public write access.

Laminating HP Body Tubes / Airframes 1 week 5 days ago #2769

  • Robert Bantly
  • Robert Bantly's Avatar
  • Offline
  • Junior Boarder
  • Posts: 34
  • Thank you received: 3
  • Karma: 1
:cheer: :ohmy: :lol:
I watched the youtube vids on how to wrap an airframe tube in fiberglass cloth and laminate; these looked quite difficult - getting a perfect parallel start on the cloth, no wrinkles, and keeping it flat. With this stuff, was successful on the first try. It may or may not be as strong as a 100% wrap with 6oz fiberglass cloth, but it worked.

Cheers / Robert
The administrator has disabled public write access.

Laminating HP Body Tubes / Airframes 1 week 3 days ago #2770

  • Robert Bantly
  • Robert Bantly's Avatar
  • Offline
  • Junior Boarder
  • Posts: 34
  • Thank you received: 3
  • Karma: 1
Total weight added to 5.5" LOC tube is "app." 5-6oz. I didn't weigh the tube, motor mount, rings, and eyebolt before installing so I had to go research them up from the web. That won't happen again.

Pretty good for the strength increase.

Cheers / Robert
The administrator has disabled public write access.

Laminating HP Body Tubes / Airframes 1 day 6 hours ago #2775

  • Darrell Sisson
  • Darrell Sisson's Avatar
  • Offline
  • Fresh Boarder
  • Posts: 13
  • Thank you received: 3
  • Karma: 0
How are you coming along on the build?
The administrator has disabled public write access.

Laminating HP Body Tubes / Airframes 19 hours 47 minutes ago #2776

  • Robert Bantly
  • Robert Bantly's Avatar
  • Offline
  • Junior Boarder
  • Posts: 34
  • Thank you received: 3
  • Karma: 1
Mini-Magg: cover fins, glue them up, and put her together. Too Cold to epoxy right now and using it in the house may not go over well. The smell and the cat would make that a bad situation. Fins are looking good just need some decent weather. Still thinking about paint. Gave some thought to painting it like a 44 Rem. mag shell, but it would be hard to see in brass and copper.

For the Renegade upscale, the SIG 5 ply aircraft grade came in and it is pretty awesome. Two 3/32" sheets laminated gets you 3/16" 10-ply. I also got some 1/8" 5-ply and it's probably good enough as is. Will need a band saw or laser to cut this stuff, not happening with a razor saw by hand. Also got the balsa for turning the nose cone.

OT but interesting: I played with Rocksim and had it find optimum weights for some H and I motors. Way lighter than I would have thought. My 3" Renegade upscale hits max height on an H at about 12-15 ounces. It will be around 33-35 ounces, with 11 being just the 3" LOC tube. And I am building light. Guess you do need software for accurate apogee prediction.

Cheers / Robert
The administrator has disabled public write access.
Time to create page: 0.076 seconds