Been thinking about wrapping your air frames in a smooth fiberglass coating, and not sure where to even begin? Well, this episode is for you!
We’ll talk about that, plus:
CG talks about his Rocketry radio telemetry project.
(Below) Pictures of CG’s hand-built “Block One” Telemetry system flight computer. Official “Block Two” (printed circuit board) version coming soon!
CG’s Rocketry Telemetry Receiver. (Yes, a typo on the name of the box in the pic). 😉The hand built “Block One” flight computer, ready for testing…CG’s telemetry receiver.
CG introduces our Amazon store where you can easily buy Rocketry Show Tee-Shirts!
We then move to the main topic, and that is all about techniques to fiberglass coat your airframe tubes to add strength, and a wonderful surface to apply your paint & designs.
More pictures for your reference….
Polycarbonate Film measured for a phenolic tube. Just cut with shears.
Various tubes measured in their mylar/polycarbonate film. I use a fresh sheet for every rocket.
Handle used to move the tube around. Teflon tape will prevent epoxy from adhereing to handle.
Handle moved into tube..the teflon tape will allow the handle to move.
Chef paper / freezer paper lined on the work table.
Measure your epoxy for your favorite blend. For glassing, I recommend a slow cure epoxy.
I have a couple of mixtures of epoxy ready. This cures in a while, so I have plenty of working time.
Laying down chef paper (Reynolds Freezer Paper from WalMart)
Getting ready to pour epoxy on the film being used for a tube.
Smearing the Epoxy after mixing, spreading over fiberglass sheet.
Epoxy spread into cloth, on top of the mylar, on top of the chef paper.
6 oz measured FG sheet for 5.5″ Phenolic Tube, on top of Mylar/Polycarbonate Film, on top of Chef Paper.
Mylar wrapper around the tube with Fiberglass, with Rubbermaid squeegee to move air pockets and bubble to the side.
Phenolic tube wrapped in Epoxy, no FG. This is cured and no longer wrapped in Mylar.
Phenolic wrapped in Epoxy and Mylar. No FG done here.
When you see this, you need to continue to “squeegee” out the air pockets to the end of the tube. This will go away after enough time. If it doesn’t, there is a quick way to repair this.
For tubes with slots, take masking tape and tape the inside of the slots. This will give the FG and epoxy a place to rest. Once everything is dry, simply use a hobby saw or dremel cutting tool to cut the epoxy/FG out of the tube.
Showing the masking tape over the slots.
When the epoxy is leathery, on the ends, use cutting shears or old scissors to cut off the fiberglass sheeting with “not quite cured” epoxy OFF. Once its completely dry, you can sand this off easily with 80 to 100 grit sandpaper on either a hand sander, but best to use an electric palm sander. You can get the cheap one from Harbor Freight for about $16.
For tubes with slots, take masking tape and tape the inside of the slots. This will give the FG and epoxy a place to rest. Once everything is dry, simply use a hobby knife, or Dremel to clear slots.
Tools used for cutting the dried Fiberglass and epoxy from fin slots
Clearing the slots with Hobby Knife or Dremel.
On fin slot areas where the epoxy drained and left imperfections, sand this part away with 80-100 grit paper and use that area to form fillets. The epoxy that soaks into the cardboard will produce a good bond.
Completed 4” diameter Mystic Buzz tubes completely wrapped with 6oz FG sheeting and slow cure epoxy.
Tube wrapped in Mylar drying inside at room temp.
Getting ready to remove the Mylar wrap
Mylar wrapped removed showing the frayed ends of the fiberglass wrap around the tube. When its completely dried like this, its best to cut this off with a hobby saw, then sand it down to the edge of the tube.
Mylar wrapped removed showing the frayed ends of the fiberglass wrap around the tube. When its completely dried like this, its best to cut this off with a hobby saw, then sand it down to the edge of the tube.
Phenolic tube wrapped in Epoxy, no FG. this is cured an no longer wrapped in Mylar
When the epoxy is leathery, on the ends, use cutting shears or old scissors to cut off the fiberglass sheeting with “not quite cured” epoxy OFF. Once its completely dry, you can sand this off easily with 80 to 100 grit sandpaper on either a hand sander, but best to use an electric palm sander. You can get the cheap one from Harbor Freight for about $16.
Info Dried tube showing imperfections on the tube face. Simple way to fix this is to take a small amount of 30 min epoxy and smooth into the area, then take a small piece of mylar and smooth over area removing air pockets, then taping the sides down. After all is dry, sand to blend.
Completed and dry results from a good tube coated in 6oz fiberglass and epoxy.
Once everything is dry, simply use a hobby saw or dremel cutting tool to cut the epoxy/FG for the slot out of the tube.
Binder Design Tyrannosaur tubes being sized for glassing.
As recently mentioned in the Apogee newsletter, you can use same laminating epoxy to fill in / smooth the cracks in fins.
Use some laminating epoxy (FG is optional for 4” Diameter kits), and some Mylar. Smooth the epoxy under the Mylar to wipe out any air pockets. Don’t stress the excess epoxy drooling over your fins. Once everything is dry, use 80-100 grit sandpaper on a palm sander (heck, even a hand sander) to sand this all away. Make sure to wear a mask, glasses, gloves, and a long sleeve shirt as the dust gets everywhere. Have the shop vacuum close by!
Use some laminating epoxy (FG is optional for 4″ diameter kits, and some Mylar. Smooth the epoxy unde the Mylar to wipe out any air pockets. After approx. 12 hours, the fins will dry.
Use some laminating epoxy (FG is optional for 4” Diameter kits), and some Mylar. Smooth the epoxy under the Mylar to wipe out any air pockets. After approx 12 hours, the fins will dry like this! Then remove Mylar and continue with your build.
Results of fiberglassed fin with most of the edges sanded off.
Use some laminating epoxy on your wood avionics bays with some Mylar. Smooth the epoxy under the Mylar to wipe out any air pockets. Don’t stress the excess epoxy drooling over your wood ends. Once everything is dry, use 80-100 grit sandpaper on a palm sander (heck, even a hand sander) to sand this all away. Make sure to wear a mask, glasses, gloves, and a long sleeve shirt as the dust gets everywhere. Have the shop vacuum close by!
Use some laminating epoxy on your wood bulk heads with some Mylar. Smooth the epoxy under the Mylar to wipe out any air pockets. Don’t stress the excess epoxy drooling over your wood ends. Once everything is dry, use 80-100 grit sandpaper on a palm sander (heck, even a hand sander) to sand this all away. Make sure to wear a mask, glasses, gloves, and a long sleeve shirt as the dust gets everywhere. Have the shop vacuum close by!
Use some laminating epoxy on your wood avionics bays with some Mylar. Smooth the epoxy under the Mylar to wipe out any air pockets. Don’t stress the excess epoxy drooling over your wood ends. Once everything is dry, use 80-100 grit sandpaper on a palm sander (heck, even a hand sander) to sand this all away. Make sure to wear a mask, glasses, gloves, and a long sleeve shirt as the dust gets everywhere. Have the shop vacuum close by!
Glassed rocket ready for final assembly.
Completely glassed LOC Big Nuke 4 with booster, switch band and payload displayed.
Slow cure epoxy for fillets? Why not? Look at those lines!
