DabCat
Well-Known Member
I was planning to just glass the inside. I did it on a few other 4" couplers and loved the finish. That is a good idea though.
4inch Hornet Upscale Scratch Build
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DabCat
Well-Known Member
Not much in terms of progress, but small steps keep the project moving. I sanded down the excess glue that dripped out of the slots with a mini dremel. Super cheap at harbor freight, and works somewhat decent for small jobs like this.
DabCat
Well-Known Member
Alright, bit more progress. The following was done over the course of last weekend, so I'm a bit late to documenting.
First off, I began laying the first of the external fillets. I didn't really get a good picture, but it still shows the setup. 2 at a time with a level clamped to the body tube to make sure it stayed level. I tried running a micro torch over the fillets to get rid of bubbles as a mini experiment and it worked pretty well. For my next 3 sets, I'll mix microspheres so the epoxy doesn't drip as much and it's easier to sand. That was one regret I had after laying these.
Next up was glassing the coupler. I wrapped a piece of paper around the coupler, then used it as a template to cut the glass. Wood blocks to assist with holding the paper in place. Here I'm using some scrap 6oz cloth I had on hand.
Glass cutout, epoxy mixed, and working area prepped...
Paint the inside of the coupler
I tightly rolled the glass and carefully pushed it through the coupler making sure not to contact the epoxy. Once it was properly inside the coupler, I used my fingers to smooth it out against the coupler walls (wearing gloves of course!) and then painted a bit more epoxy to make sure the cloth was properly saturated and sealed. The seam overlaps by about an inch.
Once dried, I cleaned up the edge a bit with a dremel and some sandpaper. The white speckles are the unwiped remnants from sanding it.
The finish is pretty decent. The edges still need to be cleaned up a bit, but that's a job for another day. Now since someone is probably thinking it, I intentionally did not use the balloon method. The finish still came out really nice, and I'm happy with it. For comparison, I have used the balloon method before.
Next up is laying out the altimeter bay, finishing off fillets, and finally printing the nose cone.
First off, I began laying the first of the external fillets. I didn't really get a good picture, but it still shows the setup. 2 at a time with a level clamped to the body tube to make sure it stayed level. I tried running a micro torch over the fillets to get rid of bubbles as a mini experiment and it worked pretty well. For my next 3 sets, I'll mix microspheres so the epoxy doesn't drip as much and it's easier to sand. That was one regret I had after laying these.
Next up was glassing the coupler. I wrapped a piece of paper around the coupler, then used it as a template to cut the glass. Wood blocks to assist with holding the paper in place. Here I'm using some scrap 6oz cloth I had on hand.
Glass cutout, epoxy mixed, and working area prepped...
Paint the inside of the coupler
I tightly rolled the glass and carefully pushed it through the coupler making sure not to contact the epoxy. Once it was properly inside the coupler, I used my fingers to smooth it out against the coupler walls (wearing gloves of course!) and then painted a bit more epoxy to make sure the cloth was properly saturated and sealed. The seam overlaps by about an inch.
Once dried, I cleaned up the edge a bit with a dremel and some sandpaper. The white speckles are the unwiped remnants from sanding it.
The finish is pretty decent. The edges still need to be cleaned up a bit, but that's a job for another day. Now since someone is probably thinking it, I intentionally did not use the balloon method. The finish still came out really nice, and I'm happy with it. For comparison, I have used the balloon method before.
Next up is laying out the altimeter bay, finishing off fillets, and finally printing the nose cone.
Just wondering if you are planning to glass the OD of the BT or put couplers along the ID? I've found that mailing tubes are not as dense or strong as rocket tubes like LOC. The rockets I built with mailing tubes didn't hold up so well. Of course I always end up putting in the largest motor that will fit, so that doesn't help.
DabCat
Well-Known Member
I wasn't planning on glassing the tube. This tube is actually really strong - I would say on the stronger side of the spectrum for mailing tubes. I would agree that it isn't as dense as a LOC tube, but it seems about comparable strength. It's also a fairly short rocket, so there's a lot of reinforcement from the centering rings, glassed Coupler, and nose cone shoulder.
DabCat
Well-Known Member
Layer another set of fillets, this time with micro balloons. They came out pretty freaking awesome! The picture does not do it justice. 
DabCat
Well-Known Member
Another set down. This time I've got pictures to document my process:
Scoop up some micro balloons and mix them into the epoxy. I used about 2-3 scoops to get a desirable consistency.
Glue is dabbed along the fin
Shaped with a large tongue depressor
And... boom. Sweet fillets.
I'm hoping to have some time this week to get the nosecone print started and parts cut for the av bay. The last set of fillets should mark completion of the booster. I grabbed some filler/primer, yellow, and some clear coat recently, so I'm ready to start finishing as soon as it's done.
Scoop up some micro balloons and mix them into the epoxy. I used about 2-3 scoops to get a desirable consistency.
Glue is dabbed along the fin
Shaped with a large tongue depressor
And... boom. Sweet fillets.
I'm hoping to have some time this week to get the nosecone print started and parts cut for the av bay. The last set of fillets should mark completion of the booster. I grabbed some filler/primer, yellow, and some clear coat recently, so I'm ready to start finishing as soon as it's done.
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