Fiberglass or carbon fiber? Nah. I'm thinking pants.
- Thread starter ebruce1361
- Start date
Help Support The Rocketry Forum:
ebruce1361
The man with the plan. And some duct tape.
Well, it's settled then. Next time I go to the grocery store, I need to get some parchment paper and some plastic/wax/whatever coated paper plates.
ThreeJsDad
Well-Known Member
I use parchment paper a LOT ! Meguiar's Gold Auto wax works pretty well as a mold release. It isn't as slick as my actual mold wax but it is readily available and works well enough for occasional use.
- Joined
- Aug 27, 2011
- Messages
- 11,616
- Reaction score
- 6,250
So if you use this for short stuffy rockets, are those “cut offs”?
Anybody else remember the term “dungarees”?
Anybody else remember the term “dungarees”?
ebruce1361
The man with the plan. And some duct tape.
Last night's destructive stress testing! For being my first try with this stuff, it is incredibly resilient! Forget model rocket body tubes and fins, I'm thinking of selling this to NASA JPL to use as an ablative heat shield for the next Mars lander! 
Jokes aside though, I would like to see more rigidity because I can imagine this version warping and deforming if under pressure for some length of time. If the fins were denim and the rocket were laying on its side on a table for too long, the fins might warp a bit. So, I will conduct additional tests on thicker samples, using different epoxies, crossing the fiber directions, maybe even try some heat curing. I have a coworker who suggested the possibility of being bulletproof, hence why I tried out the air rifle. Given that I live in city limits, I can't try with anything higher power than that on my own, but I will let him try out one half of the piece already made on his property with greater firepower, and I'll let him have some other ones to see what they can and cannot withstand depending on different thickness, fiber direction, type of epoxy, etc.
Jokes aside though, I would like to see more rigidity because I can imagine this version warping and deforming if under pressure for some length of time. If the fins were denim and the rocket were laying on its side on a table for too long, the fins might warp a bit. So, I will conduct additional tests on thicker samples, using different epoxies, crossing the fiber directions, maybe even try some heat curing. I have a coworker who suggested the possibility of being bulletproof, hence why I tried out the air rifle. Given that I live in city limits, I can't try with anything higher power than that on my own, but I will let him try out one half of the piece already made on his property with greater firepower, and I'll let him have some other ones to see what they can and cannot withstand depending on different thickness, fiber direction, type of epoxy, etc.
Nytrunner
Pop lugs, not drugs
Not bad for cheap mid-cure epoxy. Try laminating epoxy?
You should contact Jeff from the Taufledermaus youtube channel. Make a thicker strong crisscrossed panel (or 5) and send them to him for testing. He shoots small and large caliber bullets, shotgun slugs, and improvised rounds on high-speed video and observes how the round reacts in flight, how targets react to the rounds, and how certain protective materials respond to being shot
You should contact Jeff from the Taufledermaus youtube channel. Make a thicker strong crisscrossed panel (or 5) and send them to him for testing. He shoots small and large caliber bullets, shotgun slugs, and improvised rounds on high-speed video and observes how the round reacts in flight, how targets react to the rounds, and how certain protective materials respond to being shot
What kind of epoxy did you use? I use WEST System for anything epoxy related and with slow hardener a full cure can take a week at room temps. I think that your experimental piece might get stiffer in a few days.
Laminating epoxy like WEST and the use of a hot air gun to thin it would penetrate the denim better. I'll cut up some old holey jeans tomorrow & laminate them up with some WEST & I'll let you know how it turns out.
ebruce1361
The man with the plan. And some duct tape.
That's not a bad idea! I've seen a lot of his videos, and this would definitely be up his alley. As for the laminating epoxy, I'm not familiar with that variety, but I'll look into it.
This is pretty much the bottom-of-the-barrel grade clear epoxy. Even so, this stuff performed much better than I expected. As for what I use, I mostly go for either 15 or 30 minute Loctite or original JB Weld. I haven't ventured into the world of specialized epoxies beyond what one can find at a hardware store, so I'm still a bit of a newbie in that sense. I'll hold on to the bent piece and see if it stiffens up like you said, and make up some more pieces for comparison and see just what it takes to stop a .22LR.
Last edited:
- Joined
- Aug 25, 2019
- Messages
- 6,157
- Reaction score
- 4,346
Plasmajet motors were made with straight linen-phenolic. Others were, too, from what I've been told, but personally have flown a couple of Plasmajets back in the day.
ThreeJsDad
Well-Known Member
Yup, even with a curing oven it can be 4 days or more.
ThreeJsDad
Well-Known Member
This just popped in my head after reading something above.
I don't think it was Ratan but someone built a plane that had a dark color on top of the wing.
They walked out one morning and the wing tips were on the tarmac. The sun had softened the epoxy. Dark colors and stuff like this is not a great idea
I have personally seen CF wings get VERY hot while sitting on the ground.
I don't think it was Ratan but someone built a plane that had a dark color on top of the wing.
They walked out one morning and the wing tips were on the tarmac. The sun had softened the epoxy. Dark colors and stuff like this is not a great idea
I have personally seen CF wings get VERY hot while sitting on the ground.
Very cool to see some results. However I would make sure that your epoxy's strength isn't compromised by the acetone. You can get it to soak in by just making it warmer, which will thin it quite a bit. Of course it will cure faster so you can't leave it in a container once it's warmed, but you could also just heat up the cloth with a heat gun (or even a hair dryer) to help get the epoxy to wet out the cloth. I know that if alcohol is used as a thinner it can seriously weaken the finished epoxy.
Keep us posted, I do plan on trying this with some t-shirts.
Tony
Keep us posted, I do plan on trying this with some t-shirts.
Tony
ebruce1361
The man with the plan. And some duct tape.
@manixFan
Warming the FABRIC before applying the epoxy? That's a cool idea! (Inverse pun absolutely intended)
I've heard about alcohol weakening epoxy, but acetone is actually mentioned as a thinner on JB Weld's website. Once I get a dependable layup that I can readily repeat, I'll do a comparison with acetone thinned epoxy vs. straight epoxy.
For now, I have an additional experiment in the works: denim with JB Weld!
Warming the FABRIC before applying the epoxy? That's a cool idea! (Inverse pun absolutely intended
)I've heard about alcohol weakening epoxy, but acetone is actually mentioned as a thinner on JB Weld's website. Once I get a dependable layup that I can readily repeat, I'll do a comparison with acetone thinned epoxy vs. straight epoxy.
For now, I have an additional experiment in the works: denim with JB Weld!
ebruce1361
The man with the plan. And some duct tape.
I would absolutely love to have a denim upholstered car! Although, I would do that for a '63 to '65 beetle.
Kelly
Usually remembers to get the pointy end up
I'd be careful, though, about using laminated jeans for a body tube. It might be susceptible to... zippers.
Thanks folks, I'll be here all week, and don't forget to tip your servers!
Thanks folks, I'll be here all week, and don't forget to tip your servers!
- Joined
- Aug 25, 2019
- Messages
- 6,157
- Reaction score
- 4,346
West Systems isn't particularly heat resistant. I'd be more inclined to go with Aeropoxy or maybe even do some research for better epoxies for that. I'd also look into some sort of gelcoat with UV resistance to help mitigate heat issues.
Nytrunner
Pop lugs, not drugs
@manixFan
Warming the FABRIC before applying the epoxy? That's a cool idea! (Inverse pun absolutely intended
I've heard about alcohol weakening epoxy, but acetone is actually mentioned as a thinner on JB Weld's website. Once I get a dependable layup that I can readily repeat, I'll do a comparison with acetone thinned epoxy vs. straight epoxy.
For now, I have an additional experiment in the works: denim with JB Weld!
On the technical side, i dont foresee the JB soaking into the material very well. Youll end up with a layer cake of denim and JB instead of an impregnated fiber/matrix composite. Thus the desire for low viscosity laminating epoxy that wicks into the fibers.
On the semantics side, youre using fibers, not carbon, so this may be more appropriately named Redneck Fibaglass.
And the JB result wont exactly be glassy, so might be more like Redneck Fibabrick
boatgeek
Well-Known Member
- Joined
- Dec 27, 2014
- Messages
- 7,407
- Reaction score
- 7,948
You definitely want a laminating epoxy rather than thinning down 30-minute or JB Weld. I believe BSI 20-minute is a laminating epoxy, as is West. My favorite to work with is System 3 Silvertip (available at finer Ace Hardware stores and on Amazon, likely at marine supply stores as well).
Speaknoevil
Well-Known Member
- Joined
- Mar 18, 2018
- Messages
- 1,144
- Reaction score
- 551
I cannot believe someone would not understand the difference between laminating, structural and tacking epoxy?!?!? Why people do not use the search function on this forum, or Google is beyond me?!?!?
I remeber a website that shows how to make lightweight wings for RC gliders using epoxy and brown paper from paper bags.
ThreeJsDad
Well-Known Member
Been there, done that. It is a pretty cool process !!
ThreeJsDad
Well-Known Member
Tony makes a very good point. Heating it also drives out moisture and moisture is our enemy. When I was building gliders I would often put folded pieces of Kevlar in the kitchen oven at 150 deg for an hour or so to drive out moisture and make it absorb the epoxy more easily.
Paul
Nytrunner
Pop lugs, not drugs
We all were new to things at one point.
To someone who has never used epoxy before, they may not know there are different types, or what their applications are. Just like building rockets or making propellant, someone starting out does not know the things they don't know.
Im happy to see Bruce experimenting. And those that know more can look in from the outside and fill in the knowledge gaps that will lead to a superior product.
Yukon@K-9 Rocket Tech
Student, Drone and Rockets, Aspiring Engineer
I have tried getting ripstop nylon and rolling a tibe with it wetted in epoxy. Not stiff at all, kind of like kevlar. Also if you tried making paper tubes coated in epoxy it actually makes pretty strong tubes
Speaknoevil
Well-Known Member
- Joined
- Mar 18, 2018
- Messages
- 1,144
- Reaction score
- 551
Actually you are right. I apologize. My inclination is to do a deep dive and research all angles in any new subject/endeavor before I will comment or ask questions. But not everyone is built the same way. There are many ways of learning.
Similar threads
