I've seen a sample lately with pre-formed C-grid (and a linen base layer) The manufacturer only used a vac bag on top of it, mildly thermoformed with a heat gun to avoid excessive bridging on the grid. The remaining path let them infuse without flow mesh. Interesting, but how useful ?
This process blows my mind. I can’t wait to try to put together a low-tech version of this. I’m going to try to wet out some linen facings with poly propylene bailing twine for ribs.
I’m just an amateur who has been trying to stay in the background. I mostly watch mastery of anything as entertainment. A weird hobby that has come about in the RU-vid age. This process you displayed, it just knocked my socks off. The next weird project I do in my shop is going to be to take some 2 ounce glass and some poly propylene hay bale twine and see if I can create a stiff grid-reinforced skin for some thing.
I’m glad you found this one interesting! Would also be interested to see how other combinations of materials work. Polypropylene may struggle with adhesion especially as rope and twine may be lubricated - worth a try though! No reason metal reinforcements wouldn’t work either. Love to hear how your experiments go!
Wouldn't it have been better to achieve a far stiffer panel to have first vacuum bagged one layer of cloth with the tows, wait for cure, sand and remove the tow dust, lay down the second layer of cloth independently, wet it out and then lay the toed panel over it and then vacuum bag it a second time? You lost flatness of the second glass cloth layer by putting it over the toes.
I'm not sure I agree that it would be stiffer, but it would be more work! And I'm with you that nothing here is optimized for stiffness and the glass is flat on one side and wavy on the other. Thickness will drive stiffness - so stacking tows up or putting the glass in the middle would help - a little. Here I wanted to see how infusing in one shot would work and what it would look like. Imagine the carbon tows more load-oriented in any actual structure made this way.
Thats what this is. There is some difference in rates of thermal expansion but beyond that carbon and glass work great together. Just avoid pointing them in the same direction.
@@ExploreComposites sorry I meant tow in a weave , eg 200g , but Im thinking if you're going to do that probably just spend the extra money and use biaxial carbon behind or something
I think you're right. I always put peel ply over spiral wrap because of some bad experiences with the bag getting sucked into the slices and either popping or blocking the feed. This smaller spiral wrap may just not have opened up.
@@ExploreComposites i like to use some silvertape on the edge to avoid puncture and i run the flow mesh over the feed line so the bag will not block the resin. i had the bag blocking a infusion in a big part once and it was a nightmare.
This is quite similar to what I have planned as a test for a wing and fuselage skin for a small homebuilt airplane. I plan on using 5.9, 8 and 11 ounce CF, vacuum bagged panels, then after the skin is applied to the structure I'll add the tow to add stiffness to prevent any oil canning effect but without adding much weight. My goal is to mimic the stiffness and strength of .016 inch aluminum.
Why add the tow afterwards ? I also thought of something similar some time ago, using a tougher base layer like kevlar, to make some sort of self-stiffened covering of a truss fuselage for instance, or as an alternative covering solution. Not sure I would trust that to bear loads except for very light aircrafts like micro gliders and microlights.
@@SuperYellowsubmarin It sounds like he is trying to avoid making a mold. Making flat sheets, and cutting them to size, fitting them, and then adding reinforcement when they are in place.
@@fredygump5578 Exactly! Take a look at this video at the 3:40 mark to see where I got my inspiration. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-HbeVVoESmkk.html
@@SuperYellowsubmarin Kevlar is abrasive resistant for sure but is way too flexible for a wing or fuselage skin. My truss structure would be twill and uni CF in an angle form, than a square foam insert with rounded corners applied and overlaid with another twill and uni layer. What you'd end up with is basically a square profile with small flanges and the skins would be adhered to the truss frame. Then a crisscross lattice of tow about 3 inches apart added to resist oil canning. Test laminates will help me determine the exact twill weight and tow spacing.
