I always enjoy watching your videos. I would love to see you test some 1708 either side of a 25mm/1 inch Polyurethane insulation board.

@ExploreComposites

3 жыл бұрын

That would be neat to try. Do you have a specific product or brand in mind? I know the foil faced poly-iso insulation and the XPS (polystyrene) pink or blue board insulation... I think Last-a-foam is polyurethane... is that the kind you mean? Or something like this: www.aircraftspruce.com/catalog/cmpages/urethanefoam.php

Another relevant and helpful addition to the library, thank you. If the whole panel is 44g is it correct to suggest 50g of resin per skin? At a guess it’s probably closer to 20g which makes this a very lean method. The plastic sheet is an excellent tip for weight saving and ease of application.

@ExploreComposites

3 жыл бұрын

Sorry for the confusion - I should probably make the calculations more clear! The estimate is done in grams per square meter (50g per skin to bond core) and that is then translated to square feet (X/10.76) and compared to the measured 1 square foot panel. So per square foot its more like 5 grams per skin!

@rumplesmootheskin586

3 жыл бұрын

@@ExploreComposites thank you, that makes sense. I’m in Australia so I usually work in metric and have to do the conversion in the opposite direction. Thanks again for the content - you are helping a whole universe of people across so many applications.

There are panels made with paper cores in say cheap Ikea furniture or hollow core doors. Finding paper core honeycomb dimensionally similar to the nomex but lighter and probably less rigid then glassing it with even lighter glass would be the next step down in panel weight.. I know in rc modeling you can get down to 3/4 or even 1/2 oz glass. If I could come up with a panel that competes with dollar store foam board in weight and strength but is also paint able and moldable... That would be a cool product for the rc plane guys.

@ExploreComposites

Жыл бұрын

I've seen paper and cardboard honeycombs and wondered if they'd work - but never found any commercial ones that look like they'd be good for composites.

@pabloricardodetarragon2649

11 ай бұрын

@@ExploreComposites You have to impregnate them with a fluid epoxy resin, we did that 45 years ago like the Gougeon bros did on the 60 feet Rogue Wave trimaran et the end of the seventies . More interesting is to use polypropylene honeycomb, rather "cheap", very resilient used in trucks composites and some boat building, as it has a light veil of fiberglass "welded" to the cell the cells do not fill with resin and the adhesion of the skins is pretty good. You have Nidacore in the states, but you can get similar items at far better prices in China.

It would have been interesting to see the same test with perforated film to remove any extra epoxy . And compare the two . Great video

@ExploreComposites

Жыл бұрын

This one had perforated film - just no peel ply. I do wonder about how to make this lighter - maybe doing one side at a time so the resin from the top skin doesn't run down and fill the cells...

Very nice, lightweight laminate but in real life may have limited uses. Your skills are top notch Chris.

@SetMyLife

3 жыл бұрын

Indeed. Some experimental aircraft might benefit from the high weight saving, but they would probably prefer carbon, unless engineered with the damping properties of glass in mind. Plus I feel that such a light structure really exacerbates the fragile nature of composites.

@GrantOakes

3 жыл бұрын

@@SetMyLife For my plane project it would need to be able to safely support approximately 50 pounds per square foot supported along the perimeter. I'm going to experiment with 5.9, 8 and 11 ounce CF with uni stiffeners.

@ExploreComposites

3 жыл бұрын

Yes it sure is light - model airplane or lightweight fairing light! Carbon would make a better facesheet material in most cases but the glass makes it easy to see what's happening. This was really more of a "lets see how light I can get" test - next step in this direction would be lighter 29kg honeycomb with 60-80g spread-tow carbon...

@ExploreComposites

3 жыл бұрын

Fragile for sure - but not too many materials can match this stiffness at this weight!

@GrantOakes

3 жыл бұрын

@@ExploreComposites 60-80 gram spread tow carbon fiber is around $75 per yard! Fine for a phenomenal, lightweight and strong panel for aerospace projects. That's way out of my budget range.

man what I wouldn't give to hear you go back and tap on all these samples with a spoon!! (like at @8:16 but more comprehensive)

@ExploreComposites

2 жыл бұрын

Be careful what you wish for!

You could use s2 glass its 30%stronger so you could use lighter cloth and acheive the same strength the best part is you would need less epoxy with lighter cloth

@ExploreComposites

Жыл бұрын

That's a good idea - S-glass is on the list of things to cover/explore in one of these videos. I'm really interested in how to make the lightest somewhat-useful sandwich panel I can! Maybe 30kg Rohacell and S-glass, or very light spread-tow carbon? I am not sure honeycomb is the best because of the whole resin in the cells thing...

what is the nomex made from?

@ExploreComposites

3 жыл бұрын

This core is either Nomex or Aramid (Kevlar) paper dipped in resin. Resin may be phenolic. Nomex is very similar to Kevlar.

@trevorvanzuydam8115

3 жыл бұрын

@@ExploreComposites cool. Thanks for the info!

nice but why always try easy flat surfaces ? one can already buy various flat nomex panels. I would like to see some honeycomb sandwich work examples with carbon fiber on more challenging compound curved surfaces.

@ExploreComposites

2 жыл бұрын

Consistency and to get comparable samples to show how materials compare - and I don’t have tons of time to do this. Planning to do more complicated geometry as I get into more how-to videos.