Best way to laminate this

[whateg01]

I'll be wrapping this in 2 layers of CF. The sample I made was just a straight section, so I wrapped it in a spiral with 50% overlap, creating 2 layers. It worked, but I believe that going around the sharper curves in this is going to be problematic. If it ends up being thicker because of more overlap, that's fine, but it seems wasteful and I might not even be able to get it to conform. So, would this be better done with pieces cut to the shape and hanging over the edges? It'll be about 5/8" thick at the thicker end and 3/8" thick at the narrower end. Fazoli's cup for scale (how convenient).

 

[drmarkr]

WTH is it??

 

[whateg01]

WTH is it??

It's a spar for lack of a better name for an angel wing for a costume for a friend. (That's a lot of "for"s.) It'll have fabric and feathers attached.

 

[drmarkr]

I read CF as carbon fiber? Obviously not?

I was thinking CF wrapped/laminated.

 

[whateg01]

I read CF as carbon fiber? Obviously not?

I was thinking CF wrapped/laminated.

Sorry, I should have spelled it out. Yes, carbon fiber. I guess I should clarify that the photo just shows the shape of the part. The actual part will have a balsa wood core.

 

[PCustoms]

Why carbon?

That's going to be a ***** with those right curves, and best case it lays flat but very distorted, So i hope you're not going for cosmetics

 

[niget2002]

Yes. I'd cut the fabric to shape and fold the edges over. Cut the slits where you fold the edges on the corners in different spots when you do the other side so that one side's edge overlaps the slits from the other side.

This will also leave a nicer looking weave on the flat parts if that's important.

 

[PCustoms]

Note that cutting it kills most structural benefits

 

[drmarkr]

Is the CF for cosmetics, or strength?? If the former, maybe use some of the carbon look wrap??

 

[dcg9381]

I'd laminate with coat(s) of epoxy. If you want it to be stronger, I'd cut fiberglass to the same shape and bond it balsa/CF with epoxy. One side at a time most likely.

 

[whateg01]

Is the CF for cosmetics, or strength?? If the former, maybe use some of the carbon look wrap??

Strength. It'll be covered up by whatever she makes to go over it. In fact I'm leaving the peel ply texture so she can glue to it better.

 

[whateg01]

Note that cutting it kills most structural benefits

The edges will be overlapped if I do a front and back instead of just spiralling around it.

 

[gte718p]

I would go with what Niget2002 said. PC custom is right that it will kill a lot of the strength. You can negate that by running a bundle of unidirectional roving along the top edge. It is basically carbon string. Since the entire top edge will be under tension and would be acting along the roving you will get more strength then you ever would have had with fabric.

 

[no704]

Just make it out of 1/8” aluminum?

 

[ez-duzit]

Just make it out of 1/8” aluminum?

This. Or at least make it out of ONE piece of whatever (plywood?) you make it from, not a bunch of joints to fail.

If you're really stuck with this multi-jointed affair, then simply apply the CF to both flat surfaces. Don't worry about wrapping it.

 

[gte718p]

This. Or at least make it out of ONE piece of whatever (plywood?) you make it from, not a bunch of joints to fail.

If you're really stuck with this multi-jointed affair, then simply apply the CF to both flat surfaces. Don't worry about wrapping it.

I tend to agree with this, but I do think the top edge needs reinforcement. The top edge is going to be under tension across the entire span. That big dip is the most likely place to crack. Wrapping that will give extra strength. It would be best if it was unbroken fiber like the roving I mentioned above.

 

[whateg01]

Customer wants cf, so it'll be cf.

This. Or at least make it out of ONE piece of whatever (plywood?) you make it from, not a bunch of joints to fail.

If you're really stuck with this multi-jointed affair, then simply apply the CF to both flat surfaces. Don't worry about wrapping it.

Know where I can find balsa wood roughly 3'*3.5'?

 

[PCustoms]

Customer wants cf, so it'll be cf.

This is a paid job and you're asking about how to do it?



I'd do braid, uni stringers, and braid.

 

[whateg01]

This is a paid job and you're asking about how to do it?



I'd do braid, uni stringers, and braid.

Yeah, it's a high school friend of mine. He knows I haven't worked with carbon fiber much so there's some level of experimentation here.

 

[gte718p]

This. Or at least make it out of ONE piece of whatever (plywood?) you make it from, not a bunch of joints to fail.

If you're really stuck with this multi-jointed affair, then simply apply the CF to both flat surfaces. Don't worry about wrapping it.

If the joints are designed an glued properly (they look fine, though I would have probably moved the joint at the bottom of the first dip elsewhere) the joints are not going to be the weak point. The failure point will be at the cutout where is mounts or at the bottom of the first dip where it turns back up.

 

[sqznby]

Hmm, you'd be wasting a bit of material, but I'd get a sheet and trace the shape out and add a 1/2" all the way around.
You should be able to lay it out and get a few patterns as long as it's nested correctly.
If it's like fiberglass it should be very flexible when wetted out. Just make sure to roll it out thoroughly to get all the bubbles out.
I'd watch some YouTube videos as well, just to see the process.

I'm no expert by any means, this is just what I learned and the small amount of experience doing some glass work on a few high-end sportfishing boats.

 

[dcg9381]

Customer wants cf, so it'll be cf.
Know where I can find balsa wood roughly 3'*3.5'?

You're going to have to bond it together from sheets. Use CA glue or epoxy.

 

[whateg01]

Turns out it's pretty hard to laser cut balsa wood without it catching on fire. Lol. I have most of the pieces cut. I have the cf and epoxy resin.

 

[gte718p]

Turns out it's pretty hard to laser cut balsa wood without it catching on fire. Lol. I have most of the pieces cut. I have the cf and epoxy resin.

Do you have air assist? I have never had a problem cutting balsa. In fact it generally cuts quite well. I think fast an low power with multiple passed works best for me on my machine. Air assist is an absolute requirement or it will burn up.

 

[whateg01]

Do you have air assist? I have never had a problem cutting balsa. In fact it generally cuts quite well. I think fast an low power with multiple passed works best for me on my machine. Air assist is an absolute requirement or it will burn up.

Yeah using air assist. 1/8" or thinner is no problem. 3/16" and up was going well with 2 passes day before yesterday but tonight I caught 2 pieces on fire with the same settings. The biggest challenge I have with them is that the density is so different across the piece. All the 6"wide the store had left were pieces that were glued up. So if I can get through the dense section, it wants to burn. If I don't burn the lighter side, I don't get close to through the dense side.