rtfm
Well-Known Member
Hi,
I have been looking at the various foams available for use as the core material in a composite sandwich construction. I have used 4.5lbs/ft^2 Airex foam for my fuselage, but I need an extra sheet to complete the tail section. Unfortunately, my local supplier is out of stock at the moment (something to do with Christmas?).
So I've been looking at the foam available at Aircraftspruce. And I'm confused. I know there has been quite a lot written about the pros and cons of various foams, but these posts are scattered far and wide here on the forum, and I get a bit confused when trying to compare the different foams they talk about. I'd like to draw all these threads together in one place, and see if this helps me make more sense of this, and put me in a position to make a more informed judgement.
Type Density Thickness Length/width
Last-a-foam 4.5lbs/ft^2 10mm 24"x96"
Polystyrene 2lbs/ft^2 8" 16"x42"
Polyurethane ??? 1/2" 24"x48"
PVC (Divinycell) 3lbs/ft^2 3/8" 32"x48"
Styrofoam 2lbs/ft^2 1/2" 24"x48"
From the above, it would seem that Last-a-foam would be a good bet, since it has the same density as Airex, and the same sheet thickness. It also comes in long sheets, which is helpful. I know that its use in firewalls (for example) is not good (Orion), but I'm looking for foam to complete my tail section.
The PVC foam also looks promising. Do folk use this foam for fuselage construction? I know that Styrofoam is locally available, which makes my life a lot easier by not having to import it. Would this be suitable for my tail section?
Can anyone tell me if any of these foams is NOT suitable?
And can anyone comment on using foams of different density on different parts of the same fuse. My understanding is that the foam needs only to keep the glassfibre plies apart, and is not structural in a wider sense. I would assume from this that it wouldn't matter if I used different foams.
But I could be wrong about this, and happy to be instructed...
Regards,
Duncan
I have been looking at the various foams available for use as the core material in a composite sandwich construction. I have used 4.5lbs/ft^2 Airex foam for my fuselage, but I need an extra sheet to complete the tail section. Unfortunately, my local supplier is out of stock at the moment (something to do with Christmas?).
So I've been looking at the foam available at Aircraftspruce. And I'm confused. I know there has been quite a lot written about the pros and cons of various foams, but these posts are scattered far and wide here on the forum, and I get a bit confused when trying to compare the different foams they talk about. I'd like to draw all these threads together in one place, and see if this helps me make more sense of this, and put me in a position to make a more informed judgement.
Type Density Thickness Length/width
Last-a-foam 4.5lbs/ft^2 10mm 24"x96"
Polystyrene 2lbs/ft^2 8" 16"x42"
Polyurethane ??? 1/2" 24"x48"
PVC (Divinycell) 3lbs/ft^2 3/8" 32"x48"
Styrofoam 2lbs/ft^2 1/2" 24"x48"
From the above, it would seem that Last-a-foam would be a good bet, since it has the same density as Airex, and the same sheet thickness. It also comes in long sheets, which is helpful. I know that its use in firewalls (for example) is not good (Orion), but I'm looking for foam to complete my tail section.
The PVC foam also looks promising. Do folk use this foam for fuselage construction? I know that Styrofoam is locally available, which makes my life a lot easier by not having to import it. Would this be suitable for my tail section?
Can anyone tell me if any of these foams is NOT suitable?
And can anyone comment on using foams of different density on different parts of the same fuse. My understanding is that the foam needs only to keep the glassfibre plies apart, and is not structural in a wider sense. I would assume from this that it wouldn't matter if I used different foams.
But I could be wrong about this, and happy to be instructed...
Regards,
Duncan
