Solved Methods to make foam stronger
- Thread starter JetCrafts
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tamuct01
Well-known member
Stronger in what way? Better tensile strength? Crush/crash resistant?
Making one part of a plane stronger will shift the weakest point somewhere else on the craft. Is that point easier to repair than the nose when you crash?
Your question is rather vague and you immediately shut down some valid options because of skills you don't yet possess. Is it cheaper to build 15 plain foam noses or 1 strong one that's been glassed? If you reinforce the nose to the point that a crash breaks the spar or crumples the fuselage are you better off than remaking a simple nose? These are not meant as antagonizing questions---they are engineering decisions.
One option is to layer packing tape over the foam. This can be on top of the paper or with the paper removed. It's more puncture and weather resistant but will crush on hard impact.
Making one part of a plane stronger will shift the weakest point somewhere else on the craft. Is that point easier to repair than the nose when you crash?
Your question is rather vague and you immediately shut down some valid options because of skills you don't yet possess. Is it cheaper to build 15 plain foam noses or 1 strong one that's been glassed? If you reinforce the nose to the point that a crash breaks the spar or crumples the fuselage are you better off than remaking a simple nose? These are not meant as antagonizing questions---they are engineering decisions.
One option is to layer packing tape over the foam. This can be on top of the paper or with the paper removed. It's more puncture and weather resistant but will crush on hard impact.
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Piotrsko
Master member
Need to define stronger. Like @tamuct01 said, pick the part you want to fail next. If you crumple the nose a lot, you could add a layer of EPP foam that straightens out but will still have wrinkles. I myself would figure out why the nose is crumpling. Suspect it is impact with some sort of large object. That impact is the cause. I own planes that I know are older than you and they haven't had crumply noses
danskis
Master member
Reinforce the area you want to be stronger with balsa wood, popsicle sticks, BBQ skewers, paint stirrers etc. As long as its in front of the CG you can put a lot of reinforcement on the plane. Then re-balance the plane. If the area you want to reinforce is is behind the CG you have to be aware not to add too much weight. And then rebalance the plane. You can use Elmers glue or hot glue. If using balsa try 1/16 inch sheet balsa and take the paper off the area you want to reinforce. Some hardware stores carry balsa. I put it on the nose of my Spitfire and Kwik Fly. It really helps keep the nose in original shape.
My approach is have minimal reinforcments until after I crash. Then I add reinforcments that fix the damage and strengthen the repair. In areas such as the wing and/or landing gear that uses packing tape, I will use fiber reinforced packing tape instead to preventing tearing of the tape and a failure or possible crash. I use the fiber reinforced tape typically almost exclusively in unseen areas.
For the Mini Hellcat, Trojan, Corsair, I've added BBQ skewers to support the wing root as this is a weakness in these designs.
For everything scratch built, be like my son and fly 1/2 mistake high at full throttle at all times and become an expert at daily scratch building planes. He loves scratch building and I think needs an excuse to do so!
For the Mini Hellcat, Trojan, Corsair, I've added BBQ skewers to support the wing root as this is a weakness in these designs.
For everything scratch built, be like my son and fly 1/2 mistake high at full throttle at all times and become an expert at daily scratch building planes. He loves scratch building and I think needs an excuse to do so!
You don't need to work with epoxy to use fiberglass. Polyurethane wood finish or almost any kind of glue will work, hot glue, wood glue, even elmer's white glue will work. Granted epoxy is the best.
I use a lot of bamboo barbeque skewers in my builds, mostly in the wings, I make an I beam, a skewer on top and one on the bottom with foam in-between, makes a very strong spar.
Foamforce
Well-known member
I’ve found that the power pod is an unintentional sacrificial part. I’ve rebuild the power pods for my Storch and Cub multiple times, but I’ve never had to completely rebuild the nose or fuselage. The power pod is a nice crumple zone that saves the rest of the plane from more damage. Also, the skewers that hold the power pod in rip nicely and absorb more of the impact. With that in mind, I wonder if we could improve on that. For example, if we reinforced the skewer holes in the fuselage but not the ones in the power pod so that all the ripping took place in the power pod. Or if the power pod could stick out from the front of the plane to avoid more damage to the nose.
Also, I’ve been using fewer rubber bands to hold my wing on than I used to. I originally strapped that wing down with four rubber bands. Then I realized that it only needs two, and that allows it to come off easier in a crash, reducing damage.
These are kind of tangential thoughts to the original question, but related enough. 😂
Also, I’ve been using fewer rubber bands to hold my wing on than I used to. I originally strapped that wing down with four rubber bands. Then I realized that it only needs two, and that allows it to come off easier in a crash, reducing damage.
These are kind of tangential thoughts to the original question, but related enough. 😂
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JetCrafts
Active member
I'm building a bdf jet so the power pod is inside
JetCrafts
Active member
the other parts are durable as hell but the nose will be the weak point so I need a way to make it crush resistant'
JetCrafts
Active member
can u send a an eg of what I should buy
For fiberglass over foam, I use a light weight cloth, something like 1/2 oz cloth. If I’m just reinforcing a small area, I will use what ever glue is handy. If I’m covering a large area, like an entire wing, I will break out the oil base minwax polyurethane. I’m sure other brands of polyurethane work equally well.
cyclone3350
Master member
I did an experiment with Modge Podge Hard Coat & .75oz fiberglass over foam. I found it very easy to work with, dries to handle within an hour or less, & it makes for a protective hard shell. U can also brush it over foam by itself. If U use it over fiberglass, it needs to thinned & straight water won't do very well. I've found equal parts of denatured alcohol, distilled water, & clear ammonia free glass cleaner works for thinning. I first saw use of this stuff here:
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Exactly. For example, some of the older plans don't have doublers. My son who likes to push the limits finds the weaknesses real fast. This is part of the fun. Makes lots of fun memories and improves our building and flying skills!
I agree. I usually have extra power pods with engines already mounted to swap out sitting around. Most Power Pods are able to be fixed after a crash with fiber reinforced packing tape on the inside of the plane and both sides of the power pod. Then if the power pod gets too bad, just swap out with another power pod.
Thanks. I might give this a try.
JetCrafts
Active member
can you send pic or link or both of the 1/2 oz fiberglass
dap35
Elite member
Just be careful with the epoxy. It generates heat during the cure and can melt the foam.
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