DIY Composite Flatbed Camper Build
- Thread starter Terra Ops
- Start date
I'll start my own thread next update and link back to this one if people are looking for some background.
ITTOG
Well-known member
It is really up to the OP given it is his thread. But if you do break off I suggest having the mods move all the related posts. That will give a much cleaner result for this thread and the new thread. It is easy for them to do.
By the way, I liked the last video. That panel was pretty strong. Looked plenty good enough to build a camper with an exoskeleton.
By the way, I liked the last video. That panel was pretty strong. Looked plenty good enough to build a camper with an exoskeleton.
Yeah this is the beginning of a new build. I too enjoy seeing the process as it relates to this build, but it is different. Whether all the content is moved or not is fine with me. I'll leave it to the moderator.
The main point of my build was to show how panels could be made at home. In regards to the last video, you can see how the epoxy bond makes a rigid strong panel out of materials that otherwise wouldn't be. My cabover floor is 60" x 80". All four sides supported by 2" resting on the aluminum angle. There is no flex when lying here.
fingergunpewpew
New member
Apologies if this has already been addressed, but is there a reason people are using epoxy and not FRP adhesive like Liquid Nails for the panel creation? Is it to create extra rigidity? Curious if you need that rigidity if you build and exo-skeleton?
fingergunpewpew
New member
That's what I figured. Problems with epoxy are delams, more difficult to construct, and a lot of VOC's for quite a while. So, there are definitely trade-offs for the shear strength. For a smaller, box-drop style build, I'm curious if people have just skinned with the FRP panel, built a skeleton for shear strength and used the FRP adhesive for the foam board?
rruff
Explorer
I don't think rigidity is the issue. You need something that cures without air or moisture, since there won't be any inside the panel, and it needs to stick well to the foam, without melting it. I don't think the adhesive needs to be very strong, because the XPS is the weak link. And XPS isn't easy to bond to because it's closed cell plastic and the cells are super tiny. Epoxy works ok. Roughening or texturing the foam seems to help.
Styromax is in the business of making panels like this and they use Teroson MS 939 by Henkel. They have a lot of videos up about the processes they use: https://www.youtube.com/c/StyroMAXInsulatedPanels/videos
It would be great to see some good controlled tests of XPS/adhesive/FRP bonding.
Be careful if you make an exoskeleton out of aluminum; you'll need an adhesive that is able to stretch enough to account for differential expansion. An FRP exoskeleton would be a better bet.
fingergunpewpew
New member
The Liquid Nails claims a shear strength of 275 PSI to wood, and says it won't burn foam....
But, there is no data on shear strength with foam, or what mechanism it works. Given that it says dry air can limit working time, I don't think it needs air or moisture to cure.
For the exoskeleton, I know that Boreas uses FRP panels and a Aluminium exoskeleton. I figure some rivets and butyl tape should keep it together and watertight.
But, there is no data on shear strength with foam, or what mechanism it works. Given that it says dry air can limit working time, I don't think it needs air or moisture to cure.
For the exoskeleton, I know that Boreas uses FRP panels and a Aluminium exoskeleton. I figure some rivets and butyl tape should keep it together and watertight.
For comparison:
Sika 252 Data Tensile strength 435psi, elongation at break 400%, tensile lap strength 360psi. 3M 5200 cures faster when cold, does not like UV and does not bond to ALU as strongly.
5200 Data: Tensile 705 psi, elongation 762%, overlap shear on Aluminum = 393 psi
Weldmount Data Lap shear on aluminum 2800 psi, elongation 100-125%. Weldmount AT-6030, weld substitute structural acrylic. Fast cure, does not like low temps.
six10 Data Tensile 6440 psi, elongation 7.9%. Six10 isn't as flexible, slow cure (faster than 252) in cold.
Sika 252 Data Tensile strength 435psi, elongation at break 400%, tensile lap strength 360psi. 3M 5200 cures faster when cold, does not like UV and does not bond to ALU as strongly.
5200 Data: Tensile 705 psi, elongation 762%, overlap shear on Aluminum = 393 psi
Weldmount Data Lap shear on aluminum 2800 psi, elongation 100-125%. Weldmount AT-6030, weld substitute structural acrylic. Fast cure, does not like low temps.
six10 Data Tensile 6440 psi, elongation 7.9%. Six10 isn't as flexible, slow cure (faster than 252) in cold.
fingergunpewpew
New member
Definitely a big difference!
terra ops, are you planning to be in Virginia in October for Expo East? I'd like to see your camper up close. I have RAM 3500 cab chassis Id like to build something similar on using your techniques.
thx