Easter Egg

[Dan [Sac]]

"Hey Dan" you say, "what about those corner sections?"





Ughh...I knew someone would bring them up. Ok, you can't quite bend hardboard in two different axes, and most materials that could bend like that aren't stiff enough to keep the foam from basically turning them into a balloon. So I had to 3D print them...on my tiny printer...forms that would eventually span into roughly 15 cubic feet of space. No problem, if the pyramids can be built, anything is possible. Small steps.











One down, three to go...

[Dan [Sac]]

Alright, I'm foamed out. Let's build some doors. The red bit is more 3D printed stuff, an ABS housing for the door latch.





Hey it opens! The ribs for the door were full depth since it would see a ton of repetitive bending stresses.





The edges of the doors would serve as the sealing surface against the door seals, so they needed to be flat and stiff. I used some flexible 1/8" thick FRP from the big box store to serve as the outer skin. I screwed that skin into the ribbage, countersunk the screws, and poured some more foam. The stiffness was imparted by subsequent epoxy and fiberglass layers.















Door edging detail





It flies

[Dan [Sac]]

Keeping water from coming through the doors was also a challenge until I caught a finger in a closing car trunk and then it clicked - just build a lip and put your seal on that. So I split the entry surface into 3 sections - the top, the sides, and the bottom. Top and bottom would be aluminum flat bent normal to the surface, and the sides cut out of flat sheet. Made a jig to have a consistent bend angle.









The seal is Trim-Lok DDA2513-25 EPDM (Amazon item# B00NL48CNY). The 1/8" 'lip' is right on the outer edge of what the seal can mount on but it fits well.





The seal makes a trough all-around the door, much like your trunk seals.





Little offset to clear the closing latch.

[featherliteCT1]

Your work is so incredible it is mind boggling!

[Ottsville]

Your work is so incredible it is mind boggling!

Ditto! Very cool. I have often thought of doing something similar but instead of pouring foam, cut pieces rough, stack and glue, then shape in place.

[Dan [Sac]]

Thank you for the kind words -

Your work is so incredible it is mind boggling!

Ditto! Very cool. I have often thought of doing something similar but instead of pouring foam, cut pieces rough, stack and glue, then shape in place.

That's a great idea and should work out quite well

[Dan [Sac]]

Shall we add fiberglass? Let's do it -


The next chapter in the build journal was a mind-numbing amount of sanding, both via pneumatic DA and by hand with various blocks. Bulk foam is easily removed with 40-80 grit paper, shaping with 80-180, and finishing details with about 220. Spots of light filler skims here and there...everywhere. It was quite difficult around the ribs since the foam sanded orders of magnitude quicker than the wood, so not paying attention (that happened a lot) led to quick divots near the wood-foam interfaces. I got quite good by the end, but my arms nearly fell off in the process. Not sure I'd make that trade again.


Sometime between 112°F summer days and 34°F winter chill -





Ready for glass







Roof - the circles are foam spill-outs - I ended up filling the roof with foam to stiffen it sufficiently if I ever wanted to add a roof rack.






The 17oz wetted very well with the 635 epoxy resin. I ended up using inexpensive synthetic brushes from Harbor Freight, they worked the best for me.













Oh no...the nemesis has returned...sanding again. This is after a couple of epoxy thin layers. I'd knock off the highs, recoat, repeat.





Toward the end, after one of the coats - getting better









And glassing the door -

[Dan [Sac]]

It always looked so pretty right after the coat...






At least it was easier to sand







Fitting up a front window template






Trying to bend 1/4" thick polycarbonate turned out a harder task than it seemed. An option was to use heat and slowly bend it to shape, but that would have required a quite good template, and I didn't have a way to apply sufficient heat in a consistent manner needed and was a bit scared of ruining a $400 sheet...so I just applied a gentle cold bend since the angle was shallow and it's only curving in one plane.






Mounting the window - I drilled holes for and epoxied brass threaded inserts into the frame. I have stainless studs in there now to help guide the window on installation. Final fasteners were also stainless with rubberized washers.







Epoxy resin on the door skins after light filling -







And the first coat of primer after the fiberglass work was done -

[Squigie]

The hours in building and foaming are certainly notable.
But I can't help but think of the hours modeling, and the untold hours the printer spent squirting plastic.
I see an unbelievable amount of print time in this build.

Patience is clearly on your side.

[dabend]

Hi Dan, I just wanted to visit your build after you visited mine and you also have a beautiful camper! The trailer work is awesome and I really liked seeing how you did the folding matress/sofa because I was scheming on doing something very similar.

Take care Darrin.

[twisted lines]

Using one of the Mentioned Epoxies to Join pieces & Foam to Wood?
Thanks for sharing

[tony.latham]

Maybe I missed it but how much epoxy did the 17 oz cloth take?

This may be the most amazing "teardrop" build I have seen. :thumbs-up:

Tony

[Dan [Sac]]

The hours in building and foaming are certainly notable.
But I can't help but think of the hours modeling, and the untold hours the printer spent squirting plastic.
I see an unbelievable amount of print time in this build.

Patience is clearly on your side.

True - but printing time is just background, you set it & forget it, so you can do other things in that time, like sleep...but you're right, for example, each of those single sections in the corner form took ~24 hours to print. So there are well over 1,000 hours of print time here. Modeling was more complex, but that can be done on lunch breaks, evenings, weekends. And I had it modeled (mostly) before i started buying things, which helped a bit keeping costs down. Sunken cost fallacy crept up a few times, but I was able to ignore it and push on.

[Dan [Sac]]

Hi Dan, I just wanted to visit your build after you visited mine and you also have a beautiful camper! The trailer work is awesome and I really liked seeing how you did the folding matress/sofa because I was scheming on doing something very similar.

Take care Darrin.

Thanks Darrin - make sure you allow sufficient space for the mattress to fold up. I can't fold it in bench form when I have the mattress + the topper, so I either leave it flat or move the topper in the back when needed.

[Dan [Sac]]

Using one of the Mentioned Epoxies to Join pieces & Foam to Wood?
Thanks for sharing

If the foam is liquid when you join to wood, it'll stick without any adhesives. If it's a dry, solid foam, you can use epoxy resins to make your own glue (https://www.uscomposites.com/faq_epoxy.html), or better yet use thicker epoxy that can be used as an adhesive. I did not have much success with fillers like Cabosil, so in places where I needed adhesion to dry components I used either the thicker epoxy, dedicated adhesives, or both.

Edit - whichever combo you use, make sure the resin and foam/substrates are compatible and won't cause foam melting or release of harmful gasses. Not all resins (like polyester) are compatible with all foams or building materials.