Sandwich/gelocat panels construction

[cineview]

Hi guys, im planning on building a larger model which is around 4m, and want to use sandwich panels with gelcoat skin in 36mm size.

Altough its alot more rigid than building in plywood, i assume i need some sort of safety cage to stiffen the entire rig properly on the chassis, but question is, how much and how strong do i need to build it?
Can i integrate alu bars in the sandwich panels, or do the panels have to be attach to a cage that is hard mounted to the chassis?
Anyone else here built their camper in sandwich panels that might share their experience on this?

Cheers

[QueticoBill]

Is 4 meters length? What is width and height? Are sandwich panels and gel coat foam with fibreglass skins? If so, I'd say no framing is necessary.

[cineview]

Is 4 meters length? What is width and height? Are sandwich panels and gel coat foam with fibreglass skins? If so, I'd say no framing is necessary.

Its 4,5m long, 2,2 wide and 2,3 tall.
Yes, foam core with fibreglass gelcoated skin on both sides.
So theres really no need for extra framing, just proper glueing?

[Pmullen503]

Additional framing around doors, windows and hatches will make adding those things easier later. Same thing with interior walls or cabinetry. Just having something to screw into or clamp to makes assembly easier.

[RJ Howell]

I did a foam/fiberglass on my truck (truck camper) and used a steel skeleton. Only reason for it is the overhang (loft) over the roof.



Add elements as Pmullen recommends.

[saywhatthat]

the way we laid up or panels put them in a bowl shape underload surprisingly how strong that is .
was interior exterior bonding beam.
fiberglass to fiberglass that expands the same

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[cineview]

I did a foam/fiberglass on my truck (truck camper) and used a steel skeleton. Only reason for it is the overhang (loft) over the roof.



Add elements as Pmullen recommends.

Do you remember how many bars you used, vertically and horizontally, and how much extra weight it added?

[QueticoBill]

Is 4 meters length? What is width and height? Are sandwich panels and gel coat foam with fibreglass skins? If so, I'd say no framing is necessary.

Its 4,5m long, 2,2 wide and 2,3 tall.
Yes, foam core with fibreglass gelcoated skin on both sides.
So theres really no need for extra framing, just proper glueing?

Yes if joints like ceiling and roof are fibreglass and epoxy inside and out. Blocking as pmullen points out.

[RJ Howell]

[/quote]

Do you remember how many bars you used, vertically and horizontally, and how much extra weight it added?[/quote]



The build is here: https://www.tnttt.com/viewtopic.php?f=55&t=72408
Pictures come back on page 2...

The camper with frig, was 70lbs over the removed bed weight. I have the actual numbers somewhere...

[cineview]

Do you remember how many bars you used, vertically and horizontally, and how much extra weight it added?[/quote]



The build is here: https://www.tnttt.com/viewtopic.php?f=55&t=72408
Pictures come back on page 2...

The camper with frig, was 70lbs over the removed bed weight. I have the actual numbers somewhere...[/quote]

Brilliant, thank you!