Composite Interior Wall Panels

[VerMonsterRV]

Hey guys, I am getting to the point of installing my interior walls in my Total Composites habitat. At the same time I ordered the habitat kit I ordered some 30mm FRP skinned honeycomb cored panels for the major interior walls. I have considered a couple different ways of bonding the walls in. One way is to route out the core leaving the skins. Then make a hardwood cleat that would bond/screw to the exterior wall. Then the routed out panel would slip over the hardwood cleat with adhesive. The other way is to use aluminum L channel. The L is way easier but leaves the aluminum exposed. The routing out might be a bit tricky. Any thoughts on how I should install the panels?

 

[Victorian]

Although the use of an internal cleat is the way to go, I would not use wood. Especially in a bathroom setting. The risk of water getting in there and the wood swelling up is too high in my mind. Better if you could use some type composite material. In addition to that, you should use some 1.5"X1.5' angles on one side of the wall. These angles can be aluminum (easy to source) or FRP. Don't forget the primer if you are bonding Aluminum with the Koemmerling adhesive.

 

[nathane]

I'm planning on doing this using composite angle section on the "inside" side of the wall in question.

 

[Victorian]

Here is a picture....FRP panel with FRP edge insert and FRP L profile

 

[VerMonsterRV]

Thanks for the info guys. Andreas, where did you get the fiberglass angle? It looks like it would work very well. The other thing is since the Total Composites kit shipped with all the opening cutouts I have some pieces to experiment with the router on. Might end up with a combination of both methods as some of the edges will be covered (like all the floor ones). Can't wait to start this next step.

 

[Victorian]

Jon, those FRP angles are very hard to find in North America... All you can get are some very beefy 1/8 or 1/4" thick ones. I took this picture in Germany... Aluminum may be your only nice looking option.

 

[CoyoteThistle]

I looked at all these options too and settled on the following for outer and interior construction of our camper:

1) use thickened epoxy to slightly overfill the "end grain" of the honeycomb core panel, position the panel, clamp in place, let dry overnight or so
2) use thickened epoxy to do fillets on the inside corners, let dry (the larger the fillet, the stronger)
3) sand the fillets smooth
4) apply 4-inch wide fiberglass tape with epoxy over the fillets
5) sand the tape smooth and use thickened epoxy for fairing as needed
6) paint it

It's lots of steps, probably not as fast as using angle, but gives a clean look and is super strong. Best of luck with however you proceed!

 

[tanuki.himself]

Another general issue with pultruded FRP angles for this type of use, or especially if you want to put a vertical load on it, is that most of the fibres and therefore strength runs along the length of the section as it is pulled through the mould to make it. Personally I would make some out of either chopped strand matting and/or woven fibreglass tape using a piece of aluminium angle as a mould - you normally can't get fibreglass to bond well onto aluminium so if it is waxed or treated with a release agent it should be easy to remove your sections - and you will get a lot more fibres and therefore strength going around the corner. If you really want to increase the load bearing strength of the angle put a filler piece along the inside of the corner and then a couple of layers of CSM so you get a brace



End result is probably similar to CoyoteThistle's solution, but if you want to prefabricate them you can still route out the panel core and position them internally in the end of the panel if you want an invisible solution

 

[Badmiker]

Thanks for the info guys. Andreas, where did you get the fiberglass angle? It looks like it would work very well. The other thing is since the Total Composites kit shipped with all the opening cutouts I have some pieces to experiment with the router on. Might end up with a combination of both methods as some of the edges will be covered (like all the floor ones). Can't wait to start this next step.

I found a company called Bedford Reinforced plastics, no affiliation just researching for our build.

https://bedfordreinforced.com/

 

[LocalmotionSC]

Carbon-Core has a good page on different ways to attach composite panels here: http://www.carbon-core.com/products/laminated-panels/veneer/

 

[KiwiMtnClmbr]

Another general issue with pultruded FRP angles for this type of use, or especially if you want to put a vertical load on it, is that most of the fibres and therefore strength runs along the length of the section as it is pulled through the mould to make it. Personally I would make some out of either chopped strand matting and/or woven fibreglass tape using a piece of aluminium angle as a mould - you normally can't get fibreglass to bond well onto aluminium so if it is waxed or treated with a release agent it should be easy to remove your sections - and you will get a lot more fibres and therefore strength going around the corner. If you really want to increase the load bearing strength of the angle put a filler piece along the inside of the corner and then a couple of layers of CSM so you get a brace

View attachment 488679

End result is probably similar to CoyoteThistle's solution, but if you want to prefabricate them you can still route out the panel core and position them internally in the end of the panel if you want an invisible solution

Hey Tanuki, do you have pics of the internal mounting you proposed here?

 

[tanuki.himself]

Hey Tanuki, do you have pics of the internal mounting you proposed here?

sorry, i was away for a few days

here's a dummy up using a piece of angle steel as a mould - if you use aluminium angle make sure the internal corner radius is smoothed out so you aren't trying to force the fibreglass into too tight a fold. The woven fabric gives max strength around the fold, and i was advised by the fibreglass suppliers (who also fabricate) to alternate woven and CSM to stabilise the piece in all directions and ensure good resin distribution

 

[KiwiMtnClmbr]

What is the makeup of that filler piece (material)? Is this what you did for your subframe construction? How was that handled abuse now that you did some miles?

Thanks heaps for sharing.

 

[tanuki.himself]

What is the makeup of that filler piece (material)? Is this what you did for your subframe construction? How was that handled abuse now that you did some miles?

Thanks heaps for sharing.

the infill is just a piece of polystyrene foam i had lying around to demonstrate. For the real ones i used a type of polyurethane foam as its not affected by the vinylester resin i was using (stronger than polyester)

My subframe was made up from pultruded beams as the bending loads were along the length of the beams where they have strength, but i used this technique for the cleats to bolt them together and in places where i needed strength in both directions like the jack mounting brackets. So far so good - no sign of any cracking or delamination in those pieces

 

[opp1]

we've found it easy with fiberglass just to make your own angles using a piece of aluminum as of mold. That way It can expand at the same rate as a wall