The panels SHOULD be fine with a single layer both sides and the seams taped inside and out, but a final layer of cloth on the outside will positively lock all the panels together. It will take a little more cloth, but I will most likely run the outer layer on the bias so the strands are oriented 45 degrees from the first layer. If the extra cloth is going on anyway, it makes sense to give it the maximum strength, especially since I can only really make educated guesses as to the loadings involved.
It will also make it a little easier to fair the seams in - I can fair them before I put the outer layer on without having to seal the fairing compound or worry about anything telegraphing through the paint.
BTW, how's your Road Foamie build going ?
Or did you get sidetracked after getting the jockey box in ?
'TLAR'...that DEFINITELY needs to be a graphic on the trailer somewhere.
Thx KC, it was probably reading your mention of it that made me think of it.
EDIT: Found it !
KCStudly wrote:I call it, 'that looks about right' engineering.
I think I'm going to cut the openings oversize and use wood trim with a rabbet for windows, doorstops, etc instead of doing it all in foam. When I built the door jamb, I allowed 1" on the top and sides as a doorstop. That cut my finished opening down to 22" wide which, now that I've tried it on the trailer, is a little narrower than I'd like at the shoulders. I think I'm going to cut the stops out, glass it flush, then add wood stops later (like a residential door). That will give me back about 23 1/2" if the stops are 1/4".
With the door, I hacked out the recess to flush mount the (fixed) window and laid down some thickened epoxy but it will be tricky to sand flat without trashing the surrounding foam. It's not a big deal with that window because I'll be using black adhesive and the substrate won't show, but I'll still know...
On the others I think it will be far simpler to just lay in a 1X cedar frame around the windows like others are doing here.
The skylights are fixed pieces of tempered glass about 5' long, so I'll make a cedar surround and rout a recess for the glass, which will be glued in. It will be flush on the outside so water runs off. Cedar is my pick because I've used it with epoxy before, it's porous so it absorbs resin really well, is really light, and it's local so the price isn't too bad for clear stock...I might even have enough on hand.
To join them to the foam, I'll do what I did to join the fir threshold to the foam jamb. I used 3/8" dowels that ran from underneath the wood and up into the jamb 3" or so. The holes were a little oversize to allow for the PU glue to expand and it seems to have worked like a charm (in addition to the surface joint).
I'm off tomorrow so the plan is to get going on the nose (weather dependent), trim off the doorstops, and and to get some sealer onto the threshold. I may have lucked into a gallon of 105/205 for cheap and I have about 5 yds cloth so I may start glassing sooner than later. The curved center section of the roof will be the first on the table, so fairing that is on the list as well.