Sandwich construction

[GeorgeTelford]

Hi all,

quite fancy a tiny travel trailer, and wanted a quick version I had an Idea to square it up somewhat, so I was delighted to find the weekender.

Really would prefer some insulation, but dont fancy doing all the framework, first idea was build plywood version, then put up insulation and cover with a thein decorative ply, Next idea was make a sandwich of 1/2" Ply glue down the insulation then glue down the interior ply ie ake the sandwich before cutting to shape (botton would have batten in atr glue stage)

Here is some 40 mm I used in my old bus project



What do you all think? its pretty strong stuff.

[BobR]

George...the purpose of the interior framing is to provide support and to provide a place to anchor the bulkhead, doors, windows, shelves and whatever else you decide to put inside. With just the thin skins you won't be able to secure those items properly.

[GeorgeTelford]

Hi Bob

Thanks for replying I was beginning to think no-one was going to speak

All those items get fixed OK in the plain plywood weekender, why would that be any different with sandwich ? Please bear with me If I am being a little dumb.

[asianflava]

If you're doing a sandwich wall, you will need some forethought as to where things will attach to the wall, ie bulkheads, doors, etc. You need some "meat" for the screw to attach to.

In my case I'm using 1/8" ply for both faces weight reduction was a big factor. If you are using 1/2" you may not need all the framing on the inside, just on the perimiter to act as a closeout.

[Roly Nelson]

Hi George, I guess I am one of the rare guys that feel that 1/4" side walls are all you need. When I built the 1/2 Nelson Woody, I wanted to keep it simple, light and cheap. All of my openings are backed with 3/4 x 1 1/2" pine members, and my cabinet bulkheads, doors, windows, shelves and such only add to the strength of the whole thing. You can check out my construction pics at: http://gages-56.com/roly.html.

Just my two cents, it has worked for me for almost 3 years and during the 5500 miles to minden and back, it held together just fine. Building thicker and heavier is fine, but what do I know, I'm just a beguinner.

Roly, So Cal heat sufferer.......

[RAYVILLIAN]

I would think that a sandwich would work fine if you put some judicously placed wood where you wanted to anchor things. There was a post awhile back about doing a sandwich with plywood than foam and than plywood using frp glue and a kids swimming pool as weight to keep it together till it dried. You laid first plywood down, glued, than foam, etc. then put wax paper down to keep glue from sticking and put the pool on top and filled it with water. next day empty pool and do other panels. sounded pretty slick when I read it. I'm cinsidering it with Warrior II.Good luck.
Gary

[mikeschn]

I'm considering it with Warrior II.Good luck.
Gary

Tell me more about this Warrior II...

Mike...

[GeorgeTelford]

Hi all

I was thinking of dowelling for anchor points, water is a damned fine idea for the press, would even the pressure out beautifully.

Nice site Rolly! quite a few very neat ideas shown there and lovely finished product.

Really want to keeep the speed of the weekender + Insulation joping I can avoid pick too ( to an extent anyway)

George

[cracker39]

Roly, great minds think alike...

That is my plan...1/4" ply, 3/4" pine framing (1 1/2" unless I need wider for some reason) with 3/4" insulation foam, then 1/8" light oak paneling on the inside. The only heavy plywood I'll use is 3/4" on the bottom. Someone estimated the 3/4" to be around 75 lbs per sheet. That would make my floor weigh about 105 lbs. Prorating the weights of the 1/4 and 1/8 based on 75 lbs for the 3/4, estimating the total area of wood, I come up with a total weight of 356 lbs forall of the plywood. The foam is neglible, and the framing shouldn't weigh more than 50-60 lbs. It wouldn't be that heavy except for those rounded corner spars and the 9' lengths of 1 1/2"x2" floor support pieces on either side of the chassis. Add another 80-100 lbs for all of the interior framing and paneling (bed supports, closet, galley counter) and the weight of the mattress, the AC, Battery, 300 lbs for chassis, and another 100 lbs miscellaneous for anything I missed, I come up with less than 1200 lbs dry weight. Heavier than a TD, but still not too bad for what I am going to have. It will still be below my max load/towing capacity for my truck (2000 lbs due to 4 cyl and auto trans).

[Ron Dickey]

When I built the 1/2 Nelson Woody, You can check out my construction pics at: http://gages-56.com/roly.html.

If you could not pull it up try

http://www.gages-56.com/roly.html

Nice Job Roly