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lightweight and thrifty

PostPosted: Tue Oct 19, 2010 10:14 pm
by tuber
I'm a first time builder and have been following the two threads dealing with lightweight walls and thrifty coverings. I'm planning on making a TTT. The outside dimensions will be 56" wide x 96"long and 51" high. Inside will be 54" wide by 94" long by 48" high.

I'd like to make the floor from 1/4" luan with sandwiched 1-1/2" rigid foam insulation. Can you get luan in 10' lenghts? I'm planning to frame the sandwich with 2x2 and use 1x2 for corner braces. I'll use a 2x2 for joining the two pieces of luan making up the outer skins. My trailer is 48" wide and I want to make the floor 56" wide to accomodate a full matress and 1" walls. [The walls and ceiling will be 1/8" luan over 3/4" rigid foam with 1x2 framing and bracing.] This will give me a 3" cantilever on each side. Will this be a problem? The walls will fit over a 1x2 I've screwed to the floor. This 1x2 will serve as the bottom part of the frame for the wall sandwich. Will use similar technique to attach ceiling. I think this will give me good strength and rigidity yet light weight. What have I overlooked? I am assuming that it is fairly easy to get casing material for doors and windows that will wrap the 1" walls. Is this true?

I'm planning on using the 25/75 waterproofing on all wood parts. Do I need to coat the bottom of the floor additionally? What is a good product to use? I like the cloth and T2 outer covering idea. Should this be applied first before the bottom coating is applied?

I'm a screw and glue kind of guy so I'm planning on using white glue on all wood parts and then screws. Is there a better option? Really like the beeswax idea. Is T2 the right glue to use on the rigid foam?

Should wiring be installed in the walls before applying top luan skin or should surface wiring be used?

What questions should I have asked but I don't know enough to ask yet?

PostPosted: Wed Oct 20, 2010 6:15 am
by GPW
Tuber, all sounds Good to me .... Some cross spars in the floor may help ... use the roofing tar /cement on the bottom ... Don't seal any wood that will be glued solid or covered , the T2 or T3 is waterproof .. Do your Best work ... :thumbsup:

PostPosted: Wed Oct 20, 2010 11:21 am
by Tadlan
I'm doing ply/foam/luan sandwich walls. I am thinking of running wiring through the foam before I apply the luan inner skin. I should have some progress and pics next month. This month has not been friendly to my TD cause.

PostPosted: Wed Oct 20, 2010 11:43 am
by urban5
If I were you I would do a weight test with the 1/4 luan/ rigid foam sandwich you are talking about. Whats the reason for going so light weight?

PostPosted: Wed Oct 20, 2010 5:49 pm
by mikeschn
Your dimensions sound similar to the Puffin. Have you checked out the Puffin build here? http://www3.telus.net/~bve/files/Tears_ ... in.pdf.zip

Mike...

PostPosted: Sun Oct 24, 2010 1:22 pm
by tuber
Sorry I haven't been back since I posted the questions. Life got in the way.General question. How do I quote someones comments in my comment. Until I figure it out.

GPW wrote, "Some cross spars in the floor may help ... use the roofing tar /cement on the bottom ... Don't seal any wood that will be glued solid or covered , the T2 or T3 is waterproof " Planning one cross spar in floor, ceiling, and walls. Does this mean I only have to waterproff the interior wood walls? Will waterproofing the outer walls cause damage or is it just overkill because of the tar on the bottom and the cloth T2 on the ceiling walls? I am planning on overlapping the cloth T2 unto the bottom. I should do this before I tar the bottom, Correct? Am I correct in assuming that the 3" overhang on the sidew will not be a problem for the luan sandwich floor? Can I get casing material for the 1" thick walls for doors and windows? What is the best glue for the rigid foam insulation?

Thank you[/quote]

PostPosted: Sun Oct 24, 2010 1:24 pm
by tuber
Tadlan, What size luan and foam are you using? Were you able to find luan in 10 foot lengths? Do you have a galery?

PostPosted: Sun Oct 24, 2010 1:27 pm
by tuber
Urban 5, I want a lightweight trailer but I need to bring the floor up 3 inches to clear the fenders.

PostPosted: Sun Oct 24, 2010 1:29 pm
by tuber
mikschn, Thanks for the link to the PUFFIN. Mine is only about 52" high the Puffin is 81

PostPosted: Mon Oct 25, 2010 11:49 am
by Tadlan
No pics yet. Sorry. October has put some financial strain on my build. I did a test piece that was about 3' by 2'. It was very strong, rigid, and light. I could put it between two buckets and put my 197 pounds on it. I used epoxy to glue the ply and luan to the inner foam core. I will be using 4' by 8' of everything and will extend it to about 10', making sure none of the seams line up. I will post pics as soon as I get a little further. Hopefully next month. It is going to be a woody sided teardrop. I plan on staining the sides dark and having light trim. The trim will help serve as additional structural support, like an exoskeleton. Should be fun.

PostPosted: Mon Oct 25, 2010 12:18 pm
by urban5
tuber wrote:Urban 5, I want a lightweight trailer but I need to bring the floor up 3 inches to clear the fenders.


Yea, I understand you want a lightweight trailer, I was just saying that the floor seems a little frail to me. I would build it a little stronger, as far as the floor is concerned. I is ok to go light on everything else, but the floor is the foundation. 20 pounds ain't gonna kill the light weight aspect.

PostPosted: Tue Oct 26, 2010 5:06 am
by Lou Park
tuber wrote:Sorry I haven't been back since I posted the questions. Life got in the way.


You might want to get used to that.

PostPosted: Tue Oct 26, 2010 6:48 am
by starleen2
urban5 wrote:
tuber wrote:Urban 5, I want a lightweight trailer but I need to bring the floor up 3 inches to clear the fenders.


Yea, I understand you want a lightweight trailer, I was just saying that the floor seems a little frail to me. I would build it a little stronger, as far as the floor is concerned. I is ok to go light on everything else, but the floor is the foundation. 20 pounds ain't gonna kill the light weight aspect.

+1 :yes:

PostPosted: Tue Oct 26, 2010 9:27 pm
by DIY-Stu
When you build your sandwich walls, put one skin on, your foam, then draw out just about every thing you can possibly think of. Any lights you could possibly want. Fan locations etc. Locate a few different sizes of plastic semi rigid tubing and snake it through your walls hitting these locations. You can also stash small metal strips or "dots" between the tube and the inner wall to locate the tube in the future. Be sure to run multiple tubes from the battery or converter location to the back for your higher loads and distribution centers. One tube from the Distribution center out the bottom to the frame Just in case.

Another idea is to run these tubes from any and all possible locations to the underside so the sick out into the frame area. You can then run your bulk of wiring in the frame rail and the tubing can be smaller this way.

wiring in foam

PostPosted: Wed Oct 27, 2010 8:20 pm
by cappy208
I would suggest when making the walls, after you adhere the outside to the foam, to use a router and cut a slot in the foam, just deep enough to tuck two (or four) wires into at say 18" off the floor. You could run two or three sets of runs up to the roof wall edge too for lights. Then attach the inside skin on. Take pictures and notes of where the wiring is. Then when you want to install boxes, just use a hole saw (using a round jig to guide the bit without the center pilot bit) and just cut the interior luan. then you can dig out a larger area in the foam to put the back of the plug in (or just surface mount )
Image
In boats i have figured where i want a light or switch and 'folded' up a double wrap of extra wiring where i will fish it out later. so you could make the slot wider in the general area of the access point, to be able to fish out the wire later. You can buy 25' or 50' spools of 12 or 14 gauge stranded wire one of each color, to put these in and you don't even have to cut them to install plugs. Just use the crimp on splices http://www.harborfreight.com/50-piece-quick-splice-set-14-18-gauge-97990.html just my .02c worth.