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Some general planning questions prior to construction

PostPosted: Tue Jun 23, 2009 10:08 am
by Snide61
Looking into my first build and had some general questions that I've seen some answers mentioned, but I would like to ask again to see if there are any renewed opinions or links to articles I'm missing (there is a plethora of information on here)

I have a 4cyl to pull my future TD with, so I need to keep weight down:

- Would sandwich construction be lighter than 3/4 ply? (Assuming 3/4 based on some of what I've been seeing) I have several sheets of 1/4 luan laying around and several sheet of left over R-tech insulation from the building of my shop.

- Would coating the outter shell in fiberglass add too much weight as compared to aluminum or other sheeting materials?

- Should I not insulate the roof and sides if I only plan on camping during the hot months in the midwest (April-October)? I don't plan on installing an AC unit, only a hatch fan and 2-3 windows.

- Are the lightweight bolted frames (homemade I guess) with torsion axles very much of a weight difference over buying a leaf-sprun trailer to assemble?

- To cut the arcs for the hatch bows (etc.) do you just lay them out on a sheet of 1x12, 2x12, whatever fits the arc onto one sheet of lumber? Or is there a page I can read with a how-to?

Thanks for the help in advance!

PostPosted: Tue Jun 23, 2009 12:10 pm
by teardrop_focus
Welcome to T&TTT! :P

I too am planning a lightweight (under 600 lbs dry, but a loaded 900 lb going down the road)

You can use 1/2" cabinet-grade Baltic birch for the sides and skin it with fiberglass sheet. I think that to have aluminum as light as 'glass, the alum would have to be less than .030... and then anytime you'd look at it, it would dent.

There's a retired carpenter (just one title among his accomplishments) who's built a woody teardrop using 1/4" luan sides! His name is Roly Nelson, and if you want a lightweight teardrop, you owe it to yourself to discuss your build with him. He's a great guy and very helpful and experienced. Maybe he'll pop into this thread...

As for the chassis and suspension, I'm going with a scratch-built, welded chassis using a rubber torsion axle. I think that's the lightest, best-handling setup.

Good luck, and I'll pop 'round when I have more time later today!

PostPosted: Tue Jun 23, 2009 12:51 pm
by Roly Nelson
Hi, Snide61, I'll hop onto this one, after some prompting from Teardrop-Fucus.
First of all, you will have no trouble towing a tear with your four-banger, if you keep your build as light as possible.

I personally think 3/4 sidewalls and floor are a bit of over-kill. All I know is that my 1/4 lauan is holding up well, may not be the best looking plywood available, but was cheap and could be bought off of the shelf.

I can't answer your fiberglass question, you might want to inquier about that in a PM to Doug Hodder, a member of this forum. He is a whiz with that kind of construction and would be glad to help you out.

Regarding insulation. I have camped in the heights of the local mountains in 40 degree temps with only 1/4" lauan sides and roof and slept very comfortably in my cozy sleeping bag.

Air conditioning. I highly recommend a cheap AC unit, that you can carry in the car and hook it up after you get to the campsite. Many have come up with novel ideas on how to get the air in and out of their rigs, but my AC unit is slid into my tongue box and blows cool air in and up along the roof, through a scoop from the box to the inside of the tear.

I can't give you any advice one way or another about torsion vs leaf-sprung set ups. However, since I am one of the few that think a full-blown steel frame is not necessary, if I were to build another, it would be frame-less with only an angle iron bolted along the sides attached to torsion axles.
The tongue would go full length and attached to the wood flooring supports. A bit unconventional, but since the teardrop body gives you the strength of a solid box, a twisting, bendable, heavy steel frame, in my opinion, is unnecessary. Just my 2 cents, thinking out of the box again.

Now regarding the cutting of the hatch bows, I can tell you what I have done with some success. My "big" woody has bows like you discribed and were cut from 1x12 pine boards. The drawback is that the ends of these types of bows are weaker due to the severe cross grain. To counter this, I doubled them up with similar pine members, cut from straighter grain at the ends, which requires a joint in the middle. Glued together, with router-eased edges, they are solid as a rock. My "little" Stacker TD has bows made of a single layer of 1/2" baltic birch. They're much lighter, but fastening them from the other side of the plywood can be a challenge. I takes a bit of accurate layout, but can be done with some effort. You can see these in my album. The bows in my woody are seen at the URL below. Good luck.
Roly 8)