Sidewall construction savvy with roof regards

[Wolfgang92025]

Regis,

Yes, I used Home depot PL Premium Polyurethane Construction adhesive.
Apply a thin coat, put wood on top and added the weight set to improve the bond.


Kenny,

It's going to be a Woodie, and I really do not enjoy working with fiberglass. I did the construction you mentioned on a topper for my F150 over 20 years ago. It work, but really hate the clean up. Other than being bulky, I could lift the topper by my self, and I'm no heavy weight lifter.


Wolfgang

[kennyrayandersen]

Kenny,

It's going to be a Woodie, and I really do not enjoy working with fiberglass. I did the construction you mentioned on a topper for my F150 over 20 years ago. It work, but really hate the clean up. Other than being bulky, I could lift the topper by my self, and I'm no heavy weight lifter.




Wolfgang

I can FULLY understand that; so, for just a bit more weight (i.e. using the 1/8 plywood instead of the fiberglass) you can get the same effect by using the plywood. If you bond it to the core and frame (and the core to the frame as well). You will end up with a panel that is actually stronger than solid plywood, and lighter as well.

[aggie79]

That's true, but I'm not sure how else you would do it except to suck a vacuum on it when it's flat on a table. Your suggested method will certainly work as well. I guess the point being is that the thin plywood warps a bit, but because it’s thin, it will also straighten out fairly easily. It looks worse than it is.

This won't work for a woody, but you can place your framing - 1x or ply - on the workbench, apply glue, add the 1/8" ply veneer, tack it in place with a few staples, and then use blocking and drywall screws fastened through the blocking, then the ply and framing, into the work bench until the glue cures.

[kennyrayandersen]

That's true, but I'm not sure how else you would do it except to suck a vacuum on it when it's flat on a table. Your suggested method will certainly work as well. I guess the point being is that the thin plywood warps a bit, but because it’s thin, it will also straighten out fairly easily. It looks worse than it is.

This won't work for a woody, but you can place your framing - 1x or ply - on the workbench, apply glue, add the 1/8" ply veneer, tack it in place with a few staples, and then use blocking and drywall screws fastened through the blocking, then the ply and framing, into the work bench until the glue cures.

Yeah, I guess you could do it that way. I tend to have maple workbench tops (but probably not in sizes big enough to make a teardrop side), which would be kind of hard on the top. I'll probably have to build a big tabletop to do a tear, in which case it will probably be MDF, which is another thing that you probably wouldn't want to screw into the top of (since it pooches up around the hole and would ruin the flatness). I'll probably stick with the vacuum.

[dh]

To jump ahead a bit, the roof construction should be a factor regarding side wall construction. Some Tear builders have an area with a flat roof. Spars seem to be the norm from front to back. I am of the opinion that 1/2" plywood is useable for the first 24" of vertical for those who build with this design. 5 ply plywood can also be used for the flat roof section.

How would you blend the thicker 1" (1/8 outer skin + 3/4 framing + 1/8 inner skin) sections into the 1/2" ply flat section without an ugly "bump"? Also, you would not be able to run electric in that section of the roof.

[regis101]

You're correct that it would be hard. My thought when I wrote that was with a cargo shell and not so much a cozy camper. The 24-30" vertical measurement would depend on the front radius. The horizontal would be less than 48" depending on the side wall thickness.

I now think that a sandwich style side wall is lighter than solid plywood. Same goes for the front panel and the floor.

I am new to (all) of this, in every aspect of the word. Great things can be learned in these pages.

Put on your glasses. There's gonna be some sawdust flying this weekend.

[EffieRover]

I was at Lowe's today. The plywood choices are poor. The best they had was 1/2" 5 ply hardwood, 3/4" 7 ply hardwood with either an oak or birch finish. These were the straightest choices. The top 3 sheets of the 1/4" stuff was bowed. The 1 x 2's and most of the 2 x 2's were twisted. I did see bundled packs of 2 x 2's that seemed pretty straight. So there is hope.

If you buy bundled lumber at Lowe's, have them unbundle it before you fork over any $$$. Once they snap off those straps, you may find the wood pops out in all kinds of random twisty directions. Been there, done that. Had to fight for a reverse of the charges (we were getting ready to load it up at the time). Just FYI.

[regis101]

If you buy bundled lumber at Lowe's, have them unbundle it before you fork over any $$$. Once they snap off those straps, you may find the wood pops out in all kinds of random twisty directions. Been there, done that. Had to fight for a reverse of the charges (we were getting ready to load it up at the time). Just FYI.

Ooo. Good one. Thanks for the heads up.

[kennyrayandersen]

Regis,
I'm in the process of build my tear. I used sandwich construction. 1/4" exterior, 1/8" interior with 3/4" framing filled with Pink insulation panels.
Wolfgang

That's OK for the walls, but on the floor, you would want the 1/8th on the outside as the outer ply is in compression when you are lying on the inside. The thin 1/8 ply has no problem reacting tension loads, but is less stable in compression. On the I-beam spar upper flanges in a plane wing as well as the outer wing upper skins are thicker because they are designed for stability, not ultimate strength. The point is a bit moot anyway, as the 1/8 inner skin on the floor is also probably strong enough as it is (i.e. you could most likely use 1/8 inch skins on both skin surfaces).