Issue Constructing Big Woody hatch

[Pointlookout]

We are making our trailer from the big woody instructions and hit a huge snag at the stage where you build and attach the hatch. You’re supposed to bend and affix 1/4” hardboard plywood over the curved ribs, which we did, but now the hatch doesn’t fit in the galley as it’s being “pulled” more straight. Without the hardboard attached it fit perfectly. We’re probably going to have to rebuild but want to avoid making the same mistake. Photos attached. Any advice?

https://imgur.com/a/qeXhaLR

[Pmullen503]

If the panel isn't glued down, you could take it off, soak it in water, pre-bend it on some type of fixture and let it thoroughly dry. You'll have to bend it to a smaller radius to account for spring back.

If you have to rebuild, you know about how much it straightened out so over-curve your bows or use one or two layers of 1/8".

[halfdome, Danny]

I think you need more cross members to control the curvature of the lid.

In the past I’ve used strap clamps to control the lid while the glue dries.

Clamp one end to a flat bench to keep it true and measure opposite corner to corner on both ends to the same measurement.
Even after I built 5 teardrop's on #6 the lid wouldn’t cooperate and I had to make another one.
You’ll need to clamp it a little more than need to avoid spring back.
If you can make a jig to check the lids correct lid curve that would be helpful.
I would recommend skinning and finishing the inside too.
While our teardrop sits in the unheated garage there’s a slight seasonal deflection but adjustable side clamps takes care of the problem.
Danny

[tony.latham]

We’re probably going to have to rebuild but want to avoid making the same mistake. Photos attached. Any advice?

Dang.

I'm surprised the Wyoming Woody plans call for 1/4" ply––as you well know, it's stiff. I would suggest you use two layers of 1/8" Baltic birch plywood bent with the grain. The stuff likes to bend.

And speaking of which, does your plywood grain run along the curve or left to right? If it follows the curve, that's part of the issue.

Here's a video of my wife and me installing the headliner in teardrop. It's 1/8" Baltic. You can see how bendy the stuff is.

https://youtu.be/rIUUaEKe4mw?si=u8KUWbgGn8Roxv74

Tony

[Modstock]

Yes, grain goes across side to side. Easier to bend.

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[Pointlookout]

We’re probably going to have to rebuild but want to avoid making the same mistake. Photos attached. Any advice?

Dang.

I'm surprised the Wyoming Woody plans call for 1/4" ply––as you well know, it's stiff. I would suggest you use two layers of 1/8" Baltic birch plywood bent with the grain. The stuff likes to bend.

And speaking of which, does your plywood grain run along the curve or left to right? If it follows the curve, that's part of the issue.

Here's a video of my wife and me installing the headliner in teardrop. It's 1/8" Baltic. You can see how bendy the stuff is.

https://youtu.be/rIUUaEKe4mw?si=u8KUWbgGn8Roxv74

Awesome video! It does look really bendy. Think I can just use 1/8th inch and call it a day? We’re attaching aluminum over it anyway so I’m not really worried about “strength” per se. did you use that same material for the hatch skin?

[tony.latham]

Think I can just use 1/8th inch and call it a day?

1/8" Baltic is absolutely strong enough for the outside of a hatch. But don't you need a full 1/4" with the Big Woody? If you do, just use two layers.

Tony

[Pointlookout]

Think I can just use 1/8th inch and call it a day?

1/8" Baltic is absolutely strong enough for the outside of a hatch. But don't you need a full 1/4" with the Big Woody? If you do, just use two layers.

Tony

So would we glue them together then attach them as one piece you think? Don’t want a repeat of last time! With the 1/4 inch we were considering doing kerf cuts to try and reduce the resistance but I don’t feel like we could do that with 1/8 inch.

[Pmullen503]

Get one down and dry and then add the second layer if you need it.