Hatch skin

[txturbo]

I need to get back on this project....but I have a question. Last Spring I purchased the aluminum skin for this TD. I got all the pieces cut to shape and I built a curved hatch frame. Thats where I left off. Now I need to finish the hatch. I made the framing out of 3/4" plywood...but I don't think its going to work very well. I was planning to skin the outside with aluminum and the inside with some 1/4" plywood or something. The problem is.....the frame isn't strong enough to hold the correct radius when the inner and outer skin is attached. It is going to try and straighten out unless I have the aluminum and plywood pre-rolled before I attach it. How does everyone else accomplish this? Do I need to build a stronger frame or pre-form the inner and outer skins?

[gregp136]

I used 1x2's in the whole frame. It was strong enough to hold the bend. It may also depend on what gage aluminum you are using.

Greg(and Laurie)

[txturbo]

I cut the curved pieces out of plywood and used 1x2 everywhere else. I think the aluminum is 18 gauge....have to check on that....it may be thinner.

[Woodbutcher]

I used 3/4" baltic birch plywood for my hatch. Then 1/8" baltic birch for the skin and then .040 aluminum.

Here is the link to my build journal. Page 2 has the hatch details, maybe that will help.

http://tnttt.com/viewto ... c&start=15

[txturbo]

nice....but I still don't understand how the frame keeps from spreading when you add the plywood and metal skins.

[Woodbutcher]

Not sure what you mean by spreading. Are you are saying the stress in the plywood is straightening out the curve in your hatch? If so add in a few more hatch spares. I made mine 2" wide by 3/4" thick. If you can find 1/8th plywood there is no stress in bending that. The metal will not add any stress either. Also I doubled up the top cross member on the hinge side of the hatch so I had plenty to hold the hinge.

[txturbo]

yes....thats what I mean. I finished framing it out this morning. Wating for some glue to dry then I'll see how strong it is.