40s 50s teardrop rebuild (finally!!)

[noseoil]

You need to be very careful not to over-stress the frame as trying to fix it could cause more problems than you already have. That being said, a simple hydraulic jack with a chain or cable setup could be fastened in place (chain attached in 2 places, jack in the middle, chain on top) and the jack could then be used to gently "lift" the section needing straightening. I would use some timber to set the jack on and then figure out how much chain you need to fasten for the lift. It won't take much force to straighten the frame with a hydraulic jack, just be careful & do a little at a time, keep checking as you go.

[KCStudly]

I suspect that the 1/8 inch out of square and slight rail bend are probably the same as when it was built. The bend could be from the heat of welding the spring hanger on, and the 1/8 OOS could have been "close enough".

I wouldn't do too much worrying about it, and like your plan to pull it to the square cabin.

Noseoil makes a good point about doing more damage than good if trying to "fix" it. If you do decide to try the chain and jack method I would put some lengths of 2x4 under where the chain wraps so that it doesn't twist or crush. Also, consider placing a post between the jack and chain to get a steeper angle between the chain and frame. You want to lift the ends up, not pull them toward each other.

Some people have had good luck setting their frames on the ground on blocking and then "gently" driving their truck on, but it is something you would have to approach cautiously.

Again, if you think you can pull it to the cabin at assembly, I would take that approach. I think Aggie79 (Tom) did it that way using pipe clamps on the Silver Beatle.

[Dave K]

Upon closer inspection there where three bends in the frame. Two at the seams in the plywood floor. The floor had 4' pieces front and rear with a short section in the center creating weak points near the middle. Also had a bend the other direction where the tung attaches.

Thanks for the ideas on how to straighten the frame. Here is what I came up with using your ideas.



By putting the jack above and below I was able to take bends out in both directions. Spent a few hours going really slow moving the bending rig back and fourth and top to bottom to work the bends out. All the time using a string line to keep track of where things needed to go to get it flat again. Got it to within about 1/16" of being totally flat. Should be plenty good.

There is also about 1/4" of bow to the left side.

I am going to try to pull it out when I attach the frame to the ply wood. If it will not easily come out I will just live with it. I know I am not building a watch and things don't have to be dead square.

Now that I see the detrimental effects of the plywood seams I am going to try to find a 5'X10' sheet of ply to make the floor from.

[noseoil]

Dave, excellent job on the frame. As long as it works, who cares how it's done? Great idea with the floor jack for working in both directions.

As far as plywood is concerned, I'm not sure a 10' sheet (and the premium price you will pay for it) is really necessary. A proper joint (spline joint & waterproof glue, half-lap & waterproof glue) and a good adhesive are all that's really necessary. In boat building, they don't have 60' planks, but longer boats were built with shorter boards for centuries. If you're really concerned, use some fiberglass tape & epoxy resin for the floor joints and then a good sealant.

I just used 1/8" baltic birch, butt joints over 1x2 poplar framing, Titebond 2, & then covered it with 2 coats of urethane. After the urethane dried, I put a couple of coats of Henry's white roof coating on the bottom & left it in the sun for a while. I figure if this stuff can stand up to Tucson's summers, hail storms & rainy season, it should be fine on the bottom side of a trailer.