Ok here we go...PMF!

[dales133]

I hear you and if I'd joined all the sheets given the time frame I would have got nothing done as I had no reliable help on call.
The top spar is bowed downwards but not so much outwards... I was fighting the bottom section and available light.
It's the spar above the floor level hight that's the issue and I figured that due to the fact I'd be doing it on my own A because I'm impatient once I decide to do something and B favors arnt all that reciprocal when you recall them that I couldn't be arsed waiting on said favors that I'd just do it.
I'm interested to hear what you think.
If i copy the front curve onto a "tounge box" I'll need anyway to house my engel fridge I may look at doing that.
I'm running low on funds currently and doing a course so I'm frustrated grŕrrrr

[dales133]

As far as the sheets meeting I'm putting a shelf inbetween.
Carpet and spotted gum similar to the back
The join dosn't need to meet precisely at all or I would have waited for thankless bastards help .
What do you suggest mate?

[Sheddie]

You could put another spar across where the two sheets meet, (or even just a strip of ply) then as long as the edges of the sheets are held tight together and glued, that should pull it back down. Make sure the edges on both sheets are straight.

[dales133]

Yea it isn't there tats an issue Frank. It's the second spar up that's bowed and will stick out like dogs bits later on.
I've got the join covered, it isn't an issue at all

[felixx]

Keep coming along!

[Sheddie]

When you refer to the second one up, do you mean the one at the top of the verticals or the next one? Is it going to cause a problem on the inside as well or is it just on the outside? If it is just on the outside and you are only talking 1/4", why not just plane it flat?

[dales133]

Ok I'll try to explain it better.
The spar against the floor is perfectly straight. Both horizontal and vertically.
The 3rd one up the same.
The 4th one up that your noticing it bowed upwards and very minorly outwards...This one I was planning on planing if need be.
The 2nd spar, the spar in question is the issue as it's ended up with a considerable bow.
It's about 10 mm and whilst I can plane it out its an important spar as two people's body weight will be leaning on it plus I realy don't want to be sanding that much off the foam at the start of a curve.
I envisioned issues with the join but I intended routing a 4 mm groove in some 18mm ply and inserting the bottom sheet into it and fitting a spar on top of it and creating a shelf with a box under it containg 12v sockets below the shelf and the next sheet joining atop this.
It's not ideal but anyone who's built a tear drop can appreciate how difficult this stage on thier own coming unstuck somewhere.
Where it counts it looks great ie the sheet joins. I just don't wand a bulge out the front or a weakened structure.
One thought I had was to cut the offending spars out now the other glues set and redo them

[Atomic77]

It's hard to offer advice from a picture... But I'll say this... don't let it get to you because things like this are just going to happen. It's just part of it. If we were building from a kit it might be different...And if it was easy everybody would have one. As for the spar, do you know what caused the bow? Was it the outward pressure of the bracing? I guess I would try to pinpoint what happened, just so it doesn't happen again. My thinking is, you are probably going to have to remove the spar and replace it just so it doesn't cause problems down the road. Or, you might put vertical bracing between the spars and try to pull it in but I'm thinking it will just pull against the verticals. I had a couple spars that caused me issues as well, and as much as I hated doing it, I cut them out with a sawzall and replaced them. I was very careful to remove them from the plywood as I didn't want to damage everything but it worked. Once I got the new spars in, everything was perfect and now I'm glad I did it. Just my two cents my friend hope everything goes ok. Wish I could come give you a hand but it's a little bit far lol.

[dales133]

Lol just A little far.
I'm inclined to agree with you.
I think I might replace it with a 35x35 spar if I do as opposed to a 19 35.
I'm assuming it was the bracing that did it.
I was covered from a hole to breakfast time (nz saying) in black polyurethane adhesive, Mrs was angry at me, was getting dark and starting to rain.
If it wasn't for the fact 30 bucks worth of adhesive was going off I would have thrown in the towel til another day.
I'll look again tomorrow but I'm inclined to remove it

[KCStudly]

I'm inclined to say just leave it be. If it's going to be hidden behind your tongue box, where is the harm? Remember, you are looking at everything with a very critical eye. Unless it will bug you "forever" or will create serious problems later, I'd be inclined to leave it. Besides, I would think that you would want to leave a small gap, say 20 to 25mm between the TB and cabin to allow for any flex in the tongue and prevent any place for water or debris to get trapped.

As a corollary: On my build the first two 1x2 roof spars (on edge) after the forward cabinet frame are bowed inward (down) a similar amount. I believe this is due to the strain in the front radius and arc of my roof where the ply is trying to go flat again. The walls won't compress but the spars can pull down. It is not visible from inside, so I don't care about that, but when you stand at the side door and look across the roof it is pretty obvious. My concern now is that it may allow water to pool on the roof. If I had it to do over I would have used 2x2's. Used them for the fan frame and there is no issue there. When I get to that point I will look at adding a shim across the tops of the spars and seeing if I can get the foam to match.

[dales133]

Yea I'll look again in the morning and see what fresh a perspective brings.

[tony.latham]

Yea I'll look again in the morning and see what fresh a perspective brings.

I may be missing something, but can't you add ribs at this juncture?

Sometimes I think we need to start a fresh thread on; what kept me awake at night –staring at the dark ceiling– and thinking about, "how I'm gonna fix this?

Something will work.

Tony

[Sheddie]

Good morning Dale, it's a new day you can start looking at it with fresh ideas. If you are still wanting to flatten it out you are probably better to remove that spar, (as long as it is not too much of a mission) as once the glue has set it will be wanting to hold that shape. You will find that the ply is wanting to bulge out there because the curve starts at the next spar and the ply is wanting to straighten out. It is held firmer down the edges but the centre can push out. Going wider with the spar will not have the same benefit as going deeper, but that would mean altering all the spars and I doubt you want to do that. The other thing you could look at if you did take that spar out, would be to space out two in there instead of one. Just some more ideas to think about.

[dales133]

Think I'm going to cut it out.
Probably less performance than sanding the foam back.
About to head back home and make a decision

[dales133]

Sometimes I think we need to start a fresh thread on; what kept me awake at night –staring at the dark ceiling– and thinking about, "how I'm gonna fix this?

Something will work.

Tony[/quote]

Ain't that the truth tony.
When everything's going right you realize you forgot to do/buy something or when your trying to get something done in limited time you almost know it's going to cause a problem.
I don't know how many nights I've spent thinking about how to tackle something