Teardrops n Tiny Travel Trailers

This seems like something that should have been kicked around ad nauseum by now, but a search came up dry.
I've found one supplier for Hurricane hinges in Canada but it's a bit more than I want to spend on one. Getting one across the border is out as well, so I'm left with either forking out for the right stuff or getting a stainless piano hinge through my marine wholesaler (boatbuilder and marine tech by trade). Don't get me wrong, I have no problem if its the only thing that works...but I don't think it is:

The piano hinge I'm looking at is 3" wide and made from .060 (IIRC) 304. I'll have a strip of thin belting over the outside of the hinge and screwed in via the same fasteners so leakage shouldn't be a problem. I'll also have room on the spar below the hinge to rabbet for a seal if need to. Any thoughts/problems/concerns spring to mind with this arrangement ?

(Paper standing in for belting)

Water can leak around the fasteners through the belting.
The puckered material, when the hatch is closed, will have to "go" somewhere.
Will there be a recess?
If so, where will the water go that collects in the recess?

Using fabric or rubber with a piano hinge will work, but it works much better on top of the hinge.
The biggest consideration is sealing all the penetrations.screw holes, and letting a bit of hinge hang over the sides to direct water from abouve the hinge to exit over the side, instead of following the hinge and going inside.

Rob

2 Stanley strap hinges and some rubber.





All 4 of mine were built this way never a leak.

I will be using a piano hinge and rubber strip in an effort to streamline the looks at the wall to roof join, but all the same here is what I have gathered.

You want to make sure to use EPDM rubber due to its UV resistance and outdoor rating. Pond liner material is one option. I wanted to buy to my exact spec (size and material) so ordered some rolled strip from a rubber sheet goods supplier. The cost of the strip and hinge ended up being about the same as a hurricane hinge.

The rubber should go on the outside to keep water and debris from settling in under the hinge. The excess rubber material can then bulge up, acting like a rain diverter.

Screws shot thru the rubber do not provide stable clamping for the hinge, so it is better to attach the hinge first then add the rubber retained by additional trim strips, such as flat bar aluminum.

I plan on drilling additional screw holes in my hinge leaves for the trim screws. That way there will be a full complement of screws securing the hinge structurally, and the added trim screws only need to compress the rubber enough to bed the sealant used.

Because I want a rounded transition from roof to wall (3/4 inch radius) with nothing jutting out, the hinge will stop short of the radius, but the rubber and forward trim piece will continue to wrap down the side wall an inch or so. The rear trim will stop short of the radius with the hinge, hopefully allowing the small portion of rubber flap there to flex enough when the hatch is open, but still creating enough of a diversion for runoff and keeping it from curling back into the galley.

Yet to be seen, but that is the plan.

Thanks for all the input fellas.

Rob,
I'll be using lots of SikaFlex (LOT291) to bed all of the exterior fittings. I spent a lot of time building boats for a living and, if there's one thing you remember, it's that you can never use too much sealant ! With the material wrapped over the hinge when closed, I don't see the 'puckered area' you're talking about. I figure it should have enough flexibility to deflect out of the way when open (second pic). I thought about laying the rubber flat and using a couple strips of aluminum to clamp it (with sealant as well) but figured this would be an aesthetically 'cleaner' installation. That said, it sounds like putting on the flat is the way to go.
Thx for the reminder on the overhang - that's exactly the sort of thing I'd forget to do

Bob,
Thanks for putting up those pics ! Looks like that's definitely the way to run the rubber. Any leaks or anything you'd do differently from that example ?

KC,
Once again, thanks for doing the legwork for me...sounds like pond liner is a great choice. Good point about the rubber flexing between the hinge leaves and the mounting surface - I hadn't considered that. It might sound like a trivial consideration at first but given time, vibration and open-close cycles, especially being screwed rather than through bolted I would expect to see the threads pull out.

I plan on drilling additional screw holes in my hinge leaves for the trim screws.

So it sounds like you are mounting the hinge open on the flat (when closed) rather than the having leaves in the recess (like my first pic) ?

Ok, so it seems the take-away here is to lay the rubber flat and get a good clamp with some strips of aluminum a la Bob's pic, making sure everything is well bedded and piano hinge ought to be fine.
I had thought about using a chunk of firehose for the seal but we have hundreds of feet of ~18" wide conveyor belting at work. If it's flexible enough, it'll cost me a case of beer at the most. The piano hinge is through my marine wholesaler is $40 for a 6' length vs $125 + shipping for the hurricane hinge. If I have to bring one across the border, it'll be the same or more by the time it clears.
I can also use the piano hinge offcut elsewhere as butt hinges for the doors, etc.
Thanks again for your thoughts !

Yeah, I'm going to lay my hinge flat on top. I figure it to be about the only way to make sure that the hatch is squared up while doing the install. Now that my hatch is mostly built and the gap between the spars moved a little wider at one end, I'm glad I planned it this way; the hinge won't care if it is 1/4 inch gap at one end and 5/16 at the other.

Ah, gotcha....I've never hung anything as big as a hatch off a piano hinge but even smaller stuff is a pain to keep lined up while installing it. I was going to jig the hatch into place while I did it, but if it's going to be covered with rubber anyway I may as well keep it simple and do likewise. Thanks for the clarification.

I used strap hinges and a piece of flashing.
I bent the aluminum flashing down into the crack between the teardrop and the hatch. In a upside down _/\_ fashion. With the bend into the crack the flashing has very little flex when you open and close the hatch and no UV protection is needed with the aluminum.

So if I'm reading you right, the flashing is screwed to both the hatch and the spar and flexes (albeit not very much) at the point of the V when the hatch is raised and lowered ?
Have you noticed any work hardening (cracking) along that edge ?

I have not seen any cracks. It actually flexes a little all three bends but mostly on the two 1" sides. Try it yourself with a small piece. Like a piece of a soda can.
here is a crude drawing click to enlarge

Gotcha, I see exactly what you mean. I think it will need a bit bigger gap than I've allowed for but I like the idea, thanks for sharing it
This board is a gold mine of info for sure

Have you looked into the live plastic hinge? Mine is four years old and lives outside year round in new england, no leaks and going strong.

Thx for bringing that up, RW.
I've read nothing but favorable opinions from people who have actually used them but I'm still somehow biased against bending a piece of plastic back and forth so I narrowed to a hurricane or piano hinge. I'm thinking of using a living hinge to swing my little Delta table saw down into its cabinet, so it'll definitely in the running for the next build.

Oh yes, there will be another build.....

Wobbly Wheels wrote:I've read nothing but favorable opinions from people who have actually used them...

I recall reading at least one person report that they had what they would describe a s premature failure. IIRC, they attributed it to cold weather usage (but then again my memory doesn't seem to be getting better with age, so...).

KCStudly wrote:

Wobbly Wheels wrote:I've read nothing but favorable opinions from people who have actually used them...

I recall reading at least one person report that they had what they would describe a s premature failure. IIRC, they attributed it to cold weather usage (but then again my memory doesn't seem to be getting better with age, so...).

Yes you would expect that regardless of how well made or designed those plastic hinges are there would have to be a finite number of cycles at witch point it would fail, particularly with a heavy hatch attached
I like this piano hinge idea btw might use it myself.