Simpe (and Cheap) Door

[Glenn Butcher]

I've been using the cold days to spend hundreds of hours planning my Simple build. Yes, there's irony here. I'm also keeping Simple as Cheap as possible, because I want to save my budget bullets for a better build if I find my dear wife likes climbing into the thing. So, I've been thinking through door alternatives. I'd really like to just purchase doors and shtick them in the hole, but $500+ is an expenditure I'd like to save for Better Build. Anyway, I've designed what I think is a Simple and Cheap door, and thought I'd run it up the flagpole here for target practice...

Here's the diagram:



Dang little album images; click it to make bigger. The door doesn't fit in the hole, it overlaps it, with seal trim mounted on it and contacting the L-angle that frames the door hole. FRP is the small layer on the exterior of the wall and both sides of the door. The door opening would be rectangular, but I'd round the door corners 3"-4" for aesthetics. Plastic channel runs around the door edge to enclose it.

I found a neat offset hinge to handle the door and trim thickness:



Took a bit of looking; they're made by "Sea-Dog", and are intended for boat hatches. I know I've seen hinges like this in a former life, but cannot for the current life of me find any others on the Internet. $20/pair at bargainboatparts.com.

Not shown are the window (Lowes, the Tafco mobile home window), and plastic L trim on the trailer wall around the door if I need to shield the wall-door interface.

I'm looking for any feedback that might keep me from investing time and $$ into a door design that won't work. I may be Simple and Cheap, but I'm not (too) stupid...

[KCStudly]

Looks simple enough to work, but I wonder how well it will seal in driving rain (driving as in going down the road at highway speeds).

looking closely at the hinge pins in that pic, they don't appear to stick beyond the surface of the relatively thin top and bottom plates. Is there a load rating listed by the supplier/maker? It would suck if the pin were to pop out of the thin hole. Still that is a very attractive price, especially if they are stainless steel.

So I guess I have taken a few pop shots, but better a considerate and informed decision, than to blindly go.

[jgrote]

The only problem with this design is the seal. It works great on paper, but lines are straight on paper. For it to really seal, both the door and the wall would need to be (and stay) really flat. Even a 1/4" of warping would be a problem. My concern in the door, not the wall of the trailer. Maybe you could add some metal to the door frame?

[Glenn Butcher]

KC,

Was counting on you; you're a very well-reasoned pundit, from my observation...

With respect to the hinge, Sea-Dog website doesn't have loading on the product page. The have a "Breaking Strengths" document that I assume covers all relevant products, but they seem to be having website problems and it won't download. Their intended application is marine, but I'm reasonably sure that doesn't consider the sorts of forces present in a trailer careening down the highway.

We don't get a lot of driving rain in Colorado, but my luck runs wet. I'll probably go ahead and do the plastic L-trim around the door to mitigate that.

Hadn't noticed the hinge pin. There's another dealer that sells them individually for ~$10, I may order one to inspect it. Thanks...

jgrote,

Yep, from poring over threads, flat is my worry. I've read other threads where folks describe dismay when their walls or doors warp; 3/4" ply for doors seems to be the practical minimum to avoid warp. I'm struggling with the 1/2" ply walls, trading between weight and simple. That's mainly why I included the aluminum L-angle door hole frame. I considered using bed frame material to make a door frame, but welding defies Simple...

I wonder if I can insure enough flat-ness in my wall by framing the door opening on the inside with 1x3 or somesuch?

[citylights]

If the hinge is weight rated, it would make a great door. The design would accommodate some warping and still seal. The seal is based on the thickness of the gasket and the compression. Warped door or wall will require thicket gasket and more compression! This hinge and door design is very accommodating and adjustable for that.

My problem with it is I like my door flush mourned with the wall. I ended up using a stainless gate hinge with spacers to make it work around the door trim. Similar type of compression seal though. My wall and doors are 3/4 ply with a 1/4 finish skin for 1 inch total thick.



By the way, this is another hinge I considered... There was an thread on here about someone who used these.

http://www.amazon.com/Sea-Dog-Line-Stainless-Reach/dp/B000Y87MIG/ref=sr_1_7?ie=UTF8&qid=1393479192&sr=8-7&keywords=Sea+dog+stainless+hinge

[Glenn Butcher]

John,

You bring up a good question: Trim-Lok has a variety of seal sizes and shapes; how much can one rely on a large seal to mitigate "un-flatness"?

[citylights]

John,

You bring up a good question: Trim-Lok has a variety of seal sizes and shapes; how much can one rely on a large seal to mitigate "un-flatness"?

As long as the thickness of the gasket compression is more than the out-of-flat gap... I should still seal. When the gap is more than the gasket will accommodate, seal problems!

[mezmo]

Hi Glenn,

I've thought about this approach before, myself, as it is a more
direct method and avoids the necessity of the fine-tuned-fitting
that a flush mounted inset door requires and thus may save
time. Here's my take on it:

I like the simplicity of this "refrigerator door" overlap type approach,
but there is the consideration of "driving rain" and the door's sealing -
'driving' as in wind-driven rain and the actual effects of driving the
rig through the rain on the highway. Of course, a drip cap above the
door is needed too.

To mitigate that, I would double seal the compression sealing.
Just use 2 parallel seals set far enough apart so as to not interfere
with each seals compression. Most new cars are using double - even
triple - seals now to deal with wind-road noise at speed. It should
work just as well for weather sealing a TD door.

Another thing I would do, would be to add a wooden outer perimeter
'frame' around the surface applied door, with enough spacing for the
door to operate smoothly, say of a 1x1 or 1x2 laid flat - or
an interrupting flange of some kind, the same thickness as the door,
at least. This would be to block the surface airflow, especially when towing,
from hitting the door seals straight/directly on, to lessen the chance that air
pressure could slip air/dust/water under the seal(s). This would also
act a a stiffening flange to help the plywood around the door's wall opening
remain flat. Aluminum angle could also be a possibility for this, the
flat leg being outward around the perimeter.

Cheers,
Norm/mezmo

[grantstew8]

It took me a while to workout I needed an offset hinge. I used a cheap brass one off ebay. The seals will simply compress against the body. Yet to buy the seals. The doors are not steel-like in their fit but with a seal should be fine. My TD is stored in a garage so my risk of a leak being unnoticed is low. I may end to add eyebrows over the doors to redirect rain but if I need to do that I'll need to make a plan for rain while towing.

[KCStudly]

Grant, unless I'm mistaking, the purpose of the door eyebrow is to keep water from running down the wall and in while the door is open, although some people do install deflectors on the leading edge of their door openings to deal with driven water.

Trim Seal recommends that the seal only be compressed 1/3 to 1/2 of its nominal diameter. Any more and the seal may take a set and lose resiliency, reducing its effective life and ability to seal.

I am using the interior flange method where the seal is recessed in the door opening and seals against the inner face of the flush fitting door. I'm hoping that this shields the seal from wind driven water and also protects the seal from abrasion due to "traffic" and casual contact.

I expect that I will eventually have to put eyebrows over my doors, but that is okay because I like the look of the polished aluminum ones.

[rowerwet]

for cheap, do a wiley window.
I could see the door working after the same idea as a wiley window (surface tension and gravity). I would make an inner frame 1" smaller than the hole in the side of the tear all the way around

make the door fill the outer hole, it is the way I did mine, this keeps the side of the tear cleaner and more aerodynamic. Plus you can use the cut out piece from the side of the trailer as the door.
basically you are using the side of the tar as your rain diverter for the front edge. I would still have an eyebrow over the top though, and bevel the edges of the door and the bottom of the door frame hole in the tear wall.
It is the way I (finally) did my doors. I tried exterior doors first and had bad luck...

I have a drip rail over my doors and an inner ring for them to seal against, even if the doors warp I'm not worried about leaks. The drip rail is just a 1x2 with a groove routed in the top.
I routed the surface of the door to make up for the seal thickness with the hinges.

[grantstew8]

Trim Seal recommends that the seal only be compressed 1/3 to 1/2 of its nominal diameter. Any more and the seal may take a set and lose resiliency, reducing its effective life and ability to seal.

I am using the interior flange method where the seal is recessed in the door opening and seals against the inner face of the flush fitting door. I'm hoping that this shields the seal from wind driven water and also protects the seal from abrasion due to "traffic" and casual contact.

Thanks KC. I've only looked at specific seals yet but your info has saved me re-inventing the wheel

[Glenn Butcher]

I updated my door design based on suggestions:



It has a second trim seal that contacts the wall and the end of the door frame L-angle, and plastic L trim glued to the wall, surrounding the door. Recall the door will have rounded corners, so the plastic L-trim will curve to follow that.

Thanks all for the great feedback! Now, to clean out the garage and get started...

[rowerwet]

as long as your door doesn't warp, it will work, an external door will look clunky IMO.

[Glenn Butcher]

rowerwet,

I do agree, it's not going to look as good as a nice flush door. What I'm trying to do is build a proof-of-concept tear to see if my loving wife, in the profile picture at left, will take to this form of camping. She's already nicknamed it "Coffin", and she has a bit of claustrophobia, so I'm spending more time designing a skylight. If she likes it, I'm then going to build a nice 5x8 with a galley and Nice Doors, and maybe scrap Clunky; otherwise I'm stuck with Clunky to go fishing and train riding, just me.

The third possible outcome is if she likes camping, but not the tear, so I have to consider a larger trailer, like a Scamp. I'd still keep Clunky then, but I'd have to find room in my closet for it...