Hatch seal with no notch walls

[Carl01234]

I know i have seen a post on here about how to do this. I am ready to start my hatch construction and can not get how this will work. I understand the hinge side. Just cant find the pics showing the seals. Build thread.....viewtopic.php?f=50&t=70427

[Woodbutcher]

I'm not sure exactly what you are looking for. What style of hinge are you using. If it's a hurricane hinge, is it flush or offset. There needs to be space for the gasket to fit under the galley lid. Most people run the galley skin over the sidewalls of the trailer and the gasket goes on the trailer wall. Some detailed pics of what you have might help.

[Carl01234]

The hinge is going to be flush. Maybe i misunderstood. I didnt cut my walls down any along the hatch. Is there a way to seal without cutting them down. I guess it wont be too hard to trim them down a half inch or so. I thought someone had posted a pic of how to trim it out without being cut down, but i can not find the image anywhere.

[Carl01234]

Here is the post i had read. http://tnttt.com/viewtopic.php?f=21&t=59270. I can not figure out how you have room for the seal without notching the wall?

[Carl01234]

So using the 1/4 inch offset hurricane raised the galley up enough for clearance of the seal? Can someone confirm this is correct? I am a little slow sometimes.

[Graniterich]

Yes, that is what the offset hinge is for

Sent from my A1-840FHD using Tapatalk

[Woodbutcher]

Are you placing 1/4" roofing on top of your side walls? If so, that gets you 1/4" gap using a flush, flat hinge. If you use an offset, then you have a 1/2" for gasket material.

Are you using a metal skin on your trailer? If so you will need some sort of edge molding to hold that skin down. So you must consider that thickness when you plan. If not I would suggest some sort of metal. There is an edge molding that is about 7/8" wide and has a 1/4" leg. (makes an L ) This can be put down on the edge of the side where the galley lid will close. This helps with the water not being trapped against wood when the galley is closed.



I do not have a great picture to show you. This is a different hinge then you are using but is a flush style hinge. I cut a notch for the gasket in my side walls. The side of the trailer had edge molding without the insert. The top piece on the galley lid had edge molding with an insert to cover the screws. If you want to do a real good job, I cut a thin strip of aluminum under the galley lid where the seal will go and drill through the insert molding on top of the galley and tap some small screws to hold the aluminum strip in place. This gives to a metal to metal area for the gasket and no trapped water can destroy your galley. But you need to make a sample mock up with all the thicknesses of everything to be sure that the gasket works. If you can not make sense out of what I'm saying I can draw a picture to clear it up.

in this picture you can see how the hatch works with all the metal.

[Carl01234]

WB, thank you for your time on this. I think i see it now. I had envisioned the roofing to run all the way to the outer edge of the walls, but using the wide t molding the roof will run to the t moulding, and the t moulding will bridge to outer of walls leaving a 1/4" gap. Using the offset hing will get me another 1/4" less the thickness of my trim on the walls? Thank you again for your time.

[Woodbutcher]

The roofing does run all the way to the outside edge of the sides. In other words if the trailer is 60" wide at the floor, then the roof panels should be 60" wide also. Place a heavy duty thick roof spar where the roof ends and the galley opening starts. When the roof material covers the spar and the side walls which should all be flush before putting the roof goes on. The spar that the roof and the galley hinge is important to be on square with the sides. The plywood roof is an excellent "square" to get the spar right. If the spar is off the galley hatch will not close right. No spar placement is more important then that one.

[Carl01234]

This is what I think im trying to do? This image is from Frank Bears website. If I do it like this the roof would stop at the inside of the t moulding and not go a the way to the outer edger of the the wall?

[aggie79]

That type of design would require either (a) a notch in the sidewall or (b) an offset hurricane hinge.

If you have a router, the notch is not to hard to add even if you're walls are standing up. Here's link with description, sketches, and pictures of how I cut my notch after walls were up: http://www.tnttt.com/viewtopic.php?p=1113721#p1113721

[Carl01234]

[quote="aggie79"]That type of design would require either (a) a notch in the sidewall or (b) an offset hurricane hinge.

If i set the t moulding on top of 1/4 inch roofing, will that not get me 1/4 clearance for a seal? I am going with an offset hinge to pick up another 1/4 inch.

[Staryder61]

That type of design would require either (a) a notch in the sidewall or (b) an offset hurricane hinge.

If you have a router, the notch is not to hard to add even if you're walls are standing up. Here's link with description, sketches, and pictures of how I cut my notch after walls were up: http://www.tnttt.com/viewtopic.php?p=1113721#p1113721

Hey Tom, great to see you on ,, your post is just what I needed.. getting close enough to start the hatch, so will use your post as a guideline..

[aggie79]

Your 2nd teardrop is looking great!

I know the hardest part of my build was, not necessarily building the hatch, but trying to get my head right on how to build the hatch. At least for me, thinking in 3D is a challenge.

My approach was to think backwards. I used a 3/8" seal. As a general rule of thumb, you want to compress the seal about 1/3 of the way. This worked out to a 1/4" gap. This gap needs to be 1/4" all the way around the sidewall - 1/4" up and 1/4" out.

I wanted to keep the hatch profile on the same general profile of the teardrop sidewall. To do this, the outer edge of the hatch "ribs" matched the profile, but the sidewall was notched to create the gap. Here is a (poorly drawn) sketch of what I did:



The sidewall edge is the heavy black line. The hatch rib is shown with the blue lines.

The other option is to offset the hatch "out" from the sidewall profile. In this example, the hatch ribs need to extend the chosen gap distance beyond the sidewall. Here is a sketch of this approach:



If you go this route, you have to use an offset hinge, and the ribs must be cut the gap distance beyond the profile.

If you use an offset hinge, but cut the ribs to match the profile, you'll have the desired gap at the hinge but you won't get the desired gap at the bottom of the hatch. The offset hinge will lift the ribs "up" but it won't lift the ribs "out". I believe this is the situation you are trying to work around.

In theory, you could use a thicker plywood "skin" on the hatch than on the roof to build out the hatch profile to the gap distance. However, the hatch is the last place you want additional weight, and adding more/thicker plywood will increase the chances of spring back in the hatch.

One solution to keeping your existing ribs and not notching the sidewall would be to add a "batten strip" beneath the hatch side of the t-molding and on top of the hatch skin to lift the sidewall side of the t-molding to the desired offset/gap.

[halfdome, Danny]

Vintage Technologies website has some pictures you may find helpful.
Found the following two photos under technical tips.
https://www.teardroptrailerparts.com/hurricane-hinge-w-flat-bar.html




HT06 Flat Hurricane Hinge
2-Piece Extruded Aluminum - Mill Finish!
Lower Profile Crown
Tighter "Nesting Pocket" within the Crown (less slop/play)
No Lid-to-Roof Offset!
Hurricane Hinge comes in several different lengths
Prices:
4ft -$52.00 - free shipping
5ft -$71.00 - free shipping
6ft - $90.00 - free shipping
add $19.00 for each additional foot up to 8' maximum length
Packaging Fee applies $15.00

HT06-01 Flat Hurricane Hinge w/Flat Bar
2-Piece Extruded Aluminum Mill Finish with 5/16" x 1" Flat Bar
Lower Profile Crown
Tighter "Nesting Pocket" within the Crown (less slop/play)
1/4" Lid-to-Roof Offset! (No need to notch wall)
Prices:
4ft -$62.00 - free shipping
5ft -$83.50 - free shipping
6ft - $105.00 - free shipping
add $19.00 for each additional foot up to 8' maximum length
Packaging Fee applies: $15.00
For more information on how to install this hurricane hinge look under technical tips
Hope this is of some help. Danny