Kenskill style build in Delavan, WI (Now Cub Modern)

[breb]

I have a couple of minutes before I have to go into work this morning. 4-5 hours today is probably it for me for the week . last week I didn't log any time on the part time. I may be getting closer to calling it on this part time and become a full time on my TD. I see your rib at the floor is flush to the back edge of the trailer. Are you finishing that back edge of trailer deck with some trim and are you putting a cap piece on the face of those ribs or just in between them? Or both? Are you putting any bridging between the rib's? Just getting your thought's on it.

[KCStudly]

For me the hatch rib orientation didn't require much thought at all. The plywood skins, both inner and outer of a traditional curved profile build, are always going to want to spring back to flat, so the rib structure needs to resist that. The deeper the rib section the higher its moment of inertia (I^4... ability to resist bending).

If done with just two outer profile ribs with horizontal spar like spacers in between, only the outer ribs are resisting the 'un'-bending, and the spars would just act like spacers... for the most part. Yeah, there is some resistance due to the different arc lengths and the skins desire not to compress or stretch to overcome this, but that is the same in both configurations; one might even argue that it is enhanced in the vertical rib orientation where fasteners/glue can be placed more frequently along the critical axis.

Think about it this way, if you built a hatch with only horizontal ribs and no vertical ribs along the sides would you expect it to hold its curve? I envision those articulated hinged toy snakes from our youth.

Okay, maybe not that bad, but I hope I am getting my point across on why vertical ribs are better for a curved hatch.

[Carl01234]

I am about to start my hatch assembly as well. Keep the pictures coming.

[breb]

Did you have to look long for the I.E snake ? I like but I see so many that do just the opposite and run the horizontal. My own dilemma on the hatch is more on the side seals. I have the thickness of outer wall, inner core and interior wall to contend with and i'm not sure i will cover with T trim . I have thought of a way to reach outer wall where seal will be mounted but it involves a lot of detail work. The construction of the rest I don't see as issue and actually looking forward to that part. It'll mean I'm that much closer to the end.

[Mr. Lahey]

Just finished cutting the replacements for the two ribs I screwed up yesterday. Glad I did it. They are way better and will fit much nicer to the hatch skin.

Here is the plan for the rest of the hatch. First off I'm using a Fredericks style side wall seal system. So the outer most hatch ribs are made of 3 parts.
1. Outer exterior rib
2. 3/4" wide by 1" tall inner seal spacer
3. Inner galley rib
Those 3 parts laminate together to make a deep U shaped channel to mount the weather strip in.

In the photo below is how I'm going to handle where the hatch meets the body/rear bulk head. I used a large oak beam across the tear body. I have a second matching beam that will be the leading edge of the hatch. The two beams will be spaced to allow my weather strip to compress between them when the hatch is closed. The plywood spacer shown between the beams gives me the right crush distance for my rubber weatherstrip.

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The second photo shows my hinge and rubber seal strip. They are not in the right place. Just laid up there to get a pic.

The beams are as wide as they are because I have about a 3" wide piano hinge for the hatch. I wanted to screw that hinge into hardwood. I am going to seal the hinge with a continuous strip of rubber. I am leaning toward using the rubber under the hinge like a gasket. Down side is I'll be drilling a lot of screw holes through the rubber. Alternate would be to cover over the top of the hinge. Which now requires more metal strips to secure the lead and trailing edge of the rubber to the body. All my surfing on the site here says both methods have been used successfully. I do think the rubber under method would look nicer. I'm all about the look. So most likely I'll go that route.

As you can see in the top photo above the beam oak beam will touch the outer rib and get screwed and glued to it. You can also see the center weatherstrip spacer right next to the rib and touching the beam. The underside of the beam is undercut to match the thickness of the weatherstrip spacer. So my seal will have a continuous rail to glue to from rib to beam. The galley side inner rib is not shown in this picture. It will sandwich next to the seal spacer.

As far as mounting all the inner ribs to the beam I'm thinking I will make some deep dado cuts in the beam to position and mount the ribs to the beam. I will "l" notch the ribs to match the dado cuts so I get a smooth upper skin surface from the beam to rib mount/transition point.

The bottom edge of hatch ribs will have an oak face cap to attach too, across the full width of the trailer. The inside edge of the body will get a 90 degree aluminum L angle across the top edge and rear face of trailer body. The oak beam will be spaced away from the rear trailer face for weatherstrip crush distance. All the weatherstrip will be mounted to the hatch. Not the body.

I have 2 barn door spring lock bolts I am going to use to lock the hatch. These usually go at the tops of doors, have a chain and ring that hangs down. You pull on the ring and chain to release the bolt and open the door. I am going to use them horizontal and attach the ring and chains to an exterior locking garage door T handle.

I also plan several horizontal stiffeners between the vertical ribs. I'm very tempted to use some leftover cedar fence pickets to make them from. Very light weight and will glue an hold to the hatch well. I am also going to cut some aluminum plate I have to follow a good 8-10 inches of the hatch ribs. These plates will be screwed to the ribs to reinforce them for mounting my gas lift struts. The skin will be PL adhesive attached to the ribs and stapled with 1" staples. Going to frame and skin the hatch in place. then remove it. I will take out my rear galley cabinet before I build the hatch, so I can get to the galley from the cabin. Then I can unscrew the hatch from the body when it's built.

I was really debating the whole horizontal vs vertical ribs thing. To the point of "analysis paralysis". In other words not getting anything done. I truly did leave my rib direction choice to fate if I had the material on hand or not. As KC Studly pointed out there is a strong theoretical case to use vertical ribs. As dozens of builders up here have proven, horizontal works fine too. Multiple practical success stories on the board here for that way too. Truly a coin toss to me.

Next week I will have another 8 day stretch off from work. Hope to get at least 5 days of it out in the shop hammering away on this. I'll keep the progress pics coming. As always I welcome some alternate ideas or feedback to my hatch plan.

[KCStudly]

My piano hinge is similar to yours and can fold back on itself far enough with plenty of extra throw, allowing it to be installed flat side up with the barrel nestled down in the gap between hatch and cabin. That will allow the rubber strip to lay flat across the hinge and look much sleeker to my eye, even with the extra hold down trim. No bulge over the barrel. This will hopefully help the rubber to form more easily around the radius I added between roof and side wall, without puckering or buckling up in the middle of a would be crease. The idea of wrapping onto the side wall is kind of like the same concept as extending a hurricane hinge out past the side wall to keep water from rolling back into the gap... the rubber will wrap off the roof/hatch onto the side wall slightly covering the vertical gap at the front sides of the hatch). By wrapping the trim around the radius onto the cabin side and leaving it short on the hatch side I hope to still have enough flexibility for the extra flap of rubber on the side edge of the hatch to lift up (without tearing) and form a taco shaped gutter or down spout w/ the hatch up (preventing water rolling off of the roof from wicking around the end of the hinge). With the hatch closed it should still lay flat on the side wall like a horizontal shingle not tending to lift while driving. By having the front trim wrap down the side wall slightly I hope to prevent driving rain from getting into the leading edge of the hatch, while also keeping the rubber from fluttering in the breeze. We will see, it is all just conceptual at the moment.

You're absolutely correct, plenty of people have reported success using all manner of different techniques. i happen to buy into the argument, and some peoples experience, that putting the rubber under the hinge can allow the hinge to squirm around and the fasteners to get loose under the high leverage action it sees (maybe a combination of other choices skewing the success bell curve... screws into pine, not oak... no sealant used... who knows?). It is a little more work, but I drilled a second set of off set screw holes through my hinge leaves so that the hinge can be solidly screwed to the oak headers first; and the the rubber can be sandwiched by the trim using the second set of holes. That way the hinge is not relying on screws that sandwich rubber, either top or bottom, to stay secure; one set locks the hinge in place and the other adds to it by sandwiching the rubber.

Another argument for rubber on top is that it keeps moisture a debris from collecting in the hinge; would much rather have that stuff shed off than nestle in.

[Mr. Lahey]

KC- You just made my day.

I could have looked at that hinge for hours and never thought to install it with the barrel down in the gap! Pure gold of a tip there, and thank you for that. Funny thing is that as I was rethinking things today I had decided to put the rubber on top of the hinge as well. For the same reasons you stated, to keep the weather and debris out of it.

My thought was to just over hang hinge and rubber ala hurricane hinge. I will have a look at your concept of wrapping the rubber around and see what I think. Just came in from an after work belt sanding session on my hatch ribs. I clamped them together, but had to do that in two stacks. Did not have big enough clamps to get them in one stack. They came out great. So the skin will have a consistent shaped surface across the width of the frame to attach too.

I thought I was through for the evening. Just came in now for a quick dinner. Was going to call it a night and snap on the TV and Netflix. Now you have got me going back out there again. No way I can't try flopping that hinge over, and playing with that a bit before the night is over.

[KCStudly]

Hope it works out for you, too!

[Mr. Lahey]

Only had a couple hours to work on it today. So I jumped back on the lower galley cabinet I had set aside. I now have all the storage cubes fitted with there shelves. So I'm done with the cubes. I'm glad. Wasn't my favorite work for whatever reason. Also cut the doors for the cabinet. They aren't fit yet, but cut to rough size. Trimmed down 2 piano hinges I had around to use with the cabinet doors. Slowly chipping away at it.

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[ojgrsoi]

I'm really enjoying your build. When I grow up I want to hand you tools.

[Mr. Lahey]

Mark
Now that's a good one. Got a good laugh out of that for sure.

However since I don't know your current skill set, we may want to start you out a little easier at first than tool handler guy.
Maybe you could stop over and mow the lawn for me. Give me more time to work on the tear.
We can see how you do there first. Then talk about promoting you to tools.


Not too much progress to report. Took the lower galley cabinet back out, so I could install the spare tire hold down hardware to the galley wall. Also forgot to mark the cabin side of galley cabinet for it's birch plywood skin. I want the cabin side to match interior wood. So it will have to go in and out again. No big deal.

So while I had it out I changed something that was bothering me about it. The partition wall for the spare tire followed the top curve of the spare tire. At the end of the cabinet it stopped flush. As I looked at it it just bothered my eye. So I lap jointed a piece of ply on the cabinet and continued the curve of the tire. Right down to the floor of the trailer. Looks world's better to me. I just knew I would be sitting in a lawn chair camping some day. Looking at that unfinished curve and have it bother me. So no more worries there. Talk about being a nit picker...

[breb]

Ok read your last post and figure your busy with the the part time job. Your progress looks good . I am deep into the interior cabinets , very detailed and even switching plans a little which lead to more cabinetry. I read a post you made on another build journal . I wonder do you have any photo of your northern fenders mocked in position? I see they sell a 10 1/2 wide plastic , which is what i need. I looked at the northern web site didn't know I could get fender's that wide which is what i need. My wheel stance is just a tad long away from the side of trailer . So i could use something in 10"- 11" wide. Are you working on your galley hatch?

[Mr. Lahey]

I figured if you had not posted in a while you were making sawdust in the shop. Glad to hear it.

Mostly I've been bogged down in the details of things. Took longer than I thought to final fit upper galley bulkhead cabinet doors. Had to get them done so I could install the upper half of the galley bulkhead. It is now glued and final installed in place and fit to the oak beam on the body side. Then I went to mock up galley side oak beam for the ribs. Turns out it had a weird dip in it from a knot and wild grain section. The exterior skin would have followed that dip. Would not have looked to cool. These beams are recycled pallet lumber. One was excellent. This other one not so much. So I just today cut a replacement for the bad one from an oak 1x3.

Found an issue with the outer hatch rib weather strip channel on one side. It was too deep and not crushing the rubber enough. Had cut an 1/8" x 3/4" pine strip and glue/clamp it into the weatherstrip channel. Now things crush just fine.

Needed a tad over 5' of aluminum angle to face the lower edge of galley. Home center wanted outrageous money ($18) for a too short 4' piece. Was almost going to do without and go a different way. Then I remembered the old school lumber yard were I got the 10' long sidewall plywood was also a metals supplier. Picked up a 6' chunk of required angle from him for under $10. Just what the doctor ordered.

Been spending a lot of time in my staring chair over this hatch framing. Figuring how I want to attach ribs at top and bottom. I also want to build lower edge to let weather strip seal, but not crush. In addition to the spring bolt latches I have in mind I also have rubber T handle like bungee latches. One for each side for the bottom of hatch as well. I don't want the pull from those to crush and distort the weather strip. So the seal area needs a positive stop to keep correct gap for weather strip. I think i have most of this figured out.

Have not mocked up my fender. Mine are only 9" wide as they are for 13" tires. These fenders have a backside to them. You can mount them off the body if you need to. Leave a gap between fender and camper body if tires are out wide from body.

Going to toss a pizza in the oven now, then take it out to the shop and eat while I stare/figure/re-figure that hatch framing some more. Later

[Mr. Lahey]

I've been fitting the inside faces of the outer hatch ribs. I also wanted to prep them for the spring bolt latches. It's seems to be going well. So much of this is luck. That this unrelated hardware appears to be working out. The bolts will be for security to allow me to have a locking hatch. There is so much play in the bolt receiver that it would allow the hatch to rattle a good bit if not perfectly adjusted. So I will also have exterior rubber latches to keep the hatch shut tight.

A couple picks of rib fit for the latch bolt receiver. It looks like I can keep the bolt away from the weather strip and have it hit the receiver before it does damage to the weather strip seal surface. Plus it clears the the rest of the rib when the hatch is shut. It's not to thick for the space already there for the rib to clear the inner galley wall. Like I said, a lot of luck. I had no idea all this would all come into play to get these latches installed when I bought them.

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[breb]

Wow the hatch ribs , seals and latching mechanism. Your making this look way to easy! It's the details that drive you nuts and soak up all your time. I went to pick up 4 hinges from a woodworking store (half lap) , anyway they had only 3 and thought I would have the last one this week . When i called today the reply was oh we only put in the orders on Wednesdays . I was there last Thursday . Frustrated that I couldn't continue with those upper door panel's I switched to the other element of the inside cabinet's witch was a pull out drawer which originally was only supposed to be a pull out shelf. This single item has taken longer than any other feature on the build and not sure why. The details involved are sucking up a lot of time . I have to empty my shop vac's again . When i resigned myself to using Hickory in my project the initial thought was there only face frames and some doors , that won't be that much hardwood , You were right i'm up to my neck in sawdust.