[ABear]

Hello to all;

After building two arbors (with arches on top) for the wife she has moved on to a garden gate project. This gate will actually sit under the most recent arbor/arch I built. I have built gates before, even monster sized gates that have never sagged because I overbuilt them. Mostly some kind of 2 x 4 & Z type frame.

The current project will be similar to the attached picture and I am concerned about how to get this into a "sag proof" design based on the picture of what she wants in the end. I will probably make the gate out of Western Red Cedar but open to suggestions. It will be a big gate, roughly 7 foot to the top of arch, and 40" wide (more or less)

As far as the "top part", the circle area, I wonder if I can get away with routing this out of some kind of plywood for simplicity and protecting it from the elements with a couple layers of exterior paint/stain?? I could always make this out of WRC using a segment calculator, but my past arches have required a 2 x 6 board to obtain a 3.5" width and this appears wider than 3.5" - Based on: Woodturners Resource Segment Calculator

As far as frame joinery, open to suggestions, based upon simplicity but requiring strength.

Any comments about approach, design, materials, etc would be greatly appreciated.

Robert

 

[gmercer_48083]

Robert, If you are looking for a 3-1/2" thickness ring, you can use a 6" nominal board which actual measurement is 5-1/2".

 

[Bstrom]

Plywood would give you some flexibility to join the circular portion to the bottom via some sandwiching, etc. but I do wonder how it will weather over time. Perhaps some banding to seal off the edges? Very pretty door, BTW...

 

[Gaffboat]

Since the door is painted, the majority of it could be made from plywood which would prevent it from sagging, and an epoxy coating would seal the wood and make it weather-proof. Many of today's boat designs use epoxy coated plywood. The appearance of the separate vertical wood slats could be created by simply routing a groove in the face of the plywood. Alternatively, a plywood core sandwiched on both faces with solid wood might accomplish the same thing.

 

[Herb Stoops]

The way I would do it would be to glue 2x6's together all the way across with splines and waterproof glue.(like a solid door)Then with a router and a "V" bit route the inside/outside circle and vertical board pattern both sides, just like the picture, take a saber saw and cut out the hole. Also use the router to cleanup the edges of the hole. I don't think there is any worry here about sagging.
Something like that.
HErb

 

[ABear]

Thanks to all for the comments.

Some of the ideas I had thought of and some I had not thought of so I really appreciate all the input.

Since this is going to be a garden gate, the wife may want a rough wood look and I may just use cedar fence boards, undecided.

Any other comments are welcome.

 

[Bstrom]

I like the rough wood look As long as it’s sophisticated! I have a bunch of rough sawn pine to work with and never tire of it.

Cedar would be a good choice but I wouldn’t want it to gray out. Paint would be my preferred choice for color/contrast in the setting you have to put it in. Let us know what you settle on, so we can do it too!

 

[Chris Itin]

I really like the idea of sandwiching 1x rough cedar on both sides of 3/4" exterior plywood. The plywood gives needed stability to circumvent sagging, and you can get 1X cedar wider than 6" so the circle segments can be wider than 3.5". You could even recess the plywood around the whole sandwich so that cedar banding could be added to hide the plywood edges. A good epoxy like boatbuilders use would provide a weatherproof finish while keeping the rough appearance, if desired. I would guess that some sort of surface hinges like are used on a lot of gates would be needed. I don't think traditional mortised hinges like used on most doors would work with this type of construction.

 

[ABear]

Thanks to all for the latest comments. I have been playing around with some scrap wood and the wife seems to like this design which is still under consideration. She likes using a rough sawn looking 5-1/2" width board with a half inch or so in between for an informal look.

The sides would be 3-1/2" trim that would go to the top and meet the circle (not shown in the mock up).

I like the idea of a cross trim board on the upper half, wife says no go.

Back to thinking of ACX Plywood for the circle with some additional protection via paint/stain/sealant. I might use a slightly thicker plywood (like 3/4") and use 5/8" thick trim so I would have a slight raised appearance were the trim meets the circle.

Two plywood circles with pickets sandwiched in between. Trim also on both sides.

Pictures give a rough idea.

 

[ABear]

Pictures did not attach, trying again.

The one picture is shown to be clear about the raised edge look intended.

 

[Cherryville Chuck]

WRC is a good choice because of the weight and that it weathers better than most woods. I think one of the big issues would be warping without the usual Z bracing. If you can utilize the top circle as a stabilizing structural element it will help. I would also glue it with something water proof like polyurethane, epoxy, or fiberglass resin. Cedar is really porous wood so you might want to take some epoxy or fiberglass resin and thin it down and try to get any open grain closed up. Or at least get an exterior oil finish and let the wood soak up as much as possible. If you can find an oil based paint or stain you could go over the penetrating oil with that after. If you use a Varathane type finish you'll be redoing it every year to two years.

 

[ABear]

Thank you Chuck for the input. I have used some solid acrylic stains with proven wear resistance and durability on WRC. I will look into all suggestions before making a final decision.


"If you can utilize the top circle as a stabilizing structural element it will help."


Yes, this will be mandatory, especially if it is not a Z frame, otherwise, not much support at the top.

 

[ABear]

So, I have a new question and I am sure the experts will have some advice.

I have decided to proceed using 3/4" thick WRC boards for the trim and 3/4" ACX Plywood for the top part. All lumber was sourced from a reputable lumber yard not a big box store.

I plan on routing the plywood arch (actually a full circle) with a Whiteside #RU5150 Spiral Up Cut Bit - 1/2" SH X 1/2" CD X 1-1/2" CL.

Based on what I have read, the down side of the material (hand held routing operation) will be cut the cleanest vs the top side of the material. So I plan on putting the "A" side down. I also read; make sure the work piece is clamped down securely as it could lift using a spiral upcut bit. That was already planned. Probably will make about 4 or 5 passes with the circle jig.

Any other tips that might be helpful in routing 3/4 ply with this specific bit?

THANK YOU.