Kruger / Monarch style seat risers

[dogbrain]

I'm separating this from my build thread since it may be of interest to those building non decked canoes. As I said in the Kruger build thread, I'd like to stick close to Verlen Krugers design in building my boat, so that means I'll build seat risers the same as found in a Sea Wind or Mad River Monarch. The main advantage to this design is that the seat riser acts as a buttress for the coaming, which will have to take the weight and tension from straps while transporting the canoe. Another reported advantage is that you can pull the seat out and sleep in there if you can't find a good place to camp. I can visualize making a cockpit cover out of bug netting and just stringing a tarp over the whole thing as an emergency sleep shelter, but realistically I probably wouldn't use it that way.

Here are pictures of the riser and how the seat with attached portage yoke sit inside the canoe. I talked to Scott Smith, one of Verlen Krugers proteges a couple weeks ago, and he said they hand laid these panels with fiberglass topped off with kevlar on each side. They're about 1/8" thick meaning lots of layers of glass, more than I want to deal with.

I am thinking I could use a wood core to build the thickness and use fiberglass and possibly carbon or kevlar on the outside to make something strong enough. I'm not worried as much about making a panel strong enough in the vertical direction. I think any wood, even cedar, with a couple layers of glass on each side would work fine. I'm more concerned about the horizontal stiffness since there would likely be some seat movement from side to side. Too much flex in that direction could be an issue. If I had it available, and it didn't cost so much, I would buy some Okume plywood for the core. Regular plywood, maybe 1/4" would also probably work too. Looking here at home I have some left over cedar planking that is 5/32" thick and 3-3/4" wide. I thought maybe I could make a panel double that thickness by laminating a course of planks going horizontal and a course vertical, then glassing the outside. I don't think it would have much flex at all with a couple layers of glass on both sides. I suppose I could also mill some hardwood and make 1/8" planks from that and do the same thing.

Any thoughts or suggestions out there?

Mark

 

[Alan Gage]

At first I thought any good void free 1/4" ply would work so long as you sealed it with epoxy but the epoxy is almost guaranteed to wear through at the seat contact points and I wonder if it would be prone to rot in the long term.

You could use high density 1/4" foam and laminate over it. Since you need small pieces shipping wouldn't be so bad.

I wouldn't completely give up on the idea of composite. That is a lot of layers if you're using 6oz cloth but not as many if you're using something like 20oz. cloth.

Alan

 

[dogbrain]

Alan, do you have a sense of how to figure out how much 20 oz glass it would take to get to 1/8”? I have a chunk of scrap granite counter top which would be good for the layup. How would you approach laminating multiple layers of cloth in this fashion? To make the two risers I need a sheet roughly 12 x 30”.

 

[Alan Gage]

I just looked up the specs on 20oz fiberglass and see that it's .03" thick so 4 layers dry would make it 1/8" thick. I'm really not sure how much thickness epoxy and a hand layup would add.

For layup I'd probably wet out each piece individually, stack them on a hard surface, and then place something else flat and heavy on top. I'd put peel ply on the top and bottom surfaces as well as something epoxy can't penetrate between the peel ply and the surface of the granite or whatever was being used to compress the composite.

Alan

 

[Guest]

I'm separating this from my build thread since it may be of interest to those building non decked canoes. As I said in the Kruger build thread, I'd like to stick close to Verlen Krugers design in building my boat, so that means I'll build seat risers the same as found in a Sea Wind or Mad River Monarch. The main advantage to this design is that the seat riser acts as a buttress for the coaming, which will have to take the weight and tension from straps while transporting the canoe.
I talked to Scott Smith, one of Verlen Krugers proteges a couple weeks ago, and he said they hand laid these panels with fiberglass topped off with kevlar on each side. They're about 1/8" thick meaning lots of layers of glass, more than I want to deal with.

Mark, I would replicate those Krugerp-styleseat risers, including the flipped-over portage pads, provided the seat in your build is at a hull balanced position. The choice of seat height positions may vary depending on how deep the hull you built; same as a Sea Wind I’d go much the same, but only you have a sense of your preferred seat height(s). With the Monarch I wish the low position was a little higher, and the mid (high) position a little lower.

I liked the idea of a sliding seat as on the Clipper Sea-1, but never really had enough use for the sliding trim aspect to merit the rails and other frou-frou. I did like the idea of a full depth and width hull bulkhead* stiffener positioned directly behind the seat.

http://www.clippercanoes.com/sea-1/

*Not actually an open “bulkhead”, there is a bilge drainage slot cut at the bottom of that kevlar foam board.

I don’t know about Sea Winds, but those slotted trusses in the earlier MRC Monarchs were kevlar-over-some-foam board, but originally made thinner or of lesser foam, and prone to grinding wear in the seat post grooves. We needed to repair the wear on one early, oft used Monarch. The latter Monarch versions were made of significantly thicker/tougher kevlar covered foam board.

With those curvy grooves (groovey curves!) and an open-cut wood or foam board substrate I’d be tempted to lay some FRP cord or other material on the cut out seat post rests for increased durability. Dynel cord, or carbon fiber tow or ?

No doubt you have the skills to lay up and cut out some custom foam board with composite fabrics and epoxy. I believe there is some manufactured composite “honeycomb” board that is even stiffer/hardier than that foamboard, but could not find a source.

I have no such layup skills, and just bought a couple pieces kevlar covered foam board from a canoe manufacturer who uses it as bulkheads and seat risers.

P6223746 by Mike McCrea, on Flickr

I’m enviously loving this build thread, and looking forward to the outfitting minutia. Not to minimize outfitting with “minutia”; that seemingly little stuff make a huge comfort and efficiency difference.

 

[dogbrain]

The seat risers on the two Kruger style boats I have here are solid glass core. The panels on the sea wind are 3/16" and the monarch are 1/8".

I think ill look into some type of foam or core material like coremat to build up thickness. If I used wood I planned on running some poly cord all along the wear areas where the seat posts sit. Depending on what the core material looks like I would probably do the same.

mark

 

[Jim Dodd]

If I built this as a composite, I'd use Ash as the core, over foam. The foam would surely break down and delaminate before the Ash in my mind. Especially with any abrasion, and side to side stress.

I'd stay with a all cloth composition. The question as to which cloth combination, might best be answered by an engineer .

Just my $.02 worth !

Jim

 

[Guest]

The seat risers on the two Kruger style boats I have here are solid glass core. The panels on the sea wind are 3/16" and the monarch are 1/8".

I think ill look into some type of foam or core material like coremat to build up thickness. If I used wood I planned on running some poly cord all along the wear areas where the seat posts sit. Depending on what the core material looks like I would probably do the same.

The seat risers on our Monarch appear to be identical to the foam (?) core & kevlar skin in the photo above. That material is the stuff Clipper uses as the Sea-1 bulkhead from which the rear of the seat slider bars hang.

One of the early Monarchs we worked on had the same shape risers as our ’92 Monarch, but much thinner and, IIRC, without any foam core, just layers of cloth. Those thinner risers had actually bowed out (---) on each side, and were also more noticeably worn down in the grooves where the posts rest.

With any substrate, wood or foam, I like the idea of epoxying reinforcing cord where the seat posts rest, potentially grind away over time with torso rotation or changing position, or crushed when I thump my bulk onto the seat from on high at some awkward landing.

I measured the risers on our Monarch with a caliper; they are ½” thick, same thickness as the Clipper material.

That Clipper kevlar/foamboard is incredibly strong, stiff and lightweight. No idea if that is Coremat or some other “foam”. The Clipper foam board is an in-house product and Marlin at Clipper would know what they use as the foam core.

The Monarch’s riser foamboard material may be the same stuff MRC used to reinforce the hull where the foot pegs are attached.

Our Monarch has both low foot pegs (more like heel pegs) on the floor, and rudder control pedals attached through the deck. The latter, which should not be subject to the same force if bracing off the heel pegs, do not have any reinforcement, just SS bolted through the deck with fender washers.

PC110005 by Mike McCrea, on Flickr

That OEM combination of foot/heel peg and toes rudder pedal design is another story. I know some folks disliked the Monarch’s foot/heel pegs enough to remove them. Maybe that arrangement just works better height wise with size 12 feet, but it suits me just fine; I like having something more forcefully foot braceable than just rudder pedals straining at cables, especially when the rudder is retracted and I need no tactile touch on the rudder pedals.

(Let’s not discuss the times I mistakenly think the rudder is down, and am pressing on the rudder pedals harder and harder, wondering why the hell the dang boat isn’t responding.)

If you have had opportunity to paddle the example Sea Wind and Monarch, or even better still have them available just to sit in foot brace/pedal judgment, you could customized the pedal arrangement and position to whatever your personal preferences, shoe size and etc.

I did not like the rudder pedal design on the Monarch or (again, IRRC) the Sea Wind. The pedals were not easily adjustable for leg length. That would have precluded some shorter friends from reaching the pedals without adjusting the cables, and my perfect fit adjustment between barefoot and booted would not have been worth the effort.

We left the OEM track in place and found an old Harmony slider rail with adjustable foot pedals in the shop castoffs that fit that track perfectly. That simple change made the Monarch available to everyone family and friends.

PC110003 by Mike McCrea, on Flickr

We also removed the forward cable that ran through the underdeck pulley system (left the pulleys, I should have replace them with the pad eyes as above on the deck. . . . .next time I’m inside the Monarch). I concerns about that unsleeved cable sawing through a tightly stuffed dry bag. We removed it and stretched bungee forward from the rudder pedals, so the rudder self-centers if I take my feet of the pedals.

PC110007 by Mike McCrea, on Flickr

(It is amazing how often looking at a photograph serves to remind me of boat maintenance needed; the floor of the Monarch is mighty scuffed up just from sliding gear in and out; hard sided stuff and even just dry bag buckles and hardware. It could use a quick and easy refresher coat of epoxy)

Those bungee self-centerers work so well we have them on all of our ruddered boats. I ran the bungee through an under deck pad eye (mated to one topside on the deck) held in place on the backside via an overstrength cord lock, so I can re-tension the bungee when it begins to stretch out.

I expect you are now several steps further ahead on the build, or hope so. This build, and Deerfly’s Northwind build, hold a peculiar fascination for me.

 

[dogbrain]

Mike, im still undecided on the seat risers. I'm going back and forth in my mind about the whole thing. At the moment I'm leaning towards Alan's suggestion of using heavier cloth and a solid layup without a foam or wood core. I would shoot for 3/16" thickness instead of 1/8" like the '85 Monarch. The seawind doesn't show any significant wear at the seat bars and has lots of miles on it.

I've paddled both the monarch and the seawind. I like having something solid to brace against, but don't really care for the way the monarch is setup. I also don't like that the maximum distance is a bit short for me. The seawind pedals are ok, but what I really like is how the cables are all run through the body of the boat, meaning, when you look inside behind the seat there is nothing in there but a few pad eyes. I don't think I'm able to replicate that feature.

I decided to go with the Sea lect gas style pedals. They're fixed in position for bracing but they pivot for steering. They also have an easy length adjustment. Check it out online.

it's strange, but the monarch seat is mounted significantly forward of the sea wind. You would think that the pivot point for portaging would be the same on the two since the boat shape is almost the same. the seawind must be heavier towards the rear, and the rudder is part of the reason, but it doesnt seem like that accounts for all of it.

Mark

 

[OFaceFul]

I had trouble signing on and trying to post photos

These gun-rack style seat hangers for North Wind canoe are built of 6mm (1/4) craft ply with 2 layers carbon both sides. Cut so fingers fit Extreme Duty seat bought from NorthWest Canoe, which I believe is the same seat as from Ed's. The seat pops out. I also add a seat cushion for comfort and warmth.

 

[OFaceFul]

Regarding my rudder, I added SeaLect TruCourse rudder and their rudder control footbraces and cables bought from Duckworks BBS. The gudgeon is also from Duckworks. It steers the boat and I do recommend a rudder. This TruCourse rudder has a bit of flex so not the best choice if you are planning on rigging a sail.

 

[dogbrain]

I had trouble signing on and trying to post photos

These gun-rack style seat hangers for North Wind canoe are built of 6mm (1/4) craft ply with 2 layers carbon both sides. Cut so fingers fit Extreme Duty seat bought from NorthWest Canoe, which I believe is the same seat as from Ed's. The seat pops out. I also add a seat cushion for comfort and warmth.

Thanks for the description and pictures of your seat hangers and rudder. What exactly is craft plywood, and where did you get it? From your pictures it looks like somewhat high quality with 5 veneer layers. It must be pretty stiff given you used carbon. It also looks like you used 2 screws at the top. Is there a nylock nut on the other side? I have a small pile of experimental contour wood seats similar to those in your picture, so I'll pick one of those for this canoe.

How about that coaming lip, how did you construct that?

I do have the exact rudder system you've got. I'll most likely never sail my boat, but I might consider one of those downwind style sails. Either way, I plan to make a Kruger style rudder eventually that will replace the Truecourse. My gudgeon is a carbon tube that I'll glass to the stern once everything is put together.

Mark

 

[OFaceFul]

Craft plywood is birch with no voids sold in small sizes (12" x 24") at Menards near the wood dowels. I got the 6mm thick as the 3mm looked thin to support a man plopping down. Yes the seat risers are bolted thru the coaming with nut on the other side. Not yet added are pad eyes and such to tie stuff down. I added the seat after launching the canoe in December last year, which I sat on a stool moved fore and aft to determine trim where she tracked about the most straight. My seat placement: 12" deep seat is placed so forward edge of seat is 9-1/2" aft of station 8 (or 2-1/2" forward of station 9).

Coaming is 3/8" thick mahogany 200 pieces edge glued and beveled at turns and points, cut to 1-1/2" tall. The coaming lip is 4 layers carbon cloth cut in long strips and overlapping at the front and back and back corners. The lip might extend a little more than needed, because the snaps (from SailRite) for the cockpit cover are a bit harder to snap in place. I sewed a 2-piece cover with tunnel in the style Cliff Jacobson describes although the tunnel is not sized correct.

Hope you finish up soon but likely not before the ice. It looks like a very fine canoe. My brother Joe Swift just moved into Livingston from his place near Emigrant.

Larry

 

[dogbrain]

Ha! You should be careful dopping names like that online. I've known Joe for 35 years, I worked with your brother Jim too, back in the day. Your avatar name makes sense now, that's where I met the both of them. I see you are in indiana too. Identity confirmed. Their new house is 4 doors from mine. I'm watching the place while they're in California. He's seen my boat a couple times in the last month and who would have known his brother has built the same one. Small world Larry, nice to meet you.

I assume your coaming lip is all carbon then? Did you build a form with foam around the coaming and rip it out afterwards?