using foam on bulkhead vs. footbraces

Hello All, Quick question about footbraces. What do you all think of using foam against the bulkhead vs. footbraces. I assume the bulkhead should probably be beefed up, maybe glassing it and using seam tape over the fillets? Looking at other forums there seems to be no clear winner. Ie. some love the foam and some love the footbraces I realize the foam is not adjustable. Also I guess the foam might be lighter. Anyway I would love to hear more opines Thanks

Tom


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RE: using foam on bulkhead vs. footbraces

Hi W.mass, 

great question to put out there.  in two out of three of my last builds i went with foam bulkheads...so happy to share what i learned/how they are doing.

first, for the two boats i went with foam, i was very focused on building light.  one was a 29 lb petrel play for myself and the other was a 25 lb frej for my wife (pictures below)

so my thoughts in no particular order:

if you want to build the lightest boat possible, every bit counts and a set of adjustable footbraces, the bolts and the glass will set you back about 1 lb (16 oz) which is a lot.  foam, and by foam i mean, mini-cell foam, will only set you back about 3 oz.  so if you are trying to keep it light consider foam.

foam to me does not mean it's not adjustable....it just means its not adjustable when underway and requires a bit of planning.  i use minicell foam for my "foam footpegs" and they are cut in such a way(slightly oversized) such that i wedge them into the hull and against the bulkhead.  i carry some additional  'slices' in my forward compartment so that i can adjust for different foot lengths by adding or taking away slices.   

i have found no need to add more glass into the bulkhead than normal bulkhead construction.  they are plenty strong and you would be pushing them into the narrower part of the boat so you would have to break the bulkhead or the hull to move them forward.  also, the load with foam is spread pretty widely compared to the two bolts that hold a traditional track or a footbrace mounting kit....which should typically be reinforced around the holes/mounting kit with extra glass to spread the load.

the cool thing about foam is that cosemtically, they do not require holes in the hull and they are easy to re-do if you want to keep adapting them.

the downside, if you want to call it that, is that if you want 'no give' in terms of your foot pressure and the feedback it gives you, foam, becuase it has some flex, will give you a bit of spongy feel.   so far this has not been a problem....but it does feel a different if you push hard.  also, of course, if you are used to having a lot of different people use your boat and doing this on the fly (e.g., do you want to take my boat out for a spin?), i would probably want the foot pegs.

the only other thing i will share is for both boats with foam, i did pre-drill (and then filled them) the holes for regular tracks in case i ever wanted to cut it over to the other system.  since the hulls were both dark, you can't see that i did that unless you look really carefully.   but so far, no urge to make the change.

below is a picture from the cockpit of my 'foam foot-peg' on the petrel.  in this case, the forward bulkhead is also foam (3 inch thick minicell glued in with 5200 adhesive).  on my frej, the forward bulkhead happens to be wood.   so far, this system had worked well and proven very strong and light and i have been able to craft the boat to adjust to the few people i allow to use them.

happy to answer any other questions.

h

RE: using foam on bulkhead vs. footbraces

One other thought i forgot to share on foam/foot pegs.

when i decided i was going with foam i made a conscientious calculation about who i would potentially share the boat with and the range of legs i was prepared to build around.  i do a lot of kayaking and know my willingess to share different boats and i have a couple boats..so the ones i am willing to easily share have a lot of adjustment and are heavy and can take abuse of somebody who may not be a great paddler.

the boats with foam i would consider more personalized and i have the bulkhead situated such that the 'planned' feet are typically only three inches back from the structural bulkhead so i only need several inches of foam.  i don't carry slices for the full 10" or so of adjustment you would see on track systems... and not sure how it would perform if you were trying to bridge a large gap between the bulkheads and the foam/foot location.

anyway, thought i would just put that out there for consideration.

h

  

RE: using foam on bulkhead vs. footbraces

   Down sides ,not easily adjusted, takes up extra space (I sometimes will take a foot or both off the pegs  and strech)  up sides .......?

RE: using foam on bulkhead vs. footbraces

Depending on why you want to replace footbraces, there are other options. If you want to avoid holes in your hull and increase the bearing area, mounting the footbraces on stainless steel studs which are glued and glassed to the hull is a viable option. It doesn't help with the weight, though. But it does retain the adjustability while out on the water (I can release the latch with the big toe on one foot and grip/move the footbrace with the other foot, at least on my WD12), doesn't take up as much space as foam, is independent of bulkhead position and retains the feel of traditional footbraces.

Laszlo

RE: using foam on bulkhead vs. footbraces

   Thanks for the replies. I would like to make these boats as light as possible.One is a Shearwater sport the other is a Mystic Star strip build. I don't have any experience with the foam on bulkhead method but in my reading lots of folks seem to really like it. I see the downside of less adjustability but I don't think that too many other people will be using these. And I see the upside no holes in hull, less weight. I guess I am looking for some opinions on comfort of the two choices.

On another subject, I don't have a ton of glassing experience and it seems from what I have read that beginers boats are usually over the target finished weight of the boat. What would be the most obvious ways for this to happen or should I say not happen. Thanks

Tom

RE: using foam on bulkhead vs. footbraces

Hi  w.mass.

wow....the mystic star is a real beauty....i have seen one up close but never paddled it.  but the guy who did, made it move fast....real fast.  so two great projects.

on your questions, on the issue of comfort, i would simply say the main thing that impacts comfort is the seat, backband and the amount of knee bend (space) in the cockpit.  the only difference in paddling comfort between the two options (foam vs regular footpegs) as i see it, is how stiff is the foot peg going to be.  on a foam foot peg, there will typically be some give/flex.  on a standard foot peg, there is typically no discernable flex.  some folks who can't get comfortable like to be able to take their foot off the pegs and stretch their feet out, which can be accomodated in a foam footbrace if you know that is what you want.  i do understand that some folks like extra room so they can change positions but i am not sure that is the same as comfort.  my boats are very comfortable but they are like tailored clothes.....they fit and feel great but they do that without providing a lot of extra room.

on your weight question, its really all about epoxy....and using the least epoxy possible.  there is very little opportunity to save any signficant weight in wood as the amount of wood is pretty much fixed for each design.   you can save a lot of weight in epoxy with good technique and not compromize strength.  more epoxy beyond what you need, frankly is just extra weight....it does not make a boat stronger.

the main thing to minimize epoxy usage is to plan, practice and go slow....and check in with the forum on a host of tips to do that.  anytime epoxy is involved, you have to ask the question, how do i do this with the minimum epoxy?  if you look at the following link, i detailed a light build and some of the techniques i used at each stage of the construction....including the planning.... to get a light build.

https://www.clcboats.com/forum/clcforum/thread/50725.html

while some of the techniques are unique to this project, most of them have wide applicability to any kayak project your would undertake.

take a read through that as a start and then shoot some more questions over.

the only other thing i would mention, at this point, is that kits come with some pre-conceived ideas that have a big impact on weight.  in some cases, you can swap out for lighter material that can make a big difference.  this is particular true of glass weights and its interactions with how much epoxy you need and strength.  if you analyze it, a kit like the shearwater sport, will have less options to save weight than the mystic star.  a spreadsheet of the bill of materials and weights (which you will find on the link above) is a great way to experiment before you start building, on how to get a light boat.  one motto to build light is you have to engineer light.....you won't build any lighter than what you calculated on your bill of materials.  so if you don't like the spreadsheet result, continue to refine the build approach until the spreadsheet has you in the zone....you can't make it lighter after you start.

h

 

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