A Question on Ribs and Bottom Width

[taw1126]

Okay...me and the boys are out of the chute with this project, slowly. Turns out the workspace doesn't meet ADA guidelines so we've had to improvise, but you can really make a 3-year old's day by letting him have some time with a sander and some stain.

As of today, we've got two of the four side pieces stained and the two end ribs assembled with Gorilla Glue (I didn't realize that the marine epoxy I bought at Lowe's was going to be gray, and didn't want to have any gray epoxy detracting from natural wood inside the boat). My epoxy & fiberglass will be here next week so that should be the only place not bonded with epoxy.

Because I had the shop rip 11-inch pieces for the sides, I'm limited to a width of just under 26-inches unless I buy another sheet of okoume. It seems that the easy option would be to build the standard 3-rib boat, but I'd like to have as much stability as possible so I'm still looking at ways to build a 4-rib boat.

It seems that one of the things I could do is to narrow the two middle ribs- right now they are 25-inches across. Idea being that maximum waterline width would be the same, but over more of the boat's length. Is that a correct thought? Will it increase stability enough to make it worth the extra effort of shortening the ribs, chamfering them so they match the curve of the hull, etc.?

Another idea I had was to build a 3-rib boat but push the other ribs towards the bow & stern more. Do I run the risk of ending up with a weaker boat bottom, or increase the chances of oil-canning?

I expect that by going for more stability I'm losing some speed and ease of paddling. Are there other trade-offs I'm overlooking? To some degree, it seems like these UJ kits can't be screwed up.

 

[seedtick]

Guess I'm going to have to buy an UJ kit so I'll understand what ya'll are talking about...............

How does the number of ribs affect the width of the boat? If they're precut, can't they be trimmed down to give you whatever bottom width you need?

For a given bottom length and width, you can increase stability by increasing the angle of the sides ( more flare). That way as the boat is loaded, you have more waterline width giving you more stability. Be careful because more flare will give you more rocker if you don't adjust the cut of the sides

 

[oldsparkey]

The ribs and end pieces in the kit are pre-cut at the desired angles except for the center rib which is flush.

I space mine out at one third of the length so they are evenly spaced on the bottom and sides of the boat. The center rib is over the seam in the center.

When you add a 4th rib then you should have them spaced at 4ths without one over the center seam in the boat. It adds a little more width to the boat and some stability so you can stand to fish.

Personally I would make it the way it was designed and then if I had some ideas , build another and do the changes to it. This would be after doing some paddling in the built boat and actually seeing what might be done to another one as far as modifications.

Chuck.

 

[cctyer]

I love seeing the little ones getting involved. Mine are to big to convince them sanding is a much sought after job that only the most skilled and worthy applicants are allowed to do! :lol:
Bye the way TAW don't let the powers that be here see your shop clean or there will be some ribbing coming your way. By the looks of that picture it's way to clean and you should throw some junk on the floor to trip over and get some saw dust and scatter that around too! :wink:

All kidding aside Chuck, Jack, Mick, Matt, and all the other folks here are very helpful and there combined experience alone is plenty good enough for me to heed there advise. Good luck building and keep the pics coming.

Chad


Also I see you have a palm sander but if you don't already have a random orbital yet, RUN to the store and get one. I started out with that type of sander and could not believe the difference in the two, not to mention the RO sander collects a lot more dust you can throw on the floor for taking pics! :lol:

 

[taw1126]

Personally I would make it the way it was designed and then if I had some ideas , build another and do the changes to it.

I agree that would be the best way to go...just not sure how soon I'll be ready to tackle one of these projects again. I noticed the postage on the UJ boxes was from 2003.

Bye the way TAW don't let the powers that be here see your shop clean or there will be some ribbing coming your way.

The funny thing is this is what we refer to as the "toy garage"- it has my reloading bench & shooting stuff, as well as the boys' bicycles, sports gear, random odd sticks they collect as "hiking staffs", etc. The garage we actually get to use for our cars is a cluttered mess with unfinished walls...one more way the kids end up with the nicer stuff. And trust me: you're just not seeing all of the trip hazards that get placed and moved. Had some interesting near-misses with the can of stain yesterday.

 

[Kayak Jack]

...And trust me: you're just not seeing all of the trip hazards that get placed and moved. Had some interesting near-misses with the can of stain yesterday.

I have high admiration for a man who can pole vault a fence, run a hundred yard dash, leap over small dog houses with a short running start, and do tumbling tricks whilst holding an open can of boat stain. You're held in high regard, and a hero in my eyes.

 

[a Bald Cypress]

boat

1126, Fine little helper ya got there.

But I would be remiss if I did not point out that, cotton socks on a smooth toped stool while reaching and leaning are an invitation to a fall.



I know, it's none of my bidness so I'll shut my mouff now.

 

[Wannabe]

1126
Your doing good son. My first grandson ( now 16) Ws hammering nails in scrap wood when he was 3. Keep up the good work, it'l do him good one day. My granddaughter was in the garage with us when she was in diapers too.
Bob

 

[taw1126]

Re: boat

But I would be remiss if I did not point out that, cotton socks on a smooth toped stool while reaching and leaning are an invitation to a fall.



I know, it's none of my bidness so I'll shut my mouff now.

No, you're right...sometimes it's okay yo make things your business- what we referred to in the Army as an "on the spot correction", which made anyone who was screwing up fair game regardless of rank.

We're taking the weekend off for a camping trip and will be back at this next week (fiberglass & epoxy are due in on Tuesday). I don't expect to make a decision on how the ribs will get placed for awhile.

 

[hairymick]

Good on ya Taw for getting the littlun involved. I bet he is loving every minute of it.

My grand kids just love getting into the shed and helping their poppy. Special times.

Please keep the piccies coming.

 

[bearridge]

Re: boat

We're taking the weekend off for a camping trip

Friend taw,

Aint it hot down in Texas? Mebbe some cots under a tarp....stars 'n a breeze?

regards 'n good luck
bearridge

The difference between fiction and reality? Fiction has to make sense. Tom Clancy