boat braceing

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warcraft1975

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going to take a bench seat out and was wanting to re brace it ...can you buy braceing for doing this or do you have to just make stuff work?is there a place you can buy knee braces? many thanks for any help or ideas
 
I like the way you think, seems like a lot of people don't even give this a consideration before removing a structural support... but then again they probably don't even know that the bench seats in an aluminun are a lot more than something to just sit on. They add latteral strength/support and contain the floatation that keeps the boat from sinking to the bottom in case of a mishap. I personally wouldn't remove a bench from a jon, nor would I modify it (cut holes and remove floatation).

You should really try to incorporate the benches into your plans, but if you feel you must remove one you can restore some of the lost strength with a deck and bulkhead close to the general area that you removed it. Just remember to put back the same amount (cubic feet) of floatation in that area too.

What are your modification plans, if you don't mind me asking?
 
i own a 1970's sears semi v 14 foot boat really just giveing it a good once over it has four bench seats in it i plan to remove one to give me more leg room but in removeing it the sides where the seat was will need to be re braced in some fashion to keep it from flexing the boat its self is in pretty decent shape so i didnt have nothing to fix so i figured i would make it a little more comfy..lol the trailer is also the sears split trailer it came with (ted willaims ) it how ever has been gone through and needed alot old age took its toll on it every weld has been re welded three foot guide poles have been added new lights new wireing has been done rust grinded off and have about half of it re painted .....
 
Here's my suggestion.I'll see if I can explain it clearly enough.

You'll need some 3/4" plywood, 1" or 1 1/2" aluminum angle 1/8" thick, stainless 1/4-20 bolts and nyloc nuts, 1/4" closed end aluminum closed end rivets with a grip range of about 3/16"-1/4".

Measure the height of your bench from the hull up to the top, lets say it's 12". Lay out a 12"x12" right angle triangleon the plywood but don't cut it, you'll need to add the deadrise of your boat to the bottom of the triangle and then cut it. Make 2 of these and check the for a good fit where your bench was. Cut 4 pieces of angle to fit the plywood sides that will touch the side and bottom of your hull (2 for each side). Drill 4 bolt holes in each angle with 2 pairs alike. Glue your 2 pieces of ply together and the sandwich them together between the angles with the nuts and bolts. It'll look like a solid shelf bracket with flanges on both sides. Drill and rivet these to the side and bottom of your boat in the center of where your bench was, one on port and starboard sides.

These won't be as stout as the solid bench, but will be a heck of a lot better than nothing.

I'f you have problems understanding my written directions I'll draw you up something later.
 
jigngrub said:
Here's my suggestion.I'll see if I can explain it clearly enough.

You'll need some 3/4" plywood, 1" or 1 1/2" aluminum angle 1/8" thick, stainless 1/4-20 bolts and nyloc nuts, 1/4" closed end aluminum closed end rivets with a grip range of about 3/16"-1/4".

Measure the height of your bench from the hull up to the top, lets say it's 12". Lay out a 12"x12" right angle triangleon the plywood but don't cut it, you'll need to add the deadrise of your boat to the bottom of the triangle and then cut it. Make 2 of these and check the for a good fit where your bench was. Cut 4 pieces of angle to fit the plywood sides that will touch the side and bottom of your hull (2 for each side). Drill 4 bolt holes in each angle with 2 pairs alike. Glue your 2 pieces of ply together and the sandwich them together between the angles with the nuts and bolts. It'll look like a solid shelf bracket with flanges on both sides. Drill and rivet these to the side and bottom of your boat in the center of where your bench was, one on port and starboard sides.

These won't be as stout as the solid bench, but will be a heck of a lot better than nothing.

I'f you have problems understanding my written directions I'll draw you up something later.
Just out of curiousity, whats the plywood for? The angle is providing all the strength based on your post and the plywood isnt even attached to anything so why not just leave it out and save weight?
 
BassBlaster said:
Just out of curiousity, whats the plywood for? The angle is providing all the strength based on your post and the plywood isnt even attached to anything so why not just leave it out and save weight?

All the strength comes from the plywood, the angles are for fastening the plywood to the boat securely.
 
Um, okay, if you say so. Maybe I'm not understanding your post.

If I take a piece of angle and attach it to the side and floor of my hull, there is a ton of strength there. Kinda like the knee brace on the transom. Adding a piece of plywood to that and ONLY attaching it to the angle like your post says, does absolutely nothing to add any additional strength. In fact, if there was someway to rivet the plywood itself to the hull, I still doubt it would be any stronger than just the angle. I guess I just dont quite understand what you mean.

P.S. I have a backround in architecture, so I know a thing or two about structural strength.

To the OP, sorry, not trying to hijack your thread, just trying to make since of his post.
 
DSC02176.jpg


This design will distribute the lateral load over a larger area.
 
Okay, well, the pic makes since. Thats definately not the pic I drew in my mind from your post though, lol.

That would definately put the structural integrity back into the hull. May create a tripping hazard though.

There was another member who made some similar brackets last year that put the structural integrity back but didnt create a tripping hazard. He was actually able to completely hide his brackets under his flooring. Sorry, I cant remember the person who did that though.

To the OP, check out dixie boyles build. I think thats how he spells it. He removed a bench and then put decking on the floor and up the sides. He hasnt reported any flexing issues with his hull. Personally, I think removing one bench from a jon with four benches would be fine. My 1436 has three benches. I removed the front one and will be replacing it with a small deck. It will be stronger than the original bench. The center bench will be removed and left out. I plan to deck the floor with aluminum sheet and go up the sides of the hull with the same decking. In my opinion, that will be plenty strong enough. I'm not a boat builder though.
 
BassBlaster said:
Okay, well, the pic makes since. Thats definately not the pic I drew in my mind from your post though, lol.

Haha, I was in the same boat on that one. Good pic tho. Do your benches go all the way to the floor? If they do, I'm pretty sure Bufford did a mod in his that would work. Basically what he did was just cut a chunk out of his seat. Starting like 4-5 inches in from the side, he cut down to about 2 inches from the bottom,all the way over to about 4-5 inches from the other side, so basically just a big rectangle chunk was cut out. He laid a piece of ply on the floor to make it flat, then used the sides of the bench for storage. Looked pretty good, kept the majority of the structural integrity, and made it way easier to move around. The other idea with the braces is good too (now that we all understand it :wink: ). Post pics with whatever you decide to do.
 
was sitting here thinking about how to really do this and i had a thought that if i hand made longer peices for the "ribs" of the boat and extended them all the way up where the seat was that should do the trick to right? and that way theres nothing to trip over ..in my boat the ribs stop about half way up the sides ...i figure that if i over lap them and run them all the way to the top that will make it pretty ridged
 
That definitely wouldn't hurt. Theres's tons of boats on this forum that have removed a bench, and not all of them have done something to strengthen it back up. Take a look at the conversions page, its got a bunch of boats in list format that you can click on and it will show the whole build. I'm sure there are tons of ideas for you in there.
 
i have an idea for easy boat braceing will have to take pics ....found these metal braces for shelves that should work nice after i cut them in half
 
Here is a pic of the bench seats I'd like to remove the center one
 

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I'm betting the contoured shape of your v-hull would be more accepting of a bench removal than a slab sided flat bottom. I think a flat boatside would absorb more energy than a rounded one. As for removing the middle bench, I guess you could monitor it for stress.
 

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