Jon Boat Gas Tank Location in Bench

Slob-O

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Jan 21, 2011
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Does anyone know if it's "Structurally OK" to cut a rectangle in the top of the back bench seat in a jon boat to store the gas tank?

I have a 14Ft flat bottom boat (not sure what manuf) that has a back bench and a front bench, no middle bench. the gas tank wont fit behind the rear bench due to bracing for the transom so I was curious if anyone has ever cut a portion of the bench to hide the gas tank inside the bench?

i'll attache a pic of the boat and a little illustration of what I'm talking about.
Also if anyone can identify my boat, it would be awesome to know who makes it!

Thanks,
Slob-O
 

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Joined
Sep 23, 2010
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1,058
Re: Jon Boat Gas Tank Location in Bench

I had a 12 foot jon and removed the center bench without any negative effect. The front and back were design for storage so the top centers were cut out for access. Mine was fiberglass, your looks like aluminum. I say go for it.
 

robert graham

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Apr 16, 2009
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Re: Jon Boat Gas Tank Location in Bench

That back bench seat, if it's like mine, is filled with structural/flotation foam for in case your boat ever gets swamped, it won't sink, especially with the weight of the motor back there. I wouldn't do it...find a gas tank that fits your available space. Good Luck!
 

pootnic

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Aug 11, 2007
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Re: Jon Boat Gas Tank Location in Bench

The above statement is true...
I've seen it done,just don't make it to air tight.
With all that weight back there,will you have problems planeing?
Sometimes even the tank being further in the bow will help with those type issues.
 

Slob-O

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Jan 21, 2011
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Re: Jon Boat Gas Tank Location in Bench

Thanks guys, I guess I'll have to figure out a way to check if it's filled with flotation foam or any other structural members that may be in the way first. If nothing is in there I think I'll try it!

Thanks again... I'll post some pics and or info when I get to this point in my build later this winter.
 
Joined
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Re: Jon Boat Gas Tank Location in Bench

I would think it would sound hollow if there is no foam. Or drill a small hole and slip something like a clothes hanger wire down and feel around.
 

lncoop

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Apr 18, 2010
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Re: Jon Boat Gas Tank Location in Bench

Nice looking rig, Slob. Duracraft was know for that two bench configuration. Duck hunters love it because it means extra room for gas tank, decoys, dog, etc. Great for yo-yoing and trotlining too. However, yours doesn't look like a Duracraft. 14' john boats made in the 70s to 90s are so similar in construction it's tough to tell them apart. If the info is not on a plate somewhere on the hull you'll probably never know for sure who made it. Now, regarding the tank. If the one on the tailgate is the one you're using you might consider replacing it with a plastic one from an outdoors big box store. They have the same capacity but are flatter, which makes them more adaptable to tight spaces. Just a thought. Tight lines.
 

Slob-O

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Jan 21, 2011
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Re: Jon Boat Gas Tank Location in Bench

Thanks. It's going to be getting an over haul this winter though...it's actaully my granpa's boat and he just kept adding and adding things until it became too cluttered for the type of fishing I enjoy (bass, northern, Muskey). He said he was going to give it to me down the road so he's letting me change it up. I'm going to add a deck to the front third of the boat with a captains chair front trolling motor and storage underneith. I have this thing about keeping things hidden and out of the way... ya know simple for fishing. I don't know how many times I caught a lure in something just sitting in the boat last summer! I will definately look into a plastic, more shape fitting tank that i could slip in the back beind the seat. Thanks Incoop
 

steelespike

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Apr 26, 2002
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19,069
Re: Jon Boat Gas Tank Location in Bench

Sure seems to me that a driver and tank in the stern would be slow to plane and may struggle to stay on plane.The seat adds support to the hull and possibly the bottom so be carefull what you cut.If there is flotation in there perhaps you can attach it to the bottom of the seat or along the back of seat or transom.You'll have to protect it from gas as it is likrely to melt.
 

lncoop

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Re: Jon Boat Gas Tank Location in Bench

Sure seems to me that a driver and tank in the stern would be slow to plane and may struggle to stay on plane.The seat adds support to the hull and possibly the bottom so be carefull what you cut.If there is flotation in there perhaps you can attach it to the bottom of the seat or along the back of seat or transom.You'll have to protect it from gas as it is likrely to melt.

He's running a 25 on it, and those rigs use five or six gallon tanks, so I wouldn't think that would be an issue. Slob, be really careful with the addition of decking, etc. That 14 footer will get small and unstable on you quick if you overdo it.
 

Slob-O

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Jan 21, 2011
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Re: Jon Boat Gas Tank Location in Bench

Currently I am running with two batteries, a gas tank, driver, and anchor in the stern and she planes like a champ with that 25 Johnson. the addition of the deck will allow me to move one of the batteries and the anchor to the front. I plan on makind an alum L frame to support some marine plywood...carpeted of course. This should help even the weight out better and hopfully help it plane better too.
 

lncoop

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Re: Jon Boat Gas Tank Location in Bench

Of course you realize you'll have to post pics of your project. Iboats rule.;)
 

clarkbre

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Sep 3, 2008
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Re: Jon Boat Gas Tank Location in Bench

Although my boat is a 16? v-hull, I did something similar to help with weight distribution. I used to have the battery, 6 gallon tank, and myself in the rear 4?. The boat never seemed to settle down in the bow. When I installed the front 4? deck, I put the battery under it. To get the tank off of the floor, I bought a 3 gallon tank (never burnt through more than about a gallon or two in a given weekend), and carved out about 1/3 of the foam in the middle bench. This compartment stored the smaller tank and cleared the floor of the boat for crabbing and fishing.

Decked bow with storage for the battery, life jackets, anchors, and fishing gear.

IMG00076.jpg


Storage compartment for the fuel tank, bow lines, and other small items.

DSC_0027.jpg
 

fishrdan

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Jan 25, 2008
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Re: Jon Boat Gas Tank Location in Bench

Something to be aware of, small portable fuel tanks are not supposed to be stored below deck or in sealed compartments. They do not vent to outside air and will vent gas fumes into the hull or compartment.

That said, I did put my fuel tank inside the center seat of my jon boat. The compartment is vented, but... This will not fly with the USCG, not enough ventilation for the size of the compartment. You are supposed to have XXX sq inches of open space (ventilation) for every XXX cubic feet of enclosed area. Not sure of the spec, you would have to look it up.

dscf2181.jpg


If you are going to hack open the top of your seat bulk heads, you need to bend a lip on the edge of the cutout, to strengthen it. Without the lip it's going to be very weak. I bent mine over to form a a 3/4" lip, folded over slowly with a hammer and some forms clamped top and bottom of the aluminum.

I removed a big block of foam from the bulkhead, and replaced most of it by lining the compartment with 2" sheet foam insulation. Then a sheet of 1/8" tempered hardboard in the bottom so the bottom foam didn't get chewed up.

The back seat bulkhead is done the same way, but I cut the top board in 2 so I could get inside while seated. I lost some flotation by removing the blocks in the seat, but replaced it while decking the boat. Actually, there is a lot more foam in the boat now. This might be unconventional, but I foamed the undersides of the deck. Not good if you are in a wet/damp climate as it can rot the wood and water log the foam. But, I'm in the desert and the foam is still dry as a done after 3 years. (Eh, if I have to replace the decks after a couple years, so be it, this is a stealth fishing rig.)The decks are 3/8" plywood and plenty strong with the additional support of the foam. Also, the decks are screwed in, but removable, so I can clean and dry them out when/if needed. This might not be do-able seeing how you are from WI....

dscf2187.jpg


As LN said, watch the balance of the boat, get the decks too high and it can be top heavy and unstable. Try standing on a piece of plywood (spanning across the seats) while the boat is in the water, this will give you an idea of what high decking the boat will change the boat's balance.
 

Slob-O

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Jan 21, 2011
Messages
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Re: Jon Boat Gas Tank Location in Bench

WOW! excellent info guys! Thanks a million, this will def. help with decisions when building the deck and storage plans. As soon as I get my hands on the boat I'll take some pictures and keep you updated!

Thanks again!
Joe
 

Home Cookin'

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Re: Jon Boat Gas Tank Location in Bench

I'd be reluctant to put the weight in the stern and also I'm certain you'll find floatation in there--or there should be. Try driving around with tank tied in back there and see. For most boats that size, being able to put the gas forward and potr, to balance the driver, is important.
A couple more ideas:
reconsider 2 batteries; is the motor a pull start?
batteries in the stern, gas up front?
Gas under the deck you are building?
If you don't usually use a half a tank, consider 2 3 gallon tanks for your weight distribution.
I am not a fan of tall seats on small boats either. be sure you have room for you and passengers not to be sitting on them when you are running.
I don't think I'd put the batteries and gas in the same box.
 

Slob-O

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Joined
Jan 21, 2011
Messages
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Re: Jon Boat Gas Tank Location in Bench

Home Cookin, Here's a picture of what the boat is set up as now and what I plan on doing. I ran the boat a ton last summer (2-3 times a week) with majority of the weight in the stern. 2 batteries, a gas tank, a 25hp, a trolling motor, a storage box, anchor, and me and the boat planed great! With all that stuff and 2 people I could get up to 27mph (gps reading) no problem. So, I figured with adding the deck I'd move one of the batteries up front and the the weight of the boat would be more evenly distributed. It's an electric start so i'd leave 1 battery in the back to run the electric start, lights, bilage pump and what ever else, then the battery in the front would be just for the trolling motor. So I don't see an issue with stern weight. And no, I wouldn't put the batteries in the same box as the gas tank.

Deck.JPG
 

Home Cookin'

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May 26, 2009
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Re: Jon Boat Gas Tank Location in Bench

looks good. don't forget to leave an access hatch so you can pull the plug and run water out, and visually check flooding. 6" x 6" should do. Your flip top would conflict with the motor if you need access while the motor is running.

With all that, you might consider a side console; they are comfortable but not often seen in a 14.
 

Slob-O

Cadet
Joined
Jan 21, 2011
Messages
28
Re: Jon Boat Gas Tank Location in Bench

Here are some transom deck lids that I would try to copy, with the right relief cuts it looks like i could make it open to clear the motor

Transom cover.jpgRer.jpg
 

Slob-O

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Joined
Jan 21, 2011
Messages
28
Re: Jon Boat Gas Tank Location in Bench

Well, guys...it's been a while since I've been on here, but I did end up finishing the jon/bass boat build and had great luck this year fishing with it. Here are some build pix along with some fish I caught.

IMG_20110312_132335.jpg
IMG_20110501_155722.jpgIMG_20110313_134840.jpgIMG_20110415_153349.jpgIMG_20110415_174005.jpg
 
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