# Adding foam to the outside of a jon boat.



## Zip (Jan 7, 2015)

So, I think this might have been brought up before. I searched but couldnt find exactly what I was looking for. 

I am not talking about PODS for the rear, but actually sticking foam to the outside of the boat to increase stability while standing near the sides inside the boat. My questions is, how should this be done?

What brought my attention to this is a guy I watch on youtube a lot for fishing vids. For reference, his name is zoffinger on youtube, and he shows his boat that he simply just used spray expanding foam on both sides, and then shaped it. It seems to be sticking. I want to do something similar, and was just wondering what your thoughts on this were?


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## TNtroller (Jan 7, 2015)

Most, if not all foam will absorb water over time, even the closed cell type from what I've read, even the "floatation" type foam, so seems like it would absorb more water being on the outside of the hull.


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## earl60446 (Jan 7, 2015)

I have seen pictures / videos of people who have put closed end PVC drain pipe, maybe 8" diameter on the outside to help stabilize and add floatation. Especially on canoes.
Tim


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## Zip (Jan 8, 2015)

Hmm, yea I have seen the PVC route.

Makes sense that the foam will eventually absorb water. For the cost though, I think it might be worth a try to add this foam. Even if it does get water in it down the line, just scrape it off and reapply. Keeping it above the water line wouldnt affect too much I think. I might give it a try, with low expectations.


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## Jim (Jan 8, 2015)

Are you talking about the same stuff used on SportsPal & Radisson Canoes?

https://www.bwmarineproducts.com/Sponson%20Kit.htm


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## RiverBottomOutdoors (Jan 8, 2015)

Two words: bad idea


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## whitetailhntr (Jan 9, 2015)

RiverBottomOutdoors said:


> Two words: bad idea



Why is that?


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## boguesounder (Jan 9, 2015)

No words of wisdom, but I also enjoy his utube channel.


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## RiverBottomOutdoors (Jan 9, 2015)

Laundry list...but here's a few

Foam will get water logged over time
Changes the hyrdodynamics of the hull
Will NOT add any stability to the boat whatsoever
Will not hold up to wear and tear


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## JMichael (Jan 9, 2015)

RiverBottomOutdoors said:


> Two words: bad idea


+1


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## PSG-1 (Jan 9, 2015)

Perhaps something like this?







Yep, that's my jet boat. Originally, I had these sponsons on there. They are made from 10" X .050" aluminum irrigation pipe, cut/notched, bent, and welded, airtight. Secured to the gunwales with clips that were riveted in place.

Yes, EXTREMELY stable, you could put 3 or 4 people on one side of the boat, and it barely leaned. However, this also affected its handling properties, making it difficult to bank sharply, and especially being able to whip a 180

Also found out in rough seas, they caused water to come right over the bow, since there is virtually no rise in the bow, like there is with a zodiac, and therefore, no flare to deflect the water. I had 'er knee deep with water one day, coming in through the jetties, when I hit a standing wave on falling tide.

At that point, I decided to take them off the jet boat. :mrgreen:


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## DaleH (Jan 9, 2015)

Zowie, you're lucky to live through that!

I've seen and ridden in my share of RHIB or RIBs ... Rigid Hull Inflatable Boats, but the collars on them are inflatable and hence soften any wave impact, nevermind they were designed with a high forward sheer.

But that jet - cool as it is - is a RHNIB ... for rigid hull Non-Inflatable Boat. Sure glad you weren't hurt hitting that wave!


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## Clint KY (Jan 11, 2015)

If it is stability that you are trying to achieve I would consider outboard stabilizers.
Many canoe and kayak paddlers use them to be able to stand to fish.
They can be adjusted to be out of the water when underway to eliminate drag.
They are sold for canoes as below but I would consider building a set for a Jon.

https://store.springcreek.com/Spring-Creek-HD-Canoe-Stabilizers-w-UR-Complete-Package-p1580.html

Large PVC could be used for the floats and supports could be attached to the gunwales with wing nuts to be able to remove them for trailering.


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## Zip (Jan 13, 2015)

RiverBottomOutdoors said:


> Laundry list...but here's a few
> 
> Foam will get water logged over time - not a problem as you would just take it off.
> Changes the hyrdodynamics of the hull - if it sits above the water line I dont see how that is possible?
> ...



Now, dont get me wrong, I am not saying you are incorrect at all. In fact, I would lean more towards you being correct. I just figured if it was a mod that you can slap on, and have it "work" for a few months then why not. I do not agree that it will change the hydrodynamics of the boat, as long as it is above the water line. 

I think I might just give it a try. Now, I am 5'10 and weigh 145# so I stand on my 1236 with two people all day and dont feel that unstable, but I figure if the foam is near the edge of the boat and you stand on one side, it will help push the boat up as the foam will "try" to stay above water. Again, I am speculating, and the utube video just sparked an interest. I will probably give it a try just for the hell of it and record my findings and get back to you guys.


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## RiverBottomOutdoors (Jan 13, 2015)

My opinion is solid. Good luck putting it to the test. Let us know how it goes.


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## Harleyriderpete (Aug 28, 2022)

So your question never got answered..
Did it work. And if so how the hell did you get the styrofoam to stick to the side of the john boat????


#-o


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## RaisedByWolves (Sep 13, 2022)

RiverBottomOutdoors said:


> Laundry list...but here's a few
> 
> Foam will get water logged over time
> Changes the hyrdodynamics of the hull
> ...



Messing with the shape of the hull on a small boat it a gamble with the losing side being you getting dumped over the side at speed.

I’ve messed with model boats enough to know that making changes without knowing the engineering principles behind the design is bad juju.


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