Filling motor pod with foam?

[tuned]

I recall seeing photos and a write-up last year of someone who filled their new pontoon water glide with foam. I looked but could not locate the link. If we could track it down, he might be able to share personal experiences with using foam filler. Anyone else recall seeing it?

Yep. I'm that guy. Or not. It was more like 5 years ago for me. I posted all that info on 'the other' forum
I even went there to see if it was still there. It was not. If anyone wants to beat me up for defecting to the dark side, may I remind them that there were not photos of the infraction, so it didn't really happen.
From what I remember, pouring the foam was a huge job--prolly much easier on a pod. It certainly displaced water and gave me some flotation...some being the operative term here. I also was concerned about water intrusion over time. After a lot of reading, I chose either 4 or 6 pound foam because the density was supposed to hold back the water. Of course it was heavier initially. I then 'sealed' it with epoxy resin.
Mixing was an interesting process. Recommend lots of experimentation, a helper, a drill mixer, and a fair few mixing & measuring containers that you can toss afterward. Move quickly and DO NOT try to wipe up anything. Let it harden and cut or sand it off.
If you get serious about it and have further questions, let me know.
Todd

I ran some intrusion tests by weighing a sample and submerging it in a 5 gallon bucket with lid. After several years of total submersion, there was very little if any weight gain.

[crspang]

I recall seeing photos and a write-up last year of someone who filled their new pontoon water glide with foam. I looked but could not locate the link. If we could track it down, he might be able to share personal experiences with using foam filler. Anyone else recall seeing it?

Yep. I'm that guy. Or not. It was more like 5 years ago for me. I posted all that info on 'the other' forum
I even went there to see if it was still there. It was not. If anyone wants to beat me up for defecting to the dark side, may I remind them that there were not photos of the infraction, so it didn't really happen.
From what I remember, pouring the foam was a huge job--prolly much easier on a pod. It certainly displaced water and gave me some flotation...some being the operative term here. I also was concerned about water intrusion over time. After a lot of reading, I chose either 4 or 6 pound foam because the density was supposed to hold back the water. Of course it was heavier initially. I then 'sealed' it with epoxy resin.
Mixing was an interesting process. Recommend lots of experimentation, a helper, a drill mixer, and a fair few mixing & measuring containers that you can toss afterward. Move quickly and DO NOT try to wipe up anything. Let it harden and cut or sand it off.
If you get serious about it and have further questions, let me know.


Todd

I ran some intrusion tests by weighing a sample and submerging it in a 5 gallon bucket with lid. After several years of total submersion, there was very little if any weight gain.

Thanks for the info!

[WoodenPontoon]

I too would not think that the addition of foam will be of much benefit. Assuming that the pod isn't open at the bottom, the added floatation would have no effect unless the boat sank. The "floatation" of any boat is really the displacement of water as affected by the hull(s) in the water and the weight of the vessel.

When a boat sinks, the floatation materials such as poured foam, will prevent water from filling those areas and will also increase buoyancy because of the trapped air.

If you do decide to use the poured foam, make sure there is plenty of room for expansion of the material. The stuff I used in my bow sections, claimed a 35 times volume increase under ideal conditions.

A third tube would be a better choice, in my opinion,

Good Luck!

[tuned]

Agreed that a third tube, even if it is just a 'stubby', would be the best choice. The amount of work required to do either may be similar. The tube is certainly superior (although more expensive).
As far as gaining flotation by just filling a pod, it may be possible. It would depend on how low the boat is sitting and how much of the pod is in the water (the back of those pods are completely open). Here is the math that I would use:

Estimated volume of water in pod (at rest) X 62 (#/ft3)-weight of poured foam=flotation gain.

[Drago]

I would venture a guess that filling the motor pod with foam to prevent it filling with water might give a small boost in hole shot due to the water not being there during blast off. I always did wonder why the pod/transom had the hole at the bottom to allow water to fill it during no motion. I suppose there is no way to seal it from water getting in, therefore the big drain at the bottom.

[teecro]

I would venture a guess that filling the motor pod with foam to prevent it filling with water might give a small boost in hole shot due to the water not being there during blast off. I always did wonder why the pod/transom had the hole at the bottom to allow water to fill it during no motion. I suppose there is no way to seal it from water getting in, therefore the big drain at the bottom.

I have read where some folks have found ways of preventing most of the water intrusion and have thus closed off the big whole in the transom and installed some sort of a check valve to allow water to drain while underway.

[tuned]

I would venture a guess that filling the motor pod with foam to prevent it filling with water might give a small boost in hole shot due to the water not being there during blast off. I always did wonder why the pod/transom had the hole at the bottom to allow water to fill it during no motion. I suppose there is no way to seal it from water getting in, therefore the big drain at the bottom.

I have read where some folks have found ways of preventing most of the water intrusion and have thus closed off the big whole in the transom and installed some sort of a check valve to allow water to drain while underway.

I have used 'automatic scupper valves' in the past. There are several types, flappers, rubber flubbers.... They are generally pretty good. So there is another option. I haven't heard of it.

[teecro]

... I have used 'automatic scupper valves' in the past. There are several types, flappers, rubber flubbers.... They are generally pretty good. So there is another option. I haven't heard of it.

I'll admit I just don't like seeing the water flowing freely out the stern of my motor pod; something about water being only a layer of plastic away from my fuel does not sit well with me... lol

I plan on underskinning my boat sometime in the not so distant future and when I do I may experiment with closing up the motor pod to see if it affords me just a little bit more buoyancy namely when I'm loaded with friends/family....

[tuned]

I plan on underskinning my boat sometime in the not so distant future and when I do I may experiment with closing up the motor pod to see if it affords me just a little bit more buoyancy namely when I'm loaded with friends/family....

It really is an intriguing concept. I was trying to think of possible drawbacks and engineering issues. I came up with a couple of small ones, but no real deal-killers.

If you are going to fully seal it and still try to get any wayward water out with an automatic scupper, you might need a looped vent on top, kinda like most pontoons have. If you are fully sealed and confident that you won't get any water, then you'd be good to go.

Also a bit bigger item to chew on would be access to the inside of your transom in case motor has to come off for service or height adjustment.

Either way, sounds like a fun project. Good luck.