Instapak foam bags to replace wet foam in 16' aluminum?

[Waitara]

Anyone try this?
3 advantages I have so far:
1. No smell. Middle of winter and I'd be doing this in a heatable attached garage. Anything that smells in there stinks up the house and then the wife gets mad.
2. Plastic bag around the foam would keep water from coming in contact with the foam.
3. No mess. No mixing cups, quick pours, or spills.

Downside: a bit more expensive, but not by much. For $122 I can get enough bags to do my boat. $100 for the 2 gallon kit, which is more than enough.

It's a 1990 SmokerCraft and in 5-8 years I plan to upgrade to a new or newer boat. I don't need a forever solution but I don't want to screw over the next owner either. It will be kept indoors so other than cleaning or rainy day fishing, it will stay dry. The floor is aluminum, not plywood.

This seems like such a good idea, what am I not considering?

 

[GA_Boater]

Never heard of the Instapaks

What is the structure like under the deck? Closed cell foam sheets can be cut to fit and offer very good flotation with out the drawbacks of pour in foam. And not real expensive.

 

[EricT71]

I think it's an excellent idea, especially if the cost is comparable. Try it and let us know how it goes!

 

[Scott Danforth]

the instapak foam is an open cell foam for cushioning items for shipping. may as well fill the cavity with a sponge.

 

[GA_Boater]

the instapak foam is an open cell foam for cushioning items for shipping. may as well fill the cavity with a sponge.

Yeah. I looked it up to see what it is. Every time I get a package with that stuff, I crush it by hand before disposal. The bag does make less of a mess - That's good.

So you have one closed cell, the bag, and a big, fragile sponge. Also the bags aren't very durable and doubt they will stand up to the friction rubbing together. Way down the list for flotation for me.

 

[Baylinerchuck]

I agree with Scott and GA, working for a parcel delivery company I see a ton of this stuff. It is not near as hard and structural as pour in foam. It's made to cushion fragile items when it expands by surrounding it. The same item with pour in foam would be crushed when it expands. Not a good choice IMO.

 

[JASinIL2006]

Pour-in foam does not smell. It is a bit messy, but not really smelly. (Nothing like poly resin, which does have a strong permeating odor.) It outgasses CO2, but that's about it.

 

[axlr8]

As little experience I have with the pour in foam, JASinIL is right. It doesn't have enough of an odor to make a distinct problem.. Worst case scenario, get a dozen roses and pour the foam before you take her out to dinner. Guarantee it isnt a problem. Instead of the $122 you are looking at, go with the known-right solution and itll only cost you about $200 bucks, depending on where you go to dinner! :lol:

 

[Waitara]

Didn't realize it was open cell. Pour-in it is. I'd do the pink foam board but I don't get seasick so I'll be out there smashing into waves. For a 27-year-old riveted boat I'd prefer the little bit of extra structural strength provided by pour-in. Chunks of foam squeaking together while I'm trying to nap on the lake would bother me too!

 

[bunnymoney]

It seems ALL foam soaks up water sooner or later if it gets wet, some types more than others. There are plenty of opinions as to what type of floatation is best. I don't have a problem with that as everyone is entitled to their own opinion.

I have a fair amount of experience with plastic soda bottles. It's quite amazing just how strong they really are. If you can fit enough of them to float your boat you will not have to worry about them soaking up water. Stick them together with a little 3M packing tape to keep them from moving around. Another useful form of flotation is plastic cat litter jugs. (Really big ones at Costco) you can fill them with foam peanuts or just leave them empty with sealed caps. I had also thought about using contractor trash bags with appropriate amounts of foam peanuts sealed with 3M tape that would fit in the voids like pillows between the deck and hull and anywhere else that they would be out of sight.

The main idea is to keep your boat from sinking.
120 gallons, equivalent to 960 lbs, for $36.50.

 

[kcassells]

Here's a link frpm previous discussions.
http://forums.iboats.com/forum/boat.../10255687-to-foam-or-not-to-foam#post10255687
Go up top and use your search tool. The subject has been talked about many times.
KC

 

[jbcurt00]

Yep, ^^^ too many times to count, IMO.

Packing peanuts and soda bottles are way way way down the list.

Bottles are an inefficient shape to use effectively below decks and susceptible to temp chages.

 

[achris]

It seems ALL foam soaks up water sooner or later if it gets wet, some types more than others....

Nope. Have a look at syntactic foam. It's closed cell, and we use it on our machines at depths up to 4,000m (13,000 feet).

Chris.....

 

[bunnymoney]

Nope. Have a look at syntactic foam. It's closed cell, and we use it on our machines at depths up to 4,000m (13,000 feet).

Chris.....

Curious about the foam you mentioned. Everyone has seen the pictures of a styrofoam cup at great sea depths. 13,000' equals about 5629 psi.
How much "shrinkage" do you see at those depths with syntactic foam?

jbcurt00- It's obvious plastic bottles are not the perfect shape. What difference does it make if you can fit enough of them into your vessel to keep it afloat?
As to temperature change I assume you are referring to expansion/contraction of a bottle filled with plain air. What do you make of the expansion/contraction of the "gas" contained in closed cell foam due to temperature change?

Just think, if ping-pong balls were free how easy it would be. Pour them in, level with a 2x4, then attach the deck.:joyous:

 

[achris]

Curious about the foam you mentioned. Everyone has seen the pictures of a styrofoam cup at great sea depths. 13,000' equals about 5629 psi.
How much "shrinkage" do you see at those depths with syntactic foam?

Seen the cup? I have one. The reason we use syntactic is because it is glass micro bubbles, and has extremely low compression. At 4000m we see less than 1% compression.

 

[jbcurt00]

bunnymoney this topic is actually about the use of instapak foam not an infinite number of choices, some good some bad.

And numerous other choices have been discussed countless times in excruciatingly great detail. This is not the place to do it, again.

Read thru the topics found via a search, thru tnstratosfams link, and decide for yourself. Use the other boat project topics as a guide and see how many used bottles or packing peanuts.

See the OPs last post, post #9:

So pour in foam it is

Didnt ask for alternatives.

 

[Waitara]

I appreciate the discussion. That's why I come here. If I wanted a curt yes/no answer I'd have asked Siri. I've read the thread someone linked to, and numerous others. None mentioned the Instapak foam. That's why I started a new thread.

The aluminum floor has been removed once, maybe twice, so there are sharp little bits of aluminum rivet laying everywhere. I've been vacuuming them up but new ones emerge from somewhere. I don't think the plastic bag would last too long. I will put some pink foam board down under the pour-in because I have a lot of it laying around from a basement project, and to keep the pour-in from draining under the long skinny center-mounted fuel tank and blocking the path to the bilge.

I've had the floor out and a small electric fan blowing into the bilge for two weeks now. Still prying wet heavy foam out. (Drywall saw and a wonder bar is THEE setup for this!) Previous owners kept the boat in unheated barn or outside. There is a waterline inside that tells me the drain hole got clogged and water sat there for a while. Thankfully it was tilted pretty good and everything forward of the console stayed dry.

I think I'll take this opportunity to add some storage under the floor. Just a hatch and liner or two for an anchor and first aid kit.

 

[Scott Danforth]

use a cup brush on an electric drill. it will chew up the foam into dust and you can simply vacuum it out.

 

[Waitara]

This foam is either dry rotted, wet/black/moldy, or drippy wet. Nothing I'd want flinging around my garage or onto me. The drywall saw makes quick work of it and gives me big chunks I can put into a trash bag. My shop vac is one of the cheapest with a 1.5" diameter hose. Clogs easily on stuff bigger than a quarter.

 

[jbcurt00]

Yep, sounds like normal, foul smelling, old, wet foam.

The foam isnt the enemy once you put a boat back together. Neglectful, poor or complete lack of maintenance is.