Anyone tried drying foam flotation by vacuum without removing?

[stunt822]

Have a 1999 Bayliner Capri which has been kept outside too much. There is water in flotations, maybe up to waterlogging state even. When I drilled 1/8 hole in the transom (from outside rear) - got a cup of water from both sides.

Floor is relatively ok, at least i'm not going to replace it any time soon.
Just plan to dry it out so rotting stop. As from my previous boat experience - 2 years in warm dry garage did the trick.

But here is the question - if I hook up vacuum pump to the hole I drilled - water inside will evaporate quickly. On a hot summer day it will actually boil, if flotation bay is sealed well enough. The only worry is - could vacuum pressure collapse floor?

Any one tried it?

 

[jigngrub]

Re: Anyone tried drying foam flotation by vacuum without removing?

If you wear rose tinted glasses while doing this it may work... until you take the glasses off.

If a vacuum cleaner can collapse your deck, then it's not relatively ok... but it won't because your decking is being supported by the wet foam, and that's why it feels relatively ok. If your decking wasn't supported by the wet foam you'd probably put your foot through it just by walking on it.

I don't care what you do to try and dry out your foam, it isn't going to dry because the decking is sitting directly on top of it holding the moisture in... and the wet foam is saturating your decking because both are in contact with each other.

You can use the vacuum method to try and dry your foam without fear of collapsing your decking, and you'll get some of the water out... but not all of it, and you'll never dry your foam and decking out completely.

... but don't take my word for it, try it and see for yourself. Sooner or later you will be replacing the decking because of rot and you'll be able to see just how much water is in your foam when you have to dig it out and replace it too.

EDITED TO SAY:

In case you don't realize it, your saturated foam is adding hundreds of pounds of extra weight to your boat that is slowing it down and making your boat sit lower in the water than it should.

Your saturated foam is also a safety hazard because it will not float your boat in case of an emergency, should your boat get swamped or start taking on water it will sink to the bottom leaving you and your passengers in the water withou event anything to hold on to... Think about it.

 

[jbcurt00]

Re: Anyone tried drying foam flotation by vacuum without removing?

Not that I think it makes a difference realistically, but I believe stunt is referring to a pump that will draw a vacuum (vacuum pump) not a shop vac or other type of vacuum cleaner..

Vacuum pump:

interesting idea, but as I understand waterlogged foam, the 'cell' structure of the foam has been compromised by freeze/thaw cycles. This bursts the cell walls, and w/out the hundreds of thousands of cells holding small air pockets, there is no flotation value to the foam. Once reintroduced to water, they will again fill w/ water. Once the cell walls burst, they are also no longer as structurally as supportive as they once were.

If you were able to dry the foam, you may satisfy the immediate need to stop further rotting of the wooden sub-deck structure, but it won't 'repair' the damaged cells, so they will still no longer add support for the deck &/or hull nor offer as much flotation as they did originally, they'll just be dry

Interesting idea though. Got a vacuum pump & an enclosed, heated garage you can tie up for 6-36 months?

Anybody have a link to the shop vac foam drying thread? Been a bit, I wonder where that project ended up.... ???

 

[tpenfield]

Re: Anyone tried drying foam flotation by vacuum without removing?

You might be able to get some of the water out, but you should really make sure you understand where all of the water resides. Once foam is to the point where it can retain water, many of the cells in it have broken down.

Also you mentioned getting water from both sides of the transom . . . Was that through the transom and into a foam cavity, or just into the transom?

Rot will persist unless a rot treatment is given to the wood in the structure, as presumably it has absorbed water from the foam, etc. A lot of the outcome would depend on how wide spread the moisture is throughout the structure and foam cavities.

not a slam dunk by any means . . . Your chances are better if the issue is isolated.

i have been addressing some water retention issues in my boat . . . Fortunately they were reasonably well isolated to the main bulkhead. However, it will be an annual thing to monitor and continue corrective action.

FWIW - I have a thread here on iBoats and on my web site about removing moisture from the structure of my boat. Most of the moisture in the foam was captive in the fuel tank bay. I drilled a hole low against the hull and into the fuel tank bay to try to suck water out. I did not get too much water out until I made another hole from the top of the foam leading down towards the hull. Once I did that, then I would collect about 8 ounces of water every 20 minutes or so with the shop vac. I may have gotten about a quart of water total, until no more water would come out. However, it is hard to say how much moisture remained. This will be part of the annual process to see. If I get more water out, etc.

if the moisture in your boat is widespread, which it may be, your better tool is a sawz-all rather than a vacuum.

 

[jigngrub]

Re: Anyone tried drying foam flotation by vacuum without removing?

Not that I think it makes a difference realistically, but I believe stunt is referring to a pump that will draw a vacuum (vacuum pump) not a shop vac or other type of vacuum cleaner..

Vacuum pump:

interesting idea, but as I understand waterlogged foam, the 'cell' structure of the foam has been compromised by freeze/thaw cycles. This bursts the cell walls, and w/out the hundreds of thousands of cells holding small air pockets, there is no flotation value to the foam. Once reintroduced to water, they will again fill w/ water. Once the cell walls burst, they are also no longer as structurally as supportive as they once were.

If you were able to dry the foam, you may satisfy the immediate need to stop further rotting of the wooden sub-deck structure, but it won't 'repair' the damaged cells, so they will still no longer add support for the deck &/or hull nor offer as much flotation as they did originally, they'll just be dry

Interesting idea though. Got a vacuum pump & an enclosed, heated garage you can tie up for 6-36 months?

Anybody have a link to the shop vac foam drying thread? Been a bit, I wonder where that project ended up.... ???

I believe that vacuum pump would damage the fiberglass hull before it hurt the decking. Visualize a f'glass hull that looks like a prune and that's what you would get with a vacuum pump.

The shop vac thread is still sucking air over the top of the foam in the few spots it can get air over the top of the foam and under the decking, and the only way he can prove it really worked is to take the boat apart and put a moisture meter on the bottom of the foam that was against the hull. But we know that's not going to happen because everyone that wants to try something like this doesn't want to remove decking or foam... but they'll have to eventually, or sell another rotten fiberglass boat on Craigslist.

 

[jbcurt00]

Re: Anyone tried drying foam flotation by vacuum without removing?

Yep ^^^

I actually wouldn't care if my foam was 'just wet' as long as it's not waterlogged. For neglected boats, wet foam is waterlogged probably 99.5% of the time.

It really is the cell structure doing all the work, flotation or structure. Once the cells burst, it's not doing either, so dried is not an improvement overall...

I spent about 12sec looking for the vac thread, but nada... It's in here somewhere though....

Yeah, I'd 'love' to have a shop vac running 16+hrs a day out in the drive for over a month :facepalm: That'd just be just FABULOUS......

The Admiral would 'love' it even more. Neighbors too I bet...

 

[bakerjw]

Re: Anyone tried drying foam flotation by vacuum without removing?

When I saw this thread, I felt a pit in my stomach. 3 Weeks ago, I came to the realization that I owned a water logged boat. I had choices. Pass it along to someone else (would never happen). Scrap it and take a $4K loss (considered it). Buckle down, gut it and rebuild it from the hull up(am doing it).

Those are the choices. If you could put the boat into a perfect vacuum, you might get all of the water out eventually, but there will still be rot and rot means loss of structural integrity. Just my opinion though.

 

[Scott Danforth]

Re: Anyone tried drying foam flotation by vacuum without removing?

tried it, doesnt work. only thing to do with water logged foam is to remove it, repair the wood rot, re-fiberglass and move on. or simply scrap the hull.

 

[Bob_VT]

Re: Anyone tried drying foam flotation by vacuum without removing?

If the boat was built based on the foam (such as a boston whaler) the method was tried but it took MONTHS and was not 100% effective.

The Bayliner is not built based on foam but foam is part of the construction and the flotation is not in a sealed area. The hull will not collapse since nothing is sealed.

Will it work to dry out the foam........ no not with any reliability. Sorry no shortcuts. Without proper investigation below the deck.....you will not know what damage has happened or is happening. You can not be certain the foam is wet...... maybe the foam has started to break down and you might have water backed up into areas where the drains are blocked.

 

[glenn property of pam]

Re: Anyone tried drying foam flotation by vacuum without removing?

my boat was rotten in places and there was water at the bottom of the foam but the foam was not water logged but that may be the oddity rather than the rule. If you can get to a spot near the back in the engine bay or under the battery near the inside stringer you can cut a large hole at least 2" in diameter and sharpen a plastic pipe (cut teeth into it) and cut a core plug out of the foam. If the foam is water logged you will see it. A lot of boat were built so any water that gets under the floor from rain is unable to get out of that area. the foam that is under water will become soaked the question is how deep was the foam under water.

My boat was weighed before the rebuild and after the rebuild and it gained 20lbs which was odd

 

[stunt822]

Re: Anyone tried drying foam flotation by vacuum without removing?

Thank you for all the replies, appreciate it. I have also read thru couple rebuild threads - which left split impression - it's a great work to rebuild boat, but you only get a standard boat in the end, which you could have purchased in the first place.

with a small baby on hands after work and wife working it's unlikely i can repeat that heroism or rebuilding.
But i will cut a 2" tube from ski locker area to see what's inside.

Reg the floor condition - one 3x6 area of floor on the edge of ski locker was soft and rotten at the back side, looks like water was getting in to the edge of unprotected plywood because boat was under rain with nose up and leaning to that side. I have put a patch on that spot. But other than that - i didn't find any other soft spots on entire floor. I spent 20 minutes walking, jumping, banging and pressuring against the floor and all shows very solid.
No cracks/hairlines anywhere on the hull, inside or out that would have suggested compromised integrity. Also with 4 adults in the boat and a full tank - it gets up on the plane very quickly, with only 3 liter. so probably no huge weight added.
When I drilled 1/8 holes thru transom into foam and from ski locker - all wood is dry and bright in color, no rot.

About drains - never seen bayliner under floor, but aren't foam chambers all sealed? is there a drain between them like from the ski locker to engine bay?

jbcurt - yes, a pump not a shop vac. any decent level of vacuum will help water to evaporate quicker, especially if I leave small heater underneath. Here is how water boils in vacuum, for those who didn't know
Boiling water at room temperature - YouTube
Boat was born and lived in Oregon, where we hardly have any freezing in winter. Also looks like first owners kept it inside, otherwise interior would look worse. Just the last owner was an ******* and had it outside all the rainy winter.
With only 15 years on the boat - i have hopes foam is still ok.

jigngrub - sounds like you hate to see rotten boats out in the water, but don't put your fury on me even if i'll find time to redo the boat - it's wont' happen tomorrow, and i'd rather have it dry as soon as possible.

tpenfield - water was in the foam, transom wood was fresh dry and no rot. even smelled nice

if any one finds that thread about shop vac drying - can you post a link? i don't see how that would help better than just a driz-air can in the boat, but would like to take a look.

I don't expect water to be gone overnight, and have warm dry garage to store boat in, so will give it some time during coming winter. Since i'm on the cheaper boat side - it is my second wet boat. I had 1982 bayliner for $1200 4 years ago, when i knew zero about boats. When in the water empty - it would sit at an angle, with port side noticeably higher. But after 2 years(winters) in dry garage with driz-air in the boat - it was sitting levelled. My guess - it dried it self out.


Back to original question - looks like no one tried vacuum pump yet. well, if I find anything interesting in the process - will post pics.

 

[tpenfield]

Re: Anyone tried drying foam flotation by vacuum without removing?

In terms of creating lower pressure in the foam chambers as a means to evaporate/boil off the water, one thing that comes immediately to mind is that the chambers formed by the boat's structure may not be fully air tight. So, it may be difficult or impossible to create the amount of vacuum that would be needed.

I suppose if you ever came across a very large vacuum chamber, the entire boat could be subject to low pressure and moisture would readily evaporate.

I have been of the opinion that you CAN dry out a boat in many cases, and your experience with the '82 Bayliner probably shows that. However, the time and effort it takes to dry out a boat is not something that a professional would want to pursue. . . much easier, and cheaper to cut & gut, if time is money.

Another thing to consider is that once wet foam, and presumably wet structure is dried out, rot of a different form (dry rot) will most likely set in. So, preventive treatments are still necessary. This is all do-able by a D-I-Y champion, if the issue is fairly well isolated. If it is wide spread, then there may be too much to deal with. That is why I make the point of understanding how widespread the water is in your boat.

 

[Woodonglass]

Re: Anyone tried drying foam flotation by vacuum without removing?

These will be of interest...

http://forums.iboats.com/boat-restoration-building-hull-repair/dealing-saturated-foam-hull-605193.htmlRemoving Water From Waterlogged Foam - Shop Vac - Boat Design Forums

General consensus on most of the Boat restoration sites is... Attempting to remove the water from saturated flotation foam is not a good idea. However...It's your boat and you ARE free to give it a go and post your results here on the forum.

It's interesting that you state you hardly have any freezing in Oregon. My research tells me the average Low temps for most areas in Oregon are well below 32? F. Where exactly are you located in Oregon?

 

[73Chrysler105]

Re: Anyone tried drying foam flotation by vacuum without removing?

my boat was rotten in places and there was water at the bottom of the foam but the foam was not water logged but that may be the oddity rather than the rule. If you can get to a spot near the back in the engine bay or under the battery near the inside stringer you can cut a large hole at least 2" in diameter and sharpen a plastic pipe (cut teeth into it) and cut a core plug out of the foam. If the foam is water logged you will see it. A lot of boat were built so any water that gets under the floor from rain is unable to get out of that area. the foam that is under water will become soaked the question is how deep was the foam under water.

My boat was weighed before the rebuild and after the rebuild and it gained 20lbs which was odd

It gained 20lbs from all the extra mat and resin you put in to make her sealed and solid.

 

[mwe-maxxowner]

Re: Anyone tried drying foam flotation by vacuum without removing?

Thank you for all the replies, appreciate it. I have also read thru couple rebuild threads - which left split impression - it's a great work to rebuild boat, but you only get a standard boat in the end, which you could have purchased in the first place.

But for a very small fraction of the price. And you can make the boat into whatever you wish. I have 5 or 6k in my boat. I looked at a master craft yesterday that is sorta the same with more bells and whistles for 90k. A comparable middle end new runabout with no tower or anything is probably 25k.

 

[stunt822]

Re: Anyone tried drying foam flotation by vacuum without removing?

Woodonglass - i'm in Portland, OR. couple days in winter we get water on the mud puddles covered by ice, but total for maybe a week. To answer that - i did the following:

Digged a bit deeper - extracted 3/4 round cilinder of foam.
It is not all saturated, you can see white vs darker sections on the foam piece. and still floats average to ok.
wood is not rotten but wet. I left foam out on the table to see how quick it dried, because it seems to be able to.

So my plan minima - get it all dry.

Take a look at pics please - what do you think, gurus?

 

[tpenfield]

Re: Anyone tried drying foam flotation by vacuum without removing?

Here is a link to my thread of a similar topic . . . more the issue of wood than with foam. . . . but some of it may be useful.

Link: http://forums.iboats.com/boat-resto...-suggestions-drying-out-bulkheads-584200.html

In terms of the pictures that you have posted, it would be good to get some wider views so we can see what part of the boat you are drilling into, etc. The foam that you show in the wine glass is very well saturated and has little flotation capacity left, based on how low it is floating. Keep in mind that most of the structural foam used in boats has a density of 4 lbs/cu. ft. versus water with a density of 62.4 lbs/cu. ft. So, good & dry foam will float very high on the water, needing very little immersion to float.

As to the wet wood, you will want to find out how much moisture propagation has occurred throughout the structure. You can get a pricey marine moisture meter that the pros use, or buy an inexpensive direct contact meter at a home improvement store. The only difference is that you will need to drill some holes in the fiberglass to get direct contact with the wood.

I think you are still in the 'assessment' stage of the process, and the 'remedy' is not fully understood until the assessment is thorough enough.

 

[JASinIL2006]

Re: Anyone tried drying foam flotation by vacuum without removing?

That wet foam is saturated... it looks like some of the core samples I took before my restoration. I was surprised how much variation there was in the level of saturation, even within a single compartment. I took some samples that looked pretty good, then 8" away I'd get a sample that looked like yours... or worse.

With foam that wet, I'd be worried about the effect of moisture on wood, either now or in the future. Hard to see how you'd get the moisture out of that, even if you could create a vacuum. Would shifting water to a gaseous state drive it into adjacent foam?

This is very interesting...

Jim

 

[bakerjw]

Re: Anyone tried drying foam flotation by vacuum without removing?

My Stratos had moisture in virtually every piece of wood. Some bulkheads were rotted away but others were sound. But waterlogged. Just imagine how much extra weight might be in the wood of your boat. IMHO, wood that is wet is just waiting to rot.

 

[stunt822]

Re: Anyone tried drying foam flotation by vacuum without removing?

Well, if it's waiting to rot - i will let it wait a bit more. No time in my calendar for boat rebuild right now. At the end may even have someone to do it for me. Or for himself.
Additional pics - after 24 hours on the desk - foam is absolutely dry and floats significantly higher. Same with pieces of wood I drilled out. No rot signs on this wood, taken at the bottom of ski locker side. I know it doesn't speak for the rest of hull
Second pic - where I took sample, on the right back side of ski locker.
Drilled couple more 1/8 holes from the bottom - no water came out, but i can see moisture on the drilling bit. I think that will be my criteria a year from now to evaluate - did it dry out or not.

Still looking for vacuum pump and will proceed with drying aid.