Internal refurb

[Boater Sam]

Could I suggest OSB  (Oriented Strand Board ) for floors? I have had even good ply start to delaminate. And its so expensive. OSB is wood flakes in a solid resin, it stands up to being left outside in the weather, they make sheds with it and fabricated floor joists for houses. A lot less expensive and streets better than "waterproof" chipboard, which isn't. Hard on your saws though.

[WotEver]

12 minutes ago, Boater Sam said:

Could I suggest OSB

Only if it’s OSB3. Even then, you’d need thicker OSB than WBP plywood for the same rigidity. 18mm OSB will be around the same stiffness as 15mm ply. 

Neither product will be happy if constantly wet, but should cope with damp conditions (and the occasional spill). 

[Neil Smith]

Ok here goes, that board in pic 1 is mdf not chip board but is as bad if not worse, take it all up and replace with 19mm or even 22mm WBP ply depending on spacing of bearers, treat the underside of ply with 2 coats of good exterior wood treatment, and insulate with 25mm celotex if you have room for it and an air space. As said remove paving slabs and clean the base plate then I would give it 2 coats of waxoyl.

Neil

[TheBiscuits]

2 hours ago, Neil Smith said:

Ok here goes, that board in pic 1 is mdf not chip board but is as bad if not worse, take it all up and replace with 19mm or even 22mm WBP ply depending on spacing of bearers, treat the underside of ply with 2 coats of good exterior wood treatment, and insulate with 25mm celotex if you have room for it and an air space. As said remove paving slabs and clean the base plate then I would give it 2 coats of waxoyl.

Neil

Good call - I looked at the pics on my phone and the flooring looked like chipboard - but yes, MDF is even worse for holding water and growing mould.

I would never use waxoyl inside a boat cabin - on the baseplate it's exactly upside down for the job it is meant to do, and the stuff stinks for months.

I used Aldi own brand metal paint at a fiver a tin, having first cleaned and rust treated the baseplate.

[WotEver]

36 minutes ago, TheBiscuits said:

I would never use waxoyl inside a boat cabin - on the baseplate it's exactly upside down for the job it is meant to do, and the stuff stinks for months.

Agreed. And if moisture of any quantity was to sit down there it would get between the Waxoyl and the base plate anyway. 

[Neil Smith]

1 hour ago, WotEver said:

Agreed. And if moisture of any quantity was to sit down there it would get between the Waxoyl and the base plate anyway. 

Why would it get through the waxoyl as it is waterproof, and made to protect metal from rusting.

Neil

1 hour ago, TheBiscuits said:

Good call - I looked at the pics on my phone and the flooring looked like chipboard - but yes, MDF is even worse for holding water and growing mould.

I would never use waxoyl inside a boat cabin - on the baseplate it's exactly upside down for the job it is meant to do, and the stuff stinks for months.

I used Aldi own brand metal paint at a fiver a tin, having first cleaned and rust treated the baseplate.

I used waxoyl and the smell went after about a week.

Neil

[WotEver]

15 minutes ago, Neil Smith said:

Why would it get through the waxoyl as it is waterproof, and made to protect metal from rusting.

Because waxoyl dries out to become a waxy film which moisture will, through osmosis and capillary action, penetrate through to the steel. 

The same thing used to happen with underseal. You could peel it off in strips to reveal the rusty metal beneath.

Waxoyl came along to be a superior coating to underseal and it is - it takes longer to dry out. 

[Peteonthelee]

Thanks everyone. Again all very helpful.

Why would you not put floorboards straight onto the metal stiffeners? Is it a question of more airflow underfoot? 

also there is not much space in between the flagstones for insulation but I could put some on top of the flags - would that be ok if it fills the gap between the flags and the flooring?

Cheers

[Neil Smith]

15 hours ago, Peteonthelee said:

Thanks everyone. Again all very helpful.

Why would you not put floorboards straight onto the metal stiffeners? Is it a question of more airflow underfoot? 

also there is not much space in between the flagstones for insulation but I could put some on top of the flags - would that be ok if it fills the gap between the flags and the flooring?

Cheers

You should have an air gap to let air circulate in the bilge, you could just use 18x38mm treated file batten along the top of the steel bearers to give you an air gap.

Neil

[Peteonthelee]

So the plot thickens - now it appears I may have a leak on the boat but am not sure where it is coming from. I have attached pics of the wettest spot found so far. I do not see how this could be caused by condensation and the previous owner assures me there was not any significant damp areas and certainly no wet areas. Would this level of rusting and wetness caused major alarm for anyone? How worried should I be?

He did have a leak from the tank. He replaced the tank with the one in the pic - I think you can see the tank has been put on wood boards that sit across two bearers - the floor board below is clearly rotten and wet. As I have progressed from the bow of the boat the flooring has worsened in that it was more rotten and wetter. The previous owner had done some work in the shower - this may be leaking but cannot access the piping. The other possibility is a leak from the new tank but I am cants see any 'active' leak. 

The final conundrum is that he has an old toilet tank which has not been used for years and I found today that this had 3 inches of water in it. The tank is open so you can put your hand in it and the water was fresh water. I cannot see how this could be the source of the leak but at this point I am really not sure.  I suspect this may be a difficult thing to resolve on here but any ideas would be useful.

Thanks again

Pete

[rusty69]

It looks like you either have had a leak, or more likely still have a leak. It will likely be:-

1.Plumbing Leak(does pump come on when it shouldn't.Pressure relief valve on calorifier)

2.Topside cabin leak/ deck leak (think windows/vents etc/)

3.Condensation. 

4.Hull leak.

I would try and eliminate these one at a time. Possibly drain off all plumbing, tank/calorfier/pipes etc.Dry out the area and see if the leak remains. If it does, next look at windows etc on a wet day.....and so on until you identify the cause.

There is also the possibility that it is a wet bilge boat.

Edited April 12, 2018 by rusty69

[koukouvagia]

^^^ Good advice.

Now that the baseplate is exposed, you should be able to dry it out fairly quickly with a combination of a sponge followed by paper towels or some such or even a hair dryer.

What you are most worried about is if you have a hull or baseplate leak.  If it is this, it will probably manifest itself by seeping of moisture from under the scale.  This will be evident once the baseplate is dry.  I wouldn't go scraping of the scale yet until you are sure.

Having said that, you'll probably find it's some easily cured plumbing leak. 

Best of luck.

 

[rusty69]

1 hour ago, rusty69 said:

1.Plumbing Leak(does pump come on when it shouldn't.Pressure relief valve on calorifier)

2.Topside cabin leak/ deck leak (think windows/vents etc/)

3.Condensation. 

4.Hull leak.

Forgot to add:-

5.Shower tray/sink leak.

6.Stern gland leak.

Edited April 12, 2018 by rusty69

[Peteonthelee]

many thanks - will check - not around for a week or so - will post update…...

[Peteonthelee]

OK - more of an update - I think the water in the hull was due to an old leak that was not dealt with properly at the time and covered over - including replacing the water tank and just putting it on top of rotten ply! 

The hull has dried out really well but I have not taken out the flooring under the water tank -  I think I will have to do this - unavoidable. But there will be certain parts where I will not  get to the hull - i.e under the floor of the toilet/shower room which is adjacent to the water tank divided by a partition wall. I am going to put rust eater down over the whole hull after scraping all the loose stuff. 

QUESTION - would there be any problem in not doing the bit under the toilet floor? Obviously this will not be as protected. 

[George and Dragon]

On 06/05/2018 at 12:40, Peteonthelee said:

The hull has dried out really well but I have not taken out the flooring under the water tank -  I think I will have to do this - unavoidable. But there will be certain parts where I will not  get to the hull - i.e under the floor of the toilet/shower room which is adjacent to the water tank divided by a partition wall. I am going to put rust eater down over the whole hull after scraping all the loose stuff. 

QUESTION - would there be any problem in not doing the bit under the toilet floor? Obviously this will not be as protected. 

A month on so this answer may be no help whatsoever...

 

What kind of rust eater are you planning to use? If you said higher up the thread then I've missed it. 

To attempt to answer your final question (and I can't claim any expertise): to some extent it depends how bad the corrosion is under the shower/toilet floor. If you can spray your chosen product in and it doesn't have to be washed off then, at least in theory, you should stabilise the metal in its current state. Have you had an ultrasonic survey of the hull/baseplate?

[Peteonthelee]

Well yes I borrowed an ultrasound machine and the readings are very good i.e 7.8 to 8+mm so I think that is all good - I am actually less worried about the hull now so. I have used aqua steel rust eater/converter. Many thanks