? treating fungus on marine ply

[mat]

I have just purchased a second Mirror. The compartment section under the mast has never been laquered and has some black spots on the bare ply. Is this fungus? Do I need to treat it before laquering? What treatment should I use?

thanks for any responses

[bitingmidge]

Mat, do you mean in the bouyancy compartment??

I reckon you'll find it's mould, and may have a little rot round there somewhere.

If it was my boat, I'm assuming it's an old mirror, I'd give it a slosh out with a strong chlorine bleach solution, then rinse thoroughly, then dry even more thoroughly, then seal the compartment with a bit of paint.

If it was a new boat, I'd go the whole epoxy bit, but it's going to be a bugger of a job reaching up through a 4" port, so use anything that'll keep water out of the ply, and be diligent about drying it out after each use.

Cheers,

P
:D

[journeyman Mick]

Mat,
ditto what Midge said, but when you're finished throw in a handful of salt as insurance. Fungus won't grow in salty water.

Mick

[Daddles]

And don't leave the bouyancy compartment sealed when the boat isn't being used - get the boat hot, you get humidity in there and next thing you know, you've got mould.

Richard

[mat]

Thanks guys.
No it's not the bouyacy compartment, it is an area just behind. There is a section that is open at the back only with two large cutouts in the vertical board. It is about 40cm deep. The bouyancy compartment is in front of this.

It is an old boat but in surprisingly good condition. I think it has probably been stored for a prolonged period.

[Boatmik]

Mat,
ditto what Midge said, but when you're finished throw in a handful of salt as insurance. Fungus won't grow in salty water.

Mick
Sorry Mick,

Not a good idea.

The problem is that salt sucks moisture. So it will remain almost perpetually moist.

Then on a warm day the moisture will evaporate. At night the air cools and the moisture will condense over all the internal surfaces of the tank. So you end up with pure distilled water droplets gradually removing salt from the upper areas of the tank and rinsing the salt down to the bottom.

So in the end you end up with a permanent supply of fresh water for the upper reaches of the tank - so you may end up with rot around the deck structure.

I would also take issue with Richard (sooooooory mate). Not coating the interior of the boat prevents you from doing an effective job of mopping out the interior - the raw wood will absorb any water that goes in the tank and then you can't get rid of it through either a bunghole or by mopping out. So you end up with lots of water vapour in the hull when it gets warm again.

So in the end - I'm with Midge - an ignominious position I know - but I will have to live with it.

The only thing that prevents rot is preventing one (or both) of moisture or air. Epoxy is one way of doing both. I have seen so many boats built in the last 25 years using epoxy that are in excellent condition compared to my own boats of similar age which were only sealed with varnish or everdure over the same time frame. In the end the epoxy is worth the expense.

However with a boat that is already finished it is probably not worth it in terms of LABOUR - ie you cannot do a good enough job once the decks are on.

Another way from tradition is to provide good ventilation for the interior of the hull. Larger boats need to have it designed in - read some of Francis Herreshoff so hear someone banging that drum!

Or for smaller boats...

Inspection ports at opposite ends of the tanks left open when the boat is not in use - of course with the boat under cover to stop rain going in

If not in use and if you dont have a garage - store the boat upside down on the trailer or some bricks to keep it off the ground with all the inspection ports off. A tarp over the top, but clear of the ground so air can blow under.

That's very best way to long term store a boat if you don't can't swing it up under a carport.

Michael Storer

[Daddles]

I would also take issue with Richard (sooooooory mate). Not coating the interior of the boat prevents you from doing an effective job of mopping out the interior - the raw wood will absorb any water that goes in the tank and then you can't get rid of it through either a bunghole or by mopping out. So you end up with lots of water vapour in the hull when it gets warm again.


You completely misunderstood me Mik. I didn't mean not to seal the timber, which you should do. I meant not leaving the compartment sealed when not in use... much as you suggest later on


Inspection ports at opposite ends of the tanks left open when the boat is not in use


Richard

[STEPHEN MILLER]

Wattyl make a antimould additive to go in oilbased polyurethane or waterbased paints to help solve future problems. So go with epoxy when its cleaned up with bleach etc which will get rid of stain created by mould etc and it can be varnished and look like new if you want ot that way:cool: Baotmik you should learn to read plain english mate then you wouldnt need to pick on poor old Daddles and you could shorten your post then and save on RSI:rolleyes:

[Daddles]

Arrr, to be fair to Mik, he and I have had a few discussions recently about sheathing boats in poxy - we haven't specifically talked about inside tanks and he wasn't to know that I always coat the inside of tanks with poxy :D

Richard

[Boatmik]

You completely misunderstood me Mik. I didn't mean not to seal the timber, which you should do. I meant not leaving the compartment sealed when not in use... much as you suggest later on



Richard
Mea Culpa

And the really sad thing is it means that I agree with both Daddles and Midge in the one post - where I thought I was only agreeing with one of the dreadful duo!

Bless their cotton socks

[Daddles]

And the really sad thing is it means that I agree with both Daddles and Midge in the one post -

Oi, you can't do that. As punishment, you'll have to get those rowboat plans finished :D (yes, I've been rowing ruddy Redback again :( )

Richard

[bitingmidge]

Careful Richard!!

He's going to get up me because I haven't done anything on the Canoe over Christmas!!! On his Rowboat Pages (http://members.ozemail.com.au/~storerm/Rowboat/Rowboat.html) he made the silly mistake of telling the world I was making rapid progress......... and put the mokkers on me.

:(

Hopefully Mik'll have them finished in Feb, just in time for me to start!! :D :D :D

Cheers,

P

[STEPHEN MILLER]

There is definitely to much smoozen going on here lucky its still close to Christmas and its still allowed and if it gets to dribley then we will have a real problem with mould:D

[bitingmidge]

Sorry to be leaving you out Stephen,
Have a big wet green new year kiss from me!!!

P (bloody South Australians - bless their pink little hotpants!!)
:D :D :D :D :D

[Boatmik]

Sorry to be leaving you out Stephen,
Have a big wet green new year kiss from me!!!

P (bloody South Australians - bless their pink little hotpants!!)
:D :D :D :D :D

Not being a NATIVE south australian you won't catch me in hotpants!

Or that's what I used to say.

But I have noticed the last coupla times I have gone back to Sydney that I have started missing SEEING the strapping men in hotpants that litter Rundle Mall, Gouger St, Jetty Rd and other places where an Adelaidean goes to be seen.

Not to be seen in Martin Place or Pitt St or Double Pay et al

Ah well - be heading back in a coupla weeks

boatmik