Bilge Paint for wooden boats

Hi Every one,

We are building a 47m wooden boat in Qatar , the traditional way is to apply fish oil in the bilge area , however the classification society requirement is to paint the bilge area , Kindly advise if any one has applied paint to the bilge area inside and its affects on the wood.

Also would need advise on the paint that was used and photographs if you have any of how it looks . I know they do it for FRP boats but do you have paints for wooden boats.

 

A very common bilge paint is International DANBOLINE.

http://www.yachtpaint.com/MPYACMDatasheets/Danboline eng A4 Y 20100630.p

 

I'm not sure what your classification society requirements are, but painting the bilge of a wooden boat is foolish and this is backed up be the vast majority of former wooden boat manufactures.

If you paint a bilge, it looks nice and is easier to clean, but it hides problems until they become major concerns. On the other hand if you do what the majority of wooden boat manufactures did and clear coat the bilge, issues can be addressed quickly before they become a much bigger problem.

An example would be a planking fastener that hit the edge of a frame and "burst through" the side of the rib. It happens, you drive several thousand fasteners in a moderately sized hull and a few will miss or burst out. Most of these are caught and fixed during construction, but some make it until launch day. The fastener doesn't have any "purchase" and it begins to weep. In very short order, the wood surrounding the fastener will darken and stain. If the bilge is clear coated, this is easily seen and a repair can be done in a timely fashion. On the other hand if this same fastener is covered in paint, you will not notice anything until the surrounding wood has bubbled up the paint and now you have to repair a lot more then a poorly placed fastener.

In short a painted bilge requirement is a sign that your classification society are a bunch of boneheads that haven't any real wooden boat experience. All the major wooden boat players used varnish or shellac in the bilge, (inside lockers, under soles, behind cabinets, etc.) for the very reason I mention, so you can see what's going on. Wooden boats can tolerate the least amount of neglect of all build methods, so addressing issues as they come up quickly is one key to insuring long life. Clear coat the bilge with varnish, shellac or polyurethane.

 

There may be something lost in the translation. Do they specify paint or a coating?

 

Fish oil is what made all the early wood cargo holds very foul places to be, the gas it releases is also very corrosive to metals, especially modern electronics like navigation equipment and radios.

I am not sure paint is such a good idea either, but I would think a modern transparent wood preservative would be best.

What are you building? Sounds like an interesting project, is it a replica of an early trade vessel? Such as the Sohar built in Oman by Tim Severin to duplicate the Sinbad voyage?

 

International Paints makes an INTERLUX product called "bilge grey", which is a quick drying, water tolerant enamel that I have used for many years with good results. I built a 23 ton, 12.5 meter wooden boat in 1976 and this stuff is good bilge paint.

 

Also remember RED LEAD. Every wooden fishing trawler I see hauled at the yard has a red lead bilge. These boats are 30 40 years old

 

Having read Skiffs and Schooners by R D Culler I've been mixing my boat oils for the occasion and have been very successful and pleased with the results. I found nothing in a can that would work well in Alaska on my teak cap rail and that started the mix my own effort. I usually start w about 15% raw linseed oil, 15% wood preservative (from a can), (I haven't used cyan pepper yet but intend to), 25% turpentine and 45% kerosene. Kerosene penetrates the wood better than anything (it seems) and Culler even uses it on boards prior to steaming. On later applications you can up the Linseed oil slightly, quit using kerosene and use turpentine instead. To reduce the tendency for the surface of the wood to being a bit sticky from the linseed oil one can use Japan Drier and a bit more wood preservative and as a last resort less Linseed oil or perhaps boiled Linseed oil. Start w mostly Kerosene and then switch to mostly Turpentine and vary the oil and preservative for the application. My cap rails have seen 2 years of this treatment in SE ALaska and I'm happy w the results but can be a bit tacky/sticky when first applied for even a week or two but quite acceptable and it works in our crappy weather outside all year.
As a bilge treatment I can't think of anything better. Perhaps over 50% kerosene and no turpentine on the 1st or 2nd applications applied real heavy.

 

I joined this forum shortly after buying a wooden boat.

Mainly due to Par's past posts about the problems with painted bilges, I started ripping the paint off.

I'm glad I did as it wouldn't have been long before I started treading water.

Always listen to your Ma and your Par.

 

Many thanks every one for your reply, for those who have suggested bilge paints could you please send a few photographs of wooden boat bilges being painted.

I still feel application of linseed oil with Red lead is the best, however now a days red lead is not permitted hence any suggestions ?

However in order to present to the classification society I would need some data ? any idea what ?

 

...well, as PAR said, use clear, if you need fancy go clear polyurethane, cheaper is varnish, Shellac is last, but not what I would use as Shellac is far from waterproof....

and as Poida says "Always listen to your Ma and your Par"

 

vegemite,cement wash and chilli powder,
it will kill everything, its cheap and it will always smell like dinnertime

 

I've heard people talking about "red lead" for at least 40 years.
What exactly is it?

 

Lead tetroxide.
http://en.wikipedia.org/wiki/Lead_tetroxide

 

Red lead is a poisonous ponzi scheme

Its based on a mortgage with its main principle being it kills any living thing thing that comes into contact with it, but leaves buildings standing