Hull painting

[Troyboy]

I have owned my steel narrowboat for over 25 years and every 3 or 4 years have been pressure washing , wire brushing , rust proofing where necessary then painting the hull with what I thought was black bitumen .

 

Having read glowing reports about Sealex B130 I thought this year I would use that however on looking at the paint I used last time Rylard standard black I noticed it is coal tar varnish . Would I be best to use the Rylard coal tar again or can I use Sealex B130 ? Also which is the better product ?

 

I try and keep my boating as economic as possible so please dont suggest sand blasting back to bare metal and starting from scratch with expensive etch primer etc as the original red oxide applied by Peter Nicholls 30 years ago is still adhered to the hull in many places except where normal boating has scraped it off .

 

 

I have read that bitumen doesn't adhere well to red oxide which no doubt accounts for no bitumen / coal tar left on the waterline but plenty of red oxide paint showing which is obviously better than rust .

 

Being new to the forum there are a number of other questions I have but I'll start with this one . I also paint the bottom plate and when surveyed 4 years ago for insurance purposes the surveyor commented that the hull was in better condition than some almost new boats he has surveyed . He actually recommended painting the bottom plate but no doubt that recommendation will be challenged by Forum members .

 

I apologise for referring to both products as paint as I realise that the Sealex is a gelled thixotropic bitumen solution and the Rylard is a low viscosity coal tar varnish according to their manufacturers .

[smileypete]

Hi and a big welcome to the forum!

 

Why not give Spencer Coatings a call and ask them about Sealex over coal tar varnish?

 

Interesting that the red oxide is doing OK on the waterline, thought it was supposedly unsuitable underwater. Does it go down further below that?

 

cheers,

Pete.

Edited January 26, 2012 by smileypete

[Timleech]

I have owned my steel narrowboat for over 25 years and every 3 or 4 years have been pressure washing , wire brushing , rust proofing where necessary then painting the hull with what I thought was black bitumen .

 

Having read glowing reports about Sealex B130 I thought this year I would use that however on looking at the paint I used last time Rylard standard black I noticed it is coal tar varnish . Would I be best to use the Rylard coal tar again or can I use Sealex B130 ? Also which is the better product ?

 

I try and keep my boating as economic as possible so please dont suggest sand blasting back to bare metal and starting from scratch with expensive etch primer etc as the original red oxide applied by Peter Nicholls 30 years ago is still adhered to the hull in many places except where normal boating has scraped it off .

 

 

I have read that bitumen doesn't adhere well to red oxide which no doubt accounts for no bitumen / coal tar left on the waterline but plenty of red oxide paint showing which is obviously better than rust .

 

Being new to the forum there are a number of other questions I have but I'll start with this one . I also paint the bottom plate and when surveyed 4 years ago for insurance purposes the surveyor commented that the hull was in better condition than some almost new boats he has surveyed . He actually recommended painting the bottom plate but no doubt that recommendation will be challenged by Forum members .

 

I apologise for referring to both products as paint as I realise that the Sealex is a gelled thixotropic bitumen solution and the Rylard is a low viscosity coal tar varnish according to their manufacturers .

 

In general bitumen doesn't adhere well to coal tar products.

The one to go for if you want to take that route is Rytex, which is claimed to work fairly well over well weathered tar paints.

 

Coal tar coatings are generally longer-lasting than bitumen, the biggest factor against them in my book is the health & safety aspect, tar products & the solvents used in them are in general not good for the human body. Doing your own boat every few years, with proper care, probably won't do you much harm though. Standard Black does its job pretty well. Another option for you would be to use Comastic or Coflex, which are tar/pitch based and should be OK over Standard Black, I think International also have an equivalent product.

 

Tim

Edited January 26, 2012 by Timleech

[Troyboy]

I'm wondering whether what I called red oxide is in fact red lead paint as being over 30 years old there was probably red lead paint being used in ' the good old days ' . Funny you should mention Comastic Tim as looking through my 'log' I have recorded that I used Comastic in 1999 with a product called Convertex or similar name on the rust . I suspect over the years I have used a combination of bitumen and coal tar I'll do as Pete suggested and contact the manufacturers of Sealex B130 .

 

I've got a print out of the technical properties , surface preparation etc for Sealex B130 and I must say I'm bamboozled with all the figures Specific Gravity 1.06 typical , Volume Solids 44% typical , Recommended film thickness 200-300 microns wet , Theoretical spreading rate 3.3-5.0m/litres , flashpoint 33 degrees centigrade , VOC 448 g/l . Far too much information for me as all I want is some paint to stop my hull rusting .

 

Thanks for your replies I must say this is a brilliant Forum I wish I'd found it earlier .

[Chertsey]

If it's lasted that well it probably is real red lead.

[Timleech]

If it's lasted that well it probably is real red lead.

 

Even 30 years ago, red lead was pretty much a specialist product & I'd be rather surprised to find it on the outside of a hull anyway.

 

There was a product which cropped up on a lot of new hulls, starting at least 20 years ago but not sure it went back as far as 30, & that was 'Crodaprime', it was a fairly bright orangey red. A very good primer, but blacking just fell off it. Just a chance that's what the OP has.

 

Tim

[Troyboy]

I've been in touch with Spencer Coatings Ltd who manufacture if thats the right word Sealex B130 . Apparently it is OK to use Sealex B130 over coal tar products but not the other way round . Also temperature has to be above 5 degrees to apply it . Fingers crossed we don't get a cold spell at the end of February when my boat comes out