Jump to content

Help with blacking please


Karl

Featured Posts

I have read posts on here about blacking but none really answer my query. I purchased my boat six months ago from a brockerage. Had the boat taken out of water and a survey. All was good but toldto back it next year. It’s coming out again in March and getting pressure washed and I’m going to black it myself. I’ve just been reading the info pack that came with the boat and in 2009 when the boat was built it was blacked with two pack. It’s obviously been done since but we don’t know what with. Two pack or bitumen and we have no detail of type of two pack or contact details for previous owner. My question is this. Can we used general bitumen type blacking if the boat was last done with two pack ? We are worried it will react with current paint. Can anyone advise please ?

Link to comment
Share on other sites

1 minute ago, Karl said:

I have read posts on here about blacking but none really answer my query. I purchased my boat six months ago from a brockerage. Had the boat taken out of water and a survey. All was good but toldto back it next year. It’s coming out again in March and getting pressure washed and I’m going to black it myself. I’ve just been reading the info pack that came with the boat and in 2009 when the boat was built it was blacked with two pack. It’s obviously been done since but we don’t know what with. Two pack or bitumen and we have no detail of type of two pack or contact details for previous owner. My question is this. Can we used general bitumen type blacking if the boat was last done with two pack ? We are worried it will react with current paint. Can anyone advise please ?

 

Whatever you paint it with, (unless you intend to do it in a heated dry dock), DO NOT DO IT before May.

March will be too cold, too damp and too high a dew point.

Link to comment
Share on other sites

4 minutes ago, Karl said:

It says in the boat manual that when new in 2009 it was painted with 2 pack. I can only presume it has been painted/blacked since then but we don’t know what with !

Get some diesel / petrol on a rag and wipe/rub the 'blacking'

If the rag starts to lift the blacking and gets 'black on the rag; then its just 'normal blacking that's been put over the top of the 2-pack.

 

It won't tell you exactly what the blacking is, but it will tell you that it isn't 2-pack.

Link to comment
Share on other sites

If it was epoxied new in 09 the original black may well still be OK. How much use has the boat had?

As above check with a rag and white spirit or diesel.  Be aware that coal tar epoxy may show a brown stain on the rag if rubbed hard, bitumen blackinv witl make the rag really black really quick.

 

You can overcoat two pack with any  bitumen blacking, but will not then be able to coat with two pack unless the boat is blasted to bare metal.

 

You can no longer buy coal tar based two pack, so overcoating unknown two pack with another two pack is a bit of a lottery.

There is a really good heated, properly ventilated covered slipway at Circus Field Basin, Aylesbury should that be near you.

Pressure washer included in the hire fee.

 

N

Link to comment
Share on other sites

50 minutes ago, BEngo said:

 

You can overcoat two pack with any  bitumen blacking, but will not then be able to coat with two pack unless the boat is blasted to bare metal.

 

 

And that's why bitumen blacking over two- pack is a stupid idea. I don't know why it keeps coming up in the forum.

 

Even if you (not you BEngo) don't know what two-pack was used, most brands will be compatible so all you have to do is pressure wash the boat, let it dry, give the existing paint a good key with a medium grit paper, dust well and then repaint with a good surface tolerant two pack following the manufacturers mixing instructions and overcoating times.

Edited by blackrose
  • Greenie 1
Link to comment
Share on other sites

8 hours ago, blackrose said:

 

And that's why bitumen blacking over two- pack is a stupid idea. I don't know why it keeps coming up in the forum.

 

Even if you (not you BEngo) don't know what two-pack was used, most brands will be compatible so all you have to do is pressure wash the boat, let it dry, give the existing paint a good key with a medium grit paper, dust well and then repaint with a good surface tolerant two pack following the manufacturers mixing instructions and overcoating times.

 

But, if has been overpainted with a bitumen based paint then he cannot give it another coat of 2-pack, without total surface prep back to grit blasted bare steel.

 

It cost me over £1500 to get my non-2-pack paint off before I could use a 2-pack system

Link to comment
Share on other sites

11 hours ago, Karl said:

It says in the boat manual that when new in 2009 it was painted with 2 pack. I can only presume it has been painted/blacked since then but we don’t know what with !

 

Not necessarily, my 2007 boat was blacked with International 954 2 pack when built and has only needed re-blacking earlier this year.

 

I would put more 2 pack on it - it protects better and I'm my opinion is cheaper in the long run. I don't think that putting another manufacturers 2 pack on the origininal blacking will react.

 

If you put ordinary blacking over 2 pack, then when the original 2 pack begins to fail, you will have to have the hull grit blasted back to bare metal (£2k-£3k) and start again.

Link to comment
Share on other sites

8 minutes ago, cuthound said:

I would put more 2 pack on it - it protects better and I'm my opinion is cheaper in the long run. I don't think that putting another manufacturers 2 pack on the origininal blacking will react.

OP states that 'something' has been applied over the original 2-pack, he 'knows not what', until he can find out it would be better to do nothing as it could end up a costly mistake.

Link to comment
Share on other sites

11 hours ago, Karl said:

It says in the boat manual that when new in 2009 it was painted with 2 pack. I can only presume it has been painted/blacked since then but we don’t know what with !

The whole point of 2 pack is that it last much, much longer than bitumen. We had ours done in 2012 and we next took it out of the water in 2017 just to check it, but there was no need. Apart from loss of colour (black had become grey/brown) there was no loss of integrity and, once cleaned up a bit, you couldn’t see where the water line was. Certainly no rust.

 

So it’s quite possible that the boat hasn’t been blacked again since 2009, which is why it needs doing now.

Link to comment
Share on other sites

19 minutes ago, Alan de Enfield said:

OP states that 'something' has been applied over the original 2-pack, he 'knows not what', until he can find out it would be better to do nothing as it could end up a costly mistake.

 

Others have advised how to tell if it has been recoated with 2 pack or not by rubbing it with white spirit.

 

If it has been recoated with 2 pack, then my advice would be to stick with 2 pack for the reasons I have.

Link to comment
Share on other sites

5 hours ago, Alan de Enfield said:

OP states that 'something' has been applied over the original 2-pack, he 'knows not what', until he can find out it would be better to do nothing as it could end up a costly mistake.

Not necessarily. His statement that It’s obviously been done since  reads to me as an assumption rather than a fact. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.