Blacking Disappeared!

[KirstieH]

Hello

 

After 2 years of happy narrowboating having worked really hard on prepping and blacking our boat, we pulled her out of the water and jet washed her and low an behold....the blacking just pretty much washed off!  The hull looks great just a little rust round the waterline and stern where the blacking didn’t go high enough (Duh).  We used Black Jack (On advice from an old hand narrowboater - we were young and naive - turns out he doesn’t use it grrr) and are wondering if it just wasn’t high grade enough?  We are using Rytex this time (Ouch) so hoping it won’t disintegrate.  We do have a transformer and the anodes are 60% gone.

 

Does this sound about the right kind of wear in that time?  I wondered if we have put the wrong stuff over the top.  It does have some coloured paint in patches underneath where the blacking should be so maybe it is the wrong stuff...

 

Any advice welcomed 

[Alan de Enfield]

17 minutes ago, KirstieH said:

Hello

 

After 2 years of happy narrowboating having worked really hard on prepping and blacking our boat, we pulled her out of the water and jet washed her and low an behold....the blacking just pretty much washed off!  The hull looks great just a little rust round the waterline and stern where the blacking didn’t go high enough (Duh).  We used Black Jack (On advice from an old hand narrowboater - we were young and naive - turns out he doesn’t use it grrr) and are wondering if it just wasn’t high grade enough?  We are using Rytex this time (Ouch) so hoping it won’t disintegrate.  We do have a transformer and the anodes are 60% gone.

 

Does this sound about the right kind of wear in that time?  I wondered if we have put the wrong stuff over the top.  It does have some coloured paint in patches underneath where the blacking should be so maybe it is the wrong stuff...

 

Any advice welcomed 

1) If there is any diesel spills in the water then the 'old style' blacking is dissolved and 'washed off'. (Not uncommon in marinas)

2) What preparation did you do before applying the blacking

3) Did you allow 24 hours drying time between each coat and another 24/48 hours after the final coat to harden off before going back into the water ?

4) What time of year did you apply the blacking ? Location ? (Heated or unheated shed, standing in a yard etc etc)

 

Where do you keep the boat ?

Edited June 2, 2018 by Alan de Enfield

[MtB]

20 minutes ago, KirstieH said:

After 2 years of happy narrowboating having worked really hard on prepping and blacking our boat, we pulled her out of the water and jet washed her and low an behold....the blacking just pretty much washed off!

 

I'd have thought this was pretty normal.

 

Blacking is not a permanent finish and needs doing every two or three years anyway. Nor would I expect old blacking to resist the power of a jet wash.

 

 

[Dr Bob]

If the 2 year old blacking just washed off, then there must have been a significant problem when that blacking was applied. Alan's questions are therefore important to answer as this may help understand why it has happened. 

Most likely a problem with the application rather than the paint itself.

 

Another question. What coating was on the hull before you blacked it 2 years ago. Was it blacking or a more sophisticated coating?

[Robbo]

What pressure was the jet wash?  If it was in the hundreds then no it shouldn’t remove paint, if it’s in the thousands (think about 2-3000) then yes it will do.

Edited June 2, 2018 by Robbo

[Bee]

Difficult to say really, Black Jack (I think) is a general purpose bitumastic paint, I use it for freshening up the hull paint above the waterline, I doubt if it would come off with a high pressure wash but permanently submerged? not too sure. The holy grail of hull paint is something that stays on forever, if B&Q white gloss did that then I would use it but I think you are looking for something with 'marine' in the name. Many of us use expensive epoxy coatings but ideally that needs to be used from new. If I were you I would be looking at something 'surface tolerant' , perhaps something sold at, for example. Midland Chandlers or any other chandlery, Ballistic black perhaps?

[pete.i]

34 minutes ago, Mike the Boilerman said:

 

I'd have thought this was pretty normal.

 

Blacking is not a permanent finish and needs doing every two or three years anyway. Nor would I expect old blacking to resist the power of a jet wash.

 

 

This ^^^ if you are using any of the bitumin based blacking products.

[Neil Smith]

Get it blasted and apply 2 pack, will last 6 years if done correctly.

Neil

[George and Dragon]

2 hours ago, KirstieH said:

We do have a transformer and the anodes are 60% gone.

Were the anodes new when you blacked the hull? 

I'm not sure if the use of an isolation transformer would affect the rate at which your anodes deplete - hopefully someone with greater expertise can advise.

[WotEver]

10 minutes ago, George and Dragon said:

I'm not sure if the use of an isolation transformer would affect the rate at which your anodes deplete - hopefully someone with greater expertise can advise.

No, he was making two separate comments. He has an IT and therefore won’t suffer electrolytic corrosion. He has anodes, so they will also do their thing. 

[Alan de Enfield]

2 minutes ago, WotEver said:

No, he was making two separate comments. He has an IT and therefore won’t suffer electrolytic corrosion. He has anodes, so they will also do their thing. 

Not he, Kirstie claims to be a SHE (and hopefully she is in the position to know)

[blackrose]

When I had my boat built I was told by other LB owners to get it out of the water within a year because the blacking wasn't up to much. I think they just slapped one coat on because as soon as I hit it with the pressure washer it just fell off. Could it be that bitumen blacking doesn't adhere to millscale very well? I've had the boat grit blasted since then and applied epoxy, but the blasting didn't get all the scale off and just etched it in places as it was stuck on so firmly. 

Edited June 2, 2018 by blackrose

[KirstieH]

Thanks all. Yes I am a girl but I must admit I do imagine most posters to be male too!! terrible I know.  As ever, very generous with your advice and replies. We are going to de rust with a grinder fertan and then rytex 2 coats with 3 on waterline...drag her out in two years and have a proper hull inspection (base more pitted than the sides eep!). if she is sound then two pack.  

38 minutes ago, Alan de Enfield said:

Not he, Kirstie claims to be a SHE (and hopefully she is in the position to know)

I have checked...and I am ?

42 minutes ago, WotEver said:

No, he was making two separate comments. He has an IT and therefore won’t suffer electrolytic corrosion. He has anodes, so they will also do their thing. 

Correct ☺

Edited June 2, 2018 by KirstieH

[KirstieH]

2 hours ago, Alan de Enfield said:

1) If there is any diesel spills in the water then the 'old style' blacking is dissolved and 'washed off'. (Not uncommon in marinas)

2) What preparation did you do before applying the blacking

3) Did you allow 24 hours drying time between each coat and another 24/48 hours after the final coat to harden off before going back into the water ?

4) What time of year did you apply the blacking ? Location ? (Heated or unheated shed, standing in a yard etc etc)

 

Where do you keep the boat ?

Yes Diesel a problem in marina v busy

scraped off old spend a week on it and power jet wash.

yes it was rock hard as it was boiling.  72 hours between each coat and immersion

June. yard. water brackish.

 

i think we did the best we could do. more tools now :) 

 

[Alan de Enfield]

13 minutes ago, KirstieH said:

Thanks all. Yes I am a girl but I must admit I do imagine most posters to be male too!! terrible I know.  As ever, very generous with your advice and replies. We are going to de rust with a grinder fertan and then rytex 2 coats with 3 on waterline...drag her out in two years and have a proper hull inspection (base more pitted than the sides eep!). if she is sound then two pack.  

How did you prep & apply previously ?

If you just do the same again you may get the same results - it is possible that the methods used are responsible rather than the materials.

 

ideally you should allow 7 days for the complete operation.

1-2 days prep

1 day per coat (3 coats) and don't forget up the weed hatch and brush well around all joints, prop shaft etc etc where a roller may not give good coverage.

2 days for the final coat to harden before dropping back in.

 

Do not black if it is cold, damp (dew / moisture) as it will not adhere properly Read the conditions on the tin - they are there for a reason.

 

Edit to add - you posted whilst I was typing.

Sounds like you did everything correctly. Maybe its a diesel saturated marina that is responsible, and you will have to either move, live with it, or use a diesel-resistant coating.

Edited June 2, 2018 by Alan de Enfield

[KirstieH]

7 minutes ago, Alan de Enfield said:

How did you prep & apply previously ?

If you just do the same again you may get the same results - it is possible that the methods used are responsible rather than the materials.

 

ideally you should allow 7 days for the complete operation.

1-2 days prep

1 day per coat (3 coats) and don't forget up the weed hatch and brush well around all joints, prop shaft etc etc where a roller may not give good coverage.

2 days for the final coat to harden before dropping back in.

 

Do not black if it is cold, damp (dew / moisture) as it will not adhere properly Read the conditions on the tin - they are there for a reason.

 

Edit to add - you posted whilst I was typing.

Sounds like you did everything correctly. Maybe its a diesel saturated marina that is responsible, and you will have to either move, live with it, or use a diesel-resistant coating.

I am a teacher i like to follow instruction lol? can you recommend a diesel unfriendly one....I was advised that rytex was better than most. Many thanks

[Robbo]

3 minutes ago, KirstieH said:

I am a teacher i like to follow instruction lol? can you recommend a diesel unfriendly one....I was advised that rytex was better than most. Many thanks

Any non-tar based blacking would be a start.

[Troyboy]

17 minutes ago, KirstieH said:

Thanks all. Yes I am a girl but I must admit I do imagine most posters to be male too!! terrible I know.  As ever, very generous with your advice and replies. We are going to de rust with a grinder fertan and then rytex 2 coats with 3 on waterline...drag her out in two years and have a proper hull inspection (base more pitted than the sides eep!). if she is sound then two pack.  

I have checked...and I am ?

Correct ☺

'base more pitted than the sides' . Did you black the baseplate ? There are members on this site that claim baseplates do not rust so no need to black them !! I always black my baseplate and received favourable comments from the surveyor when the boat was last surveyed for insurance purposes. My view is the reason baseplates are not blacked is at many yards it is virtually impossible to get to it . Tin hat on ready for flak.

[Alan de Enfield]

7 minutes ago, KirstieH said:

I am a teacher i like to follow instruction lol? can you recommend a diesel unfriendly one....I was advised that rytex was better than most. Many thanks

Anything non-bitumen based will be an improvement but ideally Twin-Pack epoxy.

 

But not only do you have to have the bottom spotlessly clean and sandblasted (expensive & messy and not DIY) but the coating is expensive.

As a rough guide it'll cost you £3000 but will last 6-8-10 years

At the rate your anodes are eroding you will still have to lift out every couple of years so you will not get the savings that other get.

 

Or you can DIY with bitumen every 2 years at £300 a time.

 

Edit for spooling errurs

Edited June 2, 2018 by Alan de Enfield

[Neil2]

I too would just think this was normal - every time I've seen a blacked boat jet washed it's usually the same result.

 

As for "high grade" bitumen - I've asked this question many times, in what way is so called marine black any different to Black Jack or similar products that are not marketed for marine use?  I believe it's all the same and the chances of it sticking to and protecting the hull are no different whatever you choose to buy.

 

 

[KirstieH]

6 minutes ago, Neil2 said:

I too would just think this was normal - every time I've seen a blacked boat jet washed it's usually the same result.

 

As for "high grade" bitumen - I've asked this question many times, in what way is so called marine black any different to Black Jack or similar products that are not marketed for marine use?  I believe it's all the same and the chances of it sticking to and protecting the hull are no different whatever you choose to buy.

 

 

I must say the black jack has worked really well in fairness. it must have been a combo of soft diesel worn blacking and a power wash which knocked it back. Ah well I will cry in two tears when £300 of Rytex washes off than £90 of black jack lol

[WotEver]

1 hour ago, Alan de Enfield said:

Not he, Kirstie claims to be a SHE (and hopefully she is in the position to know)

Apologies to Kirstie

39 minutes ago, KirstieH said:

I have checked...and I am ?

That’s reassuring

[dmr]

If you use the boat then it will need reblacking every two years, if it lives in a marina then you might manage three.

Yes the jet wash will remove lots of "loose" blacking, and more will come off with some moderate scraping.

 

Prep should be a half day or so of hard work, don't go over the top because the blacking will still come off after two years.

 

Two pack after shot blasting will stay on much much better, but if you use the boat a lot you should still come out every three or maybe four years for inspection and to fix the big scrapes. You can then put another coat or two over the entire boat.

 

...............Dave

[peterboat]

Nobody has convinced me that 2 pack is better than the zinger I applied, since then I have used keelblack just for cosmetic reasons, however the boat comes out next month along with Johns my mate, his was 2 packed from new after blasting and that hasnt faired to well at all. So next month we will see how the keelblack has fared on both boats, mine which had no pitting or corrosion or Johns that was badly pitted and corroded last time they were both dydocked

Edited June 2, 2018 by peterboat

[blackrose]

3 hours ago, Alan de Enfield said:

Anything non-bitumen based will be an improvement but ideally Twin-Pack epoxy.

 

But not only do you have to have the bottom spotlessly clean and sandblasted (expensive & messy and not DIY) but the coating is expensive.

As a rough guide it'll cost you £3000 but will last 6-8-10 years

 

If anyone's interested, costs for DIY two pack epoxying my 57' x 12' widebeam 4 years ago. I got a blasting guy in but did the cleaning and painting myself.

 

Yard: £400

Grit blasting up to top rubbing strake including swims, uxter plate & upswept baseplate at bow but not baseplate as no access: £350

8 x 4.7 litre cans of Jotamastic 87: (2 coats Jotamastic 87 with aluminium + 2 coats Jotamastic 87 black): £450

Total: £1200

 

To get the equivalent job done in a yard I think it would probably have been at least £3k and with the baseplate too perhaps £5k or £6k?

 

The I crawled underneath but after 10 years in the water the baseplate still looked fine. Just light surface rust.

 

 

Edited June 2, 2018 by blackrose