blacking above the water line

[Phil1884]

The blacking above the water line is looking rather dull and it's at least another year till its due for its first reblacking. Is there something I can use to 'buff' up the bituminous coating in the meantime or is it a case of just touching up with a small lick of bitumin?

 

Thanks

[furnessvale]

The blacking above the water line is looking rather dull and it's at least another year till its due for its first reblacking. Is there something I can use to 'buff' up the bituminous coating in the meantime or is it a case of just touching up with a small lick of bitumin?

 

Thanks

It is quite normal to touch up any scuffs or marks on above waterline blacking.

 

Just use the same type of blacking to avoid compatibility issues. If you move a bit of ballast to the other side you can give the boat a list so you can touch up right to the waterline and below.

 

George ex nb Alton retired

[b0atman]

Problem I seem to have is my Blacking is 2 pack the quantities available are great for Blacking a boat but wheres the touch up kit ?

If your boat is sensible with hand rails then a plank with a weight on the outer end will heel the boat over

[furnessvale]

Problem I seem to have is my Blacking is 2 pack the quantities available are great for Blacking a boat but wheres the touch up kit ?

If your boat is sensible with hand rails then a plank with a weight on the outer end will heel the boat over

Nothing to stop you mixing small quantities provided you keep the proportions correct.

 

George ex nb Alton retired

[b0atman]

When 2 pack is mixed any idea it would last in a jam jar ? million dollar question there.

P.S the Goyt Inn is excellent.

[StarUKKiwi]

A friend of ours uses black emulsion to touch up above the water line

[andyb116]

Won't last in a jam jar, even if you starve it of oxygen, it still goes off because it's a chemical reaction, you just end up with a big rubbery lump in the jar, I know this from experiance.

[Timleech]

When 2 pack is mixed any idea it would last in a jam jar ? million dollar question there.

P.S the Goyt Inn is excellent.

 

Depends on the product and the conditions, but maybe 6 hours.

 

Edit to add that I've found Epicol CT still useable next morning, but it has an advertised pot life of 8 hours, while some 2-packs have pot lives of nearer to half that.

 

I think some need moisture to help the curing process, those will probably keep for longer in a sealed pot.

 

Tim

Edited May 15, 2015 by Timleech

[Paul C]

Once 2 pack is mixed it will go off.......it cures via the chemical reaction between the two components. The issue isn't mixing small amounts (that's easy, just a case of measuring and mixing in eg a jam jar) but that some aren't available in quantities less than 5 litres. For example, Interzone 954 isn't available in anything smaller and a 5 litre tin/pack (4 litres of black & 1 litre hardener) is £170 or so.

[MtB]

I thought the whole point of two-pack was that it was so tough it didn't come off and need touching up.

[Neil TNC]

All the paint on Maurice A is Hempel 2-pack. I save plastic milk bottles for touching up. Cut down they make good disposable pots. I must say I have been impressed with the 2 pack blacking on MA (now 4 years!). It recently came out for a new prop and after a quick pressure wash the blacking looked like new, only a couple of scrapes to touch up.

Riversdale, being a working boatyard, means that there is often blacking going on, so easy to nick a couple of rollerfulls for touching up!

[furnessvale]

I thought the whole point of two-pack was that it was so tough it didn't come off and need touching up.

With the best will in the world there are bound to be scars............after all, it is a "contact sport".

 

George ex nb Alton retired

[Phil1884]

Thanks for the tip, one other question, I've got a load of weed growth right at the water line , for some reason much more towards the stern. Is there a decent way to remove this and tidy it up without compromising the blacking onto which it has grown?

[BEngo]

Careen the boat ( Lean it over a bit with a weight on a plank or a tight rope from the roof centre point/handrail) then attack the water line with a pressure washer. Even the really cheapy DIY shed ones are good enough to get most or all the weed off a two-packed waterline. Undamaged two-pack, properly applied, is pressure washer proof to at least 200 bar.

 

Failing a pressure washer than a scraper and long-handled scrubber are nearly as effective.

 

Obviously you need to do one side at a time and turn-round in between sides!!

 

N

[Paul C]

I thought the whole point of two-pack was that it was so tough it didn't come off and need touching up.

 

2 pack blacking is tougher but also more brittle. There are knocks where the 2 pack blacking is able to withstand the impact but also knocks where it will not. 2 pack is recommended especially for boats which are moored for long periods and don't cruise much/at all. In these cases time between blackings can be safely up to 5 or more years, where typically its 2 years for bitumen-based.. The advantages of the toughness of 2 pack are diluted when the boat is used more and more extensively for cruising.

[Phil1884]

Cheers, i've a feeling mine is standard bitumin all the way so think I'd need to be careful with the weed removal.

 

It's only been in the water just over a year and I think the problem is that it hasn't been cruising much. It would be good to go for the 2 pack epoxy but obviously this would require complete removal of the current blacking.

[b0atman]

Thanks for the tip, one other question, I've got a load of weed growth right at the water line , for some reason much more towards the stern. Is there a decent way to remove this and tidy it up without compromising the blacking onto which it has grown?

You obviously haven't got ducks trained round your way ,its like a load of jack hammers sometimes

[Phil1884]

Ha, there are 2 swans that have a go, but they are too unreliable and most of the time peck my heels when I'm working on the side

[furnessvale]

Cheers, i've a feeling mine is standard bitumin all the way so think I'd need to be careful with the weed removal.

 

 

I would stick with a good stiff scrubbing brush.

 

George ex nb Alton retired

[Bee]

Personally I would overcoat the whole thing above the waterline with some sort of B&Q / Wickes bituminous tarry stuff and keep the expensive 2 pack for underwater, doesn't take long to slap a coat of black on and keep it looking good.

[Richard10002]

I'll be blacking with Rylard Premium Protection next week.

 

Does it need some kind of primer in thin bits or where it's back to the metal, or do you just slap it on and it sticks?

Edited May 15, 2015 by Richard10002

[Timleech]

I'll be blacking with Rylard Premium Protection next week.

 

Does it need some kind of primer in thin bits or where it's back to the metal, or do you just slap it on and it sticks?

 

Better with no primer. Just put on an extra coat in those areas if you have the time.

 

Tim

[Phil1884]

Personally I would overcoat the whole thing above the waterline with some sort of B&Q / Wickes bituminous tarry stuff and keep the expensive 2 pack for underwater, doesn't take long to slap a coat of black on and keep it looking good.

Cheers Bee, B&Q do a universal bitumin paint so I may give the entire but above the waterline.

 

As for the weed, I read another thread on this topic and a rubber brush was recommended, probably because I'd imagine it isn't too abrasive. I'll have a go with this but I'm not sure I'll get a decent tilt to be able to paint at the waterline!

[blackrose]

I thought the whole point of two-pack was that it was so tough it didn't come off and need touching up.

Unfortunately life is not that simple - of course two-pack epoxy paints will need touching up. I learned long ago that although some things last longer than others, nothing lasts forever.

 

The important thing is to key up the area with an abrasive paper and dust off before applying fresh twin-pack.

 

2 pack blacking is tougher but also more brittle. There are knocks where the 2 pack blacking is able to withstand the impact but also knocks where it will not. 2 pack is recommended especially for boats which are moored for long periods and don't cruise much/at all. In these cases time between blackings can be safely up to 5 or more years, where typically its 2 years for bitumen-based.. The advantages of the toughness of 2 pack are diluted when the boat is used more and more extensively for cruising.

I don't know which two-pack paint you've been using but I completely disagree with what you've written there. Plenty of steel boats all over the world are painted with two-pack paints. Good two-pack paints aren't brittle! In fact bitumen paint is probably far more brittle once it's oxidized and been affected by UV light. I worked on the hull of a passenger boat in a dry dock which was painted with a good epoxy paint 10 years before and apart from a few patches it was still fine. That boat moved a lot and I daresay it had plenty of scrapes too.

Edited May 15, 2015 by blackrose

[Richard10002]

Better with no primer. Just put on an extra coat in those areas if you have the time.

 

Tim

Thank you Tim. Do I need to abrade the existing blacking before coating, or just slap it on?

 

I'll be grinding, scraping, or wire brushing, any loose or rusty bits before coating.