Ballistic blacking, top coat not setting.

[Peanut]

Hi to all, a friend has just cleaned his 50 ft (ca. 15 m) narrow boat hull off with a Turco, and applied four coats of Ballistic blacking.  He applied it with a brush and left about 48 hours between coats. It appears that the last coat on the hull sides has not gone off and is still soft, you can scrape it off with a finger nail.  The first three coats seem to be alright, as is the baseplate, which appears to be good as well.

 

Do you think that this will be a problem, and has anyone else had a similar experience? What do you think might be the best way forward?

 

Ballistic bitumen, not two pack.

Edited August 16, 2023 by Peanut
bitumen

[LadyG]

1 hour ago, Peanut said:

Hi to all, a friend has just cleaned his 50 ft (ca. 15 m) narrow boat hull off with a Turco, and applied four coats of Ballistic blacking.  He applied it with a brush and left about 48 hours between coats. It appears that the last coat on the hull sides has not gone off and is still soft, you can scrape it off with a finger nail.  The first three coats seem to be alright,las is the baseplate, which appears to be good as well.

 

Do you think that this will be a problem, and has anyone else had a similar experience? What do you think might be the best way forward?

 

Ballistic bitumen, not two pack.

What are the options, I mean how long does the data sheet suggest it requires curing. I'm no expert, but unless he added thinners I would have thought it can only be a curing problem. I'm assuming all the tins were the same brand . Any unusual weather?

The manufacturer should have technical advice line.

TURCO, as in a chemical used in industry?

Edited August 16, 2023 by LadyG

[Peanut]

2 minutes ago, LadyG said:

What are the options, I mean how long does the data sheet suggest it requires curing. I'm no expert, but unless he added thinners I would have thought it can only be a curing problem. I'm assuming all the tins were the same brand . Any unusual weather?

The manufacturer should have technical advice line.

Thank you, he left between 24 and 48 hours to re-coat doing the baseplate in between, the instructions say it will be dry to re-coat after12 hrs, so a coat a day is recommended, and no thinners were added. It was the wettest July here for a time, but the first three coats went well, only the last one has failed to dry properly.

 

I think the plan at present is to see if it hardens up during the next week.  I believe the options are to live with it and rely on the three good coats, or strip the soft one off and reapply that coat. He did put it on quite thickly.

 

The manufacture says that if the hull was damp, it will have to come off, but then the first coats seemed fine. I just wondered if the failure of bitumen to cure was a problem anyone else had experienced. The bitumen has skinned, and has a high tenacity, so might just sit there unless disturbed.

[rusty69]

29 minutes ago, LadyG said:

TURCO, as in a chemical used in industry?

Probably means Tercoo, as in rotating blaster. 

[LadyG]

Just now, rusty69 said:

Probably means Tercoo, as in rotating blaster. 

Makes sense:)

[Peanut]

Sorry, yes, Tercoo, a rotary blaster. Only heard it called a “Terco” never a “Tercoo.” Dutch, apparently.

[Sea Dog]

I blacked my boat last month with SML's bitumen-based Ballastic Black. I did a coat a day over 3 days, every coat was completely dry before the next went on, and the 3rd coat was dry next morning too. That's in line with the manufacturer's advice and what you expected.

 

Now, somewhat confusingly, SML also do a 2 pack Epoxy which, for reasons best known to them, they also call Ballastic. So, it may be worth checking if somehow the tin used for the final coat was the epoxy Ballastic which, if not mixed with the hardener, would give the non-setting result you speak of.

 

 

[Peanut]

28 minutes ago, Sea Dog said:

I blacked my boat last month with SML's bitumen-based Ballastic Black. I did a coat a day over 3 days, every coat was completely dry before the next went on, and the 3rd coat was dry next morning too. That's in line with the manufacturer's advice and what you expected.

 

Now, somewhat confusingly, SML also do a 2 pack Epoxy which, for reasons best known to them, they also call Ballastic. So, it may be worth checking if somehow the tin used for the final coat was the epoxy Ballastic which, if not mixed with the hardener, would give the non-setting result you speak of.

 

 

Thank you, Sea dog, I am sure it is bitumen, I edited my first post as I saw the possible confusion with the Ballistic epoxy, and it might be misleading.

We will see if it hardens off in a day or two. It is not my boat, but only 25yds away, as we are out of the water, I am antifouling mine. Five canal boats out at the moment.

[Sea Dog]

2 minutes ago, Peanut said:

We will see if it hardens off in a day or two.

Oh good, I hope that's at least ruled something out. That's still very odd curing behaviour for Ballastic Black bitumen (or any other brand) even if it does somehow eventually "dry up". I'm not sure I'd be happy to put the boat back in the water with that as the final coat.

[MtB]

My money is on Sea Dog being right and the ladt coat was two-pack with no hardener. 

 

It's not ever going to go off so might as well re-launch it and rely on the three good coats of bitumen underneath, which is still plenty, surely!

 

 

 

 

[Peanut]

1 hour ago, MtB said:

My money is on Sea Dog being right, and the last coat was two-pack with no hardener. 

 

It's not ever going to go off so might as well re-launch it and rely on the three good coats of bitumen underneath, which is still plenty, surely!

 

 

 

 

No, definitely bitumen, it has skinned over, it is just soft, maybe weather related, but it is bitumen.

 

There is a sixth narrow boat out, a seventy-foot tug deck, with a boatman's cabin and a Gardener engine. Complete with fake rivets. I missed it as it was down by the sheds.

[beerbeerbeerbeerbeer]

I hear for extra authenticity

there’s a fake bitumen to go with fake rivets

I imagine quite expensive, 

but why scrimp,

if you have the real thing 👍

 

[MtB]

28 minutes ago, Peanut said:

and a Gardener engine

 

Gosh. Never seen one of them!

[matty40s]

35 minutes ago, MtB said:

 

Gosh. Never seen one of them!

Percy Thrower used to have one in his shed

[Peanut]

The blacking, bitumen, seems to be going off with time, maybe put on too thickly.

[blackrose]

19 minutes ago, Peanut said:

The blacking, bitumen, seems to be going off with time, maybe put on too thickly.

 

That's my guess too, especially as you say it had skinned over. The problem with applying paints thicker than the manufacturer's maximum wet film thickness specification is that once it skins over the solvents in the paint beneath cannot escape so it stays soft. Solvent release is the issue. 

On 16/08/2023 at 20:01, MtB said:

My money is on Sea Dog being right and the ladt coat was two-pack with no hardener. 

 

It's not ever going to go off so might as well re-launch it and rely on the three good coats of bitumen underneath, which is still plenty, surely!

 

That sounds highly unlikely to me. If you'd already painted 3 coats of bitumen on a boat you'd know straight away if you were using part A of an epoxy as it would need a lot of mixing and it smells completely different to bitumen.

Edited August 17, 2023 by blackrose