Hull degreasing

[jddevel]

Any recommended degreaser I can use on my hull ( gunnel to waterline) before painting please. Boat will be out of the water. Process I intend is -degrease, rinse lightly abrade then paint using a enamel based urethane modified resin system.

[Tony Brooks]

If the blacking is bitumen than a de-greaser may not be the best solution. It may well soften or remove such blacking.

[LadyG]

What is boat made of, and do you have access to a power washer?

What coatings are you contemplating on the hull?

Will it be kept on inland waters?

 

Edited August 13, 2023 by LadyG

[Tracy D'arth]

5 minutes ago, jddevel said:

Any recommended degreaser I can use on my hull ( gunnel to waterline) before painting please. Boat will be out of the water. Process I intend is -degrease, rinse lightly abrade then paint using a enamel based urethane modified resin system.

Sugar soap, not expensive and solvent free.

[BEngo]

What is on there at the moment?  Any degreaser needs to be compatible with what is there.

 

Do not even think about white spirit on bitumen, for example.

 

N

[blackrose]

Why would you need to degrease your hull? Where did the grease come from? If it's a steel hull and you're painting it with bitumen all you need is a good pressure washer, go over any areas of rust with an angle grinder/wire wheel or cup and then slap a few coats of bitumen on.

[beerbeerbeerbeerbeer]

The OP says they’re going to use enamel paints of some sort. 
 

as Tracey sez, sugar soap is cheap and a good option for cleaning a surface in readiness ready for painting. 

I don’t suppose the OP’s hull is really covered in thick grease 🤷‍♀️😃

 

but yeah, personally I’d just whack on blacking. 

[blackrose]

7 minutes ago, Goliath said:

The OP says they’re going to use enamel paints of some sort. 
 

 

Yeah, why didn't I read that? 🤪

However I wasn't the only one who missed it.

 

I wonder if enamel based urethane modified resin lasts any longer than bitumen? It certainly sounds like more hassle to apply.

Edited August 13, 2023 by blackrose

[Tony Brooks]

42 minutes ago, blackrose said:

 

Yeah, why didn't I read that? 🤪

However I wasn't the only one who missed it.

 

I wonder if enamel based urethane modified resin lasts any longer than bitumen? It certainly sounds like more hassle to apply.

 

I know it melts bitumen, so you end up with black patches in the paint. I think the OP should tell us what hull blacking he has or if it is a GRP boat.

[jddevel]

My apologies for not being more detailed. Existing is believed to be enamel. Will obviously test an area first. However reading both instructions -namely "degrease before application" and if bitumen is used any change will need stripping right back obviously.  Want to stick to existing type which I need to establish exactly what`s on there (pretty sure it`s not bitumen, first. My assumption is enamel. Don`t want to have to resort to sand blasting or stripping right back if I make a mistake. Must admit using"blacking" would be easier. Will have to see what I can find out.

 

 

 

 

[Tony Brooks]

22 minutes ago, jddevel said:

My apologies for not being more detailed. Existing is believed to be enamel. Will obviously test an area first. However reading both instructions -namely "degrease before application" and if bitumen is used any change will need stripping right back obviously.  Want to stick to existing type which I need to establish exactly what`s on there (pretty sure it`s not bitumen, first. My assumption is enamel. Don`t want to have to resort to sand blasting or stripping right back if I make a mistake. Must admit using"blacking" would be easier. Will have to see what I can find out.

 

GRP and steel cruisers boats may well have the whole hull painted in what you call enamel, but steel canal boats rarely. If the finish is smooth, hard, and won't soften when rubbed with a rag soaked in white spirit, it may be two-pack blacking. Can you talk to the previous owner or ask the yard that "painted" it what they used.

[LadyG]

1 hour ago, jddevel said:

My apologies for not being more detailed. Existing is believed to be enamel. Will obviously test an area first. However reading both instructions -namely "degrease before application" and if bitumen is used any change will need stripping right back obviously.  Want to stick to existing type which I need to establish exactly what`s on there (pretty sure it`s not bitumen, first. My assumption is enamel. Don`t want to have to resort to sand blasting or stripping right back if I make a mistake. Must admit using"blacking" would be easier. Will have to see what I can find out.

 

 

 

 

Enamel is a word used by many to describe an oil based paint such as would be used to paint wooden windows outdoors, metal garage doors, etc, .

When it comes to marine paints, there is a lot of different coatings. I would loosely term the gloss paints used as a top coat on yachts as enamel, but I would be more specific.

A glass fibre vessel , a yacht, or a river cruiser, can be painted above the waterline with an enamel like International, or other similar products but from the waterline down some sort of antifoul is often used.

On a steel hull like a narrowboat there are lots of blackings, the bitumen type is the cheapest, per litre, then there is something like Ballistic Black, then there is two pack epoxy like Jotun 90 (or variations on this), two pack system. Enamel is not something normally used on a steel hull below the waterline.

The best thing I can advise is to ask for technical advice from a company which is experienced in these matters. I use SML Paints for advice not the forum.

Do you have a photo?

 

 

 

16 hours ago, blackrose said:

Why would you need to degrease your hull? Where did the grease come from? If it's a steel hull and you're painting it with bitumen all you need is a good pressure washer, go over any areas of rust with an angle grinder/wire wheel or cup and then slap a few coats of bitumen on.

He says he is going to enamel paint the hull from the waterline to the gunwales, so sugar soap sounds OK , obviously he needs to clean the hull and abrade the existing coating, maybe down to 120 grit if a good gloss finish is reqhired, personally, I would consider an undercoat, especially  if there is a colour change, but a lot depends on facilities, time, weather, and the paint he is using. I must admit that I tend to rub down my gunwales and out of water hull, then topcoat with something compatible. On a narrowboat I think the protection aspect is very important.

A high gloss coat of enamel would not be my choice on a narrowboat hull because it will not stay that way for long .

 

 

Edited August 14, 2023 by LadyG

[Dav and Pen]

As a Deck apprentice on my first ship the third mate told me to get a small tin of enamel paint from the store man. He came from Orkney and pronounced it enaminal paint in a very broad accent when I said this to the store man he said we don’t have that so back I went to the bridge told the mate and he said you know enaminal paint for the bath. Job done. 

[ditchcrawler]

20 hours ago, jddevel said:

Any recommended degreaser I can use on my hull ( gunnel to waterline) before painting please. Boat will be out of the water. Process I intend is -degrease, rinse lightly abrade then paint using a enamel based urethane modified resin system.

Do you mean down to the water line, ie. where its always wet. Steel narrowboats are normally blacked from the base plate up to at least the first guard iron (rubbing strake)

[David Mack]

12 minutes ago, ditchcrawler said:

Do you mean down to the water line, ie. where its always wet. Steel narrowboats are normally blacked from the base plate up to at least the first guard iron (rubbing strake)

Only that far? On my boat the bottom guard is below the water line.

The boat is blacked with Jotamastic 90 all the way up to the gunwale.

Edited August 14, 2023 by David Mack

[ditchcrawler]

1 hour ago, David Mack said:

Only that far? On my boat the bottom guard is below the water line.

The boat is blacked with Jotamastic 90 all the way up to the gunwale.

So is mine, but a lot today aren't