First Attempt At Base Plate Blacking

[ChrisPy]

If you stick a pole down there it comes back covered in thick stinking black mud which produces methane gas. This collects under my baseplate and frequently bubbles up as I move around the boat - sometimes quite violently.

no .... it's farting carp what does it

[RLWP]

no .... it's farting carp what does it

 

Well, you would be frightened too if a dirty great pole got shoved through your world!

 

Richard

[FORTUNATA]

I've got problems with this job. I got to the boatyard today and the base blacking I did so far seems fine. My intention was to carry on with the work but then I realised the weather was going to be a problem. There was water below the boat itself where I would normally lie on my back in the grit and all steel was damp. I asked one of the yard workers and he told me I shouldn't try and do the blacking in such wet weather and I think he was right. I could feel damp on the steel below and there was damp in the air. So, I had no option but to throw in the towel for the day. All I could do was use the scraper and clean the surface with spirit and rags.

I checked the forecast and tomorrow it will be "cloudy" but not rainy as it was today. All the following days will be rain. There's a possibility I could try and black tomorrow. The only way of doing this job I think is to try and find some dry day and then get on as much bitumen as possible.

What I don't want to do is waste time putting it on but then it falls off as there was no adhesion due to damp.

[BEngo]

I've got problems with this job. I got to the boatyard today and the base blacking I did so far seems fine. My intention was to carry on with the work but then I realised the weather was going to be a problem. There was water below the boat itself where I would normally lie on my back in the grit and all steel was damp. I asked one of the yard workers and he told me I shouldn't try and do the blacking in such wet weather and I think he was right. I could feel damp on the steel below and there was damp in the air. So, I had no option but to throw in the towel for the day. All I could do was use the scraper and clean the surface with spirit and rags.

I checked the forecast and tomorrow it will be "cloudy" but not rainy as it was today. All the following days will be rain. There's a possibility I could try and black tomorrow. The only way of doing this job I think is to try and find some dry day and then get on as much bitumen as possible.

What I don't want to do is waste time putting it on but then it falls off as there was no adhesion due to damp.

 

From experience:

 

It's got to be dry steel.

 

Lob some heavy cardboard under the boat- or a sheet of 8 by 4 hardboard if you are flush. Slide around on that on a car mechanics guzunder. Wear paper disposable overalls. Soften the muck in your hair with cooking oil before trying shampoo.

 

The black will go on better if you warm it- stand it near a radiator overnight. Get an assistant to be i/c refills- you don't have to get out from under so often that way.

 

Put it on with the cheapest Buy it and Queue hairy roller- not a foam one. Wrap the roller in a poly bag overnight and work it in the black to soften it up again in the morning. Throw everything away when finished.

 

Praise the Lord that you don't have to do it again for four years. Have another beer.

 

Regards

B

[FORTUNATA]

Getting under and out is hard work. In fact, it's awful. I'm not yet organised so I just threw on a couple of waterproof jackets and slid under in all the grit. The first day was uncomfortable but I managed to well and truly black a few feet of steel. Today, though, it was just too damp. I didn't originally think steel below the hull would get wet at all if rain can't get to it directly. Nevertheless everything felt damp, the steel, the floor and the air.

I'd like to get the entire lot blacked as 32 feet is a lot less to cover than some other boats. The weather is going to be a huge problem, though.

 

From experience:

 

It's got to be dry steel.

 

Lob some heavy cardboard under the boat- or a sheet of 8 by 4 hardboard if you are flush. Slide around on that on a car mechanics guzunder. Wear paper disposable overalls. Soften the muck in your hair with cooking oil before trying shampoo.

 

The black will go on better if you warm it- stand it near a radiator overnight. Get an assistant to be i/c refills- you don't have to get out from under so often that way.

 

Put it on with the cheapest Buy it and Queue hairy roller- not a foam one. Wrap the roller in a poly bag overnight and work it in the black to soften it up again in the morning. Throw everything away when finished.

 

Praise the Lord that you don't have to do it again for four years. Have another beer.

 

Regards

B

[DameEdna]

Then how do the fish live, if there's no oxygen? Do they only live in the top eighteen inches of the water, but not on the bottom?

 

It's a good question Mr FtS. It worried me for a day or two. Here is the answer ( Google is my friend )

 

"From the gills, the deoxygenated water passes out the operculum, and the oxygenated blood joins the circulatory system. Goldfish, unlike most fish found in home aquariums, can survive in a non-aerated fish bowl because goldfish spend the majority of their time at the surface, where the oxygen content is highest due to the contact of the water with the atmosphere."

 

So in a stagnant environment there is more oxygen in the top 18" ... which will accelerate the oxidisation of steel.

 

"Some fish require more oxygen than others. This helps to explain why some fish thrive in specific habitats. For example, trout prefer northern streams because the cool water of the streams tends to retain dissolved oxygen, and the active trout need the extra oxygen. Carp, on the other hand, are sluggish and do not need as much oxygen, which is why carp can thrive in warm, relatively stagnant ponds, such as ornamental ponds."

 

I still subscribe to the farting fish theory - much more fun than all this talk of operculum, secondary lamellea and gills

[FORTUNATA]

I've been going through a book written by someone who had a boat designed and then he installed the engine and fitted everything out. He protected the hull in epoxy but didn't bother with the baseplate. After 5 years in the water, the sides had very minor pits and the baseplate was in perfect condition. His anodes showed signs they'd been doing their job.

If I can black the baseplate I will do but understand it's open to debate whether it's worthwhile. I think a lot of it may well scrape off in time but one thing I do find it useful for is filling in superficial pits in the steel. The boat I bought was rebottomed but hasn't been in the water for three years. There are tiny surface pits that the blacking tends to fill in if you work in a brush. The blacking here will be much harder to scrape off under water.

This week I'll try and put time aside either to rub down and clean the base steel or actually apply more blacking if I get any dry weather.

[madcat]

I got involved with this idea at the suggestion of our surveyor friend and most everybody in the midlands thinks Iam mental to bother. So after 3 drydocks experience we found that quite a lot stayed on the first time and even more the second so it will be interesting to see if there is even better adheasion of the third layers. we are booked on the Hawne basin slipway this time as travelling to Manchester and staying on the boat in dock is just too much for my hubby due to arthritis .I think Iam probably convinced its worth it allthough some does get scraped off on the nameless lumpy bits that lurk about in the canals.

[johnjo]

Our surveyor suggested that blacking the bottom did have its advantages but was not a necessity, however because our NB hasn't been done for four years and is now showing signs of minor pitting we are going to have her grit blasted, bit pricey but I'll do the rest of the work myself. While having the sides grit blasted we'll do the bottom as well because there are some quite large orange blisters there, but considering she is 19yrs old we're quite impressed with her condition. I'm going for the grit blasting not just for the speed, but also because I know I'll get fed up halfway through cleaning and finish up with a bad job. If they can't grit blast the bottom I'll probably clean of the worst bits and just black those areas.

 

In case anyone out there doesn't know, and I'm sure most of you do, most fresh metal has what's called 'mill scale' on it and any coating applied over it will eventually fall off in great lumps. Apparently many years ago, but probably still done by some of the better yards today, the bare shells were left outside to weather, this would allow the mill scale to fall away and they would then wire brush before blacking, or so I am told!

 

 

 

I used to be modest, but now I'm perfect!

Edited November 18, 2008 by johnjo

[FORTUNATA]

I am now halfway through. I was in a bad mood because rain kept holding me back but today it was good weather and I got under the boat and worked my ass off. I got blacking on my face, on my glasses, down my arms and lying on grit isn't at all pleasant. Still, half of it is blacked. I accept some of the blacking will come off in time but the blacking I worked into surface pits will last a lot longer.

My tip is see if you can get the boat lifted higher up so painting is easier. I have to lie under a small space and it's uncomfortable.

The main thing with boats is to just haul them as regularly as you can afford which is a bit like having a dentist check your teeth. If you don't delay a simple filling will suffice. If you leave it a long time bad news may darken your day.

 

Our surveyor suggested that blacking the bottom did have its advantages but was not a necessity, however because our NB hasn't been done for four years and is now showing signs of minor pitting we are going to have her grit blasted, bit pricey but I'll do the rest of the work myself. While having the sides grit blasted we'll do the bottom as well because there are some quite large orange blisters there, but considering she is 19yrs old we're quite impressed with her condition. I'm going for the grit blasting not just for the speed, but also because I know I'll get fed up halfway through cleaning and finish up with a bad job. If they can't grit blast the bottom I'll probably clean of the worst bits and just black those areas.

 

In case anyone out there doesn't know, and I'm sure most of you do, most fresh metal has what's called 'mill scale' on it and any coating applied over it will eventually fall off in great lumps. Apparently many years ago, but probably still done by some of the better yards today, the bare shells were left outside to weather, this would allow the mill scale to fall away and they would then wire brush before blacking, or so I am told!

 

 

 

I used to be modest, but now I'm perfect!

 

 

My baseplate has been out of the water for over three years since it was re-shoed. You can see tiny superficial surface pits. I find the blacking fills these in. Doing the job helps by a small percentage. Anodes are also crucial.

I've heard of people who haven't blacked the bottom plate, hauled the boat after a long time and there have been no problems. Other folks have had a different outcome. The main thing is to haul the boat out at least every couple of years to keep an eye on things.

 

I got involved with this idea at the suggestion of our surveyor friend and most everybody in the midlands thinks Iam mental to bother. So after 3 drydocks experience we found that quite a lot stayed on the first time and even more the second so it will be interesting to see if there is even better adheasion of the third layers. we are booked on the Hawne basin slipway this time as travelling to Manchester and staying on the boat in dock is just too much for my hubby due to arthritis .I think Iam probably convinced its worth it allthough some does get scraped off on the nameless lumpy bits that lurk about in the canals.