Bitumastic or Vinyl?

[Theo]

We dock at worsley (manchester) and do the job ourself.

- The paint remains very good year-to-year, for the last 16 years (about 5 or so repaints) we have just presurewashed it down to clean paint before it drys, and then slaped on the two coats fairly quickly, done whatever else (weedcutterbearings...) and called it a done job.

- The cost of the paint is about £300 for two 5L tins of the twopart vinal and a 2L tin of epoxy aluminum for the odd bear bits. Although this time, we already have some primmer left over, as we repainted the cabin last year.

- We just brush it on with two people with big brushes, and a third person premixing the next batch of paint.

 

£750 for the job done doesnt sound to extreame to me. Even just using normal every day blacking its a fiarly big job, and the paint still isnt that cheap.

Daniel

 

 

I have lots of relevant questions:

 

1. Is the two part vinyl a good investment?

 

2. What is the difference in preparation time for that compared with bitumastic?

 

3. How does the frequency of recoating compare?

 

4. If I have bitumastic on now, what preparation wold I have to do to change to vinyl?

 

5. The bottom is often not coated. Do you gain anything by doing that bit too?

 

Nick

[oldairbear]

I had my boat blacked the end of last year before the high river levels reduced cruising. I had a choice from bitumen to vinyl. I chose vinyl (Costs more) on advise from the boatyard in that it lasts longer between recoating needs - up to 4 years being quoted against every year for bitumen. The boatyard were loath to put on bitumen due to the high presence of petroleum spirit floating on the water surface, (I'm on a commercial waterway) the petrol/diesel cutting the bitumen at the water line as it floats past the boat rendering it useless in less than 12 months. single occupancy of the drydock blasting off the original blacking, primer/sealer for the metal then 2 or 3 (cant remember) coats of vinyl COST - Less than £400 all included- with them getting mucky not me. Even at ooop north prices I cant imagine it being much dearer in the afluent south. Only drawback it took 2 weeks to do not 1 as planned cos the water level rose and wouldnt let the dry dock empty!!

[DHutch]

I have lots of relevant questions:

1. Is the two part vinyl a good investment?

2. What is the difference in preparation time for that compared with bitumastic?

3. How does the frequency of recoating compare?

4. If I have bitumastic on now, what preparation wold I have to do to change to vinyl?

5. The bottom is often not coated. Do you gain anything by doing that bit too?

Urrm well, i feel i leading the topic on a bit of a tangent.

- But seaming as its is roughtly relevent, and i cant really comment about anything else...

 

We like the twpart vinal stuff.

- Orignaly the boat was done in twopart epoxy blacking, however LeighsPaints discontinued it from there product line after the first reblack, and when we went to purchase more where pointed towards the vinal as being "as good as the epoxy" and totatly compatable. And indeed, it does seam to be.

 

Certertaly im impressed with it compaired to what ive seen of other blackings.

- Last time we reblacked, after 4years in the water, the guy at the dock was supprised we where even bothing it was that good.

 

In terms of if it can go over your existing blacking, i dont know, but possable not.

- Contact Leighs Paints and ask them, there tech-help people are very nice and will be able to tell you all you need to konw im sure.

- And if the worse comes to the worse, you can just gritblast is back to bare steel...

- Its possably not the cheapest option, but it certainly does a good job, and on anything other than a real rat of boat, im sure it thats a good thing.

 

Look under 'generic types' for "vinal primers" then its there "Resistex M535 pitchfree underwater primer" one.

http://www.leighspaints.co.uk/Products.aspx

 

Daniel

[blackrose]

4. If I have bitumastic on now, what preparation wold I have to do to change to vinyl?

 

5. The bottom is often not coated. Do you gain anything by doing that bit too?

 

Nick

 

4) I'm pretty sure that they are not compatible and you will have to get all the bitumen off if you want to use vinyl.

 

5) Yes, you gain a painted baseplate! The more paint you can put on a hull the better but there are often some practical difficulties in doing this. When my boat came out the water last summer the boat was only 3ft off the bottom of the dock & I couldn't get the long pressure washer at an angle where I could clean the baseplate sufficiently so I gave up. Another, more commonplace difficulty is that the area under the beams on which the boat is resting will not be painted and some people suggest that these unpainted areas will then be more prone to corrosion than if the baseplate had been left bare. Others say you should think long term and paint these areas next time the boat comes out the water.

 

The biggest argument against painting the baseplate is that there is no oxygen at that depth, but actually each water molecule is comprised of 2 atoms of hydrogen and one atom of oxygen and there is also dissolved oxygen at any depth - otherwise how would the fish breath? Nevertheless, the waterline is the most susceptible area in terms of corrosion because of the high levels of oxygen in the water and the way that area will be in and out of the water.

 

Thems the issues, you takes your choice...

Edited February 16, 2007 by blackrose

[magnetman]

Well here's a 'hand in the pirhana tank' suggestion - see how quickly it gets devoured:

 

Given one canal boat hull (generic term covering wide and narrow beam steel "narrowboat or barge type" boats).

 

No paint on it at all, not a speck. Theoretically this provides a larger sacrificial area and will result in less corrosion overall because the corrosion isn't concentrated at a single point caused by broken paint (which is always going to occur somewhere on a boat which is actually used). I'm thinking of the corrugated iron galvanised roofing sheets which did seem to rust through quicker where the zinc plating was damaged than if they hadn't been coated in the first place.

[DHutch]

Just to add to that, we paint the bottom of our hull when it comes out.

- Im sure its no essential, and its 10mm thick anyway. however at worsley your a good 4ft up on sleepers. So access is fairly good.

- And after 3/4years of bumping along the bottom (fairly deepdraughted and active boat) the paint remains almost unbleavable good.

 

So you takes your pick and makes your choices. Upto you!

- Also, our paint comes in 5L tins, and doesnt have a massive shelflife (few years) so its all but free to slosh it on...

 

 

 

Daniel