Removing blacking...

[nastypoker]

Yay another blacking thread!

 

I need to remove the blacking from my boat and I want to know what the best method is. In an ideal world I would shot blast it back to bare steel as I am planning on using a two pack paint. Using a wire brush on a drill will take forever. I am willing to spend money on decent kit if it is worth it. I have seen the "Bristle blaster" but for £300+ it is pricey. I wouldn't mind except it is tiny and will take forever to do a 45ft hull.

 

Any ideas? I believe my boat currently has a bitumen coat on which is just the worst. Is there a particular solvent or method I am missing that will make this job a lot easier?

[Peter-Bullfinch]

A lot of us use angle grinders with wire brushes attached plus full protection against bits of wire and bitumen chips flying off. Buy lightweight ones. Heavy tools are hard work! Persuade a friend to do one side while you do the other. Reciprocate when it's time for their boat to be blacked.

In a day you can get the boat out, pressure wash it, dry, wire brush and even get the first coat on if there are two of you working and the weather is kind.

[dmr]

Wire brushes give a smooth shiny surface, (though you could rough it up slightly with course sandpaper), shot blasting gives a rougher textured surface which is just perfect for the two pack to stick to.

The two pack itself is likely to cost about £400, its a false economy not to shot blast.

If you really must do it yourself then buy a needle gun and hire a big air compressor, but that still wont be as good as shot blasting.

 

...............Dave

[Chewbacka]

If you leave any oily film on the surface then 2 pack will not stick well. Shot blasting will remove any oily film left by the wire brush and will key the surface for good adhesion. Not sure you can be confident of having a good enough surface for 2 pack if you only wire brush it.

It would be a shame if after all your work and expense (2 pack is not low cost) it were to have patchy adhesion,

[Slim]

Hire a scarifier. I hired a handheld one (Glorified angle grinder/ polisher) for about £60 and it took 20 years of bitumen off a 55' hull in a long, hard day. Main probem was that the teeth kept clogging up with soft bitumen. I found the best answer to that was a stiff brush and white spirit. You'll also need a mask, goggles, gloves and really old clothes.

 

 

Frank

[Bloomsberry]

I used a Tercoo Blaster recently and although it gave a resonable finish it was very time consuming ie. 6 hours to do the waterline + welding seems.

 

I like the idea of wire brushing then sanding the surface to get a key, it's got to be quicker than using the Tercoo although even this would be time consuming if you want to do the complete hull.

 

One thing to consider is that if you're dry docking and sharing with another boat then this boat could be in pristine condition. The owner wouldn't appreciate some maniac with a wire wheel in a grinder tearing his boat's blacking to shreds inches from his pride and joy. If I were to do it again I would try to get the boat in a place with no other boats in the vicinity although this might not be possible.

[nastypoker]

Cheers for all the tips. Shot blasting is definitely my preferred option and buying a compressor and blasting kit might actually be reasonable considering the expense of all the other good options. It would also be useful to have a compressor anyway.

 

I just need to check whether my dry standing will allow blasting.

[lesrollins]

I have used a tool called a scabbler to remove paint on the roof I don't know if this would be good for removing blacking or if it would clog up to much. It took about 6 hours of hard work to take it back to bare metal on a 70ft boat and then a needle gun to get in all the nooks and crannies

[Nightwatch]

I used a tercoo Blaster tool. The discs fit on an angle grinder, but we hired the whole cabugle from a hire shop. Think it was HSS.

[Nightwatch]

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