Pressure washer for removing blacking.

[tonyt40]

Hi. 

 

Going to be doing the blacking soon. I am obviously going to hire a commercial machine but how powerful does the pressure washer need to be to remove it? 

 

Thanks 

Tony 

Edited April 8, 2017 by tonyt40

[BEngo]

As big as you can get. Ideally at least 3000 psi AND a good flow rate- something loike 9 litres a minute.

Many hired machines are knackered because they have been used with dirty water. Take/ send it back if it is.

N

PS Get a fan nozzle not a jet or a rotating jet. Fan nozzle is much quicker at removing cr@p.

N

Edited April 7, 2017 by BEngo
PS

[mrsmelly]

52 minutes ago, tonyt40 said:

Hi. 

 

Going to be doing day blacking soon. I am obviously going to hire a commercial machine but how powerful does the pressure washer need to be to remove it? 

 

Thanks 

Tony 

Do you mean blacking the bottom of a steel hulled boat? Whenever I have done it in the past wherever I have done it have had their own and rented it to me for a small extra charge on top of docking. I dont do it anymore I let an underling do it now.

[tonyt40]

12 hours ago, mrsmelly said:

Do you mean blacking the bottom of a steel hulled boat? Whenever I have done it in the past wherever I have done it have had their own and rented it to me for a small extra charge on top of docking. I dont do it anymore I let an underling do it now.

I'll ask at the yard and see if they have one for hire. 

[rusty69]

A lot of yards won't let you use theirs. H&S you know. Some still do. 

[Neil Smith]

Whatever one you use it will only remove the crud not the old blacking apart from the bits that are flaking off.

Neil

[Bod]

If you had to hire one, would a steam cleaner be a better option?

 

Bod

[dor]

7 hours ago, Neil Smith said:

Whatever one you use it will only remove the crud not the old blacking apart from the bits that are flaking off.

Neil

If it is a decent pressure washer then anything that doesn't come off can stay there!   Certainly the last two boatyards I have used had washers that took nearly all the blacking back to bare metal.

[crossley]

The pressure washer I used last year at Portland basin drydock was I think 300 bar with a good flow.

You should need ear defenders if that's anything to go by, it should make a right racket and nearly blow you of your feet. When I first bought the boat, I had it pressure washed and wire mopped then I think two coats of rytex. A year later I had millions of tiny rust bubbles all over everywhere. I think the blacking was put on too thick, and they had rollered air bubbles into it. Wasn't impressed with it. Docked it last autumn, used the above dock and washer, which revealed millions of little bright pits, maybe active "cells" where the bubbles once were. Instead of smearing over the pitting with a wire wheel and slapping more rytex on, I put two coats of "aquasteel" all over, and lathered plenty along the rubbing strakes and any welds etc. Left overnight to go a nice blue colour, then painted, not rollered a thinned down first coat of rytex, followed by two more thicker coats. Up to now no more rusticles, touch wood. I happened to have a gallon of the aquasteel aboard, it was more than enough, it's bit like painting milk on.. plus it saved wire mopping the hull with a bloody great angle grinder. Oddly enough, one side of the rudder was quite pitted, the other side ok. There are no anodes on the rudder, or any earth bonding.May add both at the next docking . I'm not on shore power either. If your docking schedule will allow, try the aquasteel under the blacking. Seems to have worked for me, with rytex anyway.

[WotEver]

What's the difference between Aquasteel and Vactan?

[Murflynn]

must be different 'cos their website says it's unique   

 

http://aquasteel.co.uk/                      "Aquasteel is a unique corrosion control system...."

[WotEver]

2 hours ago, Murflynn said:

must be different 'cos their website says it's unique   

 

http://aquasteel.co.uk/                      "Aquasteel is a unique corrosion control system...."

Yeah, their website is crammed full of superlatives. By comparison Vactan's site reads like an encyclopaedia

[crossley]

I have used both, and they do work, vactan is I think tannic or phosphoric acid, and smells vinegarey, whereas the aquasteel smells of nothing in particular. I borrowed a gallon of it to try out, it seems to work to some extent. The blurb said it was ok under blacking so I gave it a go. It dries to a latex clear slightly rubbery finish. It does need to be shaken up well as the active ingredient must settle out then it won't work. I would like to uhp blast the hull and 2-pack epoxy, but I'm stuck with rytex for now.

[Polishicebreaker]

make sure you grind any vactan off after. It's a poor primer.  Keep it in pits only

[WotEver]

5 minutes ago, Polishicebreaker said:

make sure you grind any vactan off after. It's a poor primer.  Keep it in pits only

I've found totally the opposite. Vactan has been an excellent primer when I've used it. However, I've never used it below blacking so perhaps some of those products don't like to stick?